What’s New in Potsdam Sandstone?  (And a few that I missed)

This posting mentions articles published  since my June 1, 2021 posting, and few  that I missed previously.  

Lowe,  DeSantis,  Arnott, and  Conliffe (2022) report on silcrete in the Potsdam in upper New York State.  They postulate  groundwater silcrete linked to brine migration in a continental rift zone as an alternative to the near-surface model of silcrete.   More particularly,  a groundwater silcrete from Upper Cambrian strata of the Potsdam Group is described and interpreted to be formed in a rift where Cambrian fault reactivation coincided with silcrete formation.   They state “The silcrete horizon documented here caps strata of the middle allounit, termed Allounit 2, and consists of Upper Cambrian braided and ephemeral fluvial quartz arenite and quartzose conglomerate.  Based on its stratigraphic position, formation of this silcrete coincides with terminal Cambrian basin inversion and unconformity development in the Ottawa Graben.  ... The silcrete horizon that caps quartz arenite strata of Allounit 2 crops out over an area of ~0.3 km2 in northwestern New York State. ... The horizon is 8–142 cm thick,”  [ I have not been down to look at their outcrops, but note that I  found a large, meter diameter, angular, loose  block of silcrete in an abandoned March formation quarry about 3 km east of Perth, Ontario.]

David Lowe (2024) discusses the aulacogens of the Neoproterozoic to Ordovician Laurentian Iapetan Margin.   He ties the deposition of the various formations of the Potsdam group into Continental rifting theory.    (Most of his paper doesn’t deal with the Potsdam.)

Daniela Garcia Ramos (2023) looked at the Thermal History of the Frontenac Arch in Southeastern Ontario, Canada Constrained From Low-temperature Thermochronology.  One interesting comment she makes is “On the basis of lithological, stratigraphic, paleontological, paleogeographic reconstructions, and thermochronological evidence, I suggest that ~ 3-4 km thick sedimentary rocks contributed to bury and reheat the rocks of the Frontenac Arch until the late Paleozoic. However, the sedimentary material has been removed by erosion since at least the Mesozoic, and only remnants of the Ordovician and Pre-Ordovician sequences are preserved today.”  Her Figure 2.8 B is a photograph of Potsdam sandstone showing soft sediment deformation/ seismites in the Nepean quartzarenite, a photo that I supplied,   Location: 44.69577°N, 76.30165°W, that had appeared in my October 22,  2015 blog post.

Elliot et al. ( 2025) looked at Potsdam sandstone outcrops in New York to provide insights into folds, deformation bands, and fractures that could influence permeability, heat exchange, and stimulation outcomes of geothermal reservoir targets.  They found that fractures show four chronological Sets A–D, striking NNW, NE, NW, and ENE, respectively. Fracture lengths and heights range from millimeters to tens of meters. Sets A and C macro-fractures, and possibly B and D, contain quartz deposits.  All sets had abundant associated quartz cemented microfractures that also record set orientations and crosscutting relations.  They state that quartz cement deposits—evidence of diagenesis—are the key to identifying attributes of outcrop fractures suitable for extrapolation to geothermal targets in sandstones because they show which fractures formed in the subsurface.

Konstantinovskaya et al. ( 2023)  conducted 3D reservoir simulations of supercritical CO 2 injection  in the  Potsdam Sandstone of the St Lawrence Platform (Gentilly Block), Quebec to predict safe CO 2 injection rates, evaluate reservoir pressure build-up in the presence of sealing and permeable faults, and estimate the gas injection cumulative, in part to estimate the risk of top and bottom seal failure and fault shear-slip reactivation.

Graham A. Young  & James W. Hagadorn (2020) looked at the  facies distribution of fossil jellyfish through time.  Their Figure 1, Plate 1 shows undescribed scyphozoan from a Cambrian arenite of the Potsdam Group, Carrières Ducharme, Québec, Canada; Pointe-du-Buisson/Musée Québéquois d’archéologie, Québec.  Their Figure 1, Plate 2 shows  Domical mouldic medusae on bedding plane surface of a Cambrian arenite in the Potsdam Group, Ausable Chasm, New York,    For the Keeseville Formation, Potsdam Group,  Ausable Chasm, New York, they report numerous medusae, stating that “The fossils are preserved as moulds  in medium-grained quartz arenites, and often appear  as simple circular mounds, but some are twisted or folded, exhibit evidence of transport, or have tripartite or  quadripartite axial regions ... They  are interpreted as scyphozoan medusae, but have not yet  received systematic description. More than 1000 medusae are known, occurring in more than six horizons. Diameters range from about 50 to 660 mm, with an average of  just over 200 mm. The depositional environment is interpreted to have been intermittently emergent, and the  arenites containing medusae have sedimentary structures indicating deposition in very shallow water less than 2 m deep.” 

One that I missed is Minter,  Buatois, Mángano , MacNaughton, Davies,  & Gibling, ( 2016)  who suggest that the eolian beds in Ontario where MacNaughton et al. ( 2002 ) reported  Diplichnites and two varieties of  Protichnites  are similar in age to interfingering eolian dunes in New York State where Hagadorn et al. ( 2011) reported  Diplichnites,  Protichnites , and paired grooves (cf.  Diplopodichnus). They provide photographs of Protichnites and Diplichnites from the eolian beds in Ontario.

I previously gave the citation for Brink,  Mehrtens  & Maguire (2019) but didn’t summarize it.  I haven’t mentioned Landing, Amati, & Franzi (2009).  Both are important.  Brink et al. (2019) describe in detail the  Altona Formation, the oldest unit in Potsdam Group, identifying six lithofacies including nonmarine sheet flood, nearshore bay/estuary, and upper and middle shoreface.   Landing et al. (2009) described fragments of an Olenellid trilobite as well as specimens of Ehmaniella from a unit below the  Ausable Sandstone which led them to suggest that the  horizons should be recognized as a separate unit termed the Altona Formation.    Landing et al. (2009) also  reported occurrences of small Cruziana and Rusophycus trace fossils from their Altona formation.

Christopher Brett

Ottawa

References and Suggested Reading

Brett, Christopher,  2015   Soft-Sediment Deformation (Seismites) in Nepean Sandstone Close to the Rideau Lake Fault.  Blog posting dated  October 22,  2015 https://fossilslanark.blogspot.com/2015/10/soft-sediment-deformation-seismites-in.html

Brett, Christopher,  2016.  What’s New in Potsdam Sandstone?  Blog posting dated  August 5,  2016 https://fossilslanark.blogspot.com/2016/08/

 Brett, Christopher, 2021.  What's New in Potsdam Sandstone? Blog posting dated  June1,  2021 

https://fossilslanark.blogspot.com/2021/06/whats-new-in-potsdam-sandstone.html

Brink, R., Mehrtens, C. & Maguire, H. 2019. Sedimentology and petrography of a lower Cambrian transgressive sequence: Altona Formation (Potsdam Group) in northeastern New York. Bulletin of Geosciences 94(3), 369–388 (18 figures, 2 tables, appendix). Czech Geological Survey, Prague. ISSN 1214-1119.   http://www.geology.cz/bulletin/fulltext/1728_Brink_191208.pdf

Elliott SJ, Forstner SR, Wang Q, Corrêa R, Shakiba M, Fulcher SA, Hebel NJ, Lee BT, Tirmizi ST, Hooker JN, Fall A, Olson JE and Laubach SE (2025)     Diagenesis is key to unlocking outcrop fracture data suitable for quantitative extrapolation to geothermal targets.  Frontiers in Earth Science, Economic Geology,  1 April 2025, Volume 13 - 2025 |      https://doi.org/10.3389/feart.2025.1545052

Garcia Ramos, Daniela, 2023    Thermal History of the Frontenac Arch in Southeastern Ontario, Canada Constrained From Low-temperature Thermochronology.  Masters of Science Thesis. Queen’s University, Kingston, Ontario 206 pages   http://hdl.handle.net/1974/31426  https://qspace.library.queensu.ca/items/c276a99a-078d-45c0-afc1-538e986686c5

Konstantinovskaya, Elena,  Jose A. Rivero, Valentina Vallega. John Brodylo, Peter Coldham

3D reservoir simulation of CO 2 injection in a deep saline aquifer of the Lower Paleozoic Potsdam Sandstone of the St Lawrence Platform, Gentilly Block, Quebec  January 2023 Geoenergy 1(1) DOI:10.1144/geoenergy2022-001

Landing, E., Amati, L. & Franzi, D.A.,  2009   Epeirogenic transgression near a triple junction; the oldest (latest EarlyMiddle Cambrian) marine onlap of cratonic New York and Quebec. Geological Magazine 146(4), 552–566.   DOI 10.1017/S0016756809006013  

Lowe, D.G.,  2024   Aulacogens of the Neoproterozoic to Ordovician Laurentian Iapetan Margin,

Earth-Science Reviews, Volume 255, 104829,

https://www.sciencedirect.com/science/article/pii/S0012825224001569

Lowe, D.G. ,  E. DeSantis, R. Arnott, J. Conliffe, 2022   Groundwater silcrete linked to brine migration in a continental rift: an alternative to the near-surface model of silcrete .  Geosphere, 18 (3) (2022), pp. 1055-1076  https://pubs.geoscienceworld.org/gsa/geosphere/article/18/3/1055/612948/Groundwater-silcrete-linked-to-brine-migration-in

Minter, N. J., Buatois, L., Mángano, G., MacNaughton, R., Davies, N., & Gibling, M., 2016.  The prelude to continental invasion. In G. Mángano, & L. Buatois (Eds.), The trace-fossil record of major evolutionary events: Volume 1: Precambrian and Paleozoic (Vol. 39, pp. 157-204). (Topics in Geobiology; Vol. 39). Springer. https://doi.org/10.1007/978-94-017-9600-2

https://www.researchgate.net/publication/310483425_The_Prelude_to_Continental_Invasion

Yochelson, E.L.  and M. Parrish, 1992    Reconstruction of the enigmatic Late Cambrian Climactichnites.   The Paleontological Society Special Publications , Volume 6: Fifth North American Paleontological Convention-Abstracts and Program , 1992 , pp. 321.  Published online by Cambridge University Press:  26 July 2017  DOI: https://doi.org/10.1017/S2475262200008819 https://www.cambridge.org/core/journals/paleontological-society-special-publications/article/reconstruction-of-the-enigmatic-late-cambrian-climactichnites/3704BDF67A29C82871FD8C394BF468B6

Young, Graham A.  & James W. Hagadorn, 2020  Evolving preservation and facies distribution of fossil jellyfish:  a slowly closing taphonomic window .  Bollettino della Società Paleontologica Italiana, 59 (3), 2020, 185-203. Modena   https://www.academia.edu/48910995/Evolving_preservation_and_facies_distribution_of_fossil_jellyfish_a_slowly_closing_taphonomic_window     

 

Logan’s Original Protichnites Specimens From Beauharnois Were Found in the Collection of the Canadian Museum of Nature

I noticed a recent 2026  article in a leading geological journal which mentioned that Logan’s specimens of Proctichnites from Beauharnois were lost, but that original plaster casts of the specimens had been located in the Amherst College Museum of Natural History.   While the specimens were lost, they were found in 2014 in the collection of  Canada’s Museum of Nature at their research facility in Gatineau, Quebec, indexed with the wrong identification   [Kouphichnium] or not indexed with any identification.   I looked at them on July 29, 2014 with Dr. Robert MacNaughton, Michelle Coyne,  Keiran Shepherd and  Margaret Currie,    

Dr. MacNaughton  gave a talk in 2017 at the Canadian Paleontological Conference in Calgary, Alberta where he described how the specimens were found and the significance of the specimens.  The text of the abstract for his talk mentioned that “most of Logan’s specimens from Beauharnois were rediscovered in the collections of the Canadian Museum of Nature”.   As the abstract is not available online, it  is reproduced below.  

