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New Insights Into Carboniferous Cyclothems. The Fourth Biennial Field Conference Of The American Association Of Petroleum Geologists (Aapg) Midcontinent Section Fourth Biennial Field Conference Abstracts And Guidebook, Robert Matthew Joeckel, Christopher R. Fielding
New Insights Into Carboniferous Cyclothems. The Fourth Biennial Field Conference Of The American Association Of Petroleum Geologists (Aapg) Midcontinent Section Fourth Biennial Field Conference Abstracts And Guidebook, Robert Matthew Joeckel, Christopher R. Fielding
Conservation and Survey Division
The term “cyclothem” was coined by Wanless & Weller (1932) to describe repetitive stratigraphic successions of Carboniferous age in Illinois. Nonetheless, comparable rhythmicity had been identified in Carboniferous rocks both in the central and eastern USA, and in Europe during the preceding century. Cyclothems were found to comprise repetitive vertical successions of sandstones, heterolithic (thinly interbedded) sandstones and mudrocks, mudrocks, limestones, and coals, in many cases with pedogenic overprinting of these lithologies. As usage of the term “cyclothem” increased, so did the diversity of successions to which the term was applied, to the point where many geologists advocated abandonment of …
Encrusting Sclerobiont Paleoecology And Bioerosion Of Oysters In The Type Campanian (Upper Cretaceous) Of Southwestern France, Macy A. Conrad
Encrusting Sclerobiont Paleoecology And Bioerosion Of Oysters In The Type Campanian (Upper Cretaceous) Of Southwestern France, Macy A. Conrad
Senior Independent Study Theses
The Campanian Stage of the Upper Cretaceous was established by Henri Coquand in 1857 based on a sequence of richly fossiliferous shallow water carbonates in the Charente and Charente-Maritime departments of southwestern France. One of the most common macrofossils is the gryphaeid oyster Pycnodonte vesicularis (Lamarck, 1806), which often forms extensive shell beds. This bivalve lived primarily on soft marly substrates, forming hard substrate islands. They frequently supported sclerobiont communities comprising encrusters (diverse cheilostome and cyclostome bryozoans, foraminiferans, oysters, bivalves, sabