Saturday 30 March 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 Facility?

That may seem like an odd title to readers, unless the reader has taken the time to read three of my earlier blog postings:   March 7, 2014 - My Hunt for Sir William Logan’s Specimens of Protichnites;  October 6, 2017- Things To Do on October 14th; and October 27,  2017 - Protichnites, etc. on display at the Canadian Museum of Nature’s Collection and Research Facility.   Briefly, while Sir William Logan’s specimens of Protichnites were thought to have gone missing, they were actually at  the Canadian Museum of Nature’s Research and Collections Facility on Pink Road in Gatineau, Quebec, and were located because Dr. MacNaughton spotted them, mislabeled, in a publication of the Museum entitled “Photographic Catalogue of  Trackways in the Canadian Museum of Nature.”  As well, another missing GSC holotype specimen (Gyrichnites gaspensis) was also located at the Canadian Museum of Nature’s Research and Collections Facility.

In my March 7, 2014 blog posting I mentioned that my research had revealed various reports dating from  1875  to 1896 stating that  the Museum of the Survey, first in Montreal and later in  Ottawa,  had in its collection  Logan’s specimens of  Protichnites  from Beauharnois.    When I wrote my March 7, 2014 posting one thing I did not include was my suspicion that the slabs  had been misplaced when Canada’s Parliament Buildings burned down in February, 1916 and Parliament was moved to the Victoria Memorial Museum, displacing the Geological Survey of Canada from the building.

Since then I have located Harlan Smith’s (1916) report of the fire and the haste with which the exhibits of the  Museum of the Geological Survey and staff were moved from the Victoria Museum to make way for the museum to be used as a temporary home for Parliament.  In 1911 Harlan  Smith joined the Geological Survey of Canada as head of its archeology division and would have personally taken part in the crating of specimens.

The fire that destroyed the Parliament Buildings started about  9 p.m. , Thursday,  February 3, 1916 .  Before  the fire started the Geological Survey had occupied practically all of the Victoria Memorial Museum building.   Harlan Smith notes that   “About ten a.m. [on Friday] February 4th, the morning after the fire, the Survey staff was informed of the intended use of the building as a temporary home for the Dominion Parliament.”   Many museum exhibits were crated and moved, and put into storage, some before the end of the day on Friday.  Here is Harlan Smith’s account of the packing of the minerals, geological specimens, invertebrate palaeontological exhibits and vertebrate palaeontological exhibits:

    “The west hall was occupied by the tentative exhibit of minerals. This exhibit was packed and removed in six hours, or by 4 p.m., Friday, which was less than twenty hours after the fire began. The costly cases in which these minerals were exhibited had meanwhile been taken apart and placed in storage. Rooms for the members of the Senate were made here.
    The west wing, which was being prepared for geological and mineralogical exhibits, was cleared before Monday noon. The Senate met at 8 p.m. on Tuesday in this new chamber, which had been vacated by the museum within seventy-five hours after it became known that the Senate would meet in the museum.
    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.”


Is it any wonder that some specimens were misplaced?

+++++++++

Where is the Holotype of Aspidella?


Elkanah Billings, Paleontologist to the Geological Survey of Canada, originally briefly described and figured Aspidella in 1872.  His drawing shows a small slab with two elliptical discs.   Unfortunately  that slab is missing.  Below I mention that  Hoffman (1970)  states that the slab is missing, and that Gehling, Narbonne,  and Anderson (2000) confirm that it was still missing.  However I also mention that Dr. Alice E. Wilson (1957) states that she can  remember Billings’s specimens in the Museum of the Geological Survey, that after the burning of the Parliament Buildings the  exhibits were packed and stored, and that in 1957 “Aspidella terranovica is still in storage.”

H. J. Hoffman, 1970 – the Holotype of Aspidella is missing


I expect that everyone in Canada with an interest in Ediacaran and other  Precambrian fossils has at  one time picked up H. J. Hoffman’s (1970) book entitled “Precambrian Fossils, Pseudofossils, and Problematica in Canada.”   Somewhat surprisingly (as I was more interested in minerals than fossils), I’ve been aware of the publication since shortly after it was first published.    I had a friend in university in biology who told me in the fall of ‘72 or ‘73 that he was writing a paper on the origin of life, and I was able to direct him to Hoffman’s publication, and to take him over to the Geology Department’s library and show him the text.

Hoffman (1970) mentions that “The holotype slab (GSC type 221) is missing from the collections of the Geological Survey of Canada, but a platotype (cast?) (Pl. 5, fig. 1) of the holotype is fortunately available for study (GSC type 221c).  This metal plastotype slab bears the outline of two parallel-oriented elliptical specimens of Aspidella terranovica.  ... Two other specimens ... labelled Aspidella terranovica, are in the same collection as the platotype.   Specimen 221a (Pl. 5, fig 2) is from Ferryland...  Specimen 221b (Pl. 5, fig 3) is from
St. John’s.

Gehling, Narbonne,  and Anderson,  2000 - Still Missing


Gehling, Narbonne,  and Anderson (2000) state that “Billings (1872) originally named Aspidella from a small slab bearing two raised oval-shaped discs, without identifying one specimen as the holotype.  On the metal platotype, which is all that remains of the original slab, a small cross adjacent to the largest specimen may be interpreted as indicating the intended holotype (GSC type 221c).   Walcott (1899, pl. 27, figs 7-8, 14-15) illustrated two other specimens in the type collection under the same name and number, from the same locality (... GSC 221a-221b). 
   

Alice E. Wilson, 1957 – Billing’s  Specimens of Aspidella are in Storage

           
Dr. Alice E. Wilson provides hope that the holotype slab can be found.   In a paper entitled ‘Life in the Proterozoic’, which was a Chapter in a book entitled ‘The Proterozoic in Canada,” she discusses Aspidella and commented:

“Billings (1873, 1874) described and illustrated by drawings (not photographs) some forms from the “Huronian” near St. John’s, Newfoundland.  He named them Aspidella terranovica. The writer remembers these specimens in the Museum of the Geological Survey.  After the burning of the Parliament Buildings, when Parliament was moved to the Museum Building, the exhibits were packed and stored.  Aspidella terranovica is still in storage. No tests were ever made upon the specimens.”
           
I believe that Dr. Alice E. Wilson can be relied on when she says that the specimens of Aspidclla were packed and  put in storage in 1916, and were still in storage in 1957 .   She worked for the Geological Survey of Canada from 1909, starting in the Museum,  until her forced retirement at age 65 in 1946.   She maintained an office at the Survey – and kept publishing articles on paleontology –  until shortly before her death in 1964.  She would have been involved in the crating and storage of the specimens.

The issue is then: Where are they stored?   The first place that I will start looking is at the Canadian Museum of Nature’s Research Facility in Gatineau, Quebec where Logan’s specimens of Protichnites were located.  Hence the cryptic title to this blog posting.

Located


Addendum (April 1 & 2):  In answer to my email I  received back an email with a photo of GSC221, the holotype of Aspidella.  Interestingly the slab is larger than I expected and shows at least six elliptical discs.  However, it is at the GSC’s offices at 601 Booth Street in Ottawa, and not at Canadian Museum of Nature’s Research and Collections Facility on Pink Road in Gatineau, Quebec.  It was found a year or so ago.  I have booked an appointment to attend and photograph the holotype specimen and will put the photographs that I take on my blog..