"SIR WILLIAM LOGAN AND THE ADVENTURE OF THE  ANCIENT AMPHIBIOUS ARTHROPOD 

R.B. MacNaughton, C.P. Brett, M. Coyne  and K. Shepherd

  Keywords: ichnology; Protichnites; Cambrian; Potsdam Group; Sir William Logan 

In his first literary appearance, Sherlock Holmes opined that “There is no branch of detective science which is so important … as the art of tracing footsteps.” The study of footsteps has an equally proud pedigree in paleontology. Forty years before the great sleuth made his debut, fossilized trackways produced by a long-vanished arthropod were found at several sites in Cambrian strata of the Potsdam Group at Beauharnois, Québec. Sir William Logan, the founding Director of the Geological Survey of Canada, carefully documented these localities and collected several very large specimens. Logan transported the trackways to the United Kingdom, where the anatomist Sir Richard Owen described them formally in 1852. Owen named the trackways Protichnites, the first time that arthropod-produced fossil trackways were given a formal Linnaean name. Owen documented six ichnospecies of Protichnites, providing detailed, but densely written descriptions illustrated by high-quality lithographic plates. Logan, in a very early example of applied comparative sedimentology, documented sedimentological evidence that the track-makers might have come out of the sea to walk about on land, providing the fullest account of his reasoning in the classic 1863 text The Geology of Canada. Logan’s prescient ideas would be borne out by studies a century and a half later, and Protichnites now provides evidence for the earliest-known forays of animals onto dry land. Recently, most of Logan’s specimens from Beauharnois were rediscovered in the collections of the Canadian Museum of Nature, providing an opportunity to reassess the ichnotaxonomy of Protichnites and to view at first hand some of the evidence on which Logan based his conclusions regarding the environmental range of the track-making arthropod. In honour of the 175th anniversary of the Geological Survey of Canada, this talk will discuss the importance of Protichnites as a record of early non-marine animal behaviour, while celebrating Logan’s pioneering, downright Holmesian work on the subject. "

In fairness to those that didn’t realize that the specimens had been found, I note that the title to the talk did not disclose that the specimens had been found, and that the abstract could not be found online.

Photos of Logan’s specimens of  Protichnites septemnotatus, Protichnites alternans and Protichnites lineatus can be found in my October 17, 2017 blog posting.

I suspect that Logan’s specimens were 'lost' when the Centre Block of Canada’s Parliament Building burned down in February, 1916  (fifteen months after the start of the First World War)  and the Geological Survey of Canada  had to quickly vacate the Victoria Memorial Museum so that Parliament could sit at the museum, and so that offices could be provided for the members of the House of Commons..  Most specimens were crated and moved out within 40 hours of the start of the fire.   Harlan (1916) describes the hurried crating of specimens.  Here is part of his description:

    “The east hall, with invertebrate palaeontological exhibits, similar in size to the other exhibition halls, contained thousands of small and delicate specimens. These were all carefully wrapped, packed and taken away. Forty hours after the beginning of the fire, all the museum specimens and cases had been moved from this part of the building, which was made into offices for the members of the House of Commons.   

    Of the east wing, containing tentative vertebrate palaeontological exhibits, three-quarters were cleared, and these exhibits were stored, with those of the' other quarters, along the walls of the southern half of the hall. This clearing involved not only the moving of small exhibits in cases, but also of such heavy fragile specimens as the titanotherium and the skulls of dinosaurs and mammoths, yet it was all done within two hours after this notification, that is by noon, or in less than twenty hours from the time that the fire broke out.” 

The Victoria Memorial Museum  served as the home of the Parliament of Canada from 1916 to 1920 while the Centre Block was being rebuilt.  I expect that the Protichnites specimens  were just left in storage when the Geological Survey of Canada moved back into the Victoria Memorial Museum in 1920,  and over time the significance of the specimens was overlooked and forgotten.  Or it may have been that the fossil dinosaurs collected in Alberta by the GSC (see Russell, 2012)  were deemed more appealing to museum visitors.

Christopher Brett

Ottawa

Reference and Selected Reading

MacNaughton, R.B., Brett, C.P., Coyne, M., and Shepherd, K., 2017. Sir William Logan and the Adventure of the Ancient Amphibious Arthropod. In: Gouwy, S., and Bell, K. (eds.), Canadian Paleontology Conference Proceedings No. 14, (The Geological Association of Canada - Paleontology Division; St. John’s, NF), p. 19.

 

Brett, Christopher, 2014:  My Hunt for Sir William Logan’s Specimens of Protichnites.   March 7, 2014 blog posting  https://fossilslanark.blogspot.com/2014/03/my-hunt-for-sir-william-logans.html

 Brett, Christopher:  2017  Protichnites, etc. on display at the Canadian Museum of Nature’s Collection and Research Facility.  October 27, 2017 blog posting   https://fossilslanark.blogspot.com/2017/10/protichnites-etc-on-display-at-canadian.html

 Brett, Christopher, 2019  Are Elkanhah Billing’s Specimens of Aspidella Truly Missing, or are they just Hanging Out with Logan’s slabs of Protichnites at the Canadian Museum of Nature’s Research.   March 30, 2019 blog posting   https://fossilslanark.blogspot.com/2019/03/

Brett, Christopher, 2020  Reports of Trace Fossils from the Potsdam Group Sandstones of Ontario, Quebec and New York State  See: subheading:  Logan’s Specimens of Protichnites Were Found

https://fossilslanark.blogspot.com/2020/10/reports-of-trace-fossils-from-potsdam.html

Anonymous,  Charles Mortram Sternberg, Wikipedia, retrieved May 18, 2026

https://en.wikipedia.org/wiki/Charles_Mortram_Sternberg

Russell, Loris S., 2012  History of Palaeontology in Canada.  The Canadian Encyclopedia.  Published Online May 7, 2012, retrieved May 18, 2026  https://thecanadianencyclopedia.ca/en/article/history-of-palaeontology-in-canada

 Smith, Harlan, 1916  The Fire and the Museum at Ottawa.  The Ottawa Naturalist, March, 1916, pages 164-167  https://www.biodiversitylibrary.org/item/28021#page/172/mode/1up

Robert Abraham (August 14, 1804 - November 10, 1854): Medical Doctor, Writer, Editor, Lawyer: The first to report on the tracks we now call Protichnites

 In my August 29, 2013 blog posting entitled “Abraham, Logan and Owen: The Discovery of the First Protichnites trackways " I described the first reporting of  trackways at Beauharnois, Quebec by Robert Abraham in an 1847 edition of the Montreal Gazette newspaper, and Logan’s and Owen’s subsequent descriptions of the trackways in scientific journals.  I also  provided a few details on Robert Abraham life.   In this posting I will provide additional details on Robert Abraham.

GEOLOGICAL WRITINGS OF ROBERT ABRAHAM

In my earlier blog posting I provided extracts from  Robert Abraham’s 1851 article entitled

“Tracks of a Chelonian Reptile in the Lower Silurian formation, at Beauharnois” where he described finding the tracks at Beauharnois that we now call Protichnites. 

I was able to find only one other geological paper authored by Robert Abraham: a single page 1842 report entitled “Geology of the Ward of Allerdale above Derwent” which appeared in a book entitled ‘The History and Antiquities of Allerdale Ward, above Derwent, in the county of Cumberland’.  Allerdale Above Derwent lies within the Lake District National Park in Cumberland.  This is part of Robert Abraham’s submission:

      “ At the back of the Ward we find mountains of red granite. Gable is the centre, at the head of the valleys of Wasdale, Ennerdale, and Borrowdale, and the minor ones of Miterdale and Calder. In the depths of these valleys lie the lakes, cavities scooped out when the elevation of the mountains took place, and afterwards filled with water. Reposing on the granite are mountains of great elevation, of trap or primitive rocks. At the bases of these, climbing their sides, or occupying the valleys, we find the transition rocks, principally grauwacke and clay-slate. In the latter are found the minerals, namely calcareous and siliceous spars, and the ores of zinc, silver, lead, antimony, manganese, and other metals.

     Coming now to the secondary formations, we have first the blue or mountain limestone, full of marine remains, and rich in the hapatic iron ore. A broad belt of it extends from the Derwent to the Ehcn, namely from Cockermouth to Egremont. At the latter town it is lost, and is not seen again until we reach the other extremity of the Ward, the borders of the Duddon, near Broughton in Furness.

     The next formation is the coal measures, which in various degrees of productiveness occupies the whole country from the limestone to the sea under which it dips, from the Derwent to Whitehaven. This formation contains the gray iron ore, plastic clay, and ferruginous shale.

     To the southwest of Whitehaven, at St. Bees head, we find the new red sandstone with gypsum and magnesian limestone, overlying the coal measures, which are thrown down ninety fathoms and cut off by dykes injected with trap or basalt from beneath.”

As Robert Abraham was a medical graduate of Edinburgh University it is not surprising that he had more than a basic understanding of geology, as  other medical graduates of Edinburgh University contributed to the geological knowledge of Canada during the 1800's, include Dr. James Wilson, Dr. Andrew Fernando Holmes and Dr. Bigsby (see my blog postings).  It is also worth noting that William Logan enrolled at Edinburgh University as a medical student,  did  well scholastically, but left after a year to work.

