Middle Academic Period


Photograph by: Carlton E. Brett, View from "The Narrows" downstream toward the powerhouse.


Middle Academic Period (1900's to 1960's)

At the close of the 19th century a revolution took place in geological studies. Basic geological tools of observation had been developed and large numbers of fossil taxa had been indentified and described. It was now obvious that there was a need to address fundamental questions concerning processes of origin and modification of rock bodies. This did not happen. The “Middle Academic Period”, instead, represented a transition period in which increased specialization and more intense detailed studies replaced the broader studies of earlier workers. However, the foundation was laid for a Federal Geological Survey.

In the first half of the 20th century the nation was involved in two World Wars, several major military expeditions, and the largest monetary depression in U.S. history. Activities in geological studies were steady and made progress, but often were dominated by the search for much needed natural resources. Thus it is not surprising that broad studies were not included in state or federal financial plans.

The following discussion presents an outline of important individuals who made significant contributions to the development of the geology of Trenton Falls.

John M. Clarke, William J. Miller, Percy E. Raymond, Rudolf Ruedemann, George Marshall Kay, Donald W. Fisher

(click on the geologist's name above for more information about them and their contribution to the study of Trenton Falls.)



John Mason Clarke, born in Canandaigua, New York, grew up the neighborhood of some of the most spectacular Devonian outcrop exposures in the Finger Lakes region. His interests early on led him to pursue degrees in geology, and he received a B.S. from Amherst College in 1877. He never completed his Ph.D. work at the University of Göttingen in Germany, but returned to the United States and was hired as professor of geology and mineralogy at Smith College. After four years of teaching at Smith, Clarke returned to Amherst in 1884, where he taught for an additional two years. His teaching responsibilities included basic geology and mineralogy, but Clarke was eager to expand his knowledge of paleontology and to return to studies of the Devonian. In 1886 he became Assistant Paleontologist of the state of New York and began working in earnest on paleontologic endeavors. After James Hall's death in 1898, J.M. Clarke became his successor as State Paleontologist, and six years later, in 1904, he also became State Geologist. (Fisher, 1978)

As State Paleontologist and State Geologist, Clarke was known for his "firm and persuasive manner [that] was tempered by politeness, quietness, and compromise" (Fisher, 1978; p. 14). This was in stark contrast to Hall's often tyrannical behavior. Clarke's contribution to New York State geology is known for his pioneering efforts toward the support of both state and university-sponsored research. He supported the USGS's topographic mapping programs, and through his sponsorship, the state's mapping program for both bedrock distribution and surficial deposits was intensified, with complete coverage of the state by the end of his tenure.

Clarke was not directly involved in Trenton Falls research, but his sponsorship of university research programs, including those of Professors: W. J. Miller of Hamilton College, Amadeus W. Grabau of Columbia University, Henry Platt Cushing of Western Reserve University, Herman Leroy Fairchild of the University of Rochester, James H. Stoller of Union College and Percy E. Raymond of Cornell University, Yale University and Harvard University, contributed greatly to our current understanding of the geology of New York State. Of the geologists listed above, W.J. Miller's program of mapping the Adirondacks and its lowland areas included the responsibility for mapping the Trenton Falls region.

In addition to his support of state sponsored research programs, Clarke took his service to the people of the state a step further. Just after he became director, Clarke, having recognized the need for the preservation of unique scientifically important localities, was able to secure the donation of several sites to the New York State Museum . These sites were established as "scientific reservations" and Clarke "promoted their use as outdoor exhibits (and as advertising for the museum outside of Albany) and in research" (Landing, 2004). Unfortunately, Trenton Falls, although it was a good candidate for the "scientific reservations" program, had already been purchased by the Utica Electric Light and Power Company for the purpose of erecting a power plant to service Utica with electricity.