Christopher Brett
Ottawa, Ontario

   
References and Suggested Reading

Billings, E., 1872
On some fossils from the primordial rocks of Newfoundland. Canadian Naturalist and Quarterly Journal of Science. Volume  6, New Series, pages 465- 479 at pages 478-79.
https://www.biodiversitylibrary.org/item/32756#page/497/mode/1up

MacNaughton, R. W., Brett, C. P., Coyne, M. And Shepherd, K., 2017
Sir William Logan and the Adventure of the Ancient Amphibious Arthropod.
Abstract with Program, Canadian Paleontological Conference, Calgary, Alberta


David, T. W. E., 1928
Notes on newly discovered fossils in the Adelaide series (Lipalian?), South Australia, Trans. Roy. Soc. S. Australia, vol. 52, pp 191-209, plates 13-18
https://www.biodiversitylibrary.org/item/129838#page/197/mode/1up

Gehling, J.G., Narbonne, G.M. and Anderson, M.M.,  2000:
The first named Ediacaran body fossil,  Aspidella terranovica . Palaeontology, Volume 43, pages  427-456.  DOI: 10.1111/j.0031-0239.2000.00134.x

Hoffman, H. J.  (1970)
Precambrian Fossils, Pseudofossils, and Problematica in Canada.   Geological Survey of Canada, Bulletin 189, 146 pages, 25plates, map, charts.  Aspidella  at pages 14-17 and plate 5;
  https://doi.org/10.4095/123948

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

Sprigg, R.C., 1947
Early Cambrian (?) jellyfishes from the Flinders Ranges, South Australia.
- Transactions of the Royal Society of South Australia, vol. 71, 212-224
https://www.biodiversitylibrary.org/item/128949#page/235/mode/1up   

Sprigg, R. C., 1950   [Read 8 September 1949]
Early  Cambrian   'Jellyfishes'  of  Ediacara  South  Australia  and  Mount  John,  Kimberley  District, Western Australia. Transactions of the Royal Society of South Australia, 73-99, plates
https://www.biodiversitylibrary.org/page/41362240#page/96/mode/1up

Wade, Arthur, 1923-24
Petroleum Prospect. Kimberley District of Western Australia and Northern Territory. By Federal Authority. Melbourne. 1923-24, pages 30, 34, 36 and 37. Plates vii-xii.
p. 30: "Our most interesting  find consisted of a variety of fossil remains in these (Mount John.— T. W. E. D.) siliceous flags and shales. These consisted of the tracks of forms of life unknown to us — Worm tracks, long stem-like structures sometimes in great profusion, and other more complex and more obscure forms."   Quoted in David, 1928

Wilson, Alice E,   1957
Life in the Proterozoic, a Chapter in  The Proterozoic in Canada, James E. Gill, editor, University of Toronto Press, 204 pages at pages 18-27
https://www.jstor.org/stable/10.3138/j.ctt1vgw7jv

Friday 29 March 2019

If the Ediacaran discoid holdfast Aspidella, why not Ediacaran Stalks, Spindles and Fronds in Lanark County?

I’ve now gone through all of the photographs that I took while at the quarry in the period from 2012 to 2014, and identified those that might be stalks, spindles and fronds.   I was at the quarry looking for the trace fossil Climactichnites wilsoni, and specimens exhibiting  microbial mat textures, and photographed whatever else  I saw.  That I photographed a few stalks, spindles and fronds was more by accident than design. 

Below is a cropped version of photograph  Sam 102 that was on my September 2013 blog posting.  There are two circular structures, each with a possible stalk, and one with an adjacent  potential frond.


Below is  the original photograph, Sam 102.  Additional fronds are above and to the left of  the ruler.



Below are photographs Sam 126 and Sam 127, with second being a close up of the first.  There are fronds coming out of each of the three circular discs that are above the ruler.  Interestingly, if the structures coming out of the circular discs are fronds, are the multitude of linear structures to the right of the discs in the first photograph also fronds?  Many appear to be fronds.



 Below is photograph Sam 104.  There might be stalk coming out of the disc.




Below is   photo   ‘Sam 123’.  I mentioned in an earlier posting that it might show a frond above the  4 1/4 and 4 1/2 inch markings on the ruler.


 Below is   a cropped and enlarged version of a photo that I’ve labeled ‘Sam 140Edit’ that appears to show spindles with a medial line in three of the spindles.





Christopher Brett
Ottawa, Ontario


Thursday 28 March 2019

Possible Fossil Microbial Mat Structures in Rocks Near Perth, Ontario

In previous postings (Dec. 1, 2016; Oct. 7, 2016; Dec. 29, 2015;  Dec.  23,  2015;  Nov.4, 2015)  I’ve discussed and provided photographs of  microbial mat structures in the Cambrian  Potsdam sandstones of Eastern Ontario. 
   
In this posting I will mention microbial mat structures and possible microbial mat structures in rocks photographed at Tackaberry’s quarry on Highway 7 about three miles north of Perth.  I’ve provided photos that look like structures that have been identified by others as evidence of microbial mats.  All probably aren’t.   I’ve included all of them in the hope that this posting and the others for this month are enough incentive to encourage someone with knowledge of microbial mats to study the textures exhibited by the rocks at the quarry.

The origin of polygonal crack patterns is particularly problematic, as these cracks have attracted a wide variety of suggestions for their origin: sub-aerial exposure (dessication; sun cracks), a sub-aqueous origin at the water sediment interface  (synaeresis), a microbial mat origin, organic burrowing, frost wedging, gravitational loading, gravitationally unstable density inversion, sand injectites, seismic shock, interstratal cracking, water- release (interstratal dewatering), and layer parallel contraction resulting from compaction due to burial.  Interestingly, one paper reviewed a particular suite of rocks where five of those suggestions had been raised in successive peer reviewed publications to explain the origin of the polygonal cracks, and the writer of the paper suggested a sixth.

Manchuriophycus and Rhysonetron

In my November 5, 2012 posting I discussed circular, branching lines that are found in the troughs between wave ripples, which I identified as a special kind of microbial mat shrinkage structure.  These have been given the names Manchuriophycus (sinuous curved lines) and Rhysonetron (corrugated circular and sinuous lines).  The specimens featured on that blog posting were loose specimens at Tackaberry’s quarry about 3 miles north of Perth.   For ease of reference, I am providing additional photo Sam_64 below.  





Microbial Earth

Below are photographs that I took at Tackaberry’s quarry on Highway 7 a few miles north of Perth of what I believe to be pustular microbial earth textures.   These photographs (Sam_24, Sam_44)  compare favourably with photos of pustular microbial earth textures in Retallack (2011).






Petees/Petee Ridges/Renticulate Pattern of Flattened Petee Ridges

Eriksson et al.’s ( 2007)  paper on Mat-Destruction Features is worth reading, as I believe that I photographed a number specimens with features similar to those shown in their photographs that they have named  petees, petee ridges and reticulate patterns of flattened petee ridges, and which they identify as resulting from tears or cracks in a microbial mat that were filled from above or below.  In particular, look at their photos:
- Figure  4(c)-8: Petees/petee ridges – which shows spindle shaped forms and longer, more sinuous shapes.   Their photo (B), a dense packing for two orders of petee ridges, is comparable to slabs that I photographed.
- Figure 4(c) 10: Petees/petee ridges, with (B) and (C)  being a reticulate pattern of flattened petee ridges

Petees/petee ridges might be the explanation for a few of  the photos on my  September 13,  2013 blog posting entitled ‘A Selection of Fossils from the March Formation in Lanark County, Ontario’ which appear under the heading 4:  Branching, overlapping, possibly interpenetrating, roughly parallel to bedding plan.    In particular the first, second, and fifth photograph  could each show  a  reticulate pattern of  petee ridges.   In addition the last two photos on my November 5, 2012 posting show single spindles that could be petees (or have a synaeresis origin).  Below, I’ve provided photo Sam_033 as an example of the reticulate texture, Sam_17 as an intermediate texture,  and Sam_0198 as an example showing single spindles (which are more likely to have a synaeresis than microbial mat origin) .