DETAILS OF ROBERT ABRAHAM’S LIFE

Robert Abraham was  born at Penrith, Cumbria, England on August 14, 1804.   He was the eldest son of  Thomas Abraham and  Orpah Abraham (née Clarke).    Robert Abraham had a sister Mary, a brother John born in 1813 who was a distinguished  pharmaceutical chemist in Liverpool, and five other siblings who died in infancy.  Robert Abraham’s father is reported to have worked as an accountant and also as a schoolmaster.  Interestingly, Robert’s brother John Abraham was arguably even more  accomplished than his brother.   Amongst other things John was founder of the Liverpool  Naturalists’ Field Club,  president of the Liverpool Microscopical Society, was involved in forming the Gallery of Inventions and Science in connection with the Free Library and Museum, and helped found  Liverpool’s School of Pharmacy (see Cox, 2019).

Robert Abraham’s father Thomas Abraham was  born in Seaton, Cumberland in England.    In 1803 in Penrith, Cumberland, Thomas Abraham married Orpah Clarke.   Thomas outlived his eldest son Robert, and died in Carlisle in 1861, aged 91, having lived his whole life in Cumberland.   Robert Abraham’s mother died at Carlisle in 1833.

Robert Abraham married Sarah Seed, but I have not been able to determine the date of the wedding.  When Robert Abraham  died at Montreal, Canada on November 10, 1854 he left a widow (assumed to be Sarah), and no children. 

Robert Abraham studied medicine at the University of Edinburgh, starting his studies in 1823, and graduating in 1825.  He was a Member of the London College of Physicians and a practicing surgeon, first at Guy's Hospital in London, then at Carlisle in Cumberland.   The dates on articles that he published in medical journals suggest that the practiced medicine from at least 1825 to 1827.    One source says that he gave up his practice in Carlisle as a qualified medical man to edit the Whitehaven Herald  which suggests that he practiced medicine only from 1825 to 1831.   However, his obituary notice in The Farmer’s Journal mentions that he  practiced his medical profession  during his time in Whitehaven.

 Robert Abraham  was the first editor of the Whitehaven Herald, with issue one published on August 30, 1831.  The newspaper is said to have been started at the time of passing of the Reform Act (that expanded voting privileges and reapportioned constituencies to address the unequal distribution of seats) to counter the influence of the Lowther family in Cumberland.   Robert Abraham remained  editor of Whitehaven Herald newspaper for five and a half years, leaving on  March 14, 1837, when he published a farewell (valedictory) letter to readers.      He later worked as medical editor of a Liverpool newspaper.   I have not been able to determine whether he practiced medicine in Liverpool.

About 1843, Robert Abraham came to Canada, where he became the proprietor and editor of the Montreal Gazette newspaper.  He is credited with being the first to issue daily issues of the Gazette, which he introduced in 1844 during the summer months, the time of peak commercial activity.    His connection with the Gazette continued until December, 1848, when he disposed of the paper to Mr. Ferres, and retired from its management.  

In 1849 he became senior editor of the Transcript, also a Montreal paper, and the first editor of a Lower Canada agricultural journal, which was known as the Agricultural journal and Transactions of the Lower Canada Agricultural Society from 1948 to 1952 and as The Farmer's Journal and Transactions of the Lower Canada Board of Agriculture starting in 1953.   An obituary notice for Robert Abraham appears in the December, 1854 edition of The Farmer’s Journal, and is repeated with few changes in the January, 1855 edition of The Canadian Agriculturist.  That obituary notice mentions that Mr. Abraham,  “who has conducted the Farmer’s Journal from its commencement, and who gave in its pages such earnest evidence of his deep seated interest in agricultural pursuits, ... was born, in the fine grazing and agricultural county of Cumberland . ... Mr. Abraham was originally a man of robust and herculean frame, and was famous as a young man for excelling in all the manly and athletic sports and, exercises, which prevail in the rural districts of the northern counties of England.”

Interestingly, Robert Abraham  was editor of both the Whitehaven Herald and the Montreal Gazette for under six years, about the same amount of time that he would have edited a Liverpool journal, and the period of time he edited the Montreal Transcript and The Farmer’s Journal.

Robert Abraham was called as an advocate to the Bar of Lower Canada on May 10, 1849.    In 1849 he published a well researched and informative legal booklet entitled “Some remarks upon the French tenure of "franc aleu roturier", and on its relation to the feudal and other tenures.”   In 1851 he was appointed as assistant solicitor of Montreal by the municipal council, under pressure from English speaking members, to assist Toussaint Peltier, a high profile French speaking lawyer.    His appointment has been criticized by Beullac and Surveyer (1949) in their history of the bar in Quebec who commented that Abraham’s work as editor was poor preparation for the Bar. 

 Penrith where Robert Abraham was born is a market town in Cumbria, England. It is less than 3 miles (5 km) outside the Lake District National Park and about 17 miles (27 km) south of Carlisle.  It is about 180 km (110 miles) south of Edinburgh, Scotland, and 170 km (105 miles) north of Liverpool.   Whitehaven is a town and port in Cumberland near the Lake District National Park.   By road Whitehaven is 38 miles (61 km) south-west of Carlisle.  London is 460 km (290miles) south of Penrith.   Montreal is 5,200 km (3,300 miles)  from Penrith.  I mention those places and distances  as they were all mentioned in this post, and it seemed strange that Robert Abraham, having spent most of his life in northern England, would go to Montreal when his brother John resided in Liverpool and his father Thomas in Carlisle.   The obituary notice for Robert Abraham published in the Montreal Transcript provides the answer,  stating  that “In 1842, his first connection to Canada commenced.  The then proprietors of the Montreal Gazette required some articles on commercial topics from the old country, and Mr. Abraham was engaged to furnish them. Commercial articles ... are not calculated to gain a writer much fame; but the articles furnished by Mr. Abraham soon attracted attention, and were the admiration of all competent judges. The result of this connection was, that in the summer of 1844, Mr. Abraham became the purchaser, and assumed management of the Montreal Gazette.”

In my August 29, 2013 blog posting I mentioned that in the notice of Robert Abraham's passing the Gazette highlighted his editorial writing, but also mentioned:  “As a geologist and naturalist (particularly in his favourite branch of Natural History, Entomology) he had few equals in Canada– perhaps no superior on this continent.”   The obituary notice for Robert Abraham that appeared in Montreal’s ‘la Minerve’ newpaper mentions “Il était excellent géologue ; comme naturaliste, on va même jusquà dire qu’il n'avait peût-être pas de supérieur en Amérique.”  Which translates as ‘He was an excellent geologist; as a naturalist, some would even say that he perhaps had no equal in America.’   The obituary in the Transcript noted that “As a political writer, he was , it is not saying too much, almost without equal. ... Nor was his knowledge confined to politics and literature proper.  Take him on a scientific subject, and it was the same.”   

MEDICAL WRITING OF ROBERT ABRAHAM

Robert Abraham published four articles in medical journals:

1825– A Case of Sanguineous Apoplexy, in The Edinburgh Journal of Medical Science,

1826– On the influence of civilization on the progressive increase of, certain diseases, in The Edinburgh Journal of Medical Science;  

1827– On Medicines of whose immediate action we are conscious, in The Edinburgh Journal of Medical Science; and , 

1827– Description of an Acephalous Foetus, in the London Medical and Surgical Journal. 

The first and fourth would be considered scientific, while the second and third are more philosophical than scientific.   Only the first and fourth are mentioned in summaries of his life and accomplishments.  (It is worth noting that Dr. Robert Abraham’s diagnosis of Sanguineous Apoplexy was criticized in The Medico-Chirurgical Review, 1827 new Series, Volume 4, at pages 266, 267.)

The University of Edinburgh  has in its collection an unpublished manuscript dated 1825 by Robert Abraham entitled  "An Enquiry into the Elements of General Therapeutics, with Special Illustrations, to which is prefixed an Essay on the Nature Value and Utility of Theory".   I suspect, based on the introduction to the third published paper above,  that it was taken from this unpublished manuscript, as it is said to be “detached from a larger and systematic work on the operations of medicines.”  

As Robert Abraham was editor of the Whitehaven Herald newspaper for close to six years ending March 14, 1837,  medical editor of a Liverpool newspaper, possibly from 1837 to 1843, editor of the Montreal Gazette newspaper from 1844 to 1848, editor of the Montreal Transcript newspaper from 1849 to 1854, and editor of  The Farmer's Journal from 1948 to 1954,  I assume that there are numerous medical articles that might be found by a diligent sleuth.   For example, the January, 1848  issue of the Agricultural journal and transactions of the Lower Canada Agricultural Society contains a two page article on typhus, which I attribute to Robert Abraham.

 MCGILL UNIVERSITY ARCHIVES

McGill University’s Archives has copies of various letters that Robert Abraham wrote to and received from family members, letters and notices published in Newspapers, and documents relating to the sale of the Montreal Gazette.  See:

https://archivalcollections.library.mcgill.ca/index.php/correspondence-by-robert-abraham

The documents  include:

 - an obituary notice for Robert Abraham published in the Montreal Transcript on November 14, 1854

https://digitalarchives.library.mcgill.ca/RBSC/MSG1112/rbsc_msg1112_abraham-family-letters-folder35.pdf

- a letter that he wrote dated March 7, 1830 published in the Carlisle Journal dealing with staffing of surgeons at the Carlisle Dispensary and Infirmary

https://archivalcollections.library.mcgill.ca/index.php/letter-to-the-carlisle-journal-1830

- Robert Abraham’s valedictory letter dated March 14, 1837 addressed to readers published in The Whitehaven Herald

https://digitalarchives.library.mcgill.ca/RBSC/MSG1112/rbsc_msg1112_abraham-family-letters-folder26.pdf

- an issue of the Montreal Gazette, dated  August 26, 1843, edited by Robert Abraham

https://digitalarchives.library.mcgill.ca/RBSC/MSG1112/rbsc_msg1112_abraham-family-letters-folder27.pdf

-  an issue of the Montreal Gazette, dated October 16, 1848, edited by Robert Abraham

https://digitalarchives.library.mcgill.ca/RBSC/MSG1112/rbsc_msg1112_abraham-family-letters-folder29.pdf

- a letter dated November 9, 1849 From Robert Abraham to the Editor of the Montreal Courier, published in the November 12, 1849 edition of the  Evening Courier of Montreal, responding to innuendos raised against Robert Abraham in a pamphlet by Major MacDougall of the Royal Canadian Rifles, arising from the  cross-examination of MacDougall by Abraham in a matter relating to a duel

Christopher Brett

Ottawa, Ontario

REFERENCES, SELECTED BIBLIOGRAPHY AND SUGGESTED READING

Agricultural journal and transactions of the Lower Canada Agricultural Society

https://www.canadiana.ca/view/oocihm.8_04880

Anonymous, 1854   Mort d'un réducteur. [Translation: Death of a journalist,  la Minerve, 14 novembre 1854 [ an  obituary notice of the death of Robert Abraham that appeared in Montreal’s  French language newspaper la Minerve.]