From 1894 onwards, in addition to his work in the New York State Museum, J.M. Clarke was a professor at Rensselaer Polytechnic Institute, the first president of the Paleontological Society, president of the Geological Society of America, member of the National Academy of Science, an honorary member of the American Academy of Arts and Sciences, a contributor to the American Philosophical Society, and to the Geological Society of London. Clarke was awarded the National Academy of Science's Mary Clark Thompson Medal in 1925. Were it not for his leadership and vision, the geology and paleontology of New York State would not be so well known or admired.>>Back to Top


John Mason Clarke

Image from Fisher, 1978







John Mason Clarke

Image from:





William John Miller was born in Red Bluff, California , where his interests were honed as an amateur natural historian at a young age. "Though college was a remote possibility for him, he determined that he would study some phase of natural history, but was drawn to geology by the variety of volcanic phenomena of Lassen Park [in the foothills of Mount Lassen]" (Webb et al., 1967). He was able to start his schooling at the College of the Pacific at San Jose (now University of the Pacific, Stockton) where he majored in chemistry and geology. Because of his exceptional success as a student, Miller was hired to teach chemistry at his alma mater. During the summers between 1900 and 1903, (while teaching at San Jose) he worked as a field mapping assistant in the Santa Cruz Mountains for the United States Geological Survey. He soon produced his first map of a portion of the Santa Cruz Mountains . His success as a field mapper and instructor earned Miller admission to graduate school at the Johns Hopkins University where he quickly proved himself. He was awarded his Ph.D. in geology in 1905. (Webb et al., 1967)

Having moved to the eastern United States, Miller soon became interested in the geology of the Adirondack mountains and lowlands. When he accepted the professorship of geology at Hamilton College in Clinton, New York in 1905, he proved his ability as a fine geologist. He served as professor at Hamilton College until 1914, but his studies of the Adirondacks continued until 1924. Miller pioneered mapping of the Adirondack crystalline massif, a very complex Precambrian terrain, as well as the onlapping successions of lower Paleozoic strata. In the course of his studies, he prepared several bulletins for the New York State Museum comprising 10 fifteen-minute quadrangles which included geologic maps with text. Miller's research on the Remsen Quadrangle stands out as the first document to include a regional map showing the context of Trenton Falls .

Miller's strength was not invertebrate paleontology, but he was a good stratigrapher and an even better structural geologist. During the course of his mapping projects, Miller rediscovered Vanuxem's (1842) "highly folded and broken limestone strata", and published several discussions on the nature of these structures from Trenton Falls . Previously, both Lardner Vanuxem and Theodore White had described the presence of these contorted intervals and had tried to document the formational histories of such features. Miller states: "within the folded zones the layers are, in rare instances, scarcely disturbed; sometimes they are only gently folded; most commonly they are highly twisted or contorted; while occasionally some of the layeres are broken and pushed or faulted over others" (Miller, 1908; p. 429).

After taking detailed strike and dip measurements, Miller observed that the strike measurements ranged between N 50°-65° E, and were roughly parallel to normal faults in the region. Miller further commented that despite the size of the area studied, these "highly folded layers occur only in a very local district.... and are visible only in the Trenton Falls gorge and in the bed of [nearby] Cincinnati Creek..." (Miller, 1908; p. 430). The arrangement of these disturbed strata, and their proximity to local faults was peculiar to Miller, and he questioned their formational history. White (1896) considered these structures to be representative of overburden pressures, or otherwise formed due to differential compaction. In Miller's view (1908, 1915), the preservation of these structures precludes the previous hypothesis from being plausible. Instead, Miller believed that the structures were formed by lateral compression, the same forces responsible for the faults in the region.




William John "W.J." Miller

Image from Fisher, 1978







Miller's own hypothesis was tested in a report published in 1913 by F. F. Hahn, and also in the first textbook dedicated to the principles of stratigraphy by Amadeus W. Grabau (1913). Hahn's explanation for such contorted strata, based on studies of subaqueous environs of Lake Zurich, was that they were produced by submarine slumping and gliding of semi-firm muds on the seafloor during deposition. Miller, in his 1915 paper, rebutted the hypotheses presented by Hahn and Grabau, but some of the points he used to illustrate his "tectonic hypothesis" are parsimonious with both ideas. Unfortunately, the debate surrounding intraformational deformed structures was never settled and remains a point of contention today (see Seilacher, 1969; Ettensohn et al. 2002; McLaughlin 2002; McLaughlin and Brett, 2004). Regardless of the debate, Miller's studies and ideas helped shed more light on the occurrence of such structures, and further added to the geologic interest of Trenton Falls.

Professor Miller's contributions went beyond the basic understanding of the geology of New York, for he also became well known as a lecturer and teacher of geological principles. He was a gifted and eloquent speaker and also prepared a long series of successful textbooks. William J. Miller's legacy in teaching undoubtedly influenced hundreds of modern geologists. His published texts included: Introduction to Historical Geology (in six editions, between 1916 and 1952), Geological History of New York State (1914 and 1924 editions), The Adirondack Mountains (1917), Geological History of the Connecticut Valley of Massachusetts (1921) and California Through the Ages (1957).

Although Miller left Hamilton College to teach at Smith College in 1914, and then at the University of California in 1924, his extensive research in the Adirondack Mountains of New York State was his most significant work. His specialization was on the crystalline igneous and metamorphic rocks, particularly the anorthosites, but his knowledge and keen eye for stratigraphy gave him success in the mapping of Trenton Falls. Throughout Dr. Miller's professional career of nearly fifty years, he published widely for the layman as well as for the scholar.>>Back to Top



"Fig. 2. The upper contorted zone and broken zone as seen along the footpath opposite the crest of High fall at Trenton Falls. Drawn from nature."

modified from: "Notes on the Intraformational Contorted Strata at Trenton Falls."

by: William J. Miller, 1915



"Fig 3. Diagram illustrating Hahn's hypothesis of submarine slumping."

modified from: "Notes on the Intraformational Contorted Strata at Trenton Falls."

by: William J. Miller, 1915





P.E. Raymond was born in New England and attended schools in Connecticut. He began his undergraduate geological and paleontological education at Cornell University under the tutelage of Gilbert Dennison Harris and Dr. Henry F. Cleland. During his time at Cornell, the Cornell Summer School of Field Geology was headquartered at Trenton Falls (1900). As an extraordinary participant, Percy Raymond published, in 1903, an extensive review of the stratigraphy and fossils from the gorge.

In this paper, entitled "The Faunas of the Trenton at the Type Section and at Newport , New York", Raymond recognized the recent work by White (1896) and indicated that in total for the Trenton , there were 20 faunal zones, with 11 of them represented by more than one species. Raymond only considered one of White's faunal zones to be "sufficiently characterized", and in his manuscript, he established 16 distinctive faunal zones. In summary, he states that “though most of the common species range through the whole mass, as White [1896] has remarked, yet there is such a variation in the relative abundance of these species in the various zones as to make up faunules which can easily be recognized" (Raymond, 1903; p.18). He further establishes two important observations for later paleoecologic studies: 1) "two species, Platystrophia lynx and Rafinesquina deltoidea, have limits to the range in which they are common", and 2) "that the upper third of the mass contains the greatest number of individuals, but about the same number of species as the lower part" (Raymond, 1903; p.18). Raymond's observations regarding the nature of species distribution and relative abundance estimates marked a shift in paleontologic methodologies as applied at Trenton Falls. No longer was the focus on characterizing the range of species within a formation to delineate biostratigraphic horizons. Instead, the focus began to swing toward questions regarding the nature of communities, faunal abundance and species diversity, key building concepts for later studies.

Percy Raymond's studies in Ordovician strata at the undergraduate level caught the attention of Charles E. Beecher of Yale University, and after his graduation from Cornell, Raymond went on to Yale for his Ph.D. with Beecher. He had a keen sense for paleontology, and with the unwavering support of his advisors Beecher and Charles Schuchert, he managed to complete an immense dissertation dealing with the stratigraphy and paleontology of the middle Ordovician Chazy Formation in the Lake Champlain region of New York and Vermont . Unfortunately, Charles Beecher died in the same year (1904) that Raymond completed his dissertation. Thus Beecher did not see Raymond's hard work through publication. His Ph.D. studies, however, represent one of the most complete evaluations of these critical middle Ordovician rocks.

After the completion of his degree, Raymond, having picked up Beecher's love of trilobites and early echinoderms among other taxa, went on to an outstanding career as curator, first at the Carnegie Museum, and then at the Museum of Comparative Zoology at Harvard University. During the 41 years he worked at Carnegie and Harvard, Raymond made wide-ranging contributions to the collection, curation and description of fossil specimens. He also made some profound discoveries regarding the paleoecology and evolutionary patterns of many different taxa. He published several more works on the Trenton Group and its faunas, mostly from Trenton Falls equivalents in Ontario and Quebec. His detailed stratigraphic studies enabled him to correlate the Trenton limestone through New York and across the border into Ontario, as well as into the upper Mississippi Valley where he also made significant contributions to the understanding of these widespread deposits.

Upon retiring from Harvard's Museum of Comparative Zoology in 1945, Percy Raymond returned to Yale University at Schuchert's request, to remain there as his assistant. Raymond's research efforts became reinvigorated in his old age, and in collaboration with Earl Douglass (of Carnegie dinosaur fame), he made large collections from the Ordovician Galena Group in Minnesota, the Devonian (Three Forks Shale), the Carboniferous (Lodgepole Limestone), and the Cretaceous (Pierre Shale) in Montana. Raymond collected in Dr. Charles Walcott's quarries at Burgess Pass and made contributions to the study of the Burgess Shale fauna. He also established a collection from the world-famous Mazon Creek lagerstätte.

Although his career eventually took him away from Trenton Falls, the lessons learned there under the guidance of his Cornell University geology professor were lessons that influenced his work in later years. Percy Raymond was a dedicated and influential paleontologist of the early 20th century, making significant contributions to paleontology and to natural history education.>>Back to Top



Percy Edward Raymond

Image from:







"...there is such a variation in the relative abundance of these species in the various zones as to make up faunules which can easily be recognized."

from Raymond, 1903; p. 18


Corynoides calicularis var.americanus






Diplograptus mohawkensis







Climacograptus spiniferus




Rudolf Ruedemann, a German-born geologist, immigrated to the United States in 1892 at the age of 28. Ruedemann had established himself as a metamorphic geologist after completing a Ph.D. thesis on the contact metamorphism of the Reuth batholith in the Fichtelgebirge. Although it is not known what brought him to the United States, he settled in Lowville, New York, about 35 miles northwest of Trenton Falls, and taught in the Lowville High School .

Reudemann later moved to a teaching position in Dolgeville, New York, where he became interested in the local strata. He found the interbedded shales and limestones of the Dolgeville area to be extremely rich in graptolites, and soon established a name for himself through the documentation of their occurrence in the Ordovician of New York and elsewhere. In fact, Dr. Ruedemann became the foremost authority on these fossils and was able to demonstrate their remarkable use as index fossils. Among his 163 scientific articles, Reudemann published widely on graptolites and their biostratigraphic context and paleontologic diversity. The culmination of his life's work on graptolites was published as a very large volume of the Geological Society of America's Memoir entitled Graptolites of North America (1947).

After teaching for several years, Reudemann was hired by the New York State Geological Survey. As a field geologist and mapper, he worked on the geology of several quadrangles, most notably in the lower Mohawk Valley near the Hudson. Having been a student of Johannes Walther, Rudolf was extremely well-versed in theories of stratigraphic succession. He was aware of the context of the Trenton Limestone relative to the mixed limestone shale facies of the Dolgeville and finally of the Utica black shales. Given his advisor's notion that the vertical stacking arrangement of facies in time should be born out in the horizontal dimension as facies that existed adjacent to one another laterally in space, Ruedemann had the perfect opportunity to test the notions of Walther's law using his graptolite zonations.

The relatively shale-poor Trenton Limestone at Trenton Falls has historically yielded few graptolites in comparison with more easterly shale-rich facies of the Dolgeville and Utica. Ruedemann was confounded by this observation and as a result, he spent most of his time and effort in the more eastern portion of New York State in the units overlying the Trenton. He spent a great deal of time working out the relationships of the Utica, Hudson River or Schenectady and the Lorraine Group. In these shale-rich units, graptolites were abundant and relatively transitory, enabling the construction of a fairly well-constrained biostratigraphy.

Not long after establishing himself with the New York State Survey, Ruedemann began to make major contributions toward the understanding of the Taconic Controversy. Although many paleontological questions had been already answered, the mechanism for Hall's eugeosynclinal thickening toward and juxtaposed against the metamorphosed Taconic Mountains was still elusive. Using his background in metamorphic geology, in 1909 Ruedemann made some of the first claims as to the genesis of the Taconics. Ruedemann clearly viewed the eugeosynclinal deposits, from which his beloved graptolites were so numerous, to have been formed in deep basinal settings.

In his observations, this was in stark contrast to the once shallow platform of the pre-to-early Trenton deposits. Moreover, the deep basinal shales of the Utica were succeeded by shallowing upward deposits of flysch and molasse which clearly represented a new source of sediments that originated from an easterly source which was not in place at an earlier time. Ruedemann thought that the superposition of the Taconic Allochthon at the edge of the craton, possibly by overthrusting, would have provided for the subsidence of the eugeosyncline, while continued thrusting would have pushed a portion of these thrusts above sea-level. In this method, a new supply of sediment was produced to fill the subsided eugeosyncline. Ruedemann was ahead of his time with this hypothesis. Given that plate tectonic theories were not even close to being established, Ruedemann's integrated evidence suggested some mechanism was in place to produce the compressive forces needed for overthrusting. (Fisher, 1978).

After the death of John M. Clarke in 1925, Rudolf Ruedemann was hired to replace him as State Paleontologist. During his 12-year tenure as State Paleontologist, despite a major reduction in funding, Rudemann and his limited staff managed to make great strides toward documenting the stratigraphic record of New York State. Ruedemann himself continued to publish prolifically, and made significant contributions to Ordovician stratigraphy, paleontology and the advancement of scientific knowledge, on behalf of the New York State Museum. The end of his term as State Paleontologist was quite turbulent for the museum, as it was again plagued by financial hardships associated with the Great Depression. Just after his retirement in 1937, his assistant Winifred Goldring became State Paleontologist, and her old position as the Assistant State Paleontologist was dropped. (Fisher, 1978).

Rudolf Ruedemann continued to work diligently and productively until his death in 1956. For almost twenty years, he continued his studies on Lower Paleozoic strata and graptolites, publishing in 1947 his 652-page monograph as previously mentioned. During this time, he completed 22 additional publications. Indeed, Ruedemann represented yet another major contributor to the paleontology of New York , as well as to the understanding of Ordovician stratigraphy, and to modern studies of foreland basin dynamics.>>Back to Top


Rudolf Ruedemann

Image from Fisher, 1978

New York State Paleontologist



G. Marshall Kay, or "Mr. Ordovician" as he was internationally known, was born in southwestern Ontario in the village of Paisley. Geographically, Kay was born on the Silurian outcrop belt, but was located only a few miles from the shores of Lake Huron 's Georgian Bay and the Upper Ordovician outcrop belt. As a child growing up in this region, he was most certainly aware of the fossiliferous shales and limestones of the Ordovician, including the Collingwood Shales, which were rich with trilobites such as Pseudogygites latimarginatus. It is not known if his interests in geology were influenced directly by his childhood experiences, but his choice of profession and his passion was the Ordovician. Marshall Kay was particularly renowned for his studies of the Ordovician of New York, Newfoundland, and Nevada, but his studies were global and he published prodigiously on the stratigraphy of the middle and upper Ordovician. In addition to his own studies, Kay as Professor of Geology at Columbia University, was perhaps one of the most influential faculty members of his department. Kay's students worked alongside him on many paleontologic and stratigraphic issues, and have become significant contributors to our knowledge of the Ordovician Period and of Trenton Falls.

