There are two ways of interpreting the title of this blog post. I have adopted the kinder interpretation. I am writing this posting to explain her reasoning and because I want to put on record a number of references that have been overlooked. I am not asking the question “How could she have done that?”
Many that are familiar with the March/Theresa naming controversy will probably be surprised that I used the word ‘renamed’ in the title of this blog posting. To understand why I used the word ‘renamed’ in the title, and to understand why the particular rock formation of interest was for fifty years called the March Formation in Ontario and more recently has been called the Theresa Formation in Ontario, it helps to know a bit of the history.
Logan (1863) of the Geological Survey of Canada used the term “beds of passage” for the rock exposed in Ontario and Quebec that we now call March/Theresa Formation. For example he referred to the “the beds of passage between the Potsdam and the succeeding formation,” the Calciferous. Logan also reported finding the gastropod fossil Ophileta compacta in the passage beds. Logan considered the beds of passage to be part of the Potsdam Group of sandstones and conglomerate. I cannot tell if he mapped them as part of the Potsdam, as the scale on Logan’s maps (e.g., Logan, 1865, Map 53, 1:7 920 000 ) defeats one being able to tell whether he mapped the passage beds as part of the Potsdam or the Calciferous.
The ‘beds of passage’ were recognized and reported as the passage beds or ‘transition beds’ in the earlier mapping of eastern Ontario in the latter half of the 1800's and early part of the twentieth century by the Geological Survey of Canada. For example, Ells (1901) in his report on the Geology of the Ottawa area mentioned “There is no break between the Calciferous which is for the most part a dolomitic limestone, and the Potsdam which is a sandstone. There are from twenty to thirty feet of transition beds in which the sandy part of the latter becomes more calcareous and it is from this portion that most of the fossils which have been described as Potsdam have been obtained.” Ells (1903) when reporting on rocks in the Kingston district, Ontario mentions that the Potsdam sandstones “consist for the most part of white quartzite, and these sandstones graduate upward without break into strata which become calcareous till the rock finally passes into a dolomitic limestone which constitutes the Calciferous formation. Between the sandstone proper and the dolomite there are certain layers known as the transition beds which range in thickness from five to forty feet, and these are often highly fossiliferous... “.
Ells mapped the transition beds sometimes as part of the Potsdam and sometimes as part of the Calciferous. For the area northeast of Perth, Ontario – north towards Carleton Place, and east to Smiths Falls– Ells (1901, Perth Sheet, Map 789) mapped some rock as Potsdam Sandstone and some rock as Calciferous, that the Ontario Geological Survey later mapped as March Formation (Williams and Wolf, 1984, Map P2714). In the marginal notes Ells stated “The transition beds between the [Potsdam] sandstone and the overlying Calciferous dolomites extend upward in places for a thickness of thirty feet, and render the exact boundaries of the two formations difficult to determine. They have however been indicated as closely as possible...”.
In an Appendix to a report by Ells, Ami (1905) listed and describing fossils from the Potsdam, Beekmantown (Calciferous), etc. formations on the Perth Sheet. In his report Ami (1905, p. 82J, 83J) treated the Passage Beds as a separate formation between the Potsdam and Beekmantown, and may have been the first to do so for Canada. Ami was reporting on a fossil Gastropod and commented that “The strata holding these may fairly be described as passage beds between the Potsdam sandstone and the next overlying series: the Beekmantown formations.”
Cushing (1908) proposed the term Theresa Formation for the transition beds exposed at Theresa, New York. Cushing commented “The Potsdam grades upward into a formation which consists of sandy dolomite layers and beds of weak brown sandstone which are mostly near the base and are quite like the upper beds of the Potsdam. The line between the two formations is drawn at the base of the first dolomite layer, but in all probability this is not a constant horizon over the district. The name given to the formation is mainly intended for local use and the necessity for its introduction arises from present doubt as to the exact equivalent of the formation elsewhere in the region. When fresh the dolomite is a hard and tough, bluish gray rock, which, however, quickly weathers to iron-stained sandy crusts. All the beds are somewhat sandy.”
The term Theresa was quickly picked up for the United States. Grabau (1909) mentions that Cushing found “in the Theresa quadrangle from 115 to 215 feet of strata beneath the Black River, and resting disconformably upon the Lower Beekmantown (Theresa formation), which, with its basal sandstone (called Potsdam by Cushing), has a maximum thickness of 140 feet.” Professor Grabau also made the point that as the Potsdam is “a transgressive overlapping series of strata deposited by a transgressing sea, the basal sand member would naturally rise in the series in the direction of transgression and overlap, and that hence a basal sand is not everywhere of the same age.”
One year later in a New York State Museum Bulletin report on the Geology of the Thousand Islands, Cushing et al. (1910, pages 65-66), when discussing the Theresa Formation commented that “The horizon seemed the same as, and the beds identical with beds which directly overlie the Potsdam sandstone all across northern New York, a length of outcrop of 150 miles, and which have heretofore been called "passage beds" between the Potsdam and the Beekmantown, the Beekmantown being the formation which overlies the Potsdam for much of this distance. ... It is likely, however, to prove useful as a name for the considerable thickness of alternating beds everywhere immediately overlie the Potsdam sandstone in northern New York, and which should be mapped separately.” Cushing et al. also commented (1910, pages 66-67) that “According to Ells the Theresa formation outcrops on Howe island [east of Kingston], and on the Canadian mainland to a point midway between Gananoque and Kingston. [Royal Soc. Can. Trans., ser. 2, v. 9, § 4, p. 97-108.] In the district about Kingston, as seen by us in 1908 under Dr Ami's guidance, the Potsdam is certainly present, though no Theresa was seen.”
The first reports of the Geological Survey of Canada to reference the Theresa formation in New York State were by Johnston (1909, 1911). On mapping the Pamelia beds on the Simcoe Sheet, Ontario, he compared the Pamelia beds in Ontario with those in New York State, and mentions (1909, page 99) that in New York below the Pamelia “lies the Theresa formation, supposed to be equivalent to the lower portion of the Beekmantown (Calciferous), and the Potsdam sandstone forms the base of the series ” and (1911, page 190) “In New York State the limestones of the Black River group pass downward into the Pamelia limestone of Upper Stones River age, which in turn is underlain by the Theresa formation, the upper member of which is of early Beekmantown (Calciferous) age.” Neither the Calciferous (Beekmantown) nor Potsdam were present on the Simcoe Sheet.
Willis (1912) may have applied the Theresa Formation to rocks in Ontario and Quebec. Under his supervision the United States Geological Survey in cooperation with the Geological Survey of Canada and the Instituto Geologico de Mexico compiled an Index to the Stratigraphy of North America, with an accompanying Geologic Map of North America. His map unit 18 includes the
Lower Cambrian to Lower Ordovician (Beekmantown), inclusive. In the text of the publication he reviews Cushing’s references to the Theresa Formation in New York State. He also discusses the geology of the St. Lawrence Valley, commenting (page 196) “The distribution of the Ordovician, exclusive of the Beekmantown ("Calciferous"), in the St. Lawrence Valley as here mapped is taken from the map sheets of Ontario and Quebec. ... . The Pamelia limestone and the underlying but unconformable "Theresa formation" have also been traced in the latest work (1908).[a]” His footnote ‘[a]’ references “Ami, H. M. , personal communication, Sept. 1908.” H. M. Ami was a paleontologist with the Geological Survey of Canada.