https://numerique.banq.qc.ca/patrimoine/details/52327/4130267?docsearchtext=robert%20abraham

Anonymous, 1854  An untitled  obituary notice for Robert Abraham published in the Montreal Transcript on November 14, 1824

https://digitalarchives.library.mcgill.ca/RBSC/MSG1112/rbsc_msg1112_abraham-family-letters-folder35.pdf

Anonymous, December 1854  Robert Abraham Late Editor of the Farmer’s Journal.  The Farmer's Journal and Transactions of the Lower Canada Board of Agriculture, vol. 2, no. 8, pages 123- 124    https://www.canadiana.ca/view/oocihm.8_06434_20/4

Anonymous, December, 1854  a Notice of the death of Robert Abraham.  The Journal of Education for Upper Canada,  Volumes 7, No. 12, Page 200, 

 https://www.canadiana.ca/view/oocihm.8_06242_84/13

Anonymous, January, 1855   Robert Abraham Late Editor of the Farmer’s Journal.  The Canadian Agriculturist, and Journal of Transactions of the Board of Agriculture,  Volume 7, no. 1 (Jan. 1855), pages 30-31

https://www.canadiana.ca/view/oocihm.8_04016_73/37

Anonymous, 1963    The Macmillan dictionary of Canadian biography.  Publisher London : Macmillan ; New York : St Martin's.  Robert Abraham at Page 2 

https://archive.org/details/macmillandiction00wall/mode/2up

Anonymous, 2025 [?]  Abraham, Robert, fl 1823-1825 (Physician, journalist and lawyer; University of Edinburgh alumnus).  Archives Space at Edinburgh. University of Edinburgh Archive and Manuscript Collections   [fl: The floruit date refers to the time when the person was known to be active]

https://archives.collections.ed.ac.uk/agents/people/19648

 Abraham, Robert,  1825   A Case of Sanguineous Apoplexy.  The Edinburgh Medical and Surgical Journal, 1825 Oct 1; 24(85): 301–304. “By, Robert Abraham, Surgeon, and Member of the Physical Society of Guy’s Hospital.”  Dated at end “Worcester, March 14, 1825.”

  https://pmc.ncbi.nlm.nih.gov/articles/PMC5828725/

Abraham, Robert,  1826    On the influence of civilization on the progressive increase of, certain diseases, in The Edinburgh Journal of Medical Science, Vol. 1. 1826. No. 2. Apr. p. 347-53.

https://archive.org/details/edinburghjourna00unkngoog/page/847/mode/1up  

Abraham, Robert,  1827   On Medicines of whose immediate action we are conscious.  The Edinburgh Journal of Medical Science, Volume 6, pages 266-286  “By, Robert Abraham, Surgeon, Carlisle.”  Dated at end:  Carlisle, 1 October 1826.

https://archive.org/details/s1id13297170/page/266/mode/2up

Abraham, Robert,  1827  Description of an Acephalous Foetus, in London Medical and Surgical Journal , vol 57 (vol 2) 1827, No. 336 Feb p. 135-36   “By, Robert Abraham, Surgeon, Carlisle.”  Dated at end: Carlisle; December 15th, 1826 “

   https://pmc.ncbi.nlm.nih.gov/articles/PMC5674619

Abraham, Robert, 1842   Geology of the Ward of Allerdale above Derwent, page 446 in  The History and Antiquities of Allerdale Ward, above Derwent, in the county of Cumberland: with Biographical Notices and Memoirs, by  Jefferson, Samuel.  “Communicated by Mr. Robert Abraham, of Liverpool.”

https://archive.org/details/TheHistoryAndAntiquitiesOfAllerdaleWard/page/n485/mode/1up

Abraham, Robert 1849a  Some Remarks upon the French Tenure of " Franc-Alleu Roturier," and on its relation to the Feudal and other Tenures,  Montreal: Armour and Ramsay.  pp. 81.    https://archive.org/details/cihm_22162

Abraham, Robert, 1849b   Letter to the editor of the Carlisle Journal, condemning the policy of Lord Elgin in the Rebellion losses bill, by Robert Abraham, Montreal, June 16th, 1849.  Most of the letter can be found in an article entitled ‘The Canadas - How Long Can We Hold Them?’ published in The Dublin University Magazine: A Literary and Political Journal, Vol. 34,  July to December 1849, pages 314 -330.  Letter from Abraham at pages 326 -328. 

https://archive.org/details/in.ernet.dli.2015.515571/page/n81/mode/2up

Abraham, Robert,  1851  Tracks of a Chelonian Reptile in the Lower Silurian formation, at Beauharnois.  The British American Medical & Physical Journal, Volume 7, No. 5,  pages 195-200

https://www.canadiana.ca/view/oocihm.8_05181_17/6?r=0&s=1

Beullac, Pierre et  Édouard Fabre Surveyer, 1949  Le centenaire du Barreau de Montréal, 1849-1949. Librairie Ducharme, Ltée., Montréal,     Page 22   https://numerique.banq.qc.ca/patrimoine/details/52327/3259522

Brett, Christopher P,  2013   Abraham, Logan and Owen: The Discovery of the First Protichnites trackways – Part 1; blog posting dated August 29, 2013 https://fossilslanark.blogspot.com/2013/08/abraham-logan-and-owen-discovery-of.html

Brett, Christopher P, 2017  Abraham, Logan and Owen: The Discovery of the First Protichnites trackways – Part 2, blog posting dated Monday, 4 September 2017;  https://fossilslanark.blogspot.com/2017/09/abraham-logan-and-owen-discovery-of.html

Brett, Christopher P, 2018  Where on the Internet to find Information on Sir William Edmond Logan, the First Director of the Geological Survey of Canada; blog posting dated Monday, 1 January 2018

https://fossilslanark.blogspot.com/2018/01

Brett, Christopher P, 2020  John Jeremiah Bigsby, M.D.(1792-1881) – Geologist, Physician, Entomologist, Author and Artist, blog posting dated Tuesday, 22 September 2020

https://fossilslanark.blogspot.com/2020/09

Collingwood, W. G. (Editor), 1866  Transactions of the Cumberland & Westmorland Antiquarian & Archaeological Society, VOLUME X.— NEW SERIES.   Robert Abraham At pages 335, 336.

https://archive.org/details/transactionsofcu10cumb_0/page/335/mode/1up

Cox, Norma, 2019  Four pharmacy education entrepreneurs in Victorian Britain: Robert Clay (1792- 1876), John Abraham (1813-1881), John Muter (1841-1911) and George Wills (1842-1932). Pharmaceutical Historian · 2019 · Volume 49/3, pages 74-82

https://www.ingentaconnect.com/content/bshp/ph/2019/00000049/00000003/art00002?crawler=true&mimetype=application/pdf

Creighton, Charles, 1891  A history of epidemics in Britain  

https://archive.org/details/historyofepidemi02crei/page/406/mode/2up

Foster, Joseph, 1871  A pedigree of the Forsters and Fosters, of the north of England, and of some of the families connected with them.    Robert Abraham, his parents and siblings at pages 10 and 19.  Place of publication not identified. Printed for private circulation. 

https://archive.org/details/pedigreeofforste00fost/page/n59/mode/2up  

 Gibb, G. Duncan (George Duncan), Sir, 1869  Discoveries in science by the medical philosopher: An oration delivered on the ninety-sixth anniversary of the Medical society of London, Monday, March 8th, 1869. London: Henry K. Lewis, 62 pages,  https://archive.org/details/b24882215/mode/2up 

Morgan,  Henry James, 1867   Bibliotheca Canadensis: Or, A Manual of Canadian Literature. G. E. Desbarats, Ottawa.        Robert Abraham at  Pages 4 and 5 

https://archive.org/details/bibliothecacana01morggoog/page/n20/mode/1up

p, Harriet   Sept., 2020  Cholera, flu, whooping cough: welcome to the 1830s, a blog posting on web site  Port Carlisle – a history built on hope

https://crimesofthecenturies.com/index.php/2020/09/27/cholera-flu-epidemics-1830s/

“In 1830s Cumbria (as the rest of Britain), epidemics/pandemics were a constant threat to life.... [it] …was a time of much sickness of other kinds — the Asiatic cholera of 1831-32, the influenza of 1831, 1833, and 1836-37, and the general unhealthiness of the year 1837.”

Ward, Thomas Humphry,  1885  Men of the reign; a biographical dictionary of eminent persons of British and colonial birth who have died during the reign of Queen Victoria; Publisher, G. Routledge and Son, London, New York;  Robert Abraham at page 2. https://archive.org/details/menofreignbiogra00wardrich/page/2/mode/1up

A Specimen of Eozoon Canadense at the Matheson House Museum in Perth, Ontario - Part 2

 For Dawson’s calm and steady hand

Is known feared by young and old. 

       Anonymous, 1869, extract from Eozöon canadense [ a Poem]

My  April 29, 2016 blog posting summarized the dispute as to whether Eozoön Canadense is organic (as claimed by Sir William Dawson, Sir William E.  Logan and  William B. Carpenter) or inorganic (as claimed by William King,  Thomas Rowney,  H. J. Carter, Otto Hahn,  Karl Möbius,  J. W. Gregory, and others). 

There are five main types of Eozoön Canadense (all from the Grenville province of the Precambrian Shield):

- the Burgess type, alternating bands of dark green serpentine with grains of spinel and thinner bands of grey dolomite,  from North Burgess, south of Perth, Ontario

- the Calumet type, alternating bands of a light grey clinopyroxene and bands of calcite,  from Grand Calumet along the Ottawa River

- the Côte St. Pierre type, alternating layers of white calcite and light green serpentine, from near Grenville, Quebec

- the Tudor type, parallel crescentic bands of calcite, from Tudor township in Hastings County, Ontario about 45 miles inland from the shore of Lake Ontario, in comparatively unaltered crystalline limestone

- the Huntingdon type, quartz bands alternating with bands of tremolite and calcite, from the Henderson Talc mine a few miles southeast of Madoc, in Huntingdon Township, Hastings County, Ontario

I concluded my 2016  blog posting by noting that “It was left to work in the early 1980's by Marika S. Bourque and other members of the Ontario Geological Survey to recognize and promote the Huntingdon type Eozoon, namely quartz bands alternating with bands of tremolite and calcite, from a few miles southeast of Madoc, and found in surrounding townships, as being of biogenic origin– silicified and recrystallized  algal colonies.    Bartlett and DeKemp (1987) comment “Eozoon canadense comprises several similar, but distinct morphologies.  A biogenic origin for one of these forms, the “huntingdon” type, has recently gained general acceptance, largely due to the contribution of M.S. Bourque to the present study.  This does not, however, imply an organic origin for the other Eozoon canadense forms...”   R. M. Easton (1992), relying on Bourque and deKemp, commented “Eozoon canadense huntingdon is an algal-laminate stromatolite.   Other E. canadense types, however, may not be biosedimentary in origin and should be regarded for the moment as pseudofossils...”  One is left to wonder whether the Tudor type is also a stromatolite.”