Cracks

Numerous specimens at the quarry exhibit cracks, for example the slabs shown in Sam_0137 and Sam_0144:  










Polygonal Mud Cracks 

In  June 30, 2015 blog posting I included a photograph of what I had identified as ‘mud cracks’ in a specimen at Tackaberry’s quary and mentioned that I  “showed the specimen to two geologists and they told me that it couldn’t be a mud cracks because sand doesn’t shrink that much and it must be a  microbial mat shrinkage feature.  I sent the photo to a geologist who has written extensively on microbial mats and he told unless I could find the top slab and underlying slab (in order to ensure that no mud was present) I couldn’t identify this as microbial mat shrinkage feature.”   Below is an additional photo of these  ‘mud cracks’, Sam_ 26.



The rock in which the ‘mud cracks’ occur outcrops  near the base of the quarry.  In addition to the outcrops, the same cracks appeared on bed  tops of very large blocks used to keep people from driving into a large hole.  There is little chance of finding, examining or lifting the overlying slabs.

Microbial Mat Crusts on Ripples

The third and fourth photos [Sam_133 (a bed sole)  and 135 (a bed top)] on March 17, 2019 blog posting show a crust on the ripples, that I believe might result from a microbial mat.  I say might, because although very similar to photographs of ‘loaded ripples’ in other publications that have been identified as microbial mat structures such as Bottjer and Hagadorn (2007), I did not check for clay.

One Odd Photo
Sam_0160.  I’m open to suggestions on what this is.





Christopher Brett
Ottawa

References and Suggested Reading
             
Bottjer, D. and Hagadorn, J.W., 2007
 Mat growth features, chapter 4(a)  in Atlas of Microbial Mat Features Preserved within the Siliciclastic Rock Record,  J. Scheiber et al. (Editors), Elsevier, pages 53-71

Eriksson, P.G.,  H. Porada, S. Banerjee, E. Bouougri, S. Sarkar and A.J. Bumby, 2007
Mat-Destruction Features, chapter 4(c) in Atlas of Microbial Mat Features Preserved within the Siliciclastic Rock Record,  J. Scheiber et al. (Editors), Elsevier, pages 76-105

Retallack, Gregory J.,  2011
Criteria for distinguishing microbial mats and earths. in  Microbial Mats in Siliciclastic Depositional Systems Through Time, SEPM Special Publication No. 101,  p. 139–152.

Schieber,Juergen,  Pradip Bose,  P.G. Eriksson,  Santanu Banerjee,  Subir Sarkar,  Wladyslaw Altermann, and Octavian Catuneanu, [Editors] 2007
Atlas of Microbial Mat Features Preserved within the Siliciclastic Rock Record,  Elsevier,   volumes, 324 pages

Sunday 24 March 2019

A Selection of Fossils from the ‘March Formation’ in Lanark County, Ontario - A Correction


 I was speaking with my daughter on Thursday and mentioned to her that there were a few things on my blog that were not correct.  She chimed in “Fake News!”   That convinced me to go back, correct and improve my identification of fossils shown in the  photographs that accompanied my September 13, 2013  blog posting.   These are my suggested changes.

1. Bedding Parallel Burrows and Bioturbation in a bed close to the top of the quarry.  Likely early Cambrian (or Ordovician).

2. The Trace Fossil Helminthopsis.  Simple cylindrical, curving burrows roughly parallel to bedding plane.  Possibly Ediacaran, Cambrian or Ordovician in age.

3. Larger, rougher, cylindrical, curving burrows  roughly parallel to bedding plane.  Possibly a worm burrow like Helminthopsis, but more likely arthropod burrows of Cambrian or Ordovician age.

4.  Branching, overlapping, possibly interpenetrating, roughly parallel to bedding plane, some plant like.  Three of the photos probably record Ediacaran microbial mat destruction textures, with the first, second, and fifth photographs possibly show a  reticulate pattern of petee ridges, with the ridges in the first  flattened, or simply sand cracks in a microbial mat.     The second last photo  shows a disc with stalk (below the ruler) and a number of spindle shaped objects that are potentially Ediacaran rangeomorphs. The last photo shows numerous spindle shapes that are possible Ediacaran rangeomorphs (note the medial line on three of the spindles), but the spindle shape is also consistent with examples reported by others as being petee ridges (e.g, see Eriksson et al., 2007, figures  4(c)-8B & 4(c)-9).   The fourth photo might  show Ediacaran vegetation (not rangeomorphs as there is no fractal construction) but is more likely to be a badly ripped  microbial mat.  I cannot identify the structure in the third photo, but note that the same texture is shown in the first four photos on my August 20, 2014 blog posting.

5.  Concentric discoid structure.   More likely the Ediacaran  holdfast Aspidella than medusae. 

6.  Concentric discoid structures.    The second and third  are likely the Ediacaran  holdfast Aspidella. The first might also be.  The fourth is likely Ediacaran, and might be Nemiana or Chuaria or Nimbia occlusa.

7.  A Congestion/Colony of Multiple Ediacaran discoid holdfasts.  Likely Aspidella.  Note that the second photo shows an Ediacaran rangeomorph structure (Bradgatia?) above the 4 1/4 to 4 1/2 inch marks on the ruler.

8. ‘ Lindt Truffles’ (circular, about the size of the candy, with a thin 2-4 mm rim and a different coloured centre) is the name that I used when talking about this structure with the quarry manager in 2013.  They are common at the quarry.   Possibly the Ediacarn fossil Chuaria or Beltanelliformis (=Beltanelloides, Nemiana).  Interestingly the smaller ones can often appear close to a spiral form, and while looking a bit like Gastropods are not as spiral as Arenicolites spiralis, Billings 1872 that was reported to have been associated with Aspidella in Newfoundland.

9.  Thin Film, barely there.  Sack like.   (algae?) (an Ediacaran Tawuia-like fossil?)

10.     In about 2013 I sent these photographs  to paleontologists who study Paleozoic fossil plants. I received the reply  that the photographs likely show a trace fossil.  In about 2013 I sent the same photographs to a paleontologist who has written extensively on Ediacaran and Cambrian trace fossils, who replied that it was likely a plant.   My best guess is  that it is algae or  analogous to algae.   Some linear grooves might be tool marks resulting from the blasting.

11.   Stromatolite  (Dr. Al Donaldson's identification while touring the quarry.)

In my September 13, 2013 posting I stated “The only shelled fossil that I’ve found (and I’ve only found broken parts of it) is likely a Gastropod, and Gastropods have been found in the March Formation.”   That statement is wrong.  I found broken parts of a spiral form that I mistakenly identified as a Gastropod.   I more likely found the Ediacarn fossil Chuaria or Beltanelliformis (=Beltanelloides, Nemiana).

I also no longer believe that Potsdam sandstone outcrops at the quarry. It is Precambrian sandstone of Ediacaran age.

I apologize if I have misled anyone. 
           
Christopher Brett
Ottawa, Ontario

Friday 22 March 2019

Ontario Geological Survey Summary of Field Work and Other Activities, 2018

In  December , 2018 the  Ontario Geological Survey released its Summary of Field Work and Other Activities, 2018 (OFR 6350) for electronic distribution.  It can be downloaded from

http://www.geologyontario.mndm.gov.on.ca/mndmaccess/mndm_dir.asp?type=pub&id=ofr6350

There are four papers of interest to those in Eastern Ontario, two dealing with Precambrian Geology and two with Paleozoic Geology:

Precambrian Geology – Proterozoic and Grenville Province
14.    Project SO-17-001. Precambrian Geology and Mineral Potential of the Carleton Place Area, Grenville Province, by R.M. Easton,   pages 14-1 to 14-10
15.     Project SO-18-001. Precambrian Geology of the Renfrew Area, Northeastern Central Metasedimentary Belt, Grenville Province, by M. Duguet,  pages 15-1 to 15-9

Paleozoic Geology and Energy Studies
22.   Project SO-18-006. Paleozoic Geology of Eastern Ontario: Ottawa Area, by C. Béland Otis, pages 22-1 to 22-10
23.     Project SO-18-005. Identification and Mapping of Alkali–Carbonate Reactive Layers in the Gull River Formation, Near Kingston, Ontario by K.E. Hahn and C.A. MacDonald, pages 23-1 to 23-8
       
Below I mention what I found to be the highlights of each report.

Precambrian Geology and Mineral Potential of the Carleton Place Area, Grenville Province 


Dr. Michael Easton mentions:

 • “Mafic metavolcanic rocks and associated fine- to medium-grained foliated gabbro sills appear to have been deformed and metamorphosed before, rather than during, emplacement of the Lavant gabbro and associated felsic intrusive rocks.”

 •  Peraluminous sapphirine  has been found.    “Peraluminous sapphirine is typically associated with ultra-high temperature metamorphism (>1000C, >8 kilobars).”  This is the first reported occurrence from the Central Metasedimentary Belt of the Grenville Province.       

 • “Most of the major faults shown on the Paleozoic geology map of Williams and Wolf (1984) located solely in Precambrian rocks present in the western half of the Carleton Place map area could not be validated by geology or geophysics.”

 •  The report contains a colourful simplified geological map of the Carleton Place and southern Arnprior map areas.

 • “Work in 2018 indicates that clean, high brightness, low silica content calcite and dolomite marbles are not restricted to the lower metamorphic grade portion of Sharbot Lake domain west of the Clayton shear zone, but they also occur at much higher metamorphic grades between the Maberly shear zone and the Wolf Grove structure, and in the area between the Pakenham and the Wolf Grove structures.”   In the long term this could be important for Lanark County’s economy as high-purity marble products have  been produced from marble mined at Omya Canada Inc.’s quarry at Tatlock  and refined at Omya’s plant on Highway 7 just west of Perth for more than 30 years.

Precambrian Geology of the Renfrew Area, Northeastern Central Metasedimentary Belt, Grenville Province


Dr. Manuel Duguet  mentions a “newly discovered lithostructural unit, provisionally named the Calabogie klippe, is exposed south of the Madawaska River”, which is “mostly composed of amphibolites and calcite marbles.”   His report  contains a simplified geological map of the area.

Paleozoic Geology of Eastern Ontario: Ottawa Area


Catherine  Béland Otis is continuing her a multi-year project of mapping  the Paleozoic geology of eastern Ontario, and addressing the fact that “in the last 3 decades, almost all Cambro-Ordovician stratigraphic units of eastern Ontario have been the focus of academic research.  These studies have introduced new stratigraphic units (or re-introduced old terms), revised geological contact definitions and/or proposed the application in Ontario of stratigraphic terminology used in adjacent jurisdictions instead of the current OGS nomenclature.”   Her Figure 22.2 deals with competing terminologies for Paleozoic strata in eastern Ontario, with her left  Column providing  the nomenclature currently used by the Ontario Geological Survey , while the column on the right is the nomenclature proposed in more recent publications.

In the summer of 2018, the OGS  started geological mapping of the Ontario portion of the
Ottawa National Topographic Sheet, and Catherine  Béland Otis provides a concise summary of each rock unit mapped in the Ottawa area.   Based on the terms used in her report it appears that the OGS will adopt Lowe and Arnott’s breakdown of the Potsdam Group into three formations, but may not change Nepean to Keeseville for the uppermost unit.

Identification and Mapping of Alkali–Carbonate Reactive Layers in the Gull River Formation, Near Kingston, Ontario


Katherine E. Hahn and C.A. MacDonald are dealing with an interesting problem.  While the  Gull River and Bobcaygeon formations are  being used as a source of concrete aggregate in Ontario “[b]oth of these units contain lithologies that are known to cause alkali aggregate reaction, a chemical reaction that occurs in either mortar or concrete between the hydroxyl associated with the alkalis sodium and potassium from Portland cement or other sources, with certain mineral phases in the coarse or fine aggregates.”   This is a concern because it can cause premature deterioration of concrete.  

The two main questions that their project aims to address are :
1.  Can alkali–carbonate reaction (‘ACR’) strata be mapped at the regional scale and predicted based on sedimentology and stratigraphy?
2. What are the geological controls on the distribution of ACR strata?

Field activities were conducted in 2018 with visits to 21 quarries (active and inactive) and 135 outcrop localities.  They have focused on  “a green marker bed in the Gull River Formation (probably stratigraphically equivalent to the middle member in the Kingston area) that is used to constrain where the alkali reactive beds begin; generally, aggregate for concrete purposes is not extracted within 1 m above the green bed and never below it.”   Further investigations are planned.


Christopher Brett
Ottawa

Tuesday 19 March 2019

The Trace Fossil Helminthopsis in Sedimentary Rocks of Lanark County , Ontario





The above  photograph (SAM_0037) was taken of a loose specimen collected at Tackaberry’s quarry about three miles north of Perth.  I believe it to be the trace fossil Helminthopsis, which has been described by Wetzel & Bromley (1996) as “Simple, unbranched, elongate, cylindrical tube with curves, windings, or irregular open meanders.”


I have been able to name the trace fossil Helminthopsis since the fall of 2012 when I noticed a nearly identical specimen displayed on a web page of the Miller Museum of Geology, Queen’s University at Kingston, under the heading ‘The Ediacaran of Canada’.    Excitedly I sent an email to the museum curator with the above photo claiming that I had found the Ediacaran fossil Helminthopsis in Lanark County.  Regrettably I received back an email telling me that this trace fossil cannot be used to determine the age but the environment.

Wetzel & Bromley (1996) mention that “Helminthopsis is a feeding burrow produced normally at shallow depth within sediment rich in benthic food.”   Buatois, Mángano, Maples and Lanier (1998) describe it as a grazing trace while Mangano and Buatois (2003), describe it as a simple grazing trace.   The Miller Museum of Geology’s web site stated that “It is generally agreed that simple burrows and trace-fossils (such as Helminthopsis pictured to the left) found in Upper Precambrian rocks were made by primitive worms. These worms... survived the extinction event and took part in the greatest evolutionary event in Earth’s history: The Cambrian “Explosion”.

A search on the internet shows that Helminthopsis has been recognized in many rocks aged  Cambrian and younger.  For Example, Helminthopsis has been recognized in the Fortunium (lower Cambrian) rocks of Iran (Shahkarami, 2016),  Upper Cambrian/Lower Ordovician rocks of Newfoundland (Fillion, and Pickerill, 1990), early Silurian rocks of New Brunswick (Kim, Pickerill, Wilson, 2000), shales of Switzerland (Heer, 1877),  the Carboniferous of Argentina (Mángano and Buatois, 20013),  the Carboniferous rocks of Alabama (King, Stimson, Lucas, 2018) , upper Carboniferous rocks of Kansas (Buatois, Mángano, Maples and Lanier, 1998),  Oligocene rocks (de Gibert and Sáez, , 2009),  and Eocene rocks of the San Joaquin Valley, California (SJVG, 2019).