Raymond (1912 and 1913a) was the first to clearly use Theresa for the formation in Canada. Raymond (1912) when discussing the lower part of the Beekmantown rocks at Brockville and Smiths Falls assigned the name Theresa to the formation, commenting “In the vicinity of Brockville and Smiths Falls the Beekmantown is divisible into two formations. The older formation has two members. The lower part is a rather soft calcareous sandstone, usually thin-bedded. In places, however, the cement is siliceous and the beds very hard ... Fossils are there fairly common, and the presence of Ophileta complanata, and a gastropod very like Pleurotomaria canadensis indicate the Beekmantown age of the formation. .... The upper member of this formation is a thin-bedded bluish dolomite which weathers to a rusty yellow colour. These beds contain obscure gastropods and crinoidal remains. At Smiths Falls the thickness of the whole formation is above 70 feet, ... This formation appears also in New York state, in the vicinity of Clayton, and has been given the name Theresa by Prof. Gushing. This name may be adopted in Canada also. Above the thin-bedded dolomite of the Theresa there are heavier-bedded limestones and dolomites with a rather large fauna ... found also in the lower part of the Beekmantown section in the Champlain valley .. It will, however, be necessary to give a new formational name to these beds, and Beauharnois may be suggested.”
Raymond (1913a, p. 139) in a field trip guide to the ‘Ordovician of Montreal and Ottawa’ used the term Theresa Formation for the Ordovician passage beds for outcrops in Ontario. He stated: “Theresa. — In some parts of the Ottawa valley the oldest beds of the Beekmantown are composed of reworked Potsdam sand, with a calcareous cement. These beds are therefore softer and weaker than the Potsdam beds. They contain fossils at several localities, the more common of which are Ophileta complanata and Pleurotomaria canadensis. The upper part of the Theresa is a thin-bedded, gray dolomite, with the same fossils. The Theresa is absent from the section at Montreal, and is thin near Ottawa, but thickens southward, toward Smiths Falls and Brockville.”
It is worth noting that Raymond’s (1913a) paper is usually cited as the first to divide the Beekmantown Group of the Montreal area into two formations, namely the Theresa and the overlying Beauharnois. In fact for the Theresa he was mainly commenting on the Ordovician passage beds that outcrop near Ottawa, Smith Falls and Brockville, and noted that the Theresa is absent at Montreal. In addition, it was Raymond’s second paper mentioning the Theresa.
Raymond (1913b) used “Beauharnois formation, (Beekmantown)” to refer to a formation where specimens of a trilobite could be found on the Island of Montreal.
Kindle (1916), in a report on the Ordovician limestones in the vicinity of Kingston, Ontario, commented “Prof. H. P. Cushing visited this area during the progress of his mapping of
the formations on the New York side of the St. Lawrence and has included in his report a reference to the Kingston section. In a preliminary paper on this work Cushing described two new formations, the Pamelia limestone and Theresa dolomite from near the base of the Ordovician section. In the Kingston district Cushing found no evidence of the presence of the Theresa.”
Parks (1922), in a paper discussing the development of stratigraphy and paleontology in Canada, mentions that Raymond “subdivided the Beekmantown into Theresa and Beauharnois; established the upper age of the Chazy of Ontario and Quebec , calling it the "Aylmer" formation, and subdivided the Black River into Pamelia, Lowville and Black River.”'
Cole (1923, page 11) in a report on Silica in Canada, mentions that “Directly overlying the Potsdam sandstone formation, beds are to be found, in some localities, composed mostly of grains of quartz cemented by a calcareous bond, and placed in the Theresa formation of Beekmantown age. The beds are considered to be composed of material derived from the Potsdam formation, and in some cases are hard to differentiate from beds of true Potsdam age.”
Wright (1923) in report on the geology of the Brockville-Mallorytown area, Ontario for the Geological Survey of Canada, includes a Paleozoic Section comparing the rocks of the Brockville-Mallorytown map area with those across the St. Lawrence in the Ogdensburg area, an area mapped by Cushing. In that Paleozoic section where his description is “Lens-shaped bed of bluish grey dolomite limestone. Very hard, massive, light grey sandstone. Irregular-bedded, rubbly weathering, calcareous sandy material” Wright places it in the Potsdam for Canada and under Theresa for the USA. In the text of his report he notes that “Cushing, discussing the area directly across the river, has placed the Potsdam and Theresa formations in the Cambrian...”.
In an unpublished Master of Science thesis correlating the Ordovician in Canada, Phillpotts (1928) adopted Theresa for a rock formation in Eastern Ontario and Beauharnois for a formation in Montreal and in Eastern Ontario, as the parts of the Beekmantown, referencing Raymond (1913a) in his bibliography.
Maddox (1930) in a report by the GSC on the thicknesses of the Ordovician formations in Ontario and Quebec commented “No attempt has been made to subdivide the Beekmantown into the Theresa and the Beauharnois, the lower limit of the Beekmantown being arbitrarily assumed to be where the lowest bed of dolomite occurs in the sandstone.”
Morley E. Wilson (1931a) used the term “Theresa (Transition Beds)” to identify the lower part of the Beekmantown in a table of Palaeozoic strata of the Ottawa map-area. Morley E. Wilson (1931b, c) when describing ripple marks in sandstone beds at a quarry near Perth, Ontario, noted that the beds were “formerly known as ‘Transition Beds’, but now called Theresa in New York state.” He commented (1931b, page 26): “The Potsdam sandstone is succeeded by the sandy dolomitic limestone or limey dolomite of the Beekmantown, the change from the Potsdam to the Beekmantown taking place in most places transitionally, beds of sandstone up to four feet thick alternating with beds of sandy dolomitic limestone. These alternating beds formerly known as "Transition Beds", but now called Theresa in New York state, are usually thin, the maximum thickness so far observed by the writer being 30 to 40 feet in the vicinity of Smiths Falls.”
In an unpublished Master of Science thesis, Wykes (1931), who had assisted Dr. Morley E. Wilson in the field in 1930, described the Paleozoic Formations of the Perth Sheet, Ontario as (a) a basal conglomerate (b) Potsdam sandstone, (c ) Transitional or Theresa beds - sandy dolomites or limestones; (d) Beekmantown Dolomitic limestone.
Parks (1931) followed Raymond in dividing the Beekmantown group in Quebec into the Theresa and Beauharnois formations.
Alice E. Wilson made widespread use of the term Theresa for these beds in three papers: (1932a) in an unpublished internal GSC report on the Palaeozoic rocks of the Thurso map (Quebec and Ontario), (1932b) in a Palaeontological Note in the Canadian Field-Naturalist, and (1936) in a paper summarizing of the Ordovician of Ontario and western Quebec and New York,
In the unpublished report Wilson (1932a, Page 5, 14) comments “The Theresa, the sandy phase at the base of the Beekmantown, does not in this region add any information to the question of an unconformity between the Potsdam and the Beekmantown. The Theresa passes imperceptibly into the Upper beds of the Beekmantown, evidence of a deepening sea.” ... [The Theresa] “has everywhere been recognized in the earlier mapping of eastern Ontario by Ells who designated it as "the passage beds." In New York State the member has been recognized in several quadrangles. In the Thousand Island region and in the Ogdensburg quadrangle, Cushing did not distinguish any unconformity between the Theresa and the underlying sandstone.”