Surprisingly, Eozoon Canadense is back in the news.   Sendino ( 2021) discussed the curation and conservation of the The Carpenter Eozoon Collection at the Natural History Museum in London, England.   The collection consists of “a huge collection of rock samples from around the world containing Eozoon from which more than 1000 slides were made”, which was presented  to the British Museum (Natural History) in 1892.   She notes that “The Eozoon specimens were housed in William Carpenter’s private residence from his retirement in 1879 until his death in 1885. It is during this time when Carpenter devoted most of his time to his Eozoon Collection, working on a monograph, accumulating further material and making drawings to support his interpretation of this “fossil” as a foraminiferan.”   Sendino’s (2021) blog posting follows a paper by Sendino , Cuadros , Allington-Jones, Barnbrook (2015) which sets out that the Carpenter’s Eozoon Collection was "rediscovered" by staff of the Natural History Museum and that “the collection was found to be distributed in different buildings and contained in several cabinets. Part belonged to the Mineralogy Section and part to the Palaeontology Section, reflecting the early controversy over the inorganic vs. organic origin of Eozoon.”   The collection consists of “cavity slides, thin sections and hand samples.” Worth noting is that “Surface deterioration can be seen on the rock samples, which is probably related to the experimental decalcification of some specimens that were etched in acid to show their structure more clearly. ...   The Carpenter Eozoon Collection has not only suffered deterioration from general environmental conditions contributing to granular disintegration, but also from the accumulation of dust interacting with the decalcified specimens.”   Also worth noting is that “A search of all Carpenter's manuscripts, illustrations, and letters in the archives of the NHM UK revealed several volumes of illustrations and photographs of Eozoon” , including a volume of photographs of Eozoon taken by Charles Berjeau. 

Schwartz ( 2022) in her history of the use of photography in science in Canada, and the ways in which photography contributed to the creation and circulation of knowledge in mid-to-late nineteenth-century Canada, singled out Dawson for illustrating his 1864 paper on Eozoon Canadense  with a photograph of a specimen of Eozoon Canadense from Petite Nation Seigniory,  and subsequently incorporating photographs of specimens in his papers.

Walter Etter (2022),  Curator of Palaeontology at the Natural History Museum Basel, gave a short talk entitled ‘Eozoon and the strange case of Otto Hahn.’   Etter’s abstract states:   

 “ [Hahn] at first was a decided opponent of the organic theory. But just a few years later he made a complete turnaround. He interpreted the structures not as foraminifers but mostly as algae. Then he somehow lost the ordinary judgement. He started to see Eozoon-like structures everywhere, also in magmatic and metamorphic rocks, and later even in meteorites. He published two books on the subject, both richly illustrated with photographs and drawings, and described countless new species and named them e.g., after Reich Chancellor Otto Bismark, after Darwin, and even after the German Emperor Wilhelm. His theories had, not surprisingly, very few support, and then he somehow lost interest in the subject and emigrated to Canada.” 

Seven years ago when I came across  Otto Hahn’s publication on Eozoon – ‘Die Urzelle '–  I reached a different conclusion.  I viewed it as an over-the-top piece of satire, written to ridicule and criticize Dawson’s theories, rather than a serious scientific paper.   I don’t see how it can be taken as anything but satire even if it consists of 71 pages and 30 plates.  Dawson (1881), however,  missed the point and analyzed it as a scientific paper, concluding that Hahn’s paper lacked ‘any scientific value’.  King and Rowney (1881) comment that Dawson had wasted “some pages in fruitlessly criticizing  Otto Hahn's ‘Die Urzelle ' ” is apt.  Hahn’s publication was treated as an  “enormous joke” by an anonymous reviewer in the Popular Science Review, who noted  that “it has been treated as serious by several writers, both in Germany and in this country [England]; but it seems to be ironical throughout; and every one knows that of all figures of speech irony is the one which is least readily understood.” concluding “Dr. Hahn is not quite a Swift, and even the great Dean’s irony was not appreciated by everybody.”   (See Anonymous, 1880a).    Hahn’s paper was also recognized as satire by another reviewer who commented “Dr. Dawson also criticized at length a contribution by Dr. Otto Hahn to the literature of Eozoon, which he appears to have taken for a serious instead of ironical production.” (See Anonymous, 1880b).  

This year  Bechly (2023), Dolan (2023), O’Connor (2023) to varying degrees  reviewed the history of Eozoon Canadense up until O’Brien (1970) and Hofmann (1971)  and relied on  reviews such as Schopf (2000), Adelman ( 2007), Brasier (2009), Roosth (2018) to conclude that Eozoon is inorganic, without mentioning the work by the Ontario Geological Survey.    Further, it does not appear that any of Bechly (2023), Dolan (2023), O’Connor (2023) sectioned, analysed or looked closely at any specimen of Eozoon.  

What is needed is both [A] a careful review of the five  main types of Eozoon Canadense using modern techniques, as was recently done by Lee and Riding (2021) who looked at the  stromatolite Cryptozoön of upper New York State and concluded that it is a keratose sponge microbial consortium, and [B] a comparison of specimens and outcrops of Eozoon with examples of stromatolites found in the Grenville marbles of Ontario and Quebec.   I make that suggestion because photographs of stromatolites in Precambrian carbonates in peer-reviewed publications (e.g., see Wacey (2010), figure 7b, 7c; Hickman-Lewis,  Westall & Cavalazzi (2018)   Figs. 42.2 and 42.3:  finely laminated, carbonaceous, crinkly, nonisopachous horizons interpreted as microbial mats with flat-lying and microtufted morphologies)  look suspiciously like drawings and photographs of  specimens of Eozoon. 

Christopher Brett

Ottawa, Ontario

References and Suggested Reading

Adelman, Juliana, 2007:   Eozoön: debunking the dawn animal.  Endeavour Volume 31, Issue 3, September 2007, Pages 94-98    https://doi.org/10.1016/j.endeavour.2007.07.002

 Anonymous, 1869: Eozöon canadense [ a Poem], in Exeter Change for British Lions, at  Pages 24-25, Published for the Exeter Meeting of the  British Association for the Advancement of Science.  Edited by John C. Brough (alias, Snug the Joiner). London: Benjamin Pardon & Son, 32 pages  https://www.palaeopoems.com/palaeopoems/eozoon-canadense 

 https://www.google.ca/books/edition/Exeter_Change_for_British_Lions/EAABAAAAYAAJ

 Anonymous 1880a:  The Eozoon Question.  Popular Science Review, New Series, Volume IV, No. XIV, pages- 176 - 178   https://www.biodiversitylibrary.org/item/192451#page/198/mode/1up

Anonymous 1880b: Eozoon Canadense.  Journal of the Royal Microscopical Society, Volume III, 471-472   https://www.biodiversitylibrary.org/item/37125#page/527/mode/1up

Antcliffe, Jonathan and Nicola Mcloughlin, 2009:  Deciphering fossil evidence for the origin of life and the origin of animals: Common challenges in different worlds. From Fossils to Astrobiology pp 211–229  Cellular Origin, Life in Extreme Habitats and Astrobiology, vol 12. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-8837-7_10  available on https://www.researchgate.net

Bartlett, J .R.  and DeKemp , E. A., 1987: Lithofacies, Stromatolite Localities, Metallic Mineral Occurrences, and Geochemical Anomalies associated with Carbonate Metasediments of the Burleigh Falls-Bancroft-Madoc Area, Southern Ontario.  Ontario Geological Survey, Map. P.3079 

Bechly, Günter , 2023:  Fossil Friday: Eozoön, the Dawn Animal Fallen from Grace.  Blog posting dated July 21, 2023,

https://evolutionnews.org/2023/07/fossil-friday-eozoon-the-dawn-animal-fallen-from-grace/

Black, Riley, 2020: Why It's So Difficult to Find Earth's Earliest Life.  Smithsonian Magazine.

https://www.smithsonianmag.com/science-nature/earth-earliest-life-fossils-stromatolites-180974442/    [photo of Stromatolites at Strelley Pool chert (SPC) in Western Australia ]

Brasier, Martin D., 2009:   Setting the scene: milestones in the search for early life on earth. In Wacey, D., (ed.) Early Life on Earth, Springer, Berlin, pp 1-19.  https://link.springer.com/chapter/10.1007/978-1-4020-9389-0_1

https://www.academia.edu/440648/Milestones_in_the_Search_for_Early_Life_on_Earth

Bressanon, David, 2014: Charles Darwin and the Early Search for Extraterrestrial Life

https://blogs.scientificamerican.com/history-of-geology/charles-darwin-and-the-early-search-for-extraterrestrial-life/

Brett, Christopher P., 2016:  A specimen of Eozoon Canadense at the Matheson House Museum in Perth, Ontario.  Blog posting dated Friday, April 29,  2016

http://fossilslanark.blogspot.com/2016/04/

Dawson, J. William, 1881:  Notes on Recent Controversies respecting Eozoon Canadense. Canadian Naturalist, Vol. 9, pages 228 -240 https://www.biodiversitylibrary.org/item/32317#page/241/mode/1up 

Dolan, John R., 2023: The saga of the false fossil foram Eozoon.  European Journal of Protistology, Volume 87, February 2023, 125955  https://www.sciencedirect.com/science/article/abs/pii/S093247392200092X

https://doi.org/10.1016/j.ejop.2022.125955

Easton, R. M., 1992: The Grenville Province and Proterozoic History of Central and Southern Ontario, Chapter 19 in Geology of Ontario, Ontario Geological Survey Special Volume 4, Part 1, pages 715-904 at 796-797

Etter. Walter, 2022:  Eozoon and the strange case of Otto Hahn.  Abstract Volume, 20th  Swiss  Geoscience Meeting 18-20 November 2022, Lausanne.  Abstract 5.4 at page 180.

https://geoscience-meeting.ch/sgm2022/program/session-program/ 

Carter, T.R. 1984:  Metallogeny of the Grenville Province, Southeastern Ontario, Ontario Geological Survey Open File Report 5515, 422p., 58  figures, 35 tables, and 14 photos.

http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/OFR5515//OFR5515.pDF

[Plate 10:  Fragment of a laminated, siliceous bed in dolomitic marble at the Madoc talc mine, in Madoc Township. It may represent a metamorphosed stromatolite.   Plate 11:  Laminated, siliceous rock at the Madoc talc mine that may be a metamorphosed stromatolite horizon. ]

Hahn, Otto, 1879:  Die Urzelle: Nebst dem Beweis, dass Granit, Gneiss, Serpetin, Talk, gewisse Sandsteine, auch Basalt, endlich Meteorstein und Meteoreisen aus Pflanzen bestehen: Die Entwicklungslehre durch Thatsachen neu begründet , 1879 – The Primordial Cell: In Addition to the Proof that Granite, Gneiss, Serpentine, Talc, certain Sandstones, including Basalt, finally Meteorite and Meteoric Iron Consists of Plants: The Development of Theory Newly Established by Facts, 71 pages, 30 plates

https://archive.org/details/dieurzellenebst00hahngoog/page/n9/mode/2up [in German]

Hickman-Lewis, Keyron & Westall, Frances & Cavalazzi, Barbara, 2018:  Traces of Early Life From the Barberton Greenstone Belt, South Africa.  In book: Earth's Oldest Rocks (pp.1029-1058) Publisher: Elsevier 10.1016/B978-0-444-63901-1.00042-3. 

