Saturday, 13 November 2021

Reports of Fossil Thrombolites Along the Ottawa River at Kitchissippi Lookout, at the Champlain Bridge, and at Brebeuf Park

 Residents of Eastern Ontario will be familiar with the outcrops of stromatolites along the Ottawa River. The most well known outcrop is in the bed of the Ottawa River on the Quebec side, just over the Champlain Bridge.  Other well known outcrops are at Kitchissippi Lookout near Westboro Beach, at an outcrop just east of Port O’Call Marina near Dunrobbin, and at  Fitzroy Provincial Park.   Stromatolites are also visible in the walls of the transitway from the pedestrian bridge at the end of Roosevelt Avenue in Westboro, Ottawa.

What is less well known is that fossil thrombolites are also visible along the Ottawa River.  While thrombolites and stromatolites are both microbial structures, stromatolites have a layered structure while thrombolites lack the layers and have a clotted structure.  Most who write on stromatolites and thrombolites assign the presence of the structures to different facies, where the growth of the two structures  was regulated by different microbial assemblages in response to changes in environmental factors including sea levels.
        
In 2015 I noted that Donaldson and Chiarenzelli’s (2004a)  field trip guide mentioned  that stromatolites were visible in limestone at Kitchissippi Lookout, along the Ottawa River.   When I visited the outcrop in 2015 I found both stromatolites and thrombolites.   The outcrops with stromatolites can be found in with the shrubs and trees, while the thrombolites are down at the edge of the river.    More specifically, the thrombolites are about two meters lower in the stratigraphic column.  

Eight days ago I again visited  Kitchissippi Lookout to take photographs of the stromatolites and thrombolites.   The passage of time has not been kind to the outcrops of stromatolites. Below are photographs  of the most photogenic of the stromatolites.


 

 

 Other examples are present.  The stromatolites  are not as impressive as they once were (for example, see Quentin Gall’s photograph on Ottawa-Gatineau Geoheritage Project’s  web site, mentioned below ).

What I really visited Kitchissippi Lookout for was to make sure that fossil thrombolites and trace fossils could still be found.    Below are photographs  that I took in 2015  and 2021 of  loose slabs that show thrombolites.


 


The thrombolites are up to 9 cm in diameter.  Similar slabs are present close to the water’s edge.  Additional thrombolites can be seen  in the bedrock. Below is a photograph, taken in 2015, showing the internal structure of broken thrombolites in the outcrop.  


In 2015 well developed fossil trace fossils  were also visible in bedrock at the water’s edge.   The below photograph shows burrowing.



I could not find the outcrop with trace fossils when I recently visited.  However, sand and gravel has been washed in by the river and the trace fossils might still be found with a bit of effort.

Thrombolites Beside Champlain Bridge and at Brebeuf Park

What prompted my re-attendance at Kitchissippi Lookout was that on September 16th I (and numerous others) had  received an email from Dr. Al Donaldson telling me (and the others) that the Ottawa River had dropped to a level that Dr.  Donaldson had “never before seen, allowing direct access to strata directly below the unit of stromatolites beside Champlain Bridge  ... [The river] is more than half a metre lower than I’ve seen it since I first moved to Ottawa in 1959, allowing the source bedrock of the fossil-rich slabs to be seen in direct contact with the overlying layer of stromatolites. Remarkably, the lowermost well-layered stromatolites appear to be widely cored by silicified thrombolites (laminae-free domal structures) that contain abundant fossils resembling shells of modern clams and snails that make up the cores of thromboliitic stromatolites still actively growing in Shark Bay, Australia.”
                   
Dr. Donaldson has taken a number of photographs of the thrombolites including photographs of [a] unlinked non-laminated thrombolites up to 15 cm in diameter, and [b] an oblique view of closely packed thrombolites, showing characteristic internal clotting.   The thrombolites are in the bed of the Ottawa River at the Champlain Bridge occurrence and in the bed of the Ottawa River at Brebeuf Park, Gatineau, Quebec.  Brebeuf Park is about two kilometers east of the Champlain Bridge.

Unfortunately, I failed to go over in time to look at the outcrops.  I received an email from Dr. Donaldson telling me that he had gone over “to Brebeuf Park soon after sunrise on Saturday [September 25], only to find the water had risen almost 1 m overnight.”  The thrombolites are back underwater.
                           
I will have to hope that next summer is as dry as the summer of 2021, so that the thrombolites are again visible at the Champlain Bridge and at Brebeuf Park.  However, as the last time the river was that low was sixty-two years ago, I’m not that hopeful.

   

Links to Online Photographs of Stromatolites Along the Ottawa River


While there are lots of web sites with photographs of the stromatolites in the bed of the Ottawa River  just over the Champlain Bridge in Quebec, the best photographs can be found on the Géo-Outaouais web site:   Colonie de stromatolites à Gatineau
http://geo-outaouais.blogspot.com/search?q=stromatolite

Some of the best photographs of the stromatolites at Westboro Beach/ Kitchissippi Lookout are Quentin Gall’s photographs on the web site of the  Ottawa-Gatineau Geoheritage Project, Stop  5,  Westboro Beach [Kitchissippi Lookout] Stromatolites, ... and trace fossils fossils
https://www.ottawagatineaugeoheritage.ca/subsites/5

The best photographs of the stromatolites along the transitway can be found on the Géo-Outaouais web site:  Stromatolites du Transitway, à Ottawa : suite
http://geo-outaouais.blogspot.com/2011/11/stromatolites-du-transitway-ottawa.html   

Some of the better photographs of the stromatolites just east of Port O’Call Marina near Dunrobbin can be found on my October 26, 2015 blog posting entitled “A Good Year to Look at the Stromatolites along the Ottawa River - Part 2, near Dunrobin .
http://fossilslanark.blogspot.com/2015/10/a-good-year-to-look-at-stromatolites_26.html

Donaldson , and Chiarenzelli ( 2004b) include a photograph of the laterally linked stromatolites of the Oxford Formation in the bed of the Ottawa River at Fitzroy  Provincial Park.

I believe that the paper by Nehza and Dix  (2012) is the only one to mention both the stromatolites and the thrombolites in Eastern Ontario.  Bernstein and Hofmann  (1989) gave a talk at a GAC/MAC annual meeting on stromatolites, oncolites and thrombolites of the Beekmantown Group, and an abstract of the talk is cited in a few papers, but I have not yet been able to track it down.

Christopher Brett
Ottawa


References and Suggested Reading

Bernstein, L. and Hofmann, H.J. 1989
Lower Ordovician stromatolites, oncolites and thrombolites, Beekmantown Group, Ottawa - St. Lawrence Lowland, Quebec and Ontario. Geological Association of Canada, Abstracts with Programs, v.14, p. A86.


Brett, Christopher, 2015a
A Good Year to Look at the Stromatolites along the Ottawa River. [In Quebec just across the Champlain Bridge from Ottawa.] Blog posting dated Thursday, October 1, 2015
http://fossilslanark.blogspot.com/2015/10/a-good-year-to-look-at-stromatolites.html
   
Brett, Christopher, 2015b           
A Good Year to Look at the Stromatolites along the Ottawa River - Part 2, near Dunrobin . Blog posting dated Monday, 26 October 2015
http://fossilslanark.blogspot.com/2015/10/a-good-year-to-look-at-stromatolites_26.html

Brett, Christopher, 2020a   
Stromatolites in the Ordovician Oxford Formation, Eastern Ontario . Blog posting dated Friday, September 4, 2020
http://fossilslanark.blogspot.com/2020/09/stromatolites-in-ordovician-oxford.html
   
Donaldson, J.A., 1963
Stromatolites in the Denault Formation, Marion Lake, Coast of Labrador, Newfoundland; Geological Survey of Canada, Bulletin 102, 1963, 33 pages, https://doi.org/10.4095/123903

Donaldson, J. Allan  and Jeffrey R. Chiarenzelli, 2004a,
Stromatolites and Associated Biogenic Structures in Cambrian and Ordovician Strata in and Near Ottawa, Ontario; 76th Annual Meeting, Field Trip Guidebook, New York State Geological Association, 283 pages, Trip F-1,  at pages 1-20. [Stop 1. Limestone, Ottawa Group (Ordovician) at Kitchissippi Lookout. ... a  20 cm bed of limestone containing laterally linked domal stromatolites with a synoptic relief of 10 cm.   Stop 4. Stromatolites in Pamella formation (Ordovician), Fablewood.    Figure 4. Plan-view photograph of stromatolite exposures in Gatineau, Quebec (STOP 4).

Donaldson, J. Allan, and Chiarenzelli, J. R., 2004b,
Precambrian Basement and Cambrian-Ordovician Strata , as Displayed in Three Provincial Parks of Canada, 76th Annual Meeting, Field Trip Guidebook, New York State Geological Association, 283 pages, Trip A-I,  at pages 63-78.       [Figure 4: Laterally linked stromatolites of the Oxford Formation, Fitzroy Harbour Provincial Park.]