Alice E. Wilson (1932b) in her Palaeontological Note in the Canadian Field-Naturalist commented on outcrops of Theresa formation rock near Westport, Ontario, at Thurso, Quebec and at Montreal, stating “Cushing's original intention was to consider the Theresa as "passage beds" between the Potsdam and the undoubted Beekmantown. ... The fossils found in these "passage beds" in the Westport and Perth sheets are undoubtedly Beekmantown in age. ... [T]here are two possibilities, the existence or the non-existence of an unconformity separating the Potsdam and the Theresa of the Beekmantown age. ... The change in the chemical content of the sediments of the Potsdam and the Beekmantown seas is the record of a change in material brought to the ocean. It must have preceded the change in deposition. It would seem logical to consider that the change in chemical composition would correspond with the period of erosion elsewhere. Hence the logical place to draw the line in the rocks deposited would be below the first appearance of a change in deposition, that is, the first appearance of dolomite in the matrix of the sand, which would be below these basal Theresa beds.”
Alice E. Wilson (1936) in a paper with the title ‘A Synopsis of the Ordovician of Ontario and western Quebec and the related succession in New York’ commented: “ In eastern Ontario and western Quebec there are two phases of the Beekmantown– the Theresa, or "passage beds," and the overlying calcareous or dolomitic beds, to which Raymond has given the name of Beauharnois. THERESA - The Theresa is a thin formation of alternating dolomites and loosely cemented sandstones. Raymond (1913) considers the sandy phase to be the reworked Potsdam sandstone with a calcareous cement. The lower dolomite layers contain considerable sand and grit, but higher up they become a purer, tough, bluish grey dolomite, weathering rusty in spots. These beds pass imperceptibly into the purer dolomite of the upper Beekmantown. The Theresa is very thin in the Ottawa valley, but increases in thickness at Smiths Falls and Brockville. ... The Theresa was first described in New York state, the type locality being at Theresa, Jefferson county, New York, where the division attains a maximum thickness of 80 feet. ... To the lower member Cushing (1908) gave the name "Theresa." He considered the Theresa in its most easterly phase as "passage" beds between the Potsdam sandstone and the overlying Beekmantown. ... In Ontario Logan recognized these beds as a separate phase and throughout the early Canadian literature they are spoken of as the "passage beds," and as lying above the Potsdam and below the typical Beekmantown.”
Notwithstanding her earlier use of the Theresa, Alice E. Wilson (1937b) in a paper describing erosional intervals in the Ottawa area provided a table of formations for the Ottawa area in which she included the March formation above the Nepean formation, without describing or defining the March formation. Alice E. Wilson (1937a) in an unpublished report of the Geological Survey of Canada on the Geology of the Paleozoic Rocks of the Ottawa Area, signaled her change in thinking, naming the March and Nepean formations. She commented “It has been the custom in the past to correlate the Palaeozoic rocks of Ontario and Quebec with those of, New York State and to employ the formational names used in New York. It is believed that in some instances this has clouded the true interpretation.... The word Beekmantown, for instance, sometimes signifies the age in which certain rocks were deposited or sometimes signifies indiscriminately two or three phases of rocks deposited at different period of time. ... The boundary between the Nepean and March formations is stratigraphically slightly higher than the division formerly drawn between the Potsdam and the Theresa. ... First, the two formations may have been deposited by two distinct marine invasions. The contact of the Nepean with the March formation does not exactly coincide with the contact between the Potsdam and Theresa of New York. Raymond’s interpretation that the Theresa is reworked Potsdam, while not stating it assumes an erosional interval after the deposition of the Potsdam and before that of the Theresa sea. The incoming sea would rework the upper sand of the Potsdam and redeposit it. The upper layers of sandstone, then, would be the deposition of the later invasion. Evidences of such erosion might well be very obscure. It is practically impossible to find the exact line between sand laid upon sand. The existence or non-existence of an unconformity between the Potsdam and the Theresa in New York has been discussed by Cushing and others. The New York Geological Survey considers both Potsdam and Theresa as divisions of Upper Cambrian time. In Ontario all evidence corroborates Raymond's interpretation that at least the upper beds are of Ordovician age. But the assumption of an erosional contact is not the only interpretation possible.”
Further, Alice E. Wilson ( 1938a, 1938b, 1940a, 1940b, 1941a, 1941b, 1941c, 1942, 1946a) in a series of nine maps on the Paleozoic Geology of Eastern Ontario and Western Quebec, published between 1938 and 1946 by the Geological Survey of Canada, used the term ‘March Formation’ instead of the Theresa formation for one of her mapped units. The marginal notes to her maps contained a description of the March Formation, with the descriptions on the nine maps being nearly identical. This is her description from her (1938b) Map 414a entitled ‘Ottawa Sheet (West Half) Carleton and Hull Counties, Ontario and Quebec’: “The MARCH (3) is a thin formation of Lower Ordovician age lying conformably upon the Nepean. It is composed of thick beds of interstratified grey sandstones with a calcareous cement and a sandy blue-grey dolomites, both weathering a rusty brown. Transitional between the Nepean below and the Oxford above, it has been defined as a formation because its characteristic features are persistent throughout the region. It is a water bearing horizon. The contact with the Nepean is placed at the first dolomitic layer, but it is difficult to locate in many places because the resistant sandstone layers are often widely exposed and are very like those of the upper Nepean. The upper layers grade into the Oxford. It has an estimated thickness of 25 to 30 feet.” Map 557a, Map 558a and Map 662a contain the statement that the March “grades into the overlying Oxford and for this reason is considered to be of Beekmantown age.” Map 710a adds the sentence “The few fossils in it indicate a Beekmantown age” while Map 852a adds the sentence “The formation contains fossils of Beekmantown age.”
The following map shows Geologic maps where the Paleozoic Geology was mapped by Alice E. Wilson. Eight of the maps mentioned in the previous paragraph are shown, plus two additional maps where Alice E. Wilson was not the sole author. It is worth noting that four of Alice E. Wilson’s maps cover parts of the Province of Quebec and that the geologists in Quebec never adopted March as the name of the formation (other than in an unpublished Ph.D. thesis at McGill University by Dean (1962) in which he used March for the basal formation of the Beekmantown and Beauharnois for the upper formation). .
Alice E. Wilson ( 1946b) in her Memoir on the ‘Geology of the Ottawa - St. Lawrence Lowland, Ontario and Quebec” defined the March formation, naming it for March Township (south of Ottawa) where it outcrops. She noted (1948, page 16-17 ) that “The Nepean sandstone, then, may or may not have been deposited at the same time as the Potsdam of New York, and within the Nepean itself there is no definite evidence that it is of Upper Cambrian age. The possibility is recognized, but the probability is that the sandstone was deposited in earliest Ordovician time as the basal phase of an advancing sea. The March formation, with a few of the upper sandstone layers of the Nepean sandstone, was correlated by Raymond (1913, p. 139) with the Theresa of New York, and considered by him to be the base of the Ordovician in eastern Ontario. The position of the New York Theresa has been redefined, and the name is now restricted to an Upper Cambrian formation having its type locality in New York. Fossils indicate that the March is of Ordovician age.” As she believed that her Nepean and March in the Ottawa - St. Lawrence Lowland, Ontario and Quebec, were Ordovician in age while the Potsdam and Theresa in New York were Cambrian, she rejected the name Theresa for the rock unit she had mapped in Ontario and Quebec.