[Figs. 42.2 and 42.3:  finely laminated, carbonaceous, crinkly, nonisopachous horizons interpreted as microbial mats with flat-lying and microtufted morphologies   ]

Hofmann, H. J., 1971:  Precambrian Fossils, Pseudofossils and Problematica in Canada,  Geological Survey of Canada, Bulletin 189, 146 pages

King, William and Rowney, Thomas Henry,  1881 : An Old Chapter of the Geological Record with a New Interpretation: Or, Rock-metamorphism (especially the Methylosed Kind) and Its Resultant Imitations of Organisms: With an Introduction Giving an Annotated History of the Controversy on the So-called "Eozoon Canadense," and an Appendix 

London: John Van Voorst,  https://books.google.ca/books?id=ocq7AAAAIAAJ

Lee, Jeong-Hyun and  Robert Riding, 2021:  The ‘classic stromatolite' Cryptozoön is a keratose sponge microbial consortium. Geobiology. 2021;19:189–198

https://robertriding.com/pdf/lee-riding-2021.pdf

https://pubmed.ncbi.nlm.nih.gov/33325101/

O'Brien, Charles F., 1970: Eozoon Canadense "The Dawn animal of Canada", ISIS, A Journal of the History of Science Society, Volume 61, No. 2, 206-223

O'Connor, Alan,  2023:  Canadian Pseudo-fossil: This specimen was once thought to represent the earliest life on Earth. National Museum of Ireland website. https://www.museum.ie/en-IE/Collections-Research/Collection/Documentation-Discoveries/Artefact/A-Canadian-Pseudo-fossil/4272e35f-065a-4605-9be0-90a3404eada2

[Describes and includes a photograph of  specimen NMING:F582 in the National Museum that was donated by Dawson, from Petite Nation, Canada.]

Petryk,  Allen, A. 1991:  Remnant stromatolites and cross-bedding in upper amphibolite grade Grenvillian marble and quartzite, southern Labrador Trough, Quebec.  Program with Abstracts - Geological Association of Canada 16: 99

Rayne, Elizabeth, 2021:  Could Things That Look like Fossils Trick Us into Thinking There Was Once Life on Mars?  https://www.syfy.com/syfy-wire/even-if-mars-had-alien-life-these-fake-fossils-arent-it

Riding, Robert, 2011:  The Nature of Stromatolites: 3,500 Million Years of History and a Century of Research. Pages 29 - 74 in  Reitner et al., Advances in Stromatolite Geobiology, Lecture Notes in Earth Sciences 131, DOI 10.1007/978-3-642-10415-2_3,   # Springer-Verlag Berlin Heidelberg 2011

https://robertriding.com/pdf/riding2011kalkowsky.pdf

Roosth, Sophia  2018: The Shape of Life, an Essay in aeon

https://aeon.co/essays/the-shape-of-life-before-the-dinosaurs-on-a-strange-planet

Schopf, J.William,  2000:  Solution to Darwin's dilemma: Discovery of the missing Precambrian record of life. PNAS 97(13), 6947–6953. DOI: https://doi.org/10.1073/pnas.97.13.6947

Schwartz, Joan M.,  2022:  Photography: Science, Technology, and Practice in Nineteenth-Century Canada.  Scientia Canadensis Volume 44, Number 1, 2022

https://www.erudit.org/fr/revues/scientia/2022-v44-n1-scientia07177/1098144ar/

Sendino, Consuelo, 2021:  The Carpenter Eozoon Collection, linking curation and conservation.  Blog posting dated  October 10, 2021

https://naturalhistorymuseum.blog/author/conulariahomtailcom/

Sendino, M.C.,  Cuadros J., Allington-Jones L., Barnbrook J.A.,  2015:   Chemical Analysis of the Dust on a Historically Important Collection: The W. B. Carpenter Eozoon Collection at the Natural History Museum, London. Collections: A Journal for Museum and Archives Professionals, 11 (4): 291 – 304.

https://journals.sagepub.com/doi/10.1177/155019061501100403

https://go.gale.com/ps/i.do?p=AONE&u=googlescholar&id=GALE|A490768981&v=2.1&it=r&sid=AONE&asid=6d2733f3

Wacey, David, 2010:  Stromatolites in the ~3400 Ma Strelley Pool Formation, Western Australia: Examining Biogenicity from the Macro- to the Nano-Scale.  Astrobiology 10(4):381-95

DOI:10.1089/ast.2009.0423

Wilson, Mark 2011:  Wooster's "Fossil" of the Week: The most famous pseudofossil ever (Proterozoic of Canada). Wooster Geologists May 8, 2011. https://woostergeologists.scotblogs.wooster.edu/2011/05/08/wooster's-fossil-of-the-week-the-most-famous-pseudofossil-ever-proterozoic-of-canada/

[Includes a photograph of a specimen Eozoön canadense  - the holotype in the U.S. National Museum of Natural History ]

Geodiversity Day – October 6 – and Geoheritage Day – October 8 – in Eastern Ontario

 For over a decade the geology department at Carleton University and the Ottawa-Gatineau Geoheritage Project have held an annual Geoheritage Day celebrating the geoheritage of Ottawa and surrounding areas.   This year those of us in Eastern Ontario will  also be joining in celebrating International Geodiversity Day, a worldwide celebration, bringing people together on October 6 each year, to promote the many aspects of geodiversity.  International Geodiversity Day was proclaimed by UNESCO at the 41st General Conference in 2021 and this year will be celebrated at various locations in Europe, Asia, South America, North America and Zealandia   [See https://www.geodiversityday.org/ ].

In Ottawa the Department of Earth Sciences, Carleton University, in partnership with Ingenium (Canada’s Canada Agriculture and Food Museum, Canada Aviation and Space Museum and the Canada Science and Technology Museum), presents “Celebrating Geodiversity: The Critical Foundation for Diverse Ecosystems on a Changing Planet. ” This event will be held at the Canada Science and Technology Museum from 6:00 to 9:00pm, on Thursday, October 6th as well as on zoom, and will feature a talk by Carleton Earth Sciences Professor Emeritus Dr. Claudia Schröder-Adams about her research in Canada’s High Arctic.  Following that talk, Beth McLarty Halfkenny will be moderating a discussion with Dr. Claudia Schröder-Adams  and other panelists with expertise in biodiversity, local ecosystems, and water and mineral resources, to make connections between Canada’s  landscapes, ecosystems, and human societies.    For registration information for this free event in-person or virtually on Zoom visit:  Geodiversity Symposium: The Foundation for Diverse Ecosystems on a Changing Planet | Faculty of Science (carleton.ca) [  https://science.carleton.ca/geodiversity-symposium/ ]

Another online Geodiversity Day Zoom Presentation in Canada is on the Geodiversity of Percé UNESCO Global Geopark, Gaspé, Quebec.  Max Deck-Leger will give an online presentation about the evolution of life through the Geopark, as visible in the fossils found in our five distinct geological formations covering over 500 million years.   The event takes place on Thursday,  October 6,  2022, starting at 17:30   (GMT -5:00) Eastern Time (US & Canada).  For more information: https://www.facebook.com/GeoparcdePerce/ or https://geoparcdeperce.com/

In person Geodiversity Day celebrations are also being held in Newfoundland on October 6th.

Selected Worldwide Geodiversity Day Zoom Presentations

The web site https://www.geodiversityday.org/ shows the location of many international Geodiversity Day events, including the following two zoom presentations that I found of interest.

The South Wales Geologists' Association in Cardiff, Wales is presenting an online talk by Duncan Hawley, describing William Smith's trips to South Wales before creating his  geological map of Britain in 1815.  This was the first geologic map of Britain.   The talk looks at the locations William Smith  visited and considers “why he interpreted the local limestones so wrongly.”   The event is scheduled for Thursday,  October 6, 2022, 19:30  (GMT) Western Europe Time, London, U.K, which I believe is about 4:30 pm in Eastern Ontario.  The event is open to the public. For more information see   register@swga.org.uk   

The Charnwood Forest Geopark is presenting an online event with the description:   Join us for an online extravaganza, linking amazing sites and people from around the world to celebrate all that geodiversity has to offer.   The event is scheduled for  Thursday,  October 6, 2022, at 14:00 (GMT) Western Europe Time, London, U.K., which I believe is 9 am in Eastern Ontario.  For more information:  facebook.com/CharnwoodForestGeopark

GEOHERITAGE DAY 
October 8, 10 am 3 pm in Ottawa, Ontario and Gatineau, Quebec

The 16th annual Geoheritage Day will take place on October 8th, 2022, with volunteers hosting a number of geological sites around the National Capital region.  Details can be found at:

https://earthsci.carleton.ca/outreach/explore-geoheritage-day

Other Geoheritage Resources

Beth McLarty Halfkenny, Curator, Outreach Coordinator, Department of Earth Sciences, Carleton University, gave a talk on September 23, 2022 entitled “ Geoheritage of the National Capital Region; what’s here and why care” that can be watched on YouTube at 

https://youtu.be/M6y6msgKMNg    This is a 38 minute presentation followed by seven minutes of questions 

Carleton University has web site entitled at https://geoheritageday.carleton.ca which provides a map showing the location of over 30  Geoheritage sites across Canada with a brief description and web links to web pages providing information on the sites.   The links work, but have to be pasted into a browser, as merely clicking on the link results in a blank Redirect Notice.

The Ottawa-Gatineau Geoheritage Project maintains a web site  with descriptions of twenty-six Geoheritage sites in and around Ottawa at: 

https://www.ottawagatineaugeoheritage.ca .   Also available on the site, under the link ‘Field Trips’,  are [A] a brochure entitled “Introduction to the Geodiversity of Perth”, a self-guided tour of rocks on display at the Crystal Palace, Tay Basin, Perth, Ontario; [B] Geology of the Ottawa Area, a self-guided field trip that takes you to rock exposures in the Ottawa area that show geologic features typical of the local Precambrian and  Paleozoic rock; and [C] One Billion Years of Geology, a self-guided field trip that takes you to rock exposures in the Ottawa area, plus to the Mer Bleue bog (a former channel of the Ottawa River) and to the Lemieux Landslide.