Kay used his stratigraphic studies to establish criteria for describing and classifying "geosynclinal" deposits, an idea first conceptualized by James Hall (1859) and developed in detail by James Dwight Dana (1873). According to the original "geosynclinal theory", areas of long-term active subsidence, as evidenced by the "consequent accumulation of sediments" (Dana, 1873; p. 430), were commonly located at cratonic margins. They demonstrated a large degree of variability in both thickness trends and in depositional width. Marshall Kay, in a 1951 Geological Society of America Memoir, reviewed the many "North American Geosynclines," and, using his stratigraphic evidence, distinguished several classes of geosynclines based on their "different tectonic environments." In this paper he states, "the greatest of American geosynclines, occupying belts along the present continental margins and having phases comparable to modern volcanic island arcs.... In the past decade, their nature has been consistently interpreted from data of stratigraphy, volcanology, tectonics, and geophysics, and [were] integrated into a theory of the development of continental margins" (p. v).

Although Kay had been working on this project prior to the advent of plate tectonic theory, he had clearly had begun to relate, especially through his studies of the Ordovician of New York State, concepts in sedimentology and stratigraphy with volcanology to document the empirical evidence for tectonic change. His comparisons with modern island arcs provided for his documentation of distinctive regions within the geosynclinal model. Kay had theorized the evolution of geosynclines based on his extensive stratigraphic studies, and he felt that his ideas could explain the sedimentologic evolution of many of North America 's marginal belts including the Trenton to Taconic.



George Marshall Kay

Image from Fisher, 1978








Kay's empirical observations were held in high regard, but he was plagued with concerns about the mechanism responsible for producing his paired geosynclines (miogeosyncline and eugeosyncline), as the source of subsidence was not well explained, nor was the development of his "tectonic welts." Fortunately, Kay had recognized that whatever the driving mechanism, it was active intermittently in geologic time, as he observed successive stacking of numerous geosynclinal belts on cratonic margins leading to continental margin accretion. After the publication of his 1951 GSA Memoir, much evidence began to be assembled pertaining to Alfred Wegener's (1915) idea of continental drift, and recent geophysical research of deep ocean basins. By the early part of the 1960's, the geological community began to construct the framework of plate tectonic theory, and Kay's research was monumental in helping to document some of the empirical evidence for it. After plate tectonics theory was defined, Kay immediately realized its implications for his geosynclinal model and worked very hard at reinterpreting his ideas in plate tectonic terms up to his death in 1974. (Dutch, 1999).

In addition to his broadly focused studies of geosynclinal theory, Kay's stratigraphic and paleontologic studies form the basis for our current understanding of the Trenton Group and its subjacent and superjacent strata. Marshall Kay's first publications, circa 1929, had described and correlated the Decorah formation of the Upper Mississippi Valley region with the type Black River and Trenton groups of New York; he presented both faunal and lithostratigaphic correlations between the two regions. In these and subsequent papers (1929, 1931, 1937 etc.), Kay elucidated the presence of metabentonites (altered volcanic ash beds) in these carbonate-dominated strata. Thus he began to establish criteria for assigning time-rock terms for use in correlation, rather than using a multiplicity of lithology-specific names to establish correlations.