In Eastern Ontario the designation March Formation was used for these beds from 1948 to at least 1991, relying on Alice E. Wilson’s (1946) memoir. For example [1] Keith (1949) in an Ontario Department of Mines publication on sandstone as a source of silica sands in southeastern Ontario employed the term March Formation for that part of the Beekmantown overlying the Potsdam; [2] Wynne-Edwards (1967) in his memoir on the Westport map Area, Ontario comments “The March Formation represents a transitional unit between the sandstone of the Nepean and the overlying Oxford dolomite (Wilson, 1946).” [3] Wolf and Dalrymple (1985) in a paper discussing the Covey Hill Formation and Nepean Formation mention “the overlying March Formation and its New York equivalent.” Interesting, Greggs and Gorman (1976) in a publication on the Geology of the Thousand Islands (Ontario side), describe the features of the March formation, but mention that “the March Formation is the exact lithological and stratigraphical equivalent to the Theresa [of New York].” In the early 1980s the Ontario Geological Survey re-mapped the Paleozoic rocks of Eastern Ontario (e.g., Williams and Wolf, 1984a, Map P. 2724, Paleozoic Geology of the Perth Area; Williams and Wolf, 1984b, Map P. 2725, Paleozoic Geology of the Carleton Place Area), employing exclusively March Formation. The name March Formation is still in use by the Ontario Geological Survey (e.g., Béland Otis
(2017, figure 22.1; 2018, Figure 22.1, both generalized bedrock
geology maps).
Greggs and Gorman (1976) make an interesting observation that may help explain where Alice E. Wilson went wrong. They comment : “A further confusion in determining the age of the Nepean Formation developed as a consequence of the pronounced similarity between the upper March and the Nepean sandstones. This miscorrelation of the March and Nepean led Keith (1949, p. 8) and Kirwan (1963, p. 109) to conclude that the "Nepean (Potsdam)" in the areas immediately to the east of the Frontenac Axis was of Beekmantown age (Lower Ordovician). This age determination was based on the discovery by Keith (1949) of several species of Lower Ordovician gastropods in outcrops mapped as Potsdam by Baker (1922) and Wright (1923), and later by Wilson (1938, 1946) as Nepean. The outcrop yielding the Ordovician gastropods was actually upper March. The very great lithological similarity of the Nepean and upper March sandstones makes the error of age determination understandable.” Baker and Wright were always going to map the transition beds as Potsdam. Alice E. Wilson misidentifying beds as Nepean rather than her March, would have affected her analysis.
The best description of the naming controversy can be found in Bernstein (1992) and Salad Hersi et al. (2002, 2003). Bernstein (1992, page 2683) comments “Contrary to established procedure (see Schenck and Miiller 194I), [Alice E. ]Wilson, like many of her contemporaries, regarded formations as time-restricted units. Thus, despite considering the Nepean and March correlatives of the Potsdam and Theresa in Quebec and New York State, she retained the terms Nepean and March because the Potsdam and Theresa formations were regarded as Cambrian in age at their type localities.” Bernstein (1992) rejected March and suggested that Theresa be used in Ontario and Quebec. There seems to be general agreement that Alice E. Wilson applied the wrong criteria to name the Nepean and March Formations. For example, Professor George Dix (2021, personal communication) has commented “Even in the 1930/40s when Wilson recognized that the “Nepean” and “March” strata were younger, the international stratigraphic code did not allow for age as a reason for establishing new formation names.” Another criticism of Wilson would be that from Logan to Ells to Raymond the field officers of the Geological Survey of Canada viewed the Potsdam sandstone in Ontario and Quebec as an extension of the Potsdam sandstone in Upper New York State, and viewed the overlying beds as correlating with the overlying beds in New York State, and all of Logan, Ells and Raymond had looked at the rocks in Ontario, Quebec and New York State.
Since Bernstein (1992) the trend in Ontario has been to replace March with Theresa, as the same formation is believed to be present in New York, Ontario and Quebec, and the name Theresa was in use first. Before COVID struck Catherine Béland Otis (2017, 2018, 2019) of the Ontario Geological Survey was mapping the Paleozoic geology of eastern Ontario. In each of her reports she has provided a figure with the 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. I expect that she will recommend replacing March with Theresa, as Professor Dix at Carleton University, Professor Arnott at the University of Ottawa, and their students, use Theresa in their publications. In addition Béland Otis (2017) commented that “recent academic studies suggest that the geological history of the Ottawa Embayment is closely related to that of adjacent jurisdictions, such as Quebec and northern New York....; therefore, any revision of the stratigraphic nomenclature for eastern Ontario should take these similarities into account (per Articles 7c and 7e of NACSN (2005)).”
In the past twenty years most of the articles on the March/Theresa deal with whether the March/Theresa conformably or unconformably overlies the Potsdam Group (for the recent participants to the debate see the papers mentioned in the References and Suggested Reading to my June 1, 2021 blog posting) and where to place the boundary. Salad Hersi et al. (2002, page 422) set out the background for the debate: “Wilson (1937) hypothesized that the Cambrian–Ordovician Nepean Formation in the Ottawa region possibly contains an eroded interval at the Cambro–Ordovician boundary. In a later and widely acknowledged publication, Wilson (1946) documented the Nepean–March contact as transitional, and like Cushing (1908), placed it at the base of the first dolomitic or calcareous bed.” The opposing views of the participants to the debate cannot easily be summarized or reconciled. Lowe et al. (2019) take the position that “In the southeastern Ottawa graben, the change from clastic (Keeseville) to carbonate-clastic strata (Theresa) is conformable and gradational, whereas in the west it is sharp and conformable, but locally unconformable in areas on the hanging-wall blocks of regional normal faults (e.g., the Gloucester and Ste. Justine faults) throughout the northern Ottawa graben”. Professor Dix, Professor Salad Hersi and Ed Landing are not in agreement with that sentence, with their papers supporting a disconformable Potsdam–Theresa contact at Ottawa and a regional post-Potsdam erosional surface (see Dix et al., 2004; Salad Hersi et al. 2002 a, 2002 b; Landing, 2007; Landing et al., 2019). Béland Otis (2018, page 22-6) commented that “In the Ottawa area, the lower contact of the Beekmantown Group with the underlying Potsdam Group seems conformable and gradational. As observed in both cores, the lower contact of the March (Theresa) Formation with the Nepean (Keeseville) Formation is interbedded over a few metres. Exact definition of this contact is therefore somewhat arbitrary,...”.
Williams (1991), among others, has noted that “Quartz sandstones of the March Formation are lithologically similar to those of the underlying Nepean Formation. ... Dolostones of the March Formation are lithologically similar to those of the overlying Oxford Formation.” As a consequence, mapping the location of the upper and lower boundaries is often not free from doubt. In my June 4th blog posting I mention the outcrop at Phillipsville, Ontario. Some have mapped it as Nepean; others, as March/Theresa. Two publications provide measured sections, with the first placing the whole of the section in the Theresa, while the second reports 3.55 meters of March Formation at the top, underlain by 3.1 meters of Nepean Formation. A paper by Bond and Greggs (1976) in which they discuss and attempt to redefine the March - Oxford boundary exemplifies the problem in differentiating between the March and Oxford formations. Bond and Greggs (1976) provide a measured section for an outcrop 1.6 km east of Port Elmsley, Lanark County, Ontario. They show 0.8 m of Oxford Formation underlain by 0.8 m of March Formation. Williams and Wolf (1984a) mapped the outcrop as March formation.
Williams (1991, pages 48 - 57) has the best summary of the rocks that make up the March formation, and provides a number of measured sections throughout Eastern Ontario where the March is present. Professor Dix (2020) of Carleton University has prepared a short YouTube video on a Theresa Formation outcrop in the Ottawa area. I suspect that Selleck’s (1984) paper is the best for the stratigraphy and sedimentology of the Theresa Formation, but it was published in Northeastern Geology, is not readily available, and I have not been able to obtain a copy. Bjerstedt and Erickson (1989), Erickson (1993), and Erickson and Bjerstedt (1993) have reported on Trace fossils and bioturbation in the Theresa Formation. Wilson (1956, Plate 1, No. 2, 3) contains photographs of two gastropods found in the March Formation.
Husinec and Donaldson (2014) and Selleck (1978, 1983) provide field trip guides with stops at Theresa formation outcrops in New York State.
For those in the Ottawa area Quentin Gall (2010) collated a field trip guide with a stop at the outcrop behind the Walmart in Kanata. The rocks directly behind Walmart are the underlying Nepean Formation sandstones while the rocks on the other side of Kanata Avenue are March/Theresa formation dolomitic carbonate beds as well as quartz-rich sandstone beds.
In Lanark County good outcrops of March/Theresa rock can be found south of Mississippi Lake along Drummond Concession 7, along Highway 15 just north of Smiths Falls, along highway 7 north of Perth, and along county road 43 east of Perth heading towards Port Elmsley and on to Smiths Falls.
Husinec and Donaldson (2014) comment that “The maximum estimated thickness of the Theresa Formation in northwest New York varies from 28 m (Selleck, 1984) to 43 m (Cushing, 1916).” Williams (1991, page 55) mentions that “The thickness of the March Formation [in Ontario] shows a general southeastward increase, ranging from 6.6 metres in the Carleton Place map area (31F/1) to 63.7 metres in the Alexandria map area (31G/7). ... Reduced thicknesses occur in the southern part of the Ottawa-St. Lawrence Lowland in the vicinity of prominent Precambrian topographic highs.”
Selleck (1978) provided a three part division of the Theresa, which Selleck (1983) concisely describes as “Theresa Formation consists of three informal subdivisions: lower Theresa thin-bedded calcareous siltstones of intrashelf lagoon origin; middle Theresa interbedded bioturbated dolomitic sandstones and cross-laminated quartz sandstones deposited in a shallow subtidal to low tidal flat environment; and upper Theresa sandy dolostones, dolomitic sandstones and calcareous siltstones of high tidal flat origin.” Bjerstedt and Erickson (1989) provide a composite section for the Theresa (as it is not exposed in its entirety), dividing it into three parts: a lower section consists of “gray, medium- to thick-bedded, calcareous, fine-grained sandstone” ... the lower 10 m of [which] is extremely bioturbated, and individual sedimentation units can be seen in centimeter(s)-thick, scour-based, horizontally laminated sandstones with burrowed tops”; the middle section “consists of gray, thick-bedded to massive, poorly sorted, calcareous to dolomitic, medium- to coarse-grained sandstone”; the upper section consists of “white, meter-thick, thin- to medium-bedded, fine- to medium-grained, siliceous to calcareous, planar and herringbone cross-bedded sandstone.” They interpreted the lithographic change to have “resulted from migration of low intertidal sand flats across a shallow inner shelf.” Béland Otis (2017, 2018, 2019) shows a three part division of the Theresa but appears to be mapping the March/Theresa as one unit and has not defined her parts A, B, C.
Salad Hersi and Dix (2004) divided the Theresa formation of Ontario and Quebec into three depositional units (A, B and C) which they believe “record a vertical peritidal-subtidal-peritidal depositional cycle. Unit A contains clastic-dominated sand shoal/flat facies and also is well represented in SW Quebec, beyond the eastern limits of the [Ottawa] embayment. Unit B contains predominantly normal to marginal marine subtidal bioclastic dolostones that are restricted to the eastern and central parts of the [Ottawa] embayment, as well as farther to the east in SW Quebec. Unit C contains marginal marine clastic and carbonate facies. The clastic content of Unit C decreases eastward (basinward) and intertidal to subtidal sandy to pure carbonates become predominant in the region south of Montreal.”
Greggs and Bond (1971) provide two reference sections for the March Formation at Brockville (which is not in March Township), which they divided into two parts: [A] a lowermost 90 ft (27.5 m) section of blue-gray sandstone rich in conodonts, with beds having gradational tops and bottoms, in which individual burrows are evident , apparently deposited in a shallow, offshore marine environment such as a tidal or sub-tidal flat; and [B] an upper part, the dominant lithology of which is a white or buff-colored, medium-grained, fairly massive sandstone, with bioturbation not as severe in these beds as it is in the lower sandstones.
Bond and Greggs (1973) describe six reference sections for the March Formation near Brockville, Ontario (as the March is not exposed in its entirety) in order to make a complete section. They report that “Two dominant lithologies characterize the formation: a lower succession of highly bioturbated, blue-gray dolomitic quartz arenites, and an upper unit of pale yellow-gray to yellow-brown, calcareous and siliceous, quartz arenites. ...Deposition of the upper, yellow-gray sandstones of the March Formation appears to have occurred in a shallower marine environment than the lower blue-gray sandstones.”
Béland Otis (2017) in her mapping of the Ottawa area reported that the March Formation “is composed of interbedded quartz arenite, dolomitic and calcareous arenite to quartz wacke and sandy dolomudstone to dolograinstone. The quartz beds are quite similar to that of the underlying Nepean Formation (Keeseville Formation). The other lithofacies tend to be thin to medium bedded and grey to brown, with some greenish weathering associated with glauconite. Calcite-filled vugs and gastropods were observed.”
In my June 4th blog posting I mentioned that in 1979 John Cass had authored a Master’s thesis entitled ‘Paleoenvironmental interpretation of the Beekmantown Group within the Ottawa Basin’. Cass rejected Wilson’s renaming the Theresa formation as the March formation. He had a unique view of what we now call the Theresa , breaking it down into the Theresa and Buck Bridge Formation, with the Buck Bridge formation consisting of a lower Heuvelton member and an upper March member. While this is a unique interpretation for Canada, he was following Chapman’s (1915, p. 289) breakdown of transition beds in Upper New York into the Theresa, Heuevelton and Bucks Bridge. He provides a few measured sections, including one at Phillipsville, Ontario.