 The Metcalfe Geoheritage Park in Almonte Ontario has 20 permanent rocks and one guest rocks on display. See: http://metcalfegeoheritagepark.com/specimens/

Christopher Brett

Ottawa, Ontario

A Kinked Orthopyroxene Megacryst from the Mealy Mountains Anorthosite, Labrador

While attending university I worked for three summers as a field assistant in Labrador for the Geological Survey of Canada under Dr. Ron Emslie mapping parts of the Harp Lake anorthosite body, the Mealy Mountains anorthosite complex and the Ptarmigan Complex in the Red Wine Mountains. While mapping in the Mealy Mountains I picked up a loose, highly kinked, bronzite crystal, which later thin sectioning revealed contained exsolved plagioclase and clinopyxene lamellae along (100) of the orthopyroxene host. Below are three photographs of that specimen. It was about 7 cm long, by 3.5 cm wide by 5 cm thick (before sectioning). 

 

The middle photograph shows a cut and polished surface.   In the  edited version of that photograph provided below I have used pink lines to show the kink zone  boundaries.   I’ve shown some of the (100) exsolution planes with  blue lines.  The (100) exsolution planes run roughly diagonally upwards  from right to left, but changes direction in each kink zone.  

 

 

Below are two photographs of a polished thin section made from this specimen.

The very fine lamellae are exsolved clinopyroxene.  The thicker lamellae are exsolved plagioclase.  Plagioclase grains  (some displaying twinning) can also be seen along the kink boundary.   Some of the fine clinopyroxend lamellae bend as they approach the kink boundary.

The specimen is an aluminous orthopyoxene megacryst –  an example of a Type 1 megacryst  “interpreted to have crystallized within the mantle and at deep crustal levels” (see Emslie, 1975) commonly found in anorthosite intrusions.   Most believe that the aluminum is present in the original orthopyroxene megacryst  as various Tschermak components  (Ca,Mg,Fe)Al2SiO6 and/or as Ca(Ti 3+, Fe3+) AlSiO6 where  trivalent titanium  Ti3+ or trivalent iron Fe3+  is a  cation in the M1 site, before exsolving in a reaction that produces plagioclase and any of  ilmenite,  spinel, rutile and various iron oxides.

Interestingly, while most mineralogy texts and web sites mention that the typical orthopyroxene cleavages is  parallel to (210), with planes intersecting  at ~90̊, with parting on (100) and (010), the specimen shown in the above photographs displays  very good cleavage parallel to the (100) exsolution planes, with  good parting on (010) and (001).

It is worth noting that the specimen  in the above photographs is not representative of orthopyroxene megacrysts from the Mealy Mountains as it is much more kinked than many other crystals that I found.  While mapping the Mealy Mountains anorthosite I found hundreds of large loose bronzite and hypersthene crystals scattered across the surfaces of outcrops, and many examples within the anorthosite.   The largest ones I observed were rounded and larger than a meter in diameter.   Many crystals displayed distorted zones and some displayed kink bands.  None of the other pyroxene crystals that I looked at were as kinked as the specimen shown in this blog posting. 

Others have reported and figured kinked aluminous orthopyroxene megacrysts. Ron Emslie (1975) noted that plagioclase lamelllar structure in alumious orthopyroxenes pyroxenes from anorthosites “is frequently warped and sometimes is crossed by kink bands”, and included a photograph (Fig. 1,E)  from the Morin Anorthosite showing minor kinking.  Emslie (1976) includes as figure 33.7  a photograph of a kink banded specimen from the Mealy Mountains with the caption “Orthopyroxene megacryst showing kink-banded  cleavage. Kink-banded is a common feature in these megacrysts and the enclosing rocks are not deformed.”   Nunn et al. (1986), in a report on the Atikonak River Massif, Western Labrador, for a rock unit comprised of troctolite, leucotroctolite and anorthosite, include a photograph (plate 14, page 136) showing “Strong kink banding in a giant orthopyroxene; the crystal is over 40 cm across.”

Numerous authors have remarked on the kinked orthopyroxene crystals in the Lac-Saint- Jean anorthosite in Quebec.  Benoit and Valiquette (1971) mention that along the road between Saint-Bruno and Larouche, some of the hypersthene crystals are a foot long and that “Les cristaux d'hypersthène déformés au point de montrer des faces cristallines ondulées sont d'observation commune.” [Translation:  Hypersthene crystals distorted to the point of showing wavy crystal faces are a common sight.]  Berrangé (1977), in a discussion of the Lac- Saint- John anorthosite reported that “very large hypersthene crystals are not rare” and included a photograph as Plate IV-B of a large (18 cm x 13 cm)  “Kink banded crystal of  orthopyroxene (En72 —70).”    David  Duguay (2012) in a study of aluminous pyroxene megacrysts from an  outcrop located along the Route du Pont in Arvida, Quebec, part of the Lac-Saint-Jean anorthosite complex, reported plagioclase exsolution lamellae, clinopyroxene exsolution lamellae,  ilmenite exsoloution lamellae, and exsolved  rutile, and kinkbands in the crystals.  Photographs 10C and 10D at page 24 of his thesis show spectacular kinking on par with the specimen shown above from the Mealy Mountains.   Klein and Philpotts (2016, Figure 9.47 (B)) include a photograph of a “Single crystal of orthopyroxene showing kink bands from the Lake St. John anorthosite massif, Quebec.” where the crystal is about 30 cm long by 15 cm wide.

Low (1896) in a report of an anorthosite occurrence along the Romaine River, Labrador, mentions (page 235) that it contains “masses of brown hypersthene, often several inches in diameter.  The hypersthene often exhibits a zig-zag crumpled texture.” and that the anorthosite “holds much hypersthene, often in large masses, some a foot across.”  Low also reported that the zig-zag structure in hypersthene was seen in thin section.  I suspect that Low’s "zig-zag crumpled" hypersthene crystals are kinked aluminous orthopyroxene megacrysts, but can’t find where anyone has studied them since Low visited the site in 1892-95.   Sabina (2003, page 189) mentions the Romaine River ‘zigzag, crumpled’ hypersthene occurrence in her mineral collecting guide for Labrador, but does not appear to have visited the occurrence.
 
Numerous authors have reported on kink bands in orthopyroxene crystals.   All agree that the bending and kinking of bronzite and orthopyroxene is  indicative of the intense deformation and pressure experienced by the host rock .   Berrangé (1977) notes that “ Turner and others (1960) who have studied identical [kink] bands produced in  experimentally deformed orthopyroxenes, and in orthopyroxenes  from the Adirondacks and elsewhere, attribute the kink bands to  post-crystalline plastic deformation by translation gliding on {100} parallel to [001]." Numerous authors have reported on clinopyroxene exsolution along the (100) plane of orthopyroxene.   Most believe that the exsolution of Ca-clinopyroxene from orthopyroxene is aided by deformation (in part because experiments show that highly strained  bronzite inverts to clinoenstatite along the (100) plane).   I’ve provided a number of the more interesting papers below in the list of references.  

Deformation textures such as kink bands in orthopyroxene, bent exsolution lamellae in orthopyroxene, curved cracks in pyroxenes, are a common feature of mantle xenoliths (Mundl et al, 2015; Alifirozva, T.A. and Pokhilenko, L. N. , 2008;  Engvik et al.,  2020).  Kinked pyroxenes are also common in high grade metamorphic rocks.  For example Sturt (1969) mentions that pyroxene crystals in amphibolite facies regional metamorphism “show such features as small faults, kink bands, strain-induced twin lamellae, and in some cases exsolution lamellae” and includes as plate 3B a photograph of a thin section of a pyroxene showing exsolution and kink bands.

 Below is a schematic drawing of an ideal kink band, modified from McLaren and  Etheridge (1976), who conducted a  transmission electron microscope study of naturally deformed orthopyroxene.   The kink band boundaries are A-B and E-D.

The slip planes are normal to the drawing and the slip directions are indicated by the arrows.  Note that the slip planes are bent in the areas ABC and DEF.

As noted by Plummer et al. (2021) “Kinking is a deformation mechanism ubiquitous to layered systems, ranging from the nanometer scale in layered crystalline solids, to the kilometer scale in geological formations.”   Below is a schematic drawing of an ideal kink band, modified from Donath, 1968; Rousell, 1980 and Noël and Archambault, 2006, who all studied kink bands in rock formations.

The fluorescent pink arrows show the relative direction of movement.  Here the rotation and slippage of the lamellae produces voids (blue triangles)  at the end of rotated lamellae along the kink zone boundary.  In the above photographs of thin sections of kinking in the orthopyoxene megacryst, the voids are filled by plagioclase, clinopyroxene and estatite.  The kink zone is shortened by twice the base of the blue triangles.

In a YouTube video on pyroxenes, Professor Kenneth Befus  (2020) includes a bronzite specimen to show the metallic bronze colour of bronzite.  It is almost as kinked as the specimen in my photographs.  