Christopher Brett
Ottawa   
       
References and Selected Reading

Anonymous, 2019 (herein ‘SJVG, 2019')
Guide to Trace Fossils of the San Joaquin Valley        
http://www.sjvgeology.org/geology/trace_fossils.html#helminthopsis

Buatois, L.A., Mángano, M.G., Maples, C.G. and Lanier, W.P. (1998).
Ichnology of an Upper Carboniferous fluvio-estuarine paleovalley: The Tonganoxie sandstone, Buildex Quarry, eastern Kansas, USA. Journal of Paleontology. Volume 72: 152–180.   
https://www.jstor.org/stable/1306686   [Helminthopsis hieroglyphica]
image at: http://www.kgs.ku.edu/Current/1998/buatois/fig19.html

de Gibert, Jordi M.  And Sáez, Alberto, 2009
Paleohydrological significance of trace fossil distribution in Oligocene fluvial-fan-to-lacustrine systems of the Ebro Basin (Spain), Palaeo: Palaeogeography, Palaeoclimatology, Palaeoecology
Volume 272, Issues 3–4, 15 February 2009, Pages 162-175
doi:10.1016/j.palaeo.2008.10.030
diposit.ub.edu/dspace/bitstream/2445/101832/1/564340.pdf

Fillion, D. and Pickerill, R.K., 1990
Ichnology of the Upper Cambrian? to Lower Ordovician Bell Island and Waban groups of eastern Newfoundland, Canada. Canadian Society of Petroleum Geologists.  Reprinted in  Palaeontographica Canadiana. 7: 1–41.
   
Heer, Oswald, 1877
Flora fossilis Helvetiae. : Die vorweltliche flora der Schweiz .  Zürich : J. Wurster & co., 182 p. LXX plates.      https://catalog.hathitrust.org/Record/001996956    Page 116

Kim, Jeong Yul, Pickerill,  Ron K.  and Wilson, Reg. A., 2000
Palaeophycus bolbitermiius isp. nov. from the Lower Silurian Upsalquitch Formation of New Brunswick, eastern Canada. Atlantic Geology, volume 36, 131-137(2000)
 https://journals.lib.unb.ca/index.php/ag/article/viewFile/2016/2380
[Helminthopsis hieroglyphica, Wetzel and Bromley, 1996]

King, Olivia A., Stimson, Matthew, R., and Lucas, Spencer G. , 2018
The Ichnogenus Kouphichnium and Related Xiphosuran Traces from the Steven C. Minkin Paleozoic Footprint Site (Union Chapel Mine), Alabama, USA: Ichnotaxonomic and Paleoenvironmental Implications, Ichnos, An International Journal of Plant and Animal Traces,
https://www.tandfonline.com/doi/full/10.1080/10420940.2018.1561447?af=R

Mangano, M. Gabriela and Buatois,  Luis A., 2003
Ichnologic and paleoenvironmental characterization of the Orchesteropus atavus Frenguelli type locality, Huerta de Huachi, San Juan province, Argentina. Mar 2003Ameghiniana
AMEGHINIANA 40(1):53-70  March 2003   [Helminthopsis tenuis Ksiazkiewicz]
https://www.researchgate.net/publication/285838111_Ichnologic_and_paleoenvironmental_characterization_of_the_Orchesteropus_atavus_Frenguelli_type_locality_Huerta_de_Huachi_San_Juan_province_Argentina

Shahkarami, Setareh, 2016
Ichnology of the Ediacaran–Cambrian transition: the Soltanieh formation of northern Iran and its significance for understanding the Cambrian Explosion.  Doctoral Thesis, University of Saskatchewan.     https://harvest.usask.ca/handle/10388/7699
[Four ichnozones have been recognized. Ichnozone I, containing Helminthopsis tenuis and Cochlichnus anguineus, is lower Fortunian based on small shelly fossils.]

Wetzel, A., & Bromley, R.G. 1996.
Re-evaluation of the ichnogenus Helminthopsis - a new look at the type material. Palaeontology, 39, pp. 1-19.    [Free access]
https://www.palass.org/sites/default/files/media/publications/palaeontology/volume_39/vol39_part1_pp1-19.pdf

Wetzel, A., Kamelger, Achim & Bromley, R.G. 1996.
Taxonomic review of the ichnogenus Helminthopsis Heer 1877 with a Statistical analysis of selected Ichnospecies-a discussion.  Ichnos 5(4):309-312  July 1998
https://www.researchgate.net/publication/269829963_Taxonomic_review_of_the_ichnogenus_Helminthopsis_Heer_1877_with_a_Statistical_analysis_of_selected_Ichnospecies-a_discussion

Sunday 17 March 2019

Fossil Ripple Marks in Rocks Near Perth Ontario

Fossil ripple marks were formed by the movement of water or wind over sediment, and are useful for determining the direction of the current or wind, and the environment in which the ripples were formed.  For example, geologists and paleontologists can tell the direction of water flow and wind flow from the shape of asymmetric ripples, and from symmetric ripples deduce oscillating directions of water flow which suggests a near beach environment.  They can also differentiate between ripples formed by water and ripples formed by wind.

Below are photographs of loose specimens and bedrock at Tackaberry’s quarry located on highway 7 about two miles north of Perth, in Lanark County, Ontario.    The photographs show fossil ripple marks, primarily symmetric ripples,  that originally formed under water.    (However, when I was taking photographs I was mainly looking for ripples with curvilinear cracks in the ripple troughs or shrinkage cracks on the ripples.  I was not looking for asymmetric ripples.)

The first  photo shows  ripples in bedrock at the quarry.  Sam_27






The remainder of the photographs are of loose specimens  resulting from blasting at the quarry.
An interesting point about photographing loose specimens is that it is as likely that I photographed a bed top as a bed sole. 

The next two photos show a bed sole and a bed top of symmetric ripples, though probably not parts that match.  Sam_62 and Sam_63








The previous photo also shows the curvilinear cracks that formed in many ripple troughs in specimens found at the quarry.

The next photos show a crust on the ripples, that might result from a microbial mat: Sam_133 (a bed sole)  and 135 (a bed top).
.




The next photo show a number of superimposed thin beds with symmetrical ripples on the top beds and symmetrical ripples on the lower bed, with the two sets of ripples going in  different directions.  Sam_151


The next  photos, Sam_153 and 152,  are close ups of the above photo, the second showing polygonal shrinkage cracks in the ripples.




Geologic Map



Below is an extract from Ontario Geological Survey Map P. 2724 entitled Paleozoic Geology Perth Area, issued 1984, geology by D. A. Williams and R. R. Wolf, 1982, on which I’ve plotted the location of Tackaberry’s quarry and the location of the Glen Quarry where Climactichnites wilsoni was found by Dr. James Wilson of Perth, and named by Sir William Logan after Dr. Wilson.   The map puts Tackaberrry’s quarry within the March Formation, which is thought to be Lower Ordovician in age, and places the Glen Quarry within the Nepean Formation of the Potsdam Group .   

The upper bar scale on the map is in tenths of a mile and 1 mile.  The lower bar scale is in tenths of a kilometre and 1 kilometre.  The major faults are shown on the map, with the arrow indicating the downthrown side.   The legend shows that the letters PC on the map indicate undifferentiated Precambrian igneous and metamorphic rocks, that  the number 2 on the map indicates Nepean Formation sandstones of the Potsdam Group, and that the number 3 on the map indicates March Formation interbedded quartz sandstone, sandy dolostone and dolostone.

