Thunder Bay Limestone is a geologic formation in Michigan that preserves fossils dating back to the Middle Devonian and is the uppermost formation of the Traverse Group.[1]
Description
Stratigraphy of the Devonian deposits of the northern part of the Lower Peninsula of Michigan
The name for the formation originates from the description of strata near the "south cape of Thunder Bay" by C. C. Douglas in 1841, this area also represents the type locality of the formation. Due to negligence by multiple later workers, the area was later referred to as the Partridge Point Formation by Warthin & Cooper in 1935. It wasn't until 1943 that Warthin & Cooper would rename the formation back to its original name.[2]
The type locality (Locality 30-8-11 SE) is the largest outcrop of the formation, exposing six units that have a total depth of about 4.8 meters. These units are largely made from light-colored limestones though the bottom-most unit has bluish limestone. The most unique unit would be unit 3 which mostly is made up of grey shales that grades into granular limestone at the surface.
The environment that the formation represents is a shallow carbonate platform with large amounts of coral and shelly fauna. Later formations show an increase in depth as water levels raised in the Eastern Interior seaway. Over time, the seaway would develop a stratified water column. Eventually, younger formations, like the Squaw Bay limestone, would show a deep basin environment.[3]
^Gutschick, Raymond C.; Sandberg, Charles A. (1991), "Upper Devonian biostratigraphy of Michigan Basin", Geological Society of America Special Papers, Geological Society of America, pp. 155–180, retrieved 2024-12-15
^Devonian strata of Alpena and Presque Isle Counties, Michigan
^Gutschick, Raymond C.; Sandberg, Charles A. (1991-01-01), Catacosinos, Paul A.; Daniels, Paul A., Jr. (eds.), "Late Devonian history of Michigan Basin", Early Sedimentary Evolution of the Michigan Basin, Geological Society of America, p. 0, doi:10.1130/spe256-p181, ISBN 978-0-8137-2256-6, retrieved 2024-12-15{{citation}}: CS1 maint: multiple names: editors list (link)
^Stumm, Erwin C. (1950). "Corals of the Devonian Traverse Group of Michigan. Part III, Antholites, Pleurodictyum, and Procteria". Contributions from the Museum of Paleontology, University of Michigan. 8 (8).
^ abStumm, Erwin C. (1963). "Corals of the Traverse Group of Michigan Part XI, Tortophyllum, Bethanyphyllum, Aulacophyllum, and Hallia". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN. 18 (8).
^ abcdefghijklmnopqrstuvwxyzaaabacadaeafagahaiajakalStumm, Erwin C. (1951). "Check list of fossil invertebrates described from the middle Devonian Traverse group of Michigan". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY UNIVERSITY OF MICHIGAN. 9 (1).
^Ehlers, GEORGE M.; Stumm, ERWIN C. (1949). "Corals of the Devonian Traverse Group of Michigan. Part II. Cylindrophyllum, Depasophyllum, Disphyllum, Eridophyllum, and Synaptophyllum". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY UNIVERSITY OF MICHIGAN. 8 (3).
^Stumm, Erwin C. (1962). "Corals of the Traverse Group of Michigan Part VII, The Digonophyllidae". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN. 17 (9).
^Stumm, Erwin Charles; Tyler, John H. (1964). "Corals of the Traverse Group of Michigan Part XII, The Small-Celled Species of Favosites and Emmonsia". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN. 19 (3).
^Stumm, Erwin C. (1970). "Corals of the Traverse Group of Michigan Part 13, Hexagonaria". Contributions from the Museum of Paleontology, University of Michigan. 23 (5).
^Stumm, Erwin C. (1962). "Corals of the Traverse Group of Michigan Part VIII, Stereolasma and Heterophrentis". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN. 17 (10).
^Stumm, Erwin C.; Hunt, Allen S. (1958). "Corals of the Devonian Traverse Group of Michigan. Part V. Trachypora". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY UNIVERSITY OF MICHIGAN. 14 (11).
^Pitrat, Charles W.; Keyes, Scott W. (1978). "Spiriferid brachiopods from the Traverse Group of Michigan: Cyrtinacea". Journal of Paleontology. 52 (2).
^Pitrat, Charles W. (1977). "Spiriferid Brachiopods from the Traverse Group of Michigan: Orthospirifer". Journal of Paleontology. 51 (2).
^ abOrr, R. William (1971). "Conodonts from Middle Devonian Strata from the Michigan Basin". Indiana Geological Survey Bulletin. 45.
^Kirk, Edwin (1948). "Two new inadunate crinoid genera from the Middle Devonian [Ont., Iowa, Michigan, New York]". American Journal of Science. 246 (11).
^Kesling, Robert V. (1963). "Occurrence and variations of Botryocrinus thomasi Laudon in the Thunder Bay Limestone of Michigan". Contributions from the Museum of Paleontology, University of Michigan. 18 (15).
^ abKesling, Robert Vernon (1964). "Two new crinoids of the family Periechocrinitidae from the Middle Devonian Thunder Bay Limestone of Michigan". Contributions from the Museum of Paleontology, University of Michigan. 19 (11).
^Kesling, Robert Vernon; Mintz, Leigh W. (1963). "Dolatocrinus and Stereocrinus, its junior synonym". Contributions from the Museum of Paleontology, University of Michigan. 18 (14).
^Stumm, Erwin C. (1955). "Three new species of the cystid genus Lipsanocystis from the Middle Devonian Traverse Group of Michigan". Contributions from the Museum of Paleontology, University of Michigan. 12 (6).
^Kesling, Robert Vernon; Smith, Raymond N. (1963). "The crinoid Synbathocrinus in the Middle Devonian Traverse Group of Michigan". Contributions from the Museum of Paleontology, University of Michigan. 18 (11).
^Stack, Jack; Sallan, Lauren (2018). "An examination of the Devonian fishes of Michigan". PeerJ. 6.
^ abcdeStrumm, Erwin. C (1953). "Trilobites of the Devonian Traverse group of Michigan". CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY UNIVERSITY OF MICHIGAN. 10 (6).
Michigan
United States