Christopher Brett
Ottawa, Ontario

References and Suggested Reading

Alifirozva, T.A. and Pokhilenko, L. N. , 2008
A variety of textures in mantle xenoliths of peridotites and pyroxenites from Yakutian pipes: petrological interpretation; 9th International Kimberlite Conference Extended Abstract

Anonymous
Orthopyroxene Deformation.  Structure Database.  University of Otago New Zealand. Blog at WordPress.com.
https://structuredatabase.wordpress.com/mineral-deformation/mineral-deformationorthopyroxene-deformation/

Anonymous
Phase transitions and exsolution phenomena in pyroxenes. 
https://www.uni-muenster.de/imperia/md/content/mineralogie/lecture_3_pyroxenes.pdf

Befus, Kenneth, 2020
Mineralogy: Lecture 45, Pyroxenes. Duration: 17:42.  Posted: Nov 16, 2020. https://www.youtube.com/watch?v=TZlMGDYB6xA
[includes photograph of kinked bronzite at 16:00  to 17:30 ]

Benoit , F.-W. et Guy Valiquette, 1971
Region du Lac Saint-Jean (Partie Sud).  Gouvernement du Québec, Ministère des Richesses Naturelles, Direction Generale des Mines , Service de l'exploration Géologique, Rapport Géologique 140  https://gq.mines.gouv.qc.ca/documents/examine/RG140/RG140.pdf

Berrangé, Jevan P.,  1977
Final report, Antoine-La Trappe area, Roberval county [Quebec], report DP 462.  Quebec Ministere Des Richesses Naturelles, Direction Générale  des Mines, 204 pages
https://gq.mines.gouv.qc.ca/documents/examine/DP462/DP462.pdf

Bertrand, Claude, 1963
L'hypersthène alumineux du Lac St. Jean  [Aluminous hypersthene of Saint Jean Lake] Master's thesis.  thèse de maîtrise non publiée. Ecole Polytechnique, Montreal, QC, Canada, 64 pages

Brett, Christopher P., 2014
Layering in the Mealy Mountains Anorthosite Complex, Labrador.  Blog posting dated  November 4, 2014, http://fossilslanark.blogspot.com/2014/11/layering-in-mealy-mountains-anorthosite.html

Brett, C. P. And Emslie, R. F., 1979
Orthopyroxene Megacrysts in anorthosites of the Mealy Mountains. Prog. With Abstr., Ann Meeting Geological Society of Canada

Brey  G. P. , Köhler T. ,  1990
 Geothermobarometry in four-phase lherzolites II. New thermobarometers and practical assessment of existing thermobarometers . Journal of Petrology  31 , 1353 – 1378

Bruijn , Rolf H.C. and Philip Skemer, 2014
Grain-size sensitive rheology of orthopyroxene. Geophysical  Research Letters 41,
https://cpb-us-w2.wpmucdn.com/sites.wustl.edu/dist/7/3170/files/2016/11/Bruijn-2014-2gm8yus.pdf

Bystricky, M., J. D. Lawlis, S. J. Mackwell, F. Heidelbach, and P. C. Ratteron , 2016
High-Temperature Deformation of Enstatite Aggregates.  Journal of Geophysical Research: Solid Earth, Volume 121, Issue 9 p. 6384-6400 September 2016 https://doi.org/10.1002/2016JB013011

Dewey J.F. 1965.
Nature and origin of kink bands.  Tectonophysics. 24: 213-242.

Donath F.A. , 1968
Experimental study of kink band development in strongly anisotropic rock.    In Conference on research in tectonics: kink bands and brittle deformation, eds. A.J. Baer and D.K. Norris, 255-293.

Duguay, David. 2012
Déterminer l’origine des mégacristaux de pyroxène de l’affleurement situé en bordure de la Route du Pont à Arvida .   Mémoire présenté dans le cadre du cours Projet de find’études
Université du Québecà Chicoutimi Avril 2012
https://eweb.uqac.ca/bibliotheque/archives/travaux/030300974/PFE_Memoire_DavidDuguay.pdf

Emslie, R .F. , 1975
 Pyroxene megacrysts from anorthositic rocks: New clues to the sources and evolution of parent
magmas. Can. Mineral. 13, 138-145.
https://rruff-2.geo.arizona.edu/uploads/CM13_138.pdf

 Emslie R. F., 1976
 Mealy Mountains Complex, Grenville Province, southern Labrador. In: Report of Activities, Part A. Geological Survey of Canada, Paper 76-1A, 165–170 https://doi.org/10.4095/119844

Engvik, Ane K., Cornelia Mertens, Claudia A.Trepmann, 2020
Episodic deformation and reactions in mylonitic high-grade metamorphic granulites from Dronning Maud Land, Antarctica. Journal of Structural Geology, Volume 141, December 2020, 104196
 
Etheridge, M. A., 1975
Deformation and recrystallisation of orthopyroxene from the Giles Complex, Central Australia,
Tectonophyics, 25, 87-114
 
Gasparik, Tibor,  2003
Phase Diagrams for Geoscientists: An Atlas of the Earth's Interior.   Springer Science & Business Media, Apr 9, 2003 - Science - 462 pages at pages 14 and 34
 
Harley, Simon  Leigh,  1981
Garnet-orthopyroxene  assemblages  as  pressure-temperature  indicators  •.  An  experimental  study  with  applications  to  granulites  from  Enderby  Land,   Antarctica.  Doctoral Thesis.   https://core.ac.uk/download/pdf/33314696.pdf

Harrison, Richard
Phase transitions and exsolution phenomena in pyroxenes. Natural Sciences Tripos Part 1b
GEOLOGICAL SCIENCES B, Igneous Mineralogy.
www.uni-muenster.de › content › mineralogie › lecture_3_pyroxenes

Jackson,  J. M.,  S. V. Sinogeikin  M. A. Carpenter and J.D. Bass, 2004
Novel phase transition in orthoenstatite. American Mineralogist, Volume 89, pages 239–245, 2004   http://web.gps.caltech.edu/users/jackson/pdf/Jackson_AmMin04_89_239.pdf
 
Jonnalagadda, M., M. Benoit,  S.  Harshe ,  S. Phule,  R. Tilhac, 2021
Geodynamic evolution of the Tethyan lithosphere as recorded in the Spontang Ophiolite, South Ladakh ophiolites (NW Himalaya, India).   2021Geoscience Frontiers 13(10):101297
 
Kaczmarek, M. And O. Muntener, 2008
 Juxtaposition of Melt Impregnation and High-T emperature Shear Zones in the Upper Mantle;
Field and Petrological Constraints from the Lanzo Peridotite (Northern Italy).  Journal of Petrology, Volume 49 , Number 12 , Pages 2187-2220
https://doc.rero.ch/record/299675/files/egn065.pdf

Kirby, S. H. and  M. A. Etheridge, 1981
Exsolution of Ca-clinopyroxene from orthopyroxene aided by deformation.  Physics and Chemistry of Minerals volume 7, pages 105–109 
 

Klein, Cornelis and Anthony R. Philpotts, 2016
Earth Materials: Introduction to Mineralogy and Petrology. 2nd Edition, Cambridge University Press. 616 pages

Kohlstedt, D.L. and Vander Sande, J.B., 1973.
 Transmission electron microscopy investigations of the defect microstructure of four natural orthopyroxenes. Contrib. Mineral. Petrol. 42: 169-180.
https://link.springer.com/article/10.1007/BF00371506

Low, A. P., 1896
Report on Explorations in the Labrador Peninsula Along the East Main, Koksoak, Hamilton, Manicuagan and Portions of other rivers, in 1892-93-94-95.  Geological Survey of Canada.

McLaren, A. C., Etheridge, M. A.,  1976
A transmission electron microscope study of naturally deformed orthopyroxene. Contributions to Mineralogy and Petrology, 57 (2). 163-177 doi:10.1007/bf00405223

McLaren, Alexandre C. and  M. A. Etheridge, 1980
A transmission electron microscope study of naturally deformed orthopyroxene. II : mechanics of kinking - Bulletin de Minéralogie, Année 1980 103-5 pp. 558-563
https://www.persee.fr/doc/bulmi_0180-9210_1980_num_103_5_7420

Moreva-Perekalina, T.V., 1985
 Ultramafic xenoliths from alkaline basalts of Finkenberg Siebengebirge, West Germany) Scripta Geol., 78 (1985)
 
Mundl, A. , T. Ntaflos, L. Ackerman, M. Bizimis, E. A. Bjerg, W. Wegner, C. A. Hauzenberger   2015
 Geochemical and Os–Hf–Nd–Sr Isotopic Characterization of North Patagonian Mantle Xenoliths: Implications for Extensive Melt Extraction and Percolation Processes
 Journal of Petrology, Volume 57, Issue 4, pages 685-715

Murata, Keiko  et al., 2009
Significance of serpentinization of wedge mantle peridotites beneath  Mariana forearc, western Pacific.  Geosphere; April 2009; v. 5; no. 2; p. 90–104; doi: 10.1130/GES00213.1;
 
Noël, Jean – François and Archambault, Guy, 2006
A numerical modeling attempt of failure in jointed rock masses by kink zone instability.  ARMA/USRMS 06-Paper – No 1023.  41st U.S. Symposium on Rock Mechanics. https://www.researchgate.net/publication/254542212_A_Numerical_Modeling_Attempt_of_Failure_in_Jointed_Rock_Masses_by_Kink_Zone_Instability/link/564a396508ae127ff9868ae9/download

Nunn, G.A.G., Emslie, R. F., Lefebvre, C.E., Noel, N. And Wells, S., 1986
The Atikonak River Massif and Surrounding Area, Western Labrador and Quebec., Current Research, Newfoundland Department of Mines and Energy, Mineral Development Division, Report 86-1, pages 125-145;

G.Plummer, H.Rathod, A.Srivastava, M.Radovic. T.Ouisse. M.Yildizhan, P.O.Å.Persson, K.Lambrinou, M.W.Barsoum, G.J.Tucker, 2021
On the origin of kinking in layered crystalline solids.   Materials Today, Volume 43, March 2021, Pages 45-52  https://www.sciencedirect.com/science/article/pii/S1369702120304223

Raimbourg, Hugues,  Toshihiro Kogure, Tsuyoshi Toyoshima.2011
Crystal bending, subgrain boundary development, and recrystallization in orthopyroxene during granulite-facies deformation. Contributions to Mineralogy and Petrology, Springer Verlag, 2011, 162 (5), pp.1093-1111. 10.1007/s00410-011-0642-3.  insu-00627836
https://hal-insu.archives-ouvertes.fr/insu-00627836/document
 
Raith, Michael M.,  Peter Raase & Jürgen Reinhard, 2012
Guide to Thin Section Microscopy, Second edition, at pages 42, etc.
http://www.minsocam.org/msa/OpenAccess_publications/Guide_Thin_Sctn_Mcrscpy/Thin_Sctn_Mcrscpy_2_prnt_eng.pdf

Rousell, D. H., 1980
Kink bands in the Onapin formation, Sudbury Basin, Ontario, Tectonophysics, 66, 83-97

Sabina, A. P., 2003
Rocks and minerals for the collector: Iles de la Madeleine, Quebec, the Island of Newfoundland, and Labrador.  Geological Survey of Canada, Miscellaneous Report 58, 2003, 304 pages, https://doi.org/10.4095/214397 

Steuten J.M., Van Roermund, H.L.M., 1989
An optical and electron microscopy study of defect structures in naturally deformed orthopyroxene,     Tectonophysics 157:331-338
 DOI:10.1016/0040-1951(89)90148-0

Sturt, Brian A., 1969
Wrench Fault Deformation and Annealing Recrystallization during Almandine Amphibolite Facies Regional Metamorphism.  The Journal of Geology  Vol. 77, No. 3 (May, 1969), pp. 319-332 (17 pages)

Turner, F. J., H. Heard, D.T. Griggs.  1960
Experimental deformation of enstatite and accompanying inversion to clinoenstatite.  International Geological Congress . XXI Session, Part 28, p 399-408

 Trommsdorff, V. and H.R. Wenk , 1968
Terrestrial metamorphic clinoenstatite in kinks of bronzite crystals.  Contributions to Mineralogy and Petrology volume 19, pages 158–168