On the map I’ve also shown the approximate location of the Hands quarry that was described in 1931 by Dr. Morley Wilson of the Geological Survey of Canada.  While the Hands quarry is only two miles south of Tackaberry’s current quarry on Highway 7, and both are mapped as March Formation, the rocks at the two quarries are quite different.  The map shows that  a  fault  separates two blocks that have been mapped as March formation, with Tackaberry’s quarry falling on the western block and Hands quarry falling on the southeastern block.  The rocks at Hands quarry would be considered typical March Formation (or, more accurately, typical of parts of the March Formation).    I mentioned in my September 24, 2012 blog posting that the rocks at Tackaberry’s quarry  differ from other areas that have been mapped as March Formation.  I still hold that view.   The rocks at Tackaberry’s quarry are not typical March Formation, and  there might only be a veneer of March Formation.

In my September 24, 2012 blog posting I suggested ‘Drummond sequence’ for the block where Tackaberry’s quarry is located and suggested that the rocks appear to be much older than typical March Formation rocks.  I also mentioned that Sir William Logan had  reported that he had found Climactichnites and Protichnites at a quarry in Lot 6, Concession 3, Drummond Township, which would  fall within the Drummond Sequence.  However, my subsequent investigations (see my blog postings of  January 31, 2013 ,   February 11, 2013 and  May 6, 2013) showed that the Glen quarry is actually on Lot 3, Concession 3, Drummond Township, and falls in Cambrian Potsdam sandstone rather than within the Drummond sequence that has been mapped as Lower Ordovician March Formation.  On the below map I plotted the Glen quarry on Lot 3, Concession 3, Drummond Township on property owned by the Glen family at the time Dr. James Wilson found the tracks that Logan named Climactichnites wilsoni, and where I found a small quarry.


Ripple Marks at the Hands Quarry, Lanark County, Ontario



Dr. Morley Wilson is, I believe, the only person to have written a paper devoted to Ripple marks near Perth, Lanark County.  In a short paper published in 1931in the Canadian Field-Naturalist he described ripple marks in the March Formation (known in Dr, Morley Wilson’s time as the “Transition Beds”)  and included photographs of the ripple marks.  The ripple marks occurred in a quarry “on the farm of Mr. H. J. Hands, Lot 10, Concession II, Drummond Township, Lanark County”.    Morley Wilson also mentions that “ The quarry lies about 3 miles northeast of Perth and 300 yards north of the second line of Drummond which forms a part of the original stage road from Perth to Ottawa, ...”.  The second line of Drummond is more commonly called the Franktown Road and is shown on maps as County Road 10.    Jim Hands and his son Trevor both own  property on that lot and Concession, and Jim’s  property would be familiar to many Lanark residents as Jim and Trevor are well known auctioneers, and Jim has held many an auction on his property.

Morley Wilson  mentions that the ripples occur in thin beds on the Hands quarry floor “everywhere throughout the entire extent of the quarry which is over 200 feet long and 100 feet wide and throughout a range of about 14 inches.  The total thickness of strata exposed in the quarry face is about 5 feet.   This consists of thin bedded sandy dolomitic limestone, in which beds or zones of white limestone up to 1 inch thick are intercalated sparingly near the top but more abundant near the bottom.” 

Morley Wilson also mentions that “The sandstone of ...  the Transition Beds is ripple marked in many places, the ripples being for the most part of the unsymmetrical type. The greater part of the ripples trend northeast-southwest or east-west and the steeper side of the crests of the ripples are on their south-east or south sides indicating that the current by which they were formed came from the north-west or north.”


The March Formation



D. A. Williams (1991) of the Ontario Geological Survey states that  “The March Formation consists of interbedded quartz sandstone, dolomitic quartz sandstone, sandy dolostone, and dolostone....  Shaly partings occur throughout the formation, and glauconitic partings are present in the dolostones and sandy dolostones.   ...  Quartz sandstones of the March Formation ... are thinly to thickly bedded, fine to coarse grained, and well sorted. The sandstones range in colour from white to light grey, brown, reddish brown, and green; and weather white to light grey and brown to reddish brown. Small brown-weathering spots are common, and are the result of diffusion into the surrounding pore spaces of iron derived from detrital pyrite, magnetite, or ilmenite grains.  The quartz grains are subrounded to well rounded. ... Crossbedding, ripple marks, and burrows are common.     The dolomitic quartz sandstones and sandy dolostones are light to medium brownish to bluish grey in colour, and weather brownish grey to buff to reddish brown. They are thinly to thickly bedded and contain finely to medium crystalline carbonate and well rounded, fine to coarse grained quartz sand. Some dolomitic sandstone beds are calcareous, and some sandy dolostone beds are calcitic.
...
The March Formation was deposited in a supratidal to subtidal environment. Supratidal to intertidal deposition and hypersalinity are implied by calcite-filled vugs (originally sulphate nodules) and algal lamination in the dolostones. Intertidal deposition is implied by bipolar  crossbedded quartz sandstone containing discrete vertical burrows. Subtidal deposition is indicated by highly bioturbated dolomitic quartz sandstone (Bond and Greggs 1973, p.1147-1150). A similar environment was inferred for the Theresa Formation of adjacent New York State by Selleck (1984).”

Williams’ description would cover the rocks of  the Hands’ quarry (sandy dolomitic limestone), but is not apt for the majority of rocks of Tackaberry’s quarry as cross-bedding is  not common, the  burrows  are confined to the top beds, there are no calcite-filled vugs,  and there is little dolostone in Tackaberry’s quarry.  In addition, finding the Ediacaran holdfast Aspidella in the rocks tells against the rocks being Lower Ordovician March Formation.


References and Selected Bibliography



Below I’ve provided a few references to water ripples and wind ripples.   If the reader is going to read one reference in addition to Morley Wilson’s paper,  it should probably be Kindle (1917).   That said,  Evans (1942) makes the important point that “The size of wave-formed ripple marks depends on the depth of water and the size of the generating waves. With waves of a given size, the deeper the water the smaller the ripple marks; with a given depth of water, the smaller the waves, the smaller the size of the ripple marks.”

Christopher Brett
Ottawa, Ontario

Postscript  (March 19th):   It has always impressed me that Sir William Logan was able to identify both water ripple marks  and wind ripple marks in the Potsdam sandstones at Beauharnois where he found Protichnites tracks, and that he concluded that the creature “which impressed the [Protichnites] tracks at Beauharnois must have been a littoral animal.”     See:  Logan (1860), where he named Climactichnites Wilsoni; and Logan (1863), The Geology of Canada.  It is also worth noting that  Logan (1863) provides various measured sections of Potsdam sandstone, including a section from Beauharnois in the vicinity of Henault’s field (1863, pages 105-106), where he describes the beds and indicates where ripple marks, wind marks, Protichnites tracks and Scolithus occur.  