Giles (1976), in an unpublished doctoral thesis on the Beekmantown Group within the Ottawa Basin, also rejected Wilson's name March Formation. His proposed Beekmantown Group includes four formations: Prescott, Crystal Rock, Oxford Mills, and Laggan. He suggested that his Lower Prescott could be correlated with the Theresa formation of Quebec, and his Crystal Rock, Oxford Mills, and Laggan with the Beuharnois formation in Quebec. While no one has followed Giles’ nomenclature he did make incisive comments on where to place the boundary between the Potsdam and the Theresa. At page 249 of his thesis he designates the Iroquois quarry as his principal reference section for his Prescott formation and Crystal Rock formation, and provides a measured section. The quarry is at Iroquois, along the St. Lawrence, two thirds of the way between Brockville and Morrisburg.
Christopher Brett
Ottawa
Addendum (September 29, 2021): Catherine Béland Otis of the Ontario Geological Survey was kind enough to send me two of Selleck’s papers from Northeastern Geology:
Selleck, Bruce W. , 1984.
Stratigraphy and sedimentology of the Theresa Formation (Cambrian-Ordovician) in northwestern New York State. Northeastern Geology, 6: 118 - 129
Selleck, Bruce W., 1987
Origin of Voids in Peritidal Facies of the Theresa Formation and Ogdensburg Dolostone (Lower Ordovician), New York and Ontario. Northeastern Geology, Vol. 9, No. 2, pp. 76-88
Selleck’s (1984) paper is worth reading. One point he makes is that “In those areas [in New York State] where the Theresa Formation overlaps Proterozoic quartzite ridges, boulder and cobble conglomerates are common within the lower and middle portions of the formation.” Further, a location in New York which he believes to be Theresa conglomerate has been mapped by others as Potsdam conglomerate.
Selleck (1987) believes that the calcite filled voids in the Theresa originated as anhydrite nodules and anhydrite clasts where dissolution of the evaporite mineral generated the voids, later partially to completely filled with crystalline calcite ( and minor quartz, dolomite, Pyrite, sphalerite and fluorite) . This ties in with the rounded, nodular pseudomorphs of evaporite minerals in the coastal sabkha facies of the underlying Nepean Formation .
I have also added the references to Johnston (1909, 1911), Willis (1912), Parks (1922), Phillpotts (1928) and Salad Hersi and Dix (2004).
References and Suggested Reading
Ami, H. M., 1905.
Preliminary lists of fossil organic remains from the Potsdam, Beekmantown (Calciferous), Chazy, Black River, Trenton, Utica, and Pleistocene formations comprised within the Perth Sheet (No. 119) in eastern Ontario. Geological Survey of Canada, Annual Report, New Series, Vol. 14, Part J, pp. 80 - 89
Béland Otis, Catherine, 2017
Paleozoic Mapping of Eastern Ontario, Ontario Geological Survey, Summary of Field Work and Other Activities, 2017, Open File Report 6333
http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/ofr6333//ofr6333.pdf
Béland Otis, Catherine, 2018
Paleozoic Geology of Eastern Ontario: Ottawa Area. Paleozoic Geology and Energy Studies Project SO-18-006 , pages 22-1 to 22-10, Ontario Geological Survey Summary of Field Work and Other Activities, 2018, OFR 6350
Béland Otis, Catherine, 2019
Paleozoic Geology of Eastern Ontario: Arnprior–Quyon Area, pages 20-1 to 20-10, Project SO-19-005, Ontario Geological Survey Summary of Field Work and Other Activities, 2019, OFR 6360
Bernstein, Lawrence, 1992
A revised lithostratigraphy of the Lower-Middle Ordovician Beekmantown Group, St.
Lawrence Lowlands, Quebec and Ontario. Can. J. Earth Sci. 29, 2677-2694
https://cdnsciencepub.com/doi/pdf/10.1139/e92-212
Bjerstedt, T. W. and J. M. Erickson. 1989.
Trace fossils and
bioturbation in peritidal facies of the Potsdam-Theresa Formations
(Cambrian-Ordovician), Northwest Adirondacks. Palaios, 4:203–224.
Bond, I.J., and Greggs, R.G. 1973.
Revision of the March Formation (Tremadocian) in southeastern Ontario. Canadian Journal of Earth Sciences, 10 : 1140–1155. 10.1139/e73-098
https://cdnsciencepub.com/doi/pdf/10.1139/e73-098
Bond, I.J., and Greggs, R.G. 1976
Revision of the Oxford Formation (Arenig) of southeastern Ontario and northern New York State
Canadian Journal of Earth Sciences 13(1):19-26 DOI:10.1139/e76-002
Brett, Christopher P., 2018a
Alice E. Wilson’s Scientific Papers, Maps, Field Trip Guide and Children’s Book on Geology - Part 1. Blog Posting October 17, 2018
Brett, Christopher P., 2018b
Alice E. Wilson’s Scientific Papers, Maps, Field Trip Guide and Children’s Book on Geology - Part 2. Blog posting October 20, 2018
http://fossilslanark.blogspot.com/2018/10/alice-e-wilsons-scientific-papers-maps_20.html
Byrne, A. W. 1958.
The stratigraphy and palaeontology of the Beeckmantown Group in the St. Lawrence Lowlands,
Quebec. Ph.D. thesis, McGill University, Montreal, Quebec
https://escholarship.mcgill.ca/concern/theses/k3569792v
Cass, John I. , 1979
Paleoenvironmental interpretation of the Beekmantown Group within the Ottawa Basin. Thesis, Master of Science, University of Ottawa. 189 pages plus 90 page Appendix. https://ruor.uottawa.ca/bitstream/10393/8394/1/MK43988.PDF
http://hdl.handle.net/10393/8394
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
Cushing, H. P., 1908
Lower portion of the Paleozoic section in Northwestern New York, Bull. Geol. Soc. Amer., Vol. XIX, 1908, at p. 155- 176 at 159, 160
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Cushing, H. P., H.Le Roy Fairchild, R. Ruedemann, C.H. Smyth, 1910
Geology of the Thousand Islands Region: Alexandria Bay, Cape Vincent, Clayton, Grindstone and Theresa Quadrangles, New York, Museum Bulletin 145, 194 pages
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Dean, Ronald S., 1962
A study of St. Lawrence Lowland Shales. Unpublished Ph.D. thesis, McGill University,
Mont real, Quebec
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Dix, George, 2020
Theresa Formation (Marine Shoreface). A YouTube video [2:56 minutes ; 7 Oct 2020]
https://youtu.be/EJz12HnOEg0
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
Ells, R. W., 1895
The Potsdam and Calciferous formations of Quebec and eastern Ontario: Royal Society of Canada, Proc. Trans., 12, IV, 21-30, 1895.
https://www.biodiversitylibrary.org/item/40846#page/635/mode/1up
Ells, R. W., 1901
Parts of Counties of Renfrew, Lanark, Lennox and Addington, Frontenac and Carleton (Perth Sheet, No. 110, Geological Survey of Canada, Map 789. Scale 4 miles to 1 inch
Ells, R W, 1902
Report on the geology and natural resources of the area included in the map of the City of Ottawa and vicinity . Geological Survey of Canada, Annual Report, part G, separate report 741
Ellls , R W, 1903
Notes on some interesting rock-contacts in the Kingston district, Ontario. Trans. Roy. Soc. Can., 2nd ser., Vol. IX, sec. 4, pp. 97-108, 1903.
https://www.biodiversitylibrary.org/item/41836#page/817/mode/1up
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Report on the geology of a portion of eastern Ontario (to accompany map-sheet no. 119), Geological Survey of Canada, Annual Report vol. 14 no. J
Erickson, J. Mark, 1993
Cambro-Ordovician stratigraphy, sedimentation, and ichnobiology of the St. Lawrence Lowlands; Frontenac Arch to the Champlain Valley of New York. Trip A3(1) New York State Geological Association Field Trip Guidebook, p.68-95
Erickson, J. M. and T. W. Bjerstedt. 1993
Traces Fossils and Stratigraphy in the Potsdam and Theresa Formations of the St. Lawrence Lowland;~New York. Trip A-3(2). New York State Geological Association Field Trip Guidebook, pages 97 - 119.