Perhaps one of the most significant contributions Kay made in this regard, was through the documentation of the Trenton Group both at its type section at Trenton


Falls and to the northwest into Ontario, Canada. In a series of papers published in 1933, 1937, 1943, 1948, 1953, and 1968, Marshall Kay developed the current classification scheme used for documenting the lithologies of rock units, as well as developing the series and stage level classifications used in denoting the time equivalency of the original Trenton rocks. His work built upon earlier studies of White (1896), Prosser and Cummings (1896), and Raymond (1903) to establish both time-rock terms (i.e. Series: Chazyan, Bolarian, Trentonian; Stages: Pittfieldian, Wildernessian, Barneveldian; Substages: Hunterian, Rocklandian, Kirkfieldian, Shermanian, Cobourgian; and even Sub-sub stages: Lowvillian, Chaumontian, Shorehamian and Denmarkian), and rock-terms (i.e., Selby Formation, Napanee Limestone, Kings Falls Limestone, Sugar River Limestone, Denley Limestone with Camp, Glendale, Poland, Russia and Rust Members, and the Steuben Limestone).

Throughout the course of his nearly fifty-year career as professor, educator and geologist, Marshall Kay continued to produce publication after publication on Ordovician stratigraphy of many regions. He actively involved students in his research, and disseminated information in many published books, textbooks and peer-reviewed journals, contributing much to our understanding of the Ordovician. G. Marshall Kay was indeed "Mr. Ordovician.">>Back to Top



Donald W. Fisher completed his Ph.D. dissertation at the University of Rochester, and was hired in 1955 to be State Paleontologist after the retirement of Winifred Goldring. His successful dissertation studies on the "Lower Ordovician Stratigraphy and Paleontology of the Mohawk Valley" had adequately familiarized him with the lower Paleozoic strata of New York. During his tenure, Fisher published many articles and maps on these critical strata, and helped to consolidate the disparate published resources toward the compilation of his many correlation charts (Cambrian, 1962a; Ordovician, 1962b; and Silurian, 1960).

Fisher was partial to more easterly exposures of lower Ordovician strata in the lower Mohawk and Hudson River Valley, but made it one of his priorities to document overlying strata of that region as well. Fisher's research helped to document the more easterly equivalents of the Trenton like the Amsterdam, Larrabee, and Glenns Falls limestones. Moreover, he published a bulletin on the Wells outlier (northern Hamilton County New York; 1957), which contains Trenton as well as subjacent and superjacent strata. The Wells outlier is surrounded by Precambrian Grenville, and located at some distance from the rest of the Ordovician outcrop belt. The nature of these deposits was curious to Fisher, who demonstrated that the Adirondack area had been submerged, at least in part, during the deposition of the Black River and Trenton limestones.

During his work on the Wells outlier, Fisher became aware of complex structural arrangements of strata in the region. Some studies had been reported in both published and unpublished quadrangle reports, and Fisher began to document the complexity of faults and their stratigraphic implications in the Mohawk Valley. In a series of New York State Geological Association Guidebooks (1961, 1965) and New York State Museum Educational Leaflets (1965, no. 18), he helped to document the large number of normal and reverse faults, especially in the eastern Mohawk Valley.

Fisher did no original research on Trenton Falls, but used the stratigraphic synthesis of workers such as Hall, Prosser, Raymond, Ruedemann, and Kay, integrating their findings to complete the correlation chart for the New York Ordovician (Fisher, 1962b). The data were also used to write a New York State Museum Bulletin on the "Correlation of the Hadrynian, Cambrian and Ordovician Rocks in New York State" (Fisher, 1977). In these map and chart series, Fisher helped to integrate the lateral distribution of the Trenton Group and its equivalents into a chronostratigraphic framework. His chart presents a synopsis of biostratigraphic and lithostratigraphic knowledge on these units, in space and time. No other publication on the Ordovician of New York State is as valuable. Although his preliminary map needs to be updated, it still represents a significant contribution to the study of the Ordovician.>>Back to Top





Donald William Fisher

Image from Fisher, 1978

New York State Paleontologist



© 2004 President and Fellows of Harvard College