References and Selected Bibliography



Blondeaux, P.,  Foti, E. and G. Vittori,  2015
A theoretical model of asymmetric wave ripples. Philosophical Transactions: Mathematical, Physical and Engineering Sciences. Vol. 373, No. 2033, Theme issue: Advances in fluid mechanics for offshore engineering: a modelling perspective (28 January 2015), pp. 1-20
https://www.jstor.org/stable/24506135

Das, Siddhartha Sankar and Sengupta,Supriya ,  1997
Height vs water depth for small sand ripples – An aid to palaeohydraulics, Current Science, Vol. 72, No. 9 (10 May 1997), p. 626
 https://www.jstor.org/stable/24099669

Evans, O. F. 1941.
The classification of wave-formed ripple marks. Journal of Sedimentary Petrology, 11, 37.41.
https://doi.org/10.1306/D42690DF-2B26-11D7-8648000102C1865D


Evans, Oren Frank, 1942
The relation between the size of wave-formed ripple marks, depth of water, and the size of the generating waves .  Journal of Sedimentary Research (1942) 12 (1): 31-35.
https://doi.org/10.1306/D4269139-2B26-11D7-8648000102C1865D
   
Hints, Linda, 2008
Ripple marks as indicators of Late Ordovician sedimentary environments in Northwest Estonia.  Estonian Journal of Earth Sciences, Volume 57, 1, 11-22.  doi: 10.3176/earth.2008.1.02
https://www.researchgate.net/publication/26503506

Jackson,  D. W. T.  and Cooper, J. A. G., 1999
Formation of Ephemeral Bedform Turrets in Coastal Foredunes , The Journal of Geology
Vol. 107, No. 5 (September 1999), pp. 633-639
https://www.jstor.org/stable/10.1086/314367

Johnson, Douglas W., 1916
Contributions to the Study of Ripple Marks , The Journal of Geology
The Journal of Geology, Vol. 24, No. 8 (Nov. - Dec., 1916), pp. 809-819 (11 pages)
 https://www.jstor.org/stable/30061204

Kindle, E. M.,  1917
Recent and Fossil Ripple-Marks, Geological Survey of Canada, Museum Bulletin 25, No. 1658,  Geological Series, No. 34,  121 pages    https://doi.org/10.4095/104987
https://archive.org/details/museumbulletin25geol

Kindle, E. M.,  1923
Notes on Mud Crack and Ripple Mark in Recent Calcareous Sediments.  The Journal of Geology, Vol. 31, No. 2 (Feb. - Mar., 1923), pp. 138-145
https://www.jstor.org/stable/30079396

Kindle, E. M. 1936
Notes on Shallow-Water Sand Structures
The Journal of Geology, Vol. 44, No. 7 (Oct. - Nov., 1936), pp. 861-869
https://www.jstor.org/stable/30056273 

King,  W. J. Harding, 1916
The Nature and Formation of Sand Ripples and Dunes, The Geographical Journal, Vol. 47, No. 3 (Mar., 1916), pp. 189-207
https://www.jstor.org/stable/1779300

Menard, Henry, W. 1950
Current-Ripple Profiles and Their Development ,  The Journal of Geology
Vol. 58, No. 2 (Mar., 1950), pp. 152-153
https://www.jstor.org/stable/30071109

Sarkar, Soumen, 1981
Ripple marks in intertidal Lower Bhander Sandstone (late Proterozoic), Central India: A morphological analysis - Sedimentary Geology, Volume 29, Issue 4, August 1981, Pages 241-282
https://www.sciencedirect.com/science/article/pii/0037073881900762

Seppälä,  Matti  and Krister Lindé, 1978
Wind Tunnel Studies of Ripple Formation
Geografiska Annaler. Series A, Physical Geography, Vol. 60, No. 1/2 (1978), pp. 29-42
https://www.jstor.org/stable/520963

Sharp, Robert P., 1963
Wind Ripples. The Journal of Geology Vol. 71, No. 5 (Sep., 1963), pp. 617-636
https://www.jstor.org/stable/30061128

Williams, D.A., 1991.
Paleozoic Geology of the Ottawa-St. Lawrence Lowland, Southern Ontario; Ontario Geological Survey, Open File Report 5770, 292p.
http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/OFR5770//OFR5770.pDf

Wilson, Morley Evans, 1931
Ripple marks near Perth, Lanark County, Ontario: Canadian Field-Naturalist, vol. 45, no. 2, pp. 25-27, 3 figs., February 1931.
https://www.biodiversitylibrary.org/item/89041#page/41/mode/1up

Xiao, Qianlu,  Li, Ruijie,  Li, Chunhui and Xuwen Fang, 2018
Predicting Wave-induced Ripple Geometry and Bottom Friction Factor
Journal of Coastal Research,  Special Issue 83: Advances in Sustainable Port and Ocean Engineering (Fall 2018), pp. 148-154
https://www.jstor.org/stable/26542947




Friday 8 March 2019

Concentric Structures in the Sedimentary Rocks of Lanark County, Ontario that are identical to the Ediacaran Holdfast Aspidella

As part of  my blog posting from September 13, 2013 that was entitled ‘A Selection of Fossils from the March Formation in Lanark County, Ontario’ I included a number of photographs of concentric disc shaped fossils from Tackaberry’s quarry a few miles north east of Perth, Ontario in the hopes that someone would study the fossils and provide an accurate identification.   That didn’t happen, as my blog posting failed to generate any interest.  I’ve decided to try again, with a more intriguing title.
 
Below I’ve included a number of additional photographs that I took in 2012 of concentric structures in the rocks at Tackaberry’s quarry.

 












When I first looked at the fossils I did ask a few geologists for their suggestions. One suggested  medusae.  Another suggested poorly preserved Gastropods.  To understand why their suggestions were reasonable, it helps to know that I showed them photographs of poorly preserved specimens from the large blocks surrounding the quarry,  before I started looking at specimens revealed by fresh blasting and photographed the specimens shown above and in my September 13, 2013 posting.   In addition, there are Gastropods in the March Formation and I’ve found broken specimens of Gastropods in loose blocks at Tackaberry’s quarry.

I now believe that most of the specimens I found were holdfasts, as the specimens are identical to Ediacaran fossils that have been identified as holdfasts.  While some might be medusae or badly preserved Gastropods or cross-sections of burrows, these would be in the minority.  Most appear to be Aspidella.

My photographs  may not be representative of all of the circular structures that I found, as I took photos of the most circular and best preserved specimens that I found.  There were many others that were poorly preserved, some that were more elliptical than circular, and some that were not complete circles, that did not get photographed.   Admittedly, that does bias the identification, and if I were to go back I would photograph ones with different shapes.  (I would also look for fronds.)  Interestingly, there were literally hundreds of specimens that did not get photographed.

Since I published the blog posting a tremendous number of authors have written on concentric discoid fossils, and I’ve included a number of those papers below, plus others that I found interesting, and others that included  photographs of concentric fossils that are similar to those found in Tackaberry’s quarry.  The two Youtube videos -- Cope, 2018 and Burzynski et al. 2017a -- are worth watching.   

What is interesting about the specimens that I photographed is that they are all loose specimens resulting from blasting at the quarry.   Accordingly, it is as likely that I photographed a bed top as a bed sole.   Another interesting point is that while everyone would likely concede that the top beds at the quarry belong to the March Formation and are of Ordovician age, it is not clear  how old the lowermost beds are.   The uppermost beds are variously coloured siltstones, mudstones and sandstones, and at least two uncomformities are visible.  The bottom beds are a reddish sandstone, and at least one Lanark based geologist has suggested that the bottom beds are Potsdam sandstone (which is Cambrian in age).    Interestingly, the second time I was at the quarry it was in the company of Dr. Bill Arnott and Dr. Al Donaldson.  At that time I picked up a sample of the  lowermost sandstone and suggested to Dr. Donaldson that it was Potsdam sandstone. He cautioned me that Precambrian sandstones can be as well preserved as Cambrian sandstones.

I did not find any concentric fossils in the red sandstone.