Eljalafi, Abdulah,  2017
Lithofacies, diagenesis, and chemostratigraphy of the micobialite and marginal lacustrine carbonate units within the Green River Formation, Eastern Uinta Basin , Colorado and Utah.  Master of Science Thesis , Colorado School of Mines, 137 pages
https://mountainscholar.org/bitstream/handle/11124/171849/Eljalafi_mines_0052N_11381.pdf

Eljalafi, Abdulah and J Frederick Sarg, 2018   
Lacustrine Microbialite Architectural and Chemostratigraphic Trends: Green River Formation, Eastern Uinta Basin, Colorado and Utah* Search and Discovery Article #51522 (2018)**
https://www.researchgate.net/publication/347901627_Lacustrine_Microbialite_Architectural_and_Chemostratigraphic_Trends_Green_River_Formation_Eastern_Uinta_Basin_Colorado_and_Utah
   
Greggs R.G. and Sargent M.W., 1971
Algal bioherms of the Upper Gull River Formation (Middle Ordovician) near Kingston, Ontario. Canadian Journal of Earth Sciences, 8(11): 1373–1381.   https://cdnsciencepub.com/doi/pdf/10.1139/e71-126

Palmer, James R., 1991
Distribution of Lithofacies and Inferred Depositional Environments in the Cambrian System, pages 9-38, in Geology and Mineral Resource Assessment of the Springfield 1 x 2 Quadrangle, Missourri, as Appraised in September, 1985; edited by James A. Martin and Walden P. Pratt
U.S. Geological Survey Bulletin 1942
 
Käsbohrer, Fabian  and Jochen Kuss, 2021
Lower Triassic (Induan) stromatolites and oolites of the Bernburg Formation revisited – microfacies and palaeoenvironment of lacustrine carbonates in Central Germany.  Facies (2021) 67:11  https://doi.org/10.1007/s10347-020-00611-y

Mayr, U. And  de Freitas, T, 1998
Cambrian to Upper Ordovician carbonate platform,  p. 21-56 in Mayr, U (ed.); de Freitas, T (ed.); Beauchamp, B (ed.); Eisbacher, G (ed.);   The geology of Devon Island north of 76̊, Canadian Arctic Archipelago. Geological Survey of Canada, Bulletin 526, 1998, 500 pages (1 sheet), https://doi.org/10.4095/209767    
 
Nehza, Odette and George R. Dix, 2012
Stratigraphic restriction of stromatolites in a Middle and Upper Ordovician foreland-platform succession (Ottawa Embayment, eastern Ontario).   Canadian Journal of Earth Sciences, 2012, 49(10): 1177-1199, https://doi.org/10.1139/e2012-048

 
 
 
 
 

Thursday, 4 November 2021

Non-mineralized Discoidal Impressions Preserved on a Slab of Ordovician March (Theresa) Formation Sandstone from Lanark County, Ontario

 The specimen in the following photographs is a slab of Ordovician March (Theresa) Formation sandstone collected in Lanark County, Ontario about half way between Perth and Smiths Falls.   The slab is about 14 cm long by 8.5 cm wide by 1.8 cm thick.  The sand that makes up the bulk of the slab is much coarser and a darker colour than the fine grained tan surfaces of the top and bottom of the slab.

The fine grained  surface of one side of the slab preserves a number of discoidal impressions with diameters from 5 to 16 mm.  The slab was loose on the ground when I picked it up, so I can’t be certain that  the discoidal impressions are preserved on a bed top or a bed sole.   However, I believe this to be a bed sole, largely because the other surface looks more like a bed top.  The first two photos show the same side of the slab.  In the second photo I’ve place white circles over some, but not all, of the discoidal impressions.   The circle that I’ve marked with the number ‘1' is interesting because it is more of a dark colouration than an impression.    The gradations on the ruler are in millimeters.


These non-mineralized discoidal impressions  resemble each of the following:

- [A] scyphozoan medusae [true jellyfish or "true jellies"] (Hagadorn,  Dott  and Damrow (2002, Figure 3, D, E), Hagadorn and Belt (2008, Figure 6); Hagdorn ( 2015), Young  & Hagadorn, (2020);  Lacelle, Hagadorn & Groulx (2008))
   
- [B]  blisters and fluidization structures produced by dewatering or degassing of underlying sediment or organic matter, often trapped by a microbial mat  (Bottjer  and Hagadorn (2007, Figure 4(a), 1, 2), Dornbos,  Noffke, and Hagadorn (2007, Figure 4(d)-2, C, D, E , F),  Hagadorn and Miller (2011, Figure 4 b)) 
       
- [C]  fossil eldonids   (MacGabhann and Murray (2010);  Schroeder, Paterson and Brock (2018))

 The three options appear equally likely, because weak radial furrows are present at the edges of some of the discs in the top photo, but lack definition.  Interestingly, if the discs record eldonids, true jellies, or similar creatures,  then a linear feature shown in the photographs  could be  a tentacle such as one sees in present day jellyfish or on some jellyfish fossils.   One ‘tentacle’ comes out of the black disc near the bottom of the photographs.  

I considered and rejected both discoidal Siphonophores and dicoidal Chondrophorina (capitate) as they are just weird - Lieberman et al. (2017).  (The most familiar siphonophore is the Blue Bottle or Portuguese Man-o-war.)  

The paper by Schroeder, Paterson & Brock (2018) includes photographs of two disc-shaped fossils, one with preserved concentric corrugations (called concentric lines, rays, radial furrows, or ridges by other authors), from the lower Cambrian Emu Bay Shale of South Australia, which they identify as Eldonioids  Their more complete specimen has a diameter of 20.9 mm.  Their more complete specimen looks like the disc-shaped specimens in my photographs, but with better corrugations .   The disc that I've marked '2', and the disc on its left,  have the best corrugations, but  the corrugations are hard to see in my photographs.

Below is a photograph of the side of the slab that I believe is the bed top.


 

Christopher Brett
Ottawa
   
References and Suggested Reading
   
Bottjer, D., and Hagadorn, J. W., 2007
Mat growth features, chapter 4(a), P. 53-71, in Atlas of Microbial mat features preserved within the Clastic Rock Record.  Elsevier,  450 pages.  See Figure 4(a), 1, 2.

Brett, Christopher, 2019  A Concentric Circular Structure in Rocks of the Ottawa Embayment that are Mapped as the Ordovician Gull River Formation. Blog  posting Tuesday, 22 October 2019.

http://fossilslanark.blogspot.com/2019/10/a-concentric-circular-structure-in.html

 Crockford, P.W.  , A. Mehra, E. Domack & P.F. Hoffman, 2021

An occurrence of radially symmetric sedimentary structures in the basal Ediacaran cap
dolostone (Keilberg Member) of the Otavi Group, EarthArXiv, pages 26-38
http://www.mme.gov.na/files/publications/Crockford_et_al2021_Keilberg%20Member%20sedimentary%20structures.pdf
https://eartharxiv.org/repository/view/2393/
       
Dornbos, S.Q., Noffke, N., and Hagadorn, J. W., 2007,
Mat-decay features, chapter 4(d), P. 106-110, in  Atlas of Microbial mat features preserved within the Clastic Rock Record.  Elsevier 450 pages . See  Figure 4(d)-2, C, D, E , F.

Fryer, Geoffrey and Stanley, George D. Jr.,  2004
A Silurian porpitoid hydrozoan from Cumbria, England, and a note on porpitoid relationships. Palaeontology, Vol 47:1109–1119.     doi: 10.1111/j.0031-0239.2004.00402.x.
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.0031-0239.2004.00402.x
https://www.readcube.com/articles/10.1111%2Fj.0031-0239.2004.00402.x
   
Hagadorn, James W.  and Randall F. Miller, 2011
Hypothesized Cambrian medusae from Saint John, New Brunswick, reinterpreted as sedimentary structures. Atlantic Geology Volume 47, 2011, p. 66–80
https://www.erudit.org/en/journals/ageo/1966-v2-n1-ageo47/ageo47art02/
   
Hagadorn, J.W., and Belt, E.S., 2008
Stranded in upstate New  York: Cambrian medusae from the Potsdam Sandstone.
Palaios, 23, pp. 424–441.  doi:10.2110/palo.2006.p06-104r

Hagadorn, J.W., Dott, R.H., Jr., and Damrow, D. , 2002.
Stranded  on a Late Cambrian shoreline: medusae from central Wisconsin.  Geology,  30,  pp.  147–150.  doi:10.1130/0091-7613(2002)030<0147:SOALCS>2.0.CO;2

Hagdorn,  Hans, 2015
Wirbellose des Lettenkeupers. [photos of   Hydrozoen-Medusen  „Medusina“  atava
  (POHLIG,  1892)] In book: Der Lettenkeuper -- Ein Fenster in die Zeit vor den Dinosauriern (pp.107-140)Edition: Palaeodiversity SonderbandChapter: 7. Publisher: Staatliches Museum für Naturkunde Stuttgar
http://www.palaeodiversity.org/pdf/08Suppl/07Palaeodiversity_SB_Hagdorn.pdf

Kimmig, Julien; Helena Couto,  Wade William Leibach, Bruce Lieberman, 2019
Soft-bodied fossils from the upper Valongo Formation (Middle Ordovician: Dapingian-Darriwilian) of northern Portugal.   The Science of Nature 106(5-6):27   DOI:10.1007/s00114-019-1623-z 

Lacelle, M.A., Hagadorn, J.W., & Groulx, P. (2008)     
The Widespread Distribution of Cambrian Medusae: Scyphomedusae Strandings in the Potsdam Group of Southwestern Quebec. Geological Society of America Abstracts with Programs. 2008;40:369  

Lieberman,Bruce;  Richard Kurkewicz, Heather Shinogle, Breandán Anraoi MacGabhann 2017
Disc-shaped fossils resembling porpitids or eldonids from the early Cambrian (Series 2: Stage 4) of western USA.      PeerJ 5(6):e3312    DOI:10.7717/peerj.3312
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5463991/

 Lucas, Spencer G.,  and  Allan J. Lerner, 2017
The rare and unusual pseudofossil Astropolithon   from the Lower Permian Abo Formation near  Socorro, New Mexico .  New Mexico Geology, Volume 39, Number 2, pages 40-42 [CPB: probably fossil medusa; somewhat like  Seputus pomeroii MacGabhann and Murray, and Discophyllum peltatum Hall.  See figures in MacGabhann, 2012  ] https://geoinfo.nmt.edu/publications/periodicals/nmg/39/n2/nmg_v39_n2_p40.pdf

       
MacGabhann, B. A., 2012
A Solution to Darwin's Dilemma: Differential Taphonomy of Ediacaran and Palaeozoic Non-Mineralised Discoidal Fossils.   Earth and Ocean Sciences, National University of Ireland, Galway, Ireland 1, 657 pages

MacGabhann, Breandán Anraoi and John Murray, 2010
Non-mineralised discoidal fossils from the Ordovician Bardahessiagh Formation, Co. Tyrone, Ireland.    January 2010  Irish Journal of Earth Sciences 28:1-12.  DOI:10.3318/IJES.2010.28.1
https://www.jstor.org/stable/25780702
https://www.researchgate.net/publication/235764014_Non-mineralised_discoidal_fossils_from_the_Ordovician_Bardahessiagh_Formation_Co_Tyrone_Ireland
   
MacGabhann, B.A., Murray, J., and Nicholas, C. 2007.
Ediacaria booleyi: weeded from the Garden of Ediacara?. Geological Society of London Special Publication, 286, pp. 277–295.

 MacGabhann, Breandán ; Schiffbauer, James; Hagadorn, James ; Van Roy, Peter ; Lynch, Edward ; Morrsion, Liam ; Murray, John, 2015
The taphonomy of unmineralised Palaeozoic fossils preserved as siliciclastic moulds and casts, and their utility in assessing the interaction between environmental change and the fossil record
EGU General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria. id.15384   
2015EGUGA..1715384M
       
MacGabhann,B. A., J. Schiffbauer, James W.Hagadorn, PeterVan 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, 1 January 2019, Pages 146-165   https://par.nsf.gov/servlets/purl/10125488
    DOI:10.1016/J.PALAEO.2018.11.009Corpus ID: 135003752
   
Pickerill, R.K., and Harris, I.M., 1979
Reinterpretation of Astropolithon hindii Dawson 1878. Journal of Sedimentary Petrology,
49,  pp. 1029–1036.
https://doi.org/10.1306/212F78AB-2B24-11D7-8648000102C1865D

Schroeder, Natalie; John Paterson and Glenn A Brock, 2018
Eldonioids with associated trace fossils from the lower Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia.  Journal of Paleontology , Volume 92 , Special Issue 1: Cambrian Explosion , January 2018 , pp. 80 - 86  DOI: https://doi.org/10.1017/jpa.2018.6
https://www.researchgate.net/figure/Eldonioid-from-the-early-Cambrian-Emu-Bay-Shale-Kangaroo-Island-South-Australia-SAM_fig1_322611581

Walcott, Charles D., 1914.
No. 3  Middle Cambrian Holothurians and Medusae, pp. 41 -68,   pls  8-13, in Cambrian geology and paleontology, II.Smithsonian Miscellaneous Collections, Volume 57,  Smithsonian publication 2136
https://archive.org/details/smithsonianmisce571914smit/page/n164

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
http://paleoitalia.org/media/u/archives/02_Young__Hagadorn_2020_BSPI_593_WJoiJAU.pdf

Zhu,  Mao-yan, Yuan-Long Zhao, Jun-Yuan Chen, 2002

 Revision of the Cambrian discoidal animals Stellostomites eumorphus and Pararotadiscus guizhouensis from South China.  Geobios 35 (2002) 165–185

  https://www.academia.edu/17380660/Revision_of_the_Cambrian_discoidal_animals_Stellostomites_eumorphus_and_Pararotadiscus_guizhouensis_from_South_China

 

Sunday, 31 October 2021

Abandoned Nepean Sandstone Quarries and Outcrops in the Greenspace West of Bells Corners - Part II

 Campbell’s Quarry - Continued


In 1949 the National Capital Commission took out an option to purchase the Campbell Sandstone Quarries and 340 surrounding acres in the Green Belt.  As part of the agreement Archie Campbell was permitted to continue operations on a rental basis.  Hewitt (1951) mentions that “Campbell Sandstone Quarries operate a quarry on lot 3, concession II, Nepean township, for the production of building stone and silica rock for cement”.  It was still carrying on that business in 1963 (Hewitt, 1963) but ceased operation about 1964 (Hewitt, 1964).
        
The abandoned Campbell’s Quarry is on the premises of  Natural Resources Canada’s CANMET Research Facility.   Below is a Google Satellite View of the abandoned Campbell’s Quarry.


 The quarry is on two levels, which I have marked as ‘L1' for Level 1 and ‘L2' for Level  2 (following Egner, 1994– see below).  I have marked the outer boundary of each level with fluorescent pink.  Level 1 is being used by CANMET for storage while Level 2 appears to be clear.  Based on Google’s scale, Level  1 covers an area of about 5,900 square meters while Level  2 covers an area of about 2,400 square meters, giving a total area of about 8,300 square meters.   I suspect that the quarry actually covers a larger area and that the vegetation obscures the extent of the quarry.  
    
Alice E. Wilson (1956), M.C. Egner (1994), and Sanford and Arnott (2006) have all briefly described the rocks at Campbell’s Quarry.

Alice E. Wilson (1956, page 23) had a stop at the Campbell Quarry in her field trip guide.  She noted the joint planes, asymmetric ripple marks,  'liesegang' — dark spots of iron material,   layers of course sand and mud cracks.

In a Master of Science thesis entitled ‘Weathering Characteristics of Building Stone at Ottawa,’  M.C. Egner (1994) provides the following description of the Campbell’s Quarry:

“The quarry is approximately 15 000 square metres in area and only 5m deep. ...       Several sedimentary structures are evident in the quarry. Ripples are common on the floor of levels one and two ...  Dewatering structures were seen at the north end of the quarry and on level 2. Desiccation cracks and possible burrows were seen infrequently at the north end of level 1. Liesegang banding is common on the second level, south side, and along the second level face. On both level floors, scattered depressions are left where calcite has been dissolved. Channels are apparent in both the north face, level 1, and the east face, level 2. Most  of the rock is highly siliceous, silica-cemented, and in beds at least 10 cm thick. Elsewhere the beds range from 10cm to < l cm. At the east face, level 2 near a channel, a series of fractures trends 200̊. The surface expression is a series of parallel ridges. The faces of the fractures are flat and smooth, dipping 80̊ north. A large block of stone near the northeast face of level 2 (quarry source unknown) contained a 1cm gap infilled with crumbling pyrite. Beds in the quarry that are most suitable for building stone are between 0.6 m and 2.7 m up from the floor of level 1. This rock is buff to white, thickly bedded, lacks significant pyrite, and is mainly siliceous.  Possibly some of the fractures are faults, and therefore more detailed mapping would be necessary before large quantities of stone could be properly quarried.”

Sanford and Arnott (2006, page 60) state that “Exposed at two levels (benches) are an estimated 11 m of strata consisting of white to light grey, thin to thick, uniformly bedded quartz arenite that weathers grey  to faintly pink and yellowish green. Neither the lower nor the upper contact with Precambrian basement and March formation is exposed here, though the base of the lower level of the quarry cannot be too far above the Precambrian surface at this locality.”

Enger’s estimate that the quarry is 5 meters deep does not agree with Sanford and Arnott’s estimated 11 meters of strata.  Based on the photo of the quarry in Sanford and Arnott’s publication, their estimate seems more reasonable, but one would have to visit the quarry to determine which estimate is accurate.   The gate at the entrance to the CANMET research complex, and the security guard house, prevent easy access. 

Geologic Map


Below is a marked up extract from Williams, Rae, and Wolf’s (1982) Paleozoic Geological  Map P. 2716, showing the geology of the area around the abandoned Campbell Quarry and the abandoned Henry Bishop - Tillson quarry. 

The Campbell Quarry is shown by the letter ‘C’ on yellow background in a black box.   Other symbols are similar to those I used on the extract from the NCC’s All Seasons Trail Map that was part of my last blog posting.  The location of the ‘outcrops of interest’ from the last blog posting is shown by the red square. The letter ‘Q’ in a red box represents one part of the Henry Bishop - Tillson quarry. The magenta box encompasses the outcrop of Nepean sandstone along Highway 417, which various authors designated as the principal reference section and type section for the Nepean formation. The green square shows the location of the GSC’s Borehole Geophysics Test Site. The black square shows the  location of an outcrop of March formation dolostone and dolomitic quartz arenite along Timm Road which is stop 5 for Donaldson and Chiarenzelli’s (2004) field trip.   The red crossed hammers north of Corkstown Road mark an additional abandoned Nepean Sandstone quarry that falls on lot 6, Concession I, Ottawa Front, – likely the Keefer quarry.

Points worth noting on the map are the following:
- the Campbell Quarry, the Henry Bishop - Tillson quarry, the Keefer quarry and the ‘outcrops of interest’ are all mapped as Nepean Formation Sandstone
- the area designated as the principal reference section/type section, the GSC’s Borehole Geophysics Test Site, and  stop 5 for Donaldson and Chiarenzelli’s (2004) field trip are all mapped as March (Theresa) formation dolostones and dolomitic sandstones
- a fault dipping to the south separates [1] the Nepean sandstone encompassing the Campbell Quarry, Henry Bishop - Tillson quarry, Keefer quarry, from [2] the March (Theresa) Formation dolomitic rocks encompassing the GSC’s Borehole Geophysics Test Site, and  stop 5 for Donaldson and Chiarenzelli’s field trip.
   

Principal Reference Section and Type Sections 

Alice E. Wilson (1946) did not describe a type section for the Nepean Formation. She stated “The formation is named from Nepean township, where the large quarries lie from which the stone was taken for the Parliament Building of Canada, and for many other large government and other buildings.” On the north side of the Queensway, east of March  Road and west of Moodie Drive, is an outcrop of Nepean Formation sandstone that has been proposed as the Principal Reference Section for the Nepean Formation and as the Type Section for the Nepean Formation.  The outcrop was selected because it is close  of where the large quarries were located, is one of the thickest in the area, and because it was believed (incorrectly) that all of the quarries had been filled in.  Five close, but slightly different, sections of the outcrop have been measured, with the authors noting slightly different features.   One measured section was proposed as the Principal Reference Section for the Nepean Formation by Greggs and Bond  (1972 ).   Two other measured sections from this outcrop were proposed as the Type Section for the Nepean Formation by  Brand and Rust (1977a) and by Dix, Salad Hersi and  Nowlan  (2004).   The fourth is included in a doctoral thesis: Lowe (2016).  The fifth section was measured by Williams (1991, page 251)

Greggs and Bond  (1972 ) proposed a principal reference section for the Nepean  Formation that is on the north side of the Queensway (then Highway 17; now Highway 417) “1.1 mi (1.74 km) east of the junction of the Queensway (Highway 17) and the boundary road between Nepean and March Townships” [namely, Eagleson Road/March Road].   They also stated that the “This section lies between the Queensway (Highway 17) and the Corkstown road in the northeast  corner of Lot 5, Concession II, Nepean Township.”   They noted that “The section is not ideal in that  the upper contact with the March Formation has been eroded, but less than 3 mi (0.8 km) to the south along the same ridge, outcrops of the March Formation are present.”   They provided a measured section of eight sandstone units totaling 23.8 ft (6.85 m), with each unit being between 0.5 ft (0.2 m) and 6.8 ft (1.8 m) thick.  They placed all eight units within the Nepean formation.

While Greggs and Bond (1972) said that the quarry is on the “northeast corner” of Lot 5, the map
that was published as Greggs and Bond (1973) shows the quarry on the northwest corner of Lot 5.  The standard lot in Ontario was 20 chains (1,320 feet; a 1/4 mile) wide.  Their distance of 1.1 miles east of March Road places the measured section in the northwest corner of Lot 5.

Brand and Rust (1977a) measured a section  close to that measured by Greggs and Bond .   Brand and Rust (1977a) stated that “we located our section as close as possible to that of Greggs and Bond (1972, Fig. 1; 1973, p. 329).  It is on the north side of the Queensway, 2.2 km (1.35 miles) west of the Moodie Drive intersection (Fig. 1).  In passing, it should be noted that the Queensway exposures show lateral variations from the type section; notably the presence of channels in the lower Nepean units on the south side of the highway opposite the type section, and elsewhere.”  They proposed their section as the type section for the Nepean formation.   They described eight  Nepean sandstone units and an overlying ninth unit which they assigned to the  March formation,  in a measured section about 6.8 meters (calculated using their scale bar) thick.

Greggs  and Bond (1977) commented on Brand and Rust’s (1977) paper noting the “extreme difficulty experienced in distinguishing between Nepean and March” and that “Even Wilson's definition of the base of the March Formation, advocated by Brand and Rust, as the lowest sandstone with a consistent carbonate content cannot be applied to small, isolated exposures of Nepean-March sandstones; one can never be sure that one has found the lowest bed with a carbonate content,”   ... [T]he definition proposed by Wilson, and advocated by Brand and Rust for locating the base of the March Formation, is not feasible in practice.”
       
Brand  and Rust (1977b), in a reply to Greggs and Bond’s (1977) paper , noted that “In our paper we assumed that Greggs and Bond (1972) included the uppermost bed in their principal reference section, hence the apparent disagreement. They placed all their section in the Nepean Formation, whereas we recognized the uppermost bed as the base of the March.  However, Greggs informed us that their reference section was measured at a part of the roadcut where the uppermost bed is absent.”

Williams (1991, page 251) described a 6.7 meter measured section for the Queensway roadcut.  He describes five beds of Nepean Formation quartz sandstone overlain by a bed of March Formation sandy dolomite.  This is his section “OT-3: roadcut, Nepean (Queensway)” with UTM 432450E, 5019700N.   

Williams (1991, page 249) also measured a 1.75 m section of Nepean Formation sandstone on Corkstown Road.  This is his Section AO OT-7 .   He described the outcrop as “Quartz sandstone - white, white to reddish  brown weathering; fine to medium grained; thinly to massive bedded; ripple marks, non-calcareous.”    Williams placed the outcrop on Nepean Township, Lot 6, Concession l, Nepean Township.     There are additional roadside outcrops of Nepean sandstone 500 hundred meters further west along Corkstown Road.

Dix, Salad Hersi, and  Nowlan  (2004) measured a vertical section on the north side of the Queensway (but not  the same section as Greggs and Bond (1972) or Brand and Rust (1977a)) and a section on the south side, identifying the top beds of each section as the Theresa formation.   They proposed that the boundary between the Theresa and Nepean “should be repositioned
downsection by 1.5 m [from Brand and Rust’s boundary]  ... coincident with a disconformity.”

David Lowe (2016) includes  photographs  (Figure 5.27) of the  Keeseville-Theresa contact from the western Ottawa Embayment, including one from the outcrop along the Queensway.   His photograph ‘D’ is described as “Cryptic paraconformity between sabkha facies of the upper Keeseville (below) and locally bioturbated tide-dominated marine strata of Theresa Formation (above) at the type locality of the “Nepean Formation” along Highway 417 in Ottawa (locality 222). The base of the Theresa is defined by the lowest dolomite-cemented bed, following Dix et al. (2004). Slight preferential weathering of the uppermost ~20 cm of the Keeseville is attributed to an interstitial illuvial matrix that inhibited the silica or dolomite cementation present in adjacent strata.”    Dave also includes a measured section (Figure 5.28) which he describes as a “Stratigraphic log of the “Nepean Formation” (here abandoned) type section along highway 417 in Ottawa (locality 222). Red dashed line marks the paraconformity between the Keeseville and Theresa formations.”  Dave recommended abandoning the term ‘Nepean Formation’ and using ‘Keeseville Formation.’

Searching  45.32923,-75.86422 in Google Maps, switching to Google Satellite View, then Street View, and looking north, will show the outcrop.   Below is a photograph of the outcrop taken by Google Street View.   


I’ve driven by that outcrop at about 100 to 120 km per hour over 1,000 times in the last 15 years.  While drive-by mapping has known disadvantages, on a few occasions I’ve felt that I can identify the overlying bed of March (Theresa) formation dolostone identified by  Brand and Rust (1977a) and Williams (1991).   As Highway 417 is a restricted access highway, stopping to look at the outcrop is prohibited.

Bernius and Crow et al. Logged the Core from the GSC’s Borehole Geophysics Test Site


A point worth noting is that Bernius (1981, 1996) logged the drill core from the  GSC’s Borehole Geophysics Test Site.  The drill holes intersected about 65 m of Paleozoic rocks that dip at a low angle and thicken slightly to the north-northwest, underlain by Precambrian igneous and metamorphic rocks.   The core revealed (progressing down the holes):

Paleozoic
- 11 to 16 metres of Oxford Formation grey to reddish brown, sandy dolomite;
- 4 metres of March Formation comprised of a massive quartz arenite on the top and a light-grey coloured dolomitic sandstone at the bottom
- Nepean Formation comprised of (still progressing down the holes):
    - 16 metres of pure, well sorted, massive, white sandstone
   -  a 50 cm layer of reddish-brown shale

   -  27 metres comprised of a sequence of cross-bedded sandstones with fifteen bioturbate layers that range in thickness from 2 cm to 10 cm and alternate with the cross-bedding, with zones of vertical worms holes of the species skolithos, Diplocraterion and Arenicolites
   - a thin 5 cm layer of quartz-feldspar orthoconglomerate
Precambrian
- a 15 - 17 metre highly altered/weathered zone, a saprolite layer, in the Precambrian rocks
- syenites, granites and gneisses
   
Bernius was the only one to report Oxford Formation rocks directly south of CANMET’s Research Facility.   The 50 cm layer of reddish-brown shale within the Nepean Formation is also interesting, as is his report of 43 meters of Nepean Formation sandstone, which is much thicker than other estimates for this area and much thicker than the measured sections on the Queensway.
                       
In a recent paper Crow et al. (2021) provided new geophysical data from the drill holes at the GSC’s Borehole Geophysics Test Site.  They also re-logged the drill core.  Their description of the rocks differs slightly from Benius’ description. For example, they have adopted  more current names for the formations, don’t mention the layer of reddish brown shale, and assign more rock to the Theresa (formerly the March) Formation, and  less rock to the Beauharnois (formerly lower Oxford) Formation.  This is their description of the Paleozoic rocks:

“Keeseville (Nepean) Formation (core depths 20.45 – 64.30m)
The contact with the basement occurs at a 20cm thick quartz conglomerate with some brownish limonitic layers (Bernius, 1996). A 5.2m-long interval of white quartz sandstone overlies the conglomerate. Overlying this is a sandstone sequence characterized by alternating bioturbated and cross-bedded sandstone, both with variable amounts of hematite (visible iron staining), glauconite and limonite. There are 23 bioturbated layers identified, ranging in thickness from 5 to 83cm. Burrows are frequently seen in this interval. The upper 16m of the Keeseville Formation is characterized by massive, white quartz arenite with some dark laminae and irregular layers.

Theresa and Beauharnois Formations (core depths 5.30 (top of core) – 20.45m)
The Theresa Formation is composed of interbedded sandy calcareous dolostone and calcareous
sandstone. The base of the formation contains a distinct dark grey layer of uranium-bearing and
chalcopyrite-rich pyrobitumen (Charbonneau et al., 1975; Bernius, 1996) also known as thucolite (see Hoekstra and Fuchs, 1960). The core transitions upward into a grey, fine to medium crystalline dolostone, containing a few very thin interbeds of fine grained quartz sandstone.  Calcite-filled cavities are observed in core. The upper several metres of core are broken and fractured, with visible weathering along vertical fracture surfaces. The transitional nature of the Theresa Formation upward into the Beauharnois Formation leaves assigning the contact between the two open for re-examination. The local thickness of the Theresa Formation has been interpreted to be about 10m, suggesting that the upper few metres of core could be Beauharnois Fm.”

A 120 Foot Deep Test Shaft on Lot 5, Concession II, Nepean Township


What I have not been able to locate and mark on the map is the location of a 120 foot deep test shaft dug on Lot 5, Concession II, Nepean Township.  It could be anywhere between Corkstown Road and Robertson Road,  would be west of the Henry Bishop - Tillson quarry and well east or southeast of the Campbell Quarry.  Presumably the shaft is covered.

Hewitt (1963, pages 23, 25) mentions that “In 1949 and 1950 work was carried out in the Bells Corners area under the direction of F. W. Huggins of Ottawa with a view to developing a deposit of Nepean sandstone as a source of glass sand. The average of chemical analyses of twenty-four core samples obtained in a diamond-drill program, is given as follows :  SiO2....97.3%; Al2O3. ... 0.76%, Fe2O3.... 0.116%, L. O. I.... 0.54% .  The drilling program is reported to have outlined some 7,000,000 tons of sandstone of the above composition in a 10-foot bed at a depth of 110 feet. 
    In December 1950, a test shaft 5 by 8 feet was sunk to a depth of 120 feet on lot 5, concession
II, Nepean township, to test the pure sandstone beds near the base of the Nepean Formation. A
bulk sample of 100 tons taken at the shaft area had the following analysis:  SiO2 .... 97.65%,   A12O3...0.74%,   Fe2O3...0.195%,  L. O. I. ..... 0.53%.
    A 250-ton sample of sandstone, obtained from a 30-foot room 170 feet from the shaft, was shipped to Ottawa ...   70-80 percent of the sample was recovered as glass sand of satisfactory physical requirements for the glass  industry.   It was considered that the added costs of underground mining would make the project uneconomic.”


What is interesting about Hewitt’s report is that the Nepean sandstone on lot 5 extends to a depth of 110 feet.    I suspect that this is much deeper than anyone looking at Greggs and Bond  (1972),  Brand and Rust (1977a) or  Dix, Salad Hersi and  Nowlan  (2004)  would have predicted.  However, if the shaft was dug south of the fault and east or southeast of the GSC’s Borehole Geophysics Test Site then Hewitt’s report of  10-foot bed at a depth of 110 feet could correspond with  Bernius’ (1981, 1996) report of 16 metres of pure, well sorted, massive, white sandstone extending from 20 metres  to 36 metres [66 feet to 120 feet].     Collings and Andrews (1989, page 116) summarize a report by Huggins (1950) stating “The sandstone bed was reported to be 3 m thick, to contain 7 Mt and to be overlaid by calcareous sandstone.”  Being overlain by calcareous sandstone (likely the March/Theresa Formation) places the location either close to Corkstown Road or south of the fault.

Egner’s  (1994) and Owen's (1962, 63) Reports on Drill Core from Bells Corners


There is additional drill core from this area. Egner (1994) reported that he had logged drill core from Bells Corners at the Geological Survey of Canada Core Library located at Tunney’s Pasture and Hull.  His log is at pages 164 -168 of his thesis and his section is at pages 188- 189.   He reported 25 feet of March dolomite and sandstone overlying 81 feet of Nepean sandstone.  I have not contacted the GSC Core Library to try to get the co-ordinates of the drill hole. 
 

Owen (1962, 1963) reports that Canada’s Mines Branch drilled seven test boreholes in the Nepean sandstone on lot  5, concession 1 (O. F.)  Nepean township, about a kilometer north of Corkstown Road. The holes were drilled to find a suitable location for an experimental mine to conduct experiments relating to rock mechanics.   Logs of the drill core record up to 101 feet of sandstone underlain by discontinuous beds of silty shale and conglomerate up to 5 feet in thickness, overlying  granite.  Two of the holes were drilled in a small abandoned quarry, that would have been part of Howard Rock’s quarry, one face of which is shown below.


Areas of Natural or Scientific Interest (ANSI) and Constructing the  LRT


Morrison Hershfield (2017) in a report on the Moodie Light Rail Transit  Extension for the City of Ottawa, mention that both (A) the Queensway Road Cut area which was proposed as a reference section for the Nepean (Potsdam) Formation, and (B) Campbell's Quarry have been designated by Ontario as Areas of Natural or Scientific Interest (ANSI) –Earth Sciences.    Management and stewardship of an ANSI is a municipal responsibility.   Any development plans must "demonstrate that no negative impacts on the natural features or their ecological functions will occur".  
   
As part of the the LRT extension to Kanata a Light Maintenance and Storage Facility (LMSF) is being built west of Moodie Drive between Corkstown Road and the Queensway.    From 2025 to 2031 the extension of the LRT to Kanata is slated for construction  from Moodie Drive to Eagleson Road/March Road and on through Kanata to Hazeldean Road.   Between Moodie and Eagleson/March the  LRT will run parallel with and along the north side of Highway 417 (See Manconi, 2018 , pages 20-22).    In other parts of Ottawa where the LRT has been constructed (for example, close to the University of Ottawa), the dual tracks and track bed are about 10 meters wide.    If the scale for Google Maps is accurate, then there are about 11 meters between the edge of the northern shoulder for the Queensway  and the front of the tall outcrops that face the Queensway.   The LRT will be constructed above the lower outcrops and could easily require blasting of the outcrops that are Greggs and Bond's  (1972 )  principal reference section for the Nepean  Formation.   Ominously, the map at page 20 of Manconi's (2018) report suggests construction will take out most of the outcrop.
 
Christopher Brett
Ottawa


References and Suggested Reading


Beer, H.L., 1950
"Flotation of alumina, from Bells Corners silica"; Ore Dress Inv Rep. (unnumbered); CANMET, Energy, Mines and Resources Canada, 1950. [referenced in Collings and Andrews, 1989]

Bernius, G. R., 1981,
Boreholes Near Ottawa for the Development and Testing of Borehole Logging Equipment - A preliminary Report GSC Paper 81-1C, p. 51-53
https://ftp.maps.canada.ca/pub/nrcan_rncan/publications/STPublications_PublicationsST/116/116175/pa_81_1c.pdf
  
Bernius, G. R., 1996,
Borehole Geophysical Logs from the GSC Borehole Geophysics test site at Bell’s Corners, Nepean, Ontario, GSC Open File 3157, 38 pages, doi:10.4095/207617
   
Brand, U., and Rust, B.R.,  1977a
The age and upper boundary of the Nepean formation in its type section area near Ottawa, Ontario. Canadian Journal of Earth Sciences, 14: 2002–2006.
www.nrcresearchpress.com/doi/abs/10.1139/e77-171 #.WR-TQbiN0r0

Brand, U., and Rust, B.R., 1977b
 The age and upper boundary of the Nepean formation in its type section area near Ottawa, Ontario: Reply. Canadian Journal of Earth Sciences, 14: 2671–2673.   10.1139/e77-233

Brett, Christopher, 2017
Why has hardly anyone referred to core from the GSC’s Borehole Geophysics Test Area at Bell’s Corners, Ottawa, when the core contains a 50 cm thick shale layer in the Nepean Formation and the core straddles the boundary between the Nepean Formation and the overlying March Formation?   Blog Posting, Monday, 22 May 2017
http://fossilslanark.blogspot.com/2017/05/why-has-hardly-anyone-referred-to-core.html

Collings,  R.K. and P.R.A. Andrews, 1989
Summary Report No. 4: Silica.  Mineral Processing Laboratory, CANMET Mineral Sciences Laboratory, 135 pages https://publications.gc.ca/collections/collection_2018/rncan-nrcan/m38-13/M38-13-89-1-eng.pdf
   
Crow, H L; Brewer, K D; Cartwright, T J; Gaines, S; Heagle, D; Pugin, A J -M; Russell, H A J
2021    New core and downhole geophysical data sets from the Bells Corners Borehole Calibration Facility Ottawa, Ontario.  Geological Survey of Canada, Open File 8811, 2021, 36 pages, https://doi.org/10.4095/328837          Released:   2021 09 14

Dix, George R.,  Salad Hersi, Osman, and  Nowlan, Godfrey S.,  2004
The Potsdam-Beekmantown Group boundary, Nepean Formation type section (Ottawa, Ontario): a cryptic sequence boundary, not a conformable transition, Canadian Journal of Earth Sciences, 2004, 41(8): 897-902,  http://www.nrcresearchpress.com/doi/pdf/10.1139/e04-040

Egner, M.C., 1994
Weathering Characteristics of Building Stone at Ottawa, Canada.   Carleton University, Thesis, Master of Science.  209 pages
https://doi.org/10.22215/etd/1994-02814
https://curve.carleton.ca/system/files/etd/0c68f4a1-b270-491b-a49c-434a7a865ff6/etd_pdf/e4a03c2b65def31470d3d23e7b9fa119/egner-weatheringcharacteristicsofbuildingstoneat_col.pdf
    

Fejer, P.J., 1986
Correlation and Depositional Environments of an Ordovician Succession  in the Bell's Corners Area near Ottawa, Unpub.  B.Sc. Thesis, University of Ottawa, May 1,  1986.
(Not available. Cited by Bernius (1996), but not listed in Carleton University Library catalogue https://library.carleton.ca/)


Greggs, R. G.  and Bond, I. J., 1972
A principal reference section proposed for the Nepean  Formation of probable Tremadocian age near Ottawa, Ontario. Canadian Journal of Earth Sciences, 9, pp. 933-941.         www.nrcresearchpress.com/doi/abs/10.1139/e72-078

Greggs, R. G.  and Bond, I. J., 1973.
Erratum: A principal reference section proposed for the Nepean Formation of probable Tremadocian age near Ottawa, Ontario. Canadian Journal of Earth Sciences, 10, p. 329

Greggs, R. G.  and Bond, I. J., 1977
The age and upper boundary of the Nepean formation in its type section area near Ottawa, Ontario: Discussion. Canadian Journal of Earth Sciences, 14: 2669–2671. 10.1139/e77-232

Hewitt, D.F., 1951[?]
Silica in Ontario. Industrial Mineral Circular No. 2 - Ontario. Department of Mines, 17 pages

Hewitt, D.F., 1963
Silica in Ontario. Industrial Mineral Report No. 9. Ontario. Department of Mines, 36 pages
http://ccob.ca/wp-content/uploads/2014/04/silica-in-ontario.pdf

Hewitt, D.F., 1964
Building Stones of Ontario. Part IV Sandstone. Industrial Mineral Report No. 17.  Ontario. Department of Mines, 57 pages

Huggins, F.W., 1950
Testwork on Bells Corners Sandstone.   Report (unnumbered), 1950.
[cited as  Ont. — 37 (Ref. No. 133) at page 116 in Collings  and Andrews, 1989]
   
Lowe, David G., 2016
Sedimentology, Stratigraphic Evolution and Provenance of the Cambrian – Lower Ordovician Potsdam Group in the Ottawa Embayment and Quebec Basin.  Doctoral Thesis.  University of Ottawa.  435 pages   https://ruor.uottawa.ca/handle/10393/35303

MacPherson, A.R., 1951
"Report on Bells Corners sandstone for production of glass sand"; Ore Dress Inv Rep 4; CANMET, Energy, Mines and Resources Canada, 1951  [referenced in Collings and Andrews, 1989]

Manconi, John, 2018
Kanata Light Rail Transit Planning and Environmental Assessment  Study (Moodie  Drive to  Hazeldean  Road
http://ottwatch.ca/meetings/file/519019

Morrison Hershfield, Engineers, 2017
 Moodie  Light Rail Transit  Extension. 
https://documents.ottawa.ca/sites/documents/files/Bayshore%20to%20Moodie%20BRT%20Conversion%20to%20LRT%20Environmental%20Project%20Report.pdf
    

Owen, E. B., 1962
Proposed site for an experimental mine, Bells Corners area, Carleton County, Ontario
Owen, E B; Geological Survey of Canada, Topical Report 57, 1962, 42 pages (2 sheets), https://doi.org/10.4095/289967

Owen, E. B., 1963
Experimental Mine, in Summary of Activities: Office and Laboratory, 1962; Geological Survey of Canada, Paper no. 63-2, 1963 p. 73,


Powell, R.D. and M.A. Klugman, 1979
Silica Sand Potential in Eastern Ontario Preliminary Report I, p. I-22, Ontario Geological Survey,  OFR5265 [1-E   North Elmsley; OC-A   March, p. 175] http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/records/OFR5265.html

Sanford , B. V. And Arnott, R.W.C., 2010
Stratigraphic and structural framework of the Potsdam Group in eastern Ontario, western Quebec, and northern New York State. Geological Survey of Canada, Bulletin 597, 83 pages

Vos, M.A., 1978
Silica in Ontario, Supplement; Ontario Geological Survey, Open File Report 5236, 50 p., 23 figures, 3 tables.  http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/OFR5236/OFR5236.pdf

Williams,  D.A., 1991
Paleozoic  Geology  of  the  Ottawa-St.  Lawrence  Lowland,  Southern  Ontario;  Ontario  Geological  Survey,  Open  File  Report  5770,  292p   

Williams, D. A., Rae, A. M. And Wolf, R.R., 1982
Paleozoic Geology of the Ottawa Area, Southern Ontario, Ontario Geological Survey, Map P. 2716, Geological Series, Preliminary Map, scale 1:50,000, Geology by D. A Williams, A. M. Rae,  And R.R. Wolf, 1982
    

Wilson, Alice E. 1946
 Geology  of  the  Ottawa - St. Lawrence Lowland, Ontario and Quebec.  Geological  Survey  of
Canada, Memoir  241. 65 pages


Wilson, Alice E.,  1956
 A Guide to the Geology of the Ottawa District, Volume 70, 1,  The Canadian Field-Naturalist, 73 pages, including five plates, and 1 map sheet. Campbell Quarry at page 23.
https://www.biodiversitylibrary.org/item/90128#page/33/mode/1up
 



Thursday, 21 October 2021

Abandoned Nepean Sandstone Quarries and Outcrops in the Greenspace West of Bells Corners

The National Capital Commission (‘NCC’) maintains a series of walking and biking trails through the Greenspace in Ottawa, and provides a number of parking lots to access the trails. On its web site the NCC has maps showing the trails and the parking lots. There is no charge to park in the lots. Links to the maps are provided below.

  In my November 4, 2015 blog posting (Brett, 2015b) I provided directions to, and photographs of, an outcrop showing convoluted biofilms and stromatolites in the Nepean Formation sandstone in the Greenspace at Kanata. That outcrop is just east of Eagleson Road and south of Robertson Road. It is part of the Old Quarry Trail. Parking at lot P5 off Eagleson provides easy access to that outcrop (and to an abandoned Nepean sandstone quarry). 

 This posting describes outcrops and abandoned quarries of Nepean sandstone in the NCC Greenbelt about three kilometers to the northwest of the convoluted outcrop on the Old Quarry Trail and briefly discusses their historical significance. Historically the outcrops and quarries were referred to as being west of Bells Corners, because Kanata was not in existence when the quarries were being operated. The quarries are north and south of the Queensway/Highway 417, east of Eagleson Road, west of Moodie Drive, and north of Timm Road, where the easiest access is from parking lot P3 on Corkstown Road. 

The outcrops described below are south of the outcrops along Highway 417 that were designated in the 1970's and 1980's as the principal reference section for the Nepean Formation, and which are inaccessible to the public because it is illegal to stop a car on a 400 series highway unless it is an emergency, and because six foot high fences prevent one accessing the outcrops by land. The papers discussing the proposed reference section are listed in my May 22, 2017 blog posting, which discusses drill core from Natural Resources Canada’s Borehole Geophysics Test Area. The Borehole Geophysics Test Area is a kilometer south of the outcrops accessed from parking lot P3 on Corkstown Road. 

Directions:   Exit the Queensway/Highway 417 heading north on Moodie Drive. Take the first left onto Corkstown Road. Drive about 2 kilometers south then west along Corkstown Road. One hundred meters after crossing the railroad tracks, park in Lot P3 on your right. Exit your car and walk east along Corkstown for about 100 meters, crossing the railroad tracks. Cross Corkstown and take the Trans Canada Trail (Greenbelt Pathway West) under the Queensway. Follow the trail for about 25 minutes until you pass under the high voltage Hydro Lines. Take the narrow path on the west side of the hydro lines and walk north about 60 meters to the outcrops. Plugging 45.33271, -75.85855 into Google Maps will show the location of parking lot P3 on Corkstown Road. 

The following extract from the NCC’s All Seasons Trail Map shows the location of the major roads, parking lot P3 and the Trans Canada Trail (dashed red and white). The location of the outcrops of interest is shown by the red square. The easement for the high voltage hydro lines is shown by parallel blue lines. Where the trail passes under the hydro lines the trail is shaded blue. Additional trail 20 is shown in brown, and while it does cross the outcrops of interest, the start of trail 20 was flooded on the two times that I tried to access the trail. The black box enclosing the letter ‘C’ is the approximate location of the Campbell quarry. The letter ‘Q’ in a red box represents one part of the Tillson quarry. The magenta box encompasses the outcrops of Nepean sandstone along Highway 417, which various authors tried to designate as the principal reference section for the Nepean formation. The green square shows the location of the GSC’s Borehole Geophysics Test Site. The black square gives the approximate location of an outcrop of March formation dolostone and dolomitic quartz arenite along Timm Road which is stop 5 for Donaldson and Chiarenzelli’s (2004) field trip.


 


 Plugging 45.325504,-75.860545 into Google Maps in SatelliteView will show the  outcrops along the hydro easement.   The following extract shows what can be seen in Satellite View. 



 The light green diagonal swath is the easement for the high voltage hydro lines.  I have shown the location of the Trans Canada Trail/Greenbelt Pathway West with red dots.  The two white boxes with the included letter ‘T’ are below  two hydro towers.   The outcrops of most interest are along the hydro easement between the hydro towers and the Trans Canada Trail. The outcrops appear white and gray in satellite view.  Glacial striae and chatter marks, which indicate the direction the glacier was moving are visible on the surface of glacially polished outcrops.  The white box with the letter G shows the location of additional glacially polished flat outcrops.
                       
The following two photographs show glacial striae and chatter marks at this location.

The following photograph shows ripple marks visible at this location.


The following two  photographs show a distorted microbial mat texture, an example of soft sediment deformation likely caused by an earthquake.  This feature can be found directly under the southern hydro lines about 25 meters southeast of the lower hydro tower shown in satellite view. 




The following photo shows a pitted surface.  The holes are thought to be evaporite  minerals that  weathered out. 

Donaldson and Chiarenzelli’s Outcrop

On the map I have indicated with a black square  the approximate location of an outcrop of March formation dolostone and dolomitic quartz arenite  which is stop 5 for Donaldson and Chiarenzelli’s (2004) field trip.  This is their description of the outcrop:

“This section is only a few metres above the top of the Nepean formation. The carbonate beds contain abundant burrows, including several varieties that are bedding-parallel. Despite the extensive bioturbation, wispy biofilm structures and a few possible dewatering structures can be seen at several stratigraphic levels. Both the siliciclastic and carbonate beds display abundant crossbedding, and carbonate intraclasts are evident in some of the siliclastic beds.”
                                           

Nepean Sandstone Quarries


In her memoir, Alice E. Wilson (1946) did not describe a type section for the Nepean Formation. She stated “The formation is named from Nepean township, where the large quarries lie from which the stone was taken for the Parliament Building of Canada, and for many other large government and other buildings (See Plate I).”  Most of the quarries (now abandoned) lay on Lots  4, 5 and 6 of Concession I, Ottawa Front, Nepean township, and Lots 3, 4 and  6 of Concession II of Ottawa Front, Nepean township (see Parks, 1912, pages 133-137; and Cole, 1923, page 47), all north west of Bells Corners.    Corkstown Road is the dividing line between Concession 1 and Concession 2.    Concession 1 is north of Corkstown Road while Concession II is south of Corkstown Road.  

One of the most important Nepean sandstone quarries was operated  on Lot 6, Concession II.   In the late 1800's the quarry on Lot  6, Concession II, Ottawa Front  was called the Bishop’s Quarry and was owned and operated by Henry Bishop of Bell's  Corners.  Logan and Hunt (1862) and the Geological Corps of Canada  (1876) comment that “The fine quarry from which this sandstone was obtained is on the property of  Mr.  H.  Bishop,  and from it the largest part of the stone used in the construction of the Parliament buildings at Ottawa was derived.”  It was called Bishop’s Quarry as late as 1904  (see  Hoffman, 1906).   By 1912 the quarry was owned by T. W. Tillson of Bells Corners (see Parks, 1912).  Cole (1923) also states that the quarry on Lot  6, con. II, Ottawa Front was owned by T. W. Tillson, Bells Corners.  Parks (1912) reports that sandstone from the Tillson quarry was used in the construction of the Victoria Memorial Museum (now the Museum of Nature), the Mint, the Observatory  at the Experimental Farm, and the addition to the Court House in Ottawa. 

I marked the location of an abandoned sandstone quarry at the junction of path 20 and the Trans Canada Trail with a letter ‘Q’ in a red box.  One will also notice that sandstone blocks are strewn on either side of the Trans Canada Trail from the junction of path 20  to the  outcrops of interest, and that it looks like sandstone was quarried from part of the outcrops of interest.   Both the abandoned quarry marked with the ‘Q’ and the outcrops of interest fall on Lot 6, Concession II,  and are parts of the quarry operated by  Henry Bishop and T. W. Tillson.  Parks (1912) devotes a little over two pages to a description of the quarry and the different stones taken from the quarry (one a white stone with a calcareous cement; another a white stone with a slight cast of green, with silica as the cement; the third in yellow and brown bands), noting that about 20 acres of stone were exposed on the property,  that the sequence of beds is different in different places on the property, and that stone was quarried from various openings at different levels .  

Andrew King’s  (2017) blog posting has excellent photos of sandstone blocks at the Bishop/ Tillson Quarry (which he misidentified as the Campbell Quarry).  One of Andrew King’s photos shows a six to ten inch convoluted layer at the top of an outcrop, likely representing distorted microbial mats.  One couldn’t take a better picture showing soft sediment deformation.   (I’ll have to go back and look for the outcrop.)   His photos appear to have been taken around the northern junction of path 20 with the Trans Canada Trail, the location I marked with a letter ‘Q’ in a red box. [On Sunday, October 24th I  visited the abandoned Bishop’s Quarry/ Tillson Quarry  looking for the outcrop in Andrew King's photo.  I didn't find it.  The main quarry area is quite extensive, covering about 140 meters by 80 meters.   Discarded stone blocks cover an even greater area.  There are a number of benches in the quarry but all are quite shallow (2 to 4 feet).  The quarry does not drain well and many parts were covered in up to 2 inches of water and mud.  I handicapped myself  by not wearing rubber boots.]  Andrew King will be familiar to those in Ottawa as an artist whose paintings  challenge the observers' perceptions of reality, much like Magritte’s paintings.

The Campbell Quarry, another famous Nepean Sandstone quarry, falls on Lot 3, Concession II and can be found three lots to the west of the Tillson quarry.   Nepean Sandstone is  the prime building material for Canada’s  Parliament Buildings.  When a February 1916 fire destroyed the Centre Block and Victoria Tower , the Campbell Quarry, “supplied much of the stone for the Centre Block and all of the stone for the Peace Tower [Lawrence, 2001]” when the Center Block and Peace Tower were rebuilt.  Regrettably, the Campbell Quarry is on the premises of Natural Resources Canada’s CANMET research complex and is not accessible to the public.  Baird’s (1968) field trip guide to the Ottawa area contains a photograph of workmen “removing flagstone and  building stone from the Nepean sandstone outcrops at the old Campbell's quarry, west of Bells Corners.”  That photograph is reproduced below.


Sanford and Arnott (2006) describe the quarry as two benches with an estimated 11 vertical meters of strata.  They  include a photograph of the lower bench of  Campbell’s quarry as Figure 64 at page 65 of their bulletin.  The quarry is their station O-3.   I’ve plotted the location of the Campbell Quarry on my  above  map with a black box enclosing the letter C  based on Bernius' (1981, page 52)  map showing the location of the quarry.  ( See also   the  June 29, 2017 comment by nepeanninthenders on King’s, 2017 blog.).  

The Campbell quarry had been called the Morrison Quarry before Archie Campbell joined.  While the Campbell quarry is credited by Lawrence as supplying  much of the stone for the rebuilt Centre Block and Peace Tower, Cole (1923) notes that “The Nepean Sandstone Quarries, Ltd., for several years operated [Howard]  Rock's quarry [on Lot 5, concession  I, Ottawa Front]  and produced stone for use in the new parliament building at Ottawa. Several of the other quarries furnished stone for the same purpose.”  Cole noted that at Rock’s quarry  “Three types of stone can be recognized, a white, friable variety, a hard, white, consolidated kind, and a brown and yellow variety.”

It is somewhat ironic that Alice E. Wilson (1946) did not describe a type section for the Nepean Formation (and has been criticized for failing to do so), that Greggs and Bond (1972)  designated the outcrops along Highway  17  as the principal reference section for the Nepean Formation, that the highway became a limited access highway 417 where it is not permissible to stop unless there is an emergency,   yet David Lowe in his doctoral thesis and in  Lowe et al. ( 2017) has shown that the Nepean  (Keeseville) formation is quite variable being comprised of fluvial, eolian, marginal marine, and shallow marine facies.  Alice E. Wilson was right not to describe a type section.

Christopher Brett
Ottawa, Ontario   

   

National Capital Commission Resources

   
Hiking and Walking in the Greenbelt
https://ncc-ccn.gc.ca/places/hiking-and-walking-greenbelt

All Seasons Trail Map 2020-2022
https://ncc-website-2.s3.amazonaws.com/documents/national-capital-greenbelt-all-seasons-trail-map.pdf?mtime=20200729102617&focal=none
   

References and Suggested Reading

   
Agnon, Amotz; Claudia Migowski and Shmuel Marco,  2006
Intraclast breccias in laminated sequences reviewed: Recorders of paleo-earthquakes
Geological Society of America, Special Paper 401
http://indico.ictp.it/event/a08182/session/61/contribution/39/material/0/0.pdf

Baird. D.M., 1968.

 Guide to the Geology and Scenery of the National Capital Region. Copyright Geological Survey of Canada. Misc. Report 15, 188  pages  https://doi.org/10.4095/119888

Bernius, G. R., 1981,
Boreholes Near Ottawa for the Development and Testing of Borehole Logging Equipment - A preliminary Report GSC Paper 81-1C, p. 51-53
https://ftp.maps.canada.ca/pub/nrcan_rncan/publications/STPublications_PublicationsST/116/116175/pa_81_1c.pdf
   
Bernius, G. R., 1996,
Borehole Geophysical Logs from the GSC Borehole Geophysics test site at Bell’s Corners, Nepean, Ontario, GSC Open File 3157, 38 pages, doi:10.4095/207617
(pdf  6427 KB)

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

Brett, Christopher, 2015b
In 1924 a report of Stromatolites in Nepean Sandstone by Dr. Morley E. Wilson of the Geological Survey of Canada, and Other Reports of Stromatolites and Biofilms in the Potsdam
Outcrops of Biofilms and Stromatolites in the Nepean Formation Sandstone at Kanata.. Blog posting, Wednesday, 4 November 2015   
http://fossilslanark.blogspot.com/2015/11/in-1924-report-of-stromatolites-in.html

Brett, Christopher, 2015c       
Dewatering Structures, Biofilm Structures, Glacial Striae and Chatter Marks in Potsdam Sandstone near Newboro, Eastern Ontario.  Blog posting, Wednesday, 23 December 2015

Brett, Christopher, 2015d
More Evidence of Microbial Mats in Potsdam Sandstone near Newboro, Eastern Ontario.  Blog posting,  Tuesday, 29 December 2015
http://fossilslanark.blogspot.com/search?updated-max=2016-01-26T09:11:00-08:00&max-results=7
   
Brett, Christopher, 2017
Why has hardly anyone referred to core from the GSC’s Borehole Geophysics Test Area at Bell’s Corners, Ottawa, when the core contains a 50 cm thick shale layer in the Nepean Formation and the core straddles the boundary between the Nepean Formation and the overlying March Formation?   Blog Posting, Monday, 22 May 2017
http://fossilslanark.blogspot.com/2017/05/why-has-hardly-anyone-referred-to-core.html

Cole, L. H., 1923
Silica in Canada. Its Occurrence, Exploitation, and Uses.  Part I -.Eastern Canada.  Canada Mines Branch, Publication 555, 1923, 135 pages (9 sheets), https://doi.org/10.4095/307756

Donaldson, J. Allan  and Chiarenzelli, Jeffrey R., 2004
Stromatolites and Associated Biogenic Structures in Cambrian and Ordovician Strata in and Near Ottawa, Ontario; 76th Annual Meeting, Field Trip Guidebook, New York State Geological Association, 283 pages, at pages 1-20   

Geological Corps of Canada, 1876
Descriptive catalogue of a collection of the economic minerals of Canada, and notes on a stratigraphical collection of rocks [Philadelphia International Exhibition, 1876]
Geological Corps of Canada; Geological Survey of Canada, Separate Report no. 405, 1876, 152 pages, https://doi.org/10.4095/216063

                               
Hewitt, D. F., 1964
Building Stones of Ontario, Part IV, Sandstone. Industrial Mineral Report No. 17, at pages 17-18
http://www.geologyontario.mndmf.gov.on.ca/mndmfiles/pub/data/imaging/IMR017/IMR017.pdf

Hoffman, G.C., 1906
Chemistry and Mineralogy, pages 337A-349A, in Geological Survey of Canada , Annual Report for  1904 , Annual Report (New Series) Volume XVI, published in 1906


King, Andrew,  2017
The Deserted Stone Quarry Of Canada’s Parliament Buildings.  Blog posting June 2017
https://ottawarewind.com/2017/06/28/finding-the-forgotten-quarry-of-canadas-parliament-buildings/
   
Lawrence, D.E., 2001
Building Stones Of Canada’s Federal Parliament Buildings, GeoScience Canada, Volume 28, Number 1, 18 pages

Logan, W. E. and  Hunt, T. S., 1862
Descriptive catalogue of a collection of the economic minerals of Canada, and of its crystalline rocks sent to the London International Exhibition for 1862. Geological Survey of Canada, Separate Report no. 398, 1862, 89 pages, https://doi.org/10.4095/216057    


Lowe, David G., Arnott,R.W.C.,  Nowlan, Godfrey S.,  McCracken, A.D.,  2017
Lithostratigraphic and allostratigraphic framework of the Cambrian–Ordovician Potsdam Group and correlations across Early Paleozoic southern Laurentia; Canadian Journal of Earth Sciences, Published on the web 6 February 2017,    doi: 10.1139/cjes-2016-0151

McCormick Rankin Corporation, 2009
REPORT ON Stage 1 Archaeological Assessment  West Transitway Extension  Part Lots 8 - 11, Concession 1  Part Lots 8 - 16, Concession 2  Geographic Township of Nepean  Carleton County, Ontario PIF Number:  P311-007-2009 REPORT Report Number:  09-1121-0008 (5000)
https://app06.ottawa.ca/calendar/ottawa/citycouncil/occ/2010/09-08/tc/04d%20-%20Document%204%20Appendix%20C%20-%20Stage%201%20Archaeology%20Report.pdf
 

Parks, W. A., 1912
Report on the Building and Ornamental Stones of Canada, Volume 1. Canada, Department of Mines, Mines Branch. 376 pages At pages 133-135
    

Sanford , B. V. And Arnott, R.W.C., 2010
Stratigraphic and structural framework of the Potsdam Group in eastern Ontario, western Quebec, and northern New York State. Geological Survey of Canada, Bulletin 597, 83 pages
   
Seccaspina, Linda, 2020
Tag Archives: campbell quarry           
https://lindaseccaspina.wordpress.com/tag/campbell-quarry

Wilson, Alice E., 1946
Geology of the Ottawa-St. Lawrence Lowland, Ontario and Quebec. Geological Survey of Canada.  Memoir 241

Wilson, Alice E.,  1956
 A Guide to the Geology of the Ottawa District, Volume 70, 1,  The Canadian Field-Naturalist, 73 pages, including five plates, and 1 map sheet. Campbell Quarry at page 23.
https://www.biodiversitylibrary.org/item/90128#page/33/mode/1up
   
++++++++++++
Highway Traffic Act
R.R.O. 1990, Reg. 627: USE OF CONTROLLED-ACCESS HIGHWAYS BY PEDESTRIANS
 1. (1) Subject to subsection (2), pedestrians are prohibited from using those parts of the controlled-access highways described in Schedule 1.
(2) Subsection (1) does not apply to pedestrians,
(a) engaged in police, highway maintenance, highway construction or vehicle inspection duties;
(b) within commuter parking lots established and maintained by the Ministry or proceeding directly between such lots and adjacent intersecting highways;
(c) within truck inspection stations or pulp load check areas established and maintained by the Ministry;
(d) making use of a controlled-access highway where the use is necessary because of an emergency; or
(e) crossing at a traffic control signal or a crosswalk.


Sunday, 8 August 2021

Concentric Circular Structures and an Ovoid Burrow in Rocks Mapped as the Ordovician March (Theresa) Formation

 In various blog postings dated from 2014 to 2016 I included photographs of cylindrical dewatering structures in the Cambrian Potsdam sandstone of Eastern Ontario.

For my  October 22, 2019 blog  posting I provided photographs of a concentric, circular structure observed in slabs of rock at a quarry mapped as the Ordovician Gull River Formation by the Ontario Geological Survey.

Below are three photographs of circular structures in two slabs of dolostone in Lanark County, just west of Carleton Place, where the rock has been mapped as the March (Theresa) formation by Williams  and Wolf (1984) of the  Ontario Geological Survey.  The second photo is a close up of the first slab. The third photo is of a separate slab.

 



The blue ruler records inches and centimeters.

The  concentric structures are about four inches (14 cm) in diameter.     The structures appear to be stromatolites or oncolites, both microbial structures.  In their marginal notes to Map  P. 2725, Williams  and Wolf (1984) mention that “algal mats and stromatolites are common” in the March Formation.  An alternate interpretation is that these structures  represent concentric microbial discoid structures similar to microbial-related biogenic structures from the Middle Ordovician slates of northern Portugal reported by Neto de Carvalho et al.  (2016).
            

[added November 23, 2021:]  Giles (1976; pages 53-59) reported both oncolites  and stromatolites in Beekmantown dolostones in Eastern Ontario for  his Prescott formation, which would be roughly equivalent to Alice E. Wilson’s March Formation.  The oncolites were “spheroidal, commonly oblong or elongate in shape, and are visibly banded around intraclasts of dolostone, gastropod fragments or other fossil fragments.”  The maximum diameter he recorded at two localities was  2.6 inches (6.8 cm) and 4 inches (10 cm).

Ovoid Burrow

Below is a photograph of an ovoid, scooped out, structure in a loose slab of sandy dolomite from the same locality. The ovoid structure is about 10 centimeters long by 7 centimeters wide by 3 centimeters deep.   It appears to be trace fossil – possibly a  dwelling or feeding burrow with a narrow , 1 cm wide, entrance at  the upper right.

Below is an enlarged view of this structure.


Christopher Brett
Ottawa


References and Suggested Reading
   
Brett, Christopher, 2014-2016
January 29, 2014  - Cylindrical Structures in Potsdam Group Sandstone in Eastern Ontario
August 27, 2015 - Cylindrical Structures in Potsdam Group Sandstone in Eastern Ontario - Part 2
September 28,  2015 - A Map Showing the Location of Cylindrical and Conical Structures in Potsdam (Group) Sandstone of Ontario and New York
October 22, 2015  -  Cylindrical structures in Sandstone: A Type of Soft-Sediment Deformation Sometimes Linked to Seismic Activity
December 23,  2015 - Dewatering Structures, Biofilm Structures, Glacial Striae and Chatter Marks in Potsdam Sandstone near Newboro, Eastern Ontario
September 22,  2016 - Frothed Sandstone and Cylindrical Structures Found in Potsdam Sandstone
Fossilslanark.blogspot.ca

Brett, Christopher, 2019
A Concentric Circular Structure in Rocks of the Ottawa Embayment that are Mapped as the Ordovician Gull River Formation. Blog posting dated Tuesday, 22 October 2019
http://fossilslanark.blogspot.com/2019/10/a-concentric-circular-structure-in.html

Giles, P.  S. 1976.
Stratigraphy,  petrology,  and  diagenesis  of Beekmantown carbonate  rocks. Ph.D. thesis,  University of Western Ontario,  London,  Ontario
https://ir.lib.uwo.ca/digitizedtheses/904/


Neto de Carvalho, C. , Couto, H., Figueiredo, M. V., and A. Baucon, 2016
Microbial-related biogenic structures from the Middle Ordovician slates of Canelas (northern Portugal).  Comunicações Geológicas (2016) 103, Especial I, 23-38
https://www.researchgate.net/journal/Comunicacoes-Geologicas-0873-948X

Williams, D.A., and Wolf, R.R., 1984
Paleozoic Geology of the Carleton Place Area, Southern Ontario; Ontario Geological Survey, Map P. 2725, Geological Series-Preliminary Map, scale 1:50 000. Geology 1982.