Gall, Quentin, 2010
Geology of the Ottawa Area. Ottawa-Gatineau Geoheritage Project. Field trip. https://static1.squarespace.com/static/525bf175e4b00f431dc971c0/t/525ca7f6e4b048ac9edb6cb0/1381804022438/Geology+Of+The+Ottawa+Area.pdf
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Stratigraphy, petrology, and diagenesis of Beekmantown carbonate rocks. Ph.D. thesis, University of Western Ontario, London, Ontario
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Physical and Faunal Evolution of North America during Ordovicic, Siluric and Early Devonic Time , Journal of Geology, Vol. 9, pages 209 -252
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Greggs, Robert G. and Ivor J. Bond, 1971
Conodonts from the March and Oxford Formations in the Brockville Area, Ontario. Canadian Journal of Earth Sciences, 8, 1455
Greggs, R.G. and W.A. Gorman, 1976
Geology of the Thousand Islands. Parks Canada
http://www.oliverkilian.com/ecology/thousand-islands/island-insights/geology/rocks.html
“the March Formation is the exact lithological and stratigraphical equivalent to the Theresa.”
Husinec, Antun and J Allan Donaldson, 2014
Lower Paleozoic Sedimentary Succession of the St. Lawrence River Valley, New York and Ontario, in : Geology of the Northwestern Adirondacks and St. Lawrence River Valley (pp.1-28) 86th NEGSA Annual Meeting Field Guidebook, Chapter: A-1. Publisher: New York State Geological Association
Johnston, W. A., 1909
Simcoe Sheet, pages. 97 - 102, in Geological Survey of Canada, Summary Report for the year 1908
Johnston, W. A. , 1911
Simcoe District, Ontario. Pages 188-192 , in Geological Survey of Canada, Summary Report of the Department of Mines, Geological Survey of Canada for the year 1910
Keith, M. L., 1949
Sandstone as a source of silica sands in southeastern Ontario; Ontario Dept. Mines, Vol.55, pt.5, 36p. (published 1949). Accompanied by Map 1946-9, scale l inch to 2 miles
http://www.geologyontario.mndmf.gov.on.ca/mndmfiles/pub/data/imaging/ARV55/ARV55.pdf
Kindle, E. M., 1916
The Ordovician Limestones of the Kingston Area., Appendix 1, pages 37-44 to M.B. Baker’s paper The Geology of Kingston and Vicinity, Twenty-Fifth Annual Report of the Ontario Bureau of Mines, 1916, being Volume 25, Part 3
Landing, Ed, 2007
Ediacaran-Ordovician of East Laurentia- Geologic Setting and Controls on Deposition along the New York Promontory. Pages 5-24 in Ediacaran-Ordovician of East Laurentia - S. W. Ford Memorial Volume. New York State Museum Bulletin 510, 94 pages https://exhibitions.nysm.nysed.gov/publications/bulletin/510-16505.pdf
Landing, E., Salad Hersi, O., Amati, L., Westrop, S.R., Franzi, D.A., 2019
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Paleozoic rifting and reactivation of a passive-margin rift: Insights
from detrital zircon provenance signatures of the Potsdam Group, Ottawa
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On the geology of the Beauharnois region. Geological Survey of Canada, Report of Progress
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Early Paleozoic rifting and reactivation of a passive-margin rift: Insights from detrital zircon provenance signatures of the Potsdam Group, Ottawa graben: Geological Society of America Bulletin, v. 130, no. 7/8, p. 1377–1396, https:// doi .org /10.1130 /B31749 .1 .
Lowe, D.G., Arnott, R.W.C., Chiarenzelli, J.R., and Rainbird, R.H., 2019,
Early Paleozoic rifting and reactivation of a passive-margin rift: Insights from detrital zircon provenance signatures of the Potsdam Group, Ottawa graben: Reply. Geological Society of America Bulletin, March/April 2019, v. 131, no. 3/4, pages 699-703; published online January 25, 2019. https://pubs.geoscienceworld.org/gsa/gsabulletin/article/131/3-4/699/568492/Early-Paleozoic-rifting-and-reactivation-of-a
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Thicknesses of the Ordovician formations in Ontario and Quebec, , in Summary report, 1930, part D; Geological Survey of Canada; Geological Survey of Canada, Summary Report 1930, pt. D, 1931 p. 49-57, https://doi.org/10.4095/102042
Miller, A. H.; C. A. French, and M. E. Wilson, 1929
Geophysical Survey of the Hull-Gloucester and Hazeldean Faults. Part IV in Geological Survey of Canada, Memoir 165, Studies of Geophysical Methods, 1928 and 1929
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REPORT on the Building and Ornamental Stones of Canada, Volume 1 [Ontario], Canada, Department of Mines, Mines Branch, 376 pages
Parks, William Arthur , 1922
Presidential Address [discussing the history of Stratigraphy and Paleontology in Canada], Proceedings and Transactions of the Royal Society of Canada Series 3, Volume 16, Section IV, pages 1- 46 https://www.biodiversitylibrary.org/item/41928#page/778/mode/1up
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Natural Gas in the St. Lawrence Valley, Quebec; Que. Bur. Mines, Ann. Rept. 1930, Pt.D, pp. 3-98, 1931.
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Correlation of the Ordovician in Canada. Master of Science Thesis, University of Alberta. https://archive.org/details/correlationoford00phil
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Ordovician of the Ottawa Valley. Geological Survey , Canada , summary Report 1911, pp 351-356 https://doi.org/10.4095/292550
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Ordovician of Montreal and Ottawa. 12th International Geological Congress, Montreal, Que., Guidebook 3, pp. 137-160. https://archive.org/details/guidebooksofexcu06inte_0
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L'Ordovicien a Montreal et a Ottawa. 12th International Geological Congress, Montreal, Que., Guidebook 3, pp. 147-174.
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Subsurface stratigraphy of upper Cambrian rocks in Southwestern Ontario. Canada Geological Survey, Paper 58-12, 34 pages https://doi.org/10.4095/101213 [Sandford and Quillion (1959) applied the term Theresa Formation for subsurface stratigraphy in Southwestern Ontario, overlying the Potsdam, and as an equivalent to the Theresa in New York State.]
Salad Hersi, Osman and George R. Dix, 2004
Shelf –Wide tectonic And Eustatic Control on Sedimentation of Mixed Carbonate-Clastic Sequence:Early Ordovician Theresa Formation of Eastern Ontario, Canada.
