Results 181 to 190 of about 1,927,269 (224)

Middle Devonian Bentonite in Michigan Basin

AAPG Bulletin, 1975
ABSTRACT We agree with Baltrusaitis that the thin bentonite bed that he has described as the Kawkawlin Bentonite in the Michigan basin and the Tioga Bentonite Bed that others have described in New York and in the Appalachian and Illinois basins represent one and the same ashfall.
John B. Droste, Robert H. Shaver
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Lower Devonian-Middle Devonian Boundary in Central Nevada: GEOLOGICAL NOTES

AAPG Bulletin, 1962
New fossil collections from beds immediately overlying the long established "Spirifer" pinyonensis zone show that there is a complete faunal break between these horizons in the northern Roberts Mountains and in the northern Simpson Park Range, central Nevada.
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Spores and the middle-upper Devonian boundary

Review of Palaeobotany and Palynology, 1981
The stratigraphic levels most favoured for the Middle-Upper Devonian boundary fall approximately within the range of the ammonoid Pharciceras lunulicosta Zone, i.e. from the Middle varcus Subzone to the base of the Lower asymmetricus Zone of the conodont scale.
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Tetrapod-like middle ear architecture in a Devonian fish

Nature, 2006
Few fossils show the incipient stages of complex morphological transformations. For example, the earliest stages in the remodelling of the spiracular tract and suspensorium (jaw suspension) of osteolepiform fishes into the middle ear of tetrapods have remained elusive.
Martin D, Brazeau, Per E, Ahlberg
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Stratigraphy and Facies Across Lower Devonian-Middle Devonian Boundary, Central Nevada

AAPG Bulletin, 1983
ABSTRACT A regressive episode near the end of the Early Devonian caused a nearshore quartzose carbonate facies to shift to the edge of the carbonate shelf in central Nevada. Transgression followed in the latest Early Devonian and continued in the early Middle Devonian.
G. W. Kendall, J. G. Johnson, J. O. Brow, G. Klapper   +3 more
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Middle Devonian bone beds of Ohio

Geological Society of America Bulletin, 1944
The Middle Devonian limestones of central Ohio consist of two formations, the Columbus (late Ulsterian) and the Delaware (early Erian). Within these are at least four thin bone beds: the First, 10 feet below the top of the Columbus in Franklin and southern Delaware counties, the Second, at the contact of the Columbus and the Delaware from Franklin ...
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Middle Devonian Sandstones Of The Michigan Basin.

1949
PhD ; Geology ; University of Michigan, Horace H. Rackham School of Graduate Studies ; http://deepblue.lib.umich.edu/bitstream/2027.42/182855/2/0001509 ...
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Gastropods Of The Middle Devonian Anderdon Limestone.

1960
PhD ; Geology ; University of Michigan, Horace H. Rackham School of Graduate Studies ; http://deepblue.lib.umich.edu/bitstream/2027.42/182794/2/6006900 ...
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SILICATE WEATHERING AND MIDDLE DEVONIAN PALEOCLIMATE

Geological Society of America Abstracts with Programs, 2020
Teresa D. Avila, Matthew R. Saltzman, Elizabeth M. Griffith, Michael M. Joachimski   +3 more
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The Fauna of the Middle Devonian Beauvais Sandstone of Missouri

Science, 1931
C, Croneis, A D, Hoffman
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