Christopher Brett
Ottawa


Selected Bibliography
   
Billings, E. 1872
On some fossils from the primordial rocks of Newfoundland. Canadian Naturalist and Quarterly Journal of Science. Volume  6, New Series, pages 465- 479 at pages 478-79.
https://www.biodiversitylibrary.org/item/32756#page/497/mode/1up

Boyce, W.D. and Reynolds, K., 2008
The ediacaran fossil Aspidella terranovica Billings, 1872 from St. John's Convention Centre Test Pit CjAe-33.  Current Research (2008) Newfoundland and Labrador Department of Natural Resources  Geological Survey, Report 08-1, pages 55-61
https://www.nr.gov.nl.ca/mines&en/geosurvey/publications/cr2008/Boyce.pdf

Burzynski G., and  Narbonne G.M., 2015
The discs of Avalon: relating discoid fossils to frondose organisms in the Ediacaran of Newfoundland, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 434: 34-45
DOI: 10.1016/j.palaeo.2015.01.014
https://www.researchgate.net/publication/271601343_The_discs_of_Avalon_Relating_discoid_fossils_to_frondose_organisms_in_the_Ediacaran_of_Newfoundland_Canada

Burzynski, G., Narbonne, G.M.,  Dececchi, T.A., and Dalrymple, R. W.,  2017a
The ins and outs of Ediacaran discs.  Recorded at the International Symposium on the Ediacaran-Cambrian Transition, St. John’s, Newfoundland, Canada.  Palaeo cast, Published on 26 Sep 2017    Youtube Video. 13.37 minutes
https://www.youtube.com/watch?v=OkwcUbAb0Vo

Burzynski G, Narbonne GM, Dececchi TA, and Dalrymple RW., 2017b.
The ins and outs of Ediacaran discs. Precambrian Research 300: 246-260 
https://www.sciencedirect.com/science/article/pii/S0301926817302978

Cope, J. C. W. 1983.
Precambrian faunas from the Carmarthen district. Nature in Wales, new series, volume 1, (2), 11–16, pls 1–2.   https://journals.library.wales/browse/1220475 

Cope, John C. W., 2018
The Ediacaran Fauna of the Llangynog Inlier, Carmarthenshire [Wales].
Paleocast. The Palaeontological Society, 62nd Annual meeting, 14th-17th December, 2018, University of Bristol.      Youtube Video.  14:44 minutes.
https://www.youtube.com/watch?v=JvNFQaUxd4Q


Fedonkin, Mikhail A.,  Gehling, J.G., Grey, K., Narbonne, G. M., Vickers-Rich, P.,  2008
The Rise of Animals: Evolution and Diversification of the Kingdom Animalia.
Baltimore: Johns Hopkins University Press.  344 pages,  677 color illustrations
https://books.google.ca/books?isbn=0801886791

Gehling, J.G., Narbonne, G.M. and Anderson, M.M.,  2000:
The first named Ediacaran body fossil,  Aspidella terranovica . Palaeontology, Volume 43, pages 427-456.  DOI: 10.1111/j.0031-0239.2000.00134.x
   
Grazhdankin, Dmitriy, and Gerdes Gisela, 2007
Ediacaran microbial colonies. Lethaia 40:201–210.
https://doi.org/10.1111/j.1502-3931.2007.00025.x

Howe, Mike P.A. Evans, Mark, Carney, John N.  and Wilby, Philip, R., 2012
New perspectives on the globally important Ediacaran fossil discoveries in Charnwood Forest, UK: Harley’s 1848 prequel to Ford (1958).  Proceedings of the Yorkshire Geological Society, 59 (2). 137-144.   https://doi.org/10.1144/pygs2012-321

Hofmann, H.J., 1971
Precambrian fossils, pseudofossils, and problematica in Canada. Geological Survey of Canada, Bulletin 189, 146 pages; Aspidella  at pages 14-17 and plate 5; Chuaria at page 24, plate11;.   https://doi.org/10.4095/123948

Hofmann, H. J., 1998
Synopsis of Precambrian fossil occurrences in North America,  in Geology of the Precambrian Superior and Grenville provinces and Precambrian fossils in North America; Lucas, S B; St-Onge, M R; Geological Survey of Canada, Geology of Canada Series no. 7, 1998 p. 273-376, especially plates 1 & 2.  https://doi.org/10.4095/210104
   
Hofmann ,H.J., Mountjoy, E.W., Teitz, M.W., 1991.
Ediacaran fossils and dubiofossils, Miette Group of Mount Fitzwilliam area, British Columbia. Canadian Journal of Earth Sciences, Volume 28:1541- 1552
https://doi.org/10.1139/E10-070
https://www.nrcresearchpress.com/doi/pdf/10.1139/E10-070

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Inglez, Lucas , 2018
Estruturas discoides na Formação Cerro Negro (Grupo La Providencia), Argentina e suas implicações para a paleontologia de macrorganismos pré-cambrianos
2018-04-12 Master thesis; Universidade Estadual Paulista: Instituto de Geociências e Ciências,  ExatasCampus de Rio Claro.  Language Portuguese; English Abstract
Alternative title: Discoidal structures in the Cerro Negro Formation (La Providencia Group), Argentina and their implications for the paleontology of pre-cambrian macroorganisms
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Discs and discord: The paleontological record of Ediacaran discoidal structures in the south American continent. Journal of South American Earth Sciences, Volume 89, January 2019, Pages 319-336    https://doi.org/10.1016/j.jsames.2018.11.023

Kenchington, Charlotte G. and Wilby , Philip R., 2014
Of time and taphonomy: preservation in the Ediacaran, a Chapter In:  Reading  and  Writing  of  the  Fossil  Record:  Preservational  Pathways  to  Exceptional  Fossilization.  The Paleontological Society Papers, Volume 20, Marc Laflamme, James D. Schiffbauer, and Simon A. F. Darroch (eds.).  The Paleontological Society Short Course, October 18, 2014.
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Kirkland, Christopher L.,  MacGabhann, Breandán A.,  Kirkland, Brian L. & JS Daly, 2010
Cryptic Disc Structures Resembling Ediacaran Discoidal Fossils from the Lower Silurian Hellefjord Schist, Arctic Norway. PloS one 11 (10), e0164071       
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Letsch, Dominik,  Large, Simon J.E. ,. Bernasconi , Stefano M., Christian Klug, Thomas M. Blattmann , Wilfried Winkler , Albrecht von Quadt, 2019
Northwest Africa’s Ediacaran to early Cambrian fossil record, its oldest metazoans and age constraints for the basal Taroudant Group (Morocco). Precambrian Research 320, 2019, 438-453
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Lieberman B.S., Kurkewicz R., Shinogle H., Kimmig J., MacGabhann B.A., 2017
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Liu, Alex G. and Conliffe,  James, 2015
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Remarkable insights into the paleoecology of the Avalonian Ediacaran macrobiota
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Discoidal fossils of the Ediacaran biota: a review of current understanding. Geological Society of London, Special Publications 286:297 313
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A solution to Darwin's dilemma: differential taphonomy of Ediacaran and Palaeozoic non-mineralised discoidal fossils. PhD Thesis, National University of Ireland, Galway, 1 338.
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Non-mineralised discoidal fossils from the Ordovician Bardahessiagh Formation, Co Tyrone, Ireland. Irish Journal of Earth Sciences 28:1 12.
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MacGabhann,Breandán Anraoi,  James D. Schiffbauer, James W. Hagadorn, Peter Van Roy, Edward P. Lynch, Liam Morrison, John Murray, 2019
Resolution of the earliest metazoan record: Differential taphonomy of Ediacaran and Paleozoic fossil molds and casts. Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 513, 2019, pp. 146-165
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Glaciation and ~ 770 Ma Ediacara (?) Fossils from the Lesser Karatau Microcontinent, Kazakhstan. Gondwana Research, Volume 19, Issue 4, June 2011, Pages 867-880
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Depositional and preservational environments of the Ediacara Member, Rawnsley Quartzite (South Australia): Assessment of paleoenvironmental proxies and the timing of ‘ferruginization’ Paleography, Palaeoclimatology, Palaeoecology 434, 4-13
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