Canadian Society of Petroleum Geologists Convention At Calgary, Alberta.
Abstract at: https://geoconvention.com/wp-content/uploads/abstracts/2004/052S0128.pdf
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Stratigraphy of the Upper Cambrian Strites Pond Formation, Philipsburg Group, southern Quebec, and its implications for the Cambrian platform in eastern Canada. Bulletin of Canadian Petroleum Geology, 50 : 542–565.
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Reappraisal of the Beekmantown Group sedimentology and stratigraphy, Montréal area,
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Lower–Middle Ordovician Laurentian passive margin of eastern Canada. Can. J. Earth Sci. 40: 149–176
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Lower Ordovician Stratigraphy and sedimentology, southwestern St. Lawrence Lowlands. New York State Geological Association, 55th Annual Meeting Fieldtrip Guidebook,
Potsdam, N.Y., pp. 9.1 -9.9. Also available as a Google Earth Field Trip at NYSGA1983M.kml from http://ottohmuller.com/nysga2ge/FrontPage.html
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Stratigraphy and sedimentology of the Theresa Formation (Cambrian-Ordovician) in northwestern New York State. Northeastern Geology, 6: 118 - 129
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Origin of Voids in Peritidal Facies of the Theresa Formation and Ogdensburg Dolostone (Lower Ordovician), New York and Ontario. Northeastern Geology, Vol. 9, No. 2, pp. 76-88
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Lexicon of Paleozoic names in southwestern Ontario, University of Toronto Press, 121 pages
Theresa Formation: Upper Cambrian, at page 110
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The Palaeozoic Rocks of the Thurso Area. Unpublished report of the Geological Survey of Canada
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Wilson, Alice E. 1937a
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Erosional Intervals Indicated by Contacts in the Vicinity of Ottawa, Ontario. Transactions, Royal Society of Canada, Section IV, pages 45 -60
Wilson, Alice E., 1938a:
Ottawa Sheet, (East Half) , Carleton and Hull Counties, Ontario and Quebec, Geological Survey of Canada, Map 413A, Scale 1 inch to 1 mile, Geology by A. E. Wilson, 1935
https://doi.org/10.4095/107511 Nepean, March , Oxford
Wilson, Alice E., 1938b
Ottawa Sheet, (West Half) , Carleton and Hull Counties, Ontario and Quebec, Geological Survey of Canada, Map 414A, Scale 1 inch to 1 mile, Geology by A. E. Wilson, 1935
https://doi.org/10.4095/107545 Nepean, March , Oxford
Wilson, Alice E., 1940a
Casselman, Russell, Dundas, Stormont, Prescott, Carleton, and Papineau Counties, Ontario and Québec; Geological Survey of Canada, "A" Series Map 587A, 1940, miles, Geology by A. E. Wilson, 1935, 1936, and 1937 https://doi.org/10.4095/107369 Nepean, March , Oxford
Wilson, Alice E., 1940b
Nepean, Carleton, Lanark, Grenville, Dundas, Gatineau and Papineau Counties, Ontario and Québec; Geological Survey of Canada, "A" Series Map 588A, 1940, 1 sheet, 1 inch to 2 miles. Geology by A. E. Wilson, 1935, 1936, and 1937, https://doi.org/10.4095/107428
Nepean, March , Oxford
Wilson, Alice E., 1941a
Valleyfield, Québec and Ontario; Geological Survey of Canada, "A" Series Map 660A, 1941, Geology by A. E. Wilson, 1938 and 1939 https://doi.org/10.4095/107850
Nepean, March [Beauharnois] , Oxford
Wilson, Alice E., 1941b
L'Orignal, Ontario and Québec; Geological Survey of Canada, "A" Series Map 662A, 1 sheet, 1 inch to 2 miles, Geology by A. E. Wilson, 1937 and 1938 https://doi.org/10.4095/107972 Nepean, March [Beauharnois] , Oxford
Wilson, A. E., 1941c
Maxville, Ontario and Québec; Geological Survey of Canada, "A" Series Map 661A, 1941, 1 sheet, 1 inch to 2 miles, Geology by A. E. Wilson, 1929 and 1937 https://doi.org/10.4095/107973 Nepean, March [Beauharnois] , Oxford
Wilson, A. E., 1942
Prescott, Ontario; Geological Survey of Canada, "A" Series Map 710A, 1942, 1 sheet, Geology by A.E. Wilson 1939, 1940 https://doi.org/10.4095/107616 Nepean, March , Oxford
Wilson, A. E., 1946a
Ottawa-Cornwall , Ontario and Quebec, Geological Survey of Canada, "A" Series Map 852A, Scale 1 inch to 4 Miles, Geology by A. E. Wilson, 1929 and 1935 to 1940
https://doi.org/10.4095/107544 Nepean, March , Oxford
Wilson, Alice E. 1946b
Geology of the Ottawa - St. Lawrence Lowland, Ontario and Quebec. Geological Survey of
Canada, Memoir 241. 65 pages
Wilson, Alice E., 1954:
Ottawa, Carleton, Gatineau, and Papineau Counties, Ontario and Québec; Geological Survey of Canada, "A" Series Map 1038A, 1954, 1 sheet, https://doi.org/10.4095/107547
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
https://www.biodiversitylibrary.org/item/90128#page/9/mode/1up
Wilson, Morley E., 1931a
Geology of Ottawa district, pages 192-196, chapter 2 in Geophysical Survey of the Hull-Gloucester and Hazeldean Faults. By A. H. Miller, C. A. French, and M. E. Wilson; in Geological Survey of Canada Memoir 165, Studies of Geophysical Methods, 1928 and 1929
Eve, A S; Gilchrist, L; Keys, D A; Mawdsley, J B; Swartz, J H; 227 pages
Wilson, Morley E., 1931b
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
Wilson, Morley E., 1931c
Ripple Marks in the Lower Palaeozoic of the Ottawa Valley, Canadian Mining Journal, Volume 52, 347-348
Wilson, Morley E. and Dugas, Jean, 1961,
Map 1089A, Geology, Perth, Lanark and Leeds Counties, Ontario, Geological Survey of Canada; Geology by Morley E. Wilson, 1930 and Jean Dugas, 1949; Descriptive notes by Jean Dugas.
https://doi.org/10.4095/107951
Wright, J. F., 1923
Brockville-mallorytown map area, Ontario. Geological Survey of Canada, Memoir 134, 1923, 63 pages ), https://doi.org/10.4095/100859
Wolf, Rainer R and Robert W. Dalrymple, 1985
Sedimentology of the Cambro-Ordovician Sandstones of Eastern Ontario. Geoscience Research Grant Program Summary of Research 1984-1985. Ontario Geological Survey Miscellaneous Paper 127, pages 112-118.
Wykes, Eric Robinson, 1931
The petrology of some crystalline rocks of the Perth sheet, McGill University, Master of Science Thesis, 52 pages, including maps.
https://escholarship.mcgill.ca/concern/theses/n870zt47m
Wynne-Edwards, H. R., 1967
Westport map Area, Ontario, With Special Emphasis On the Precambrian Rocks, Geological Survey of Canada, Memoir 346, 142 pages
http://geoscan.nrcan.gc.ca/starweb/geoscan/servlet.starweb?path=geoscan/fulle.web&search1=R=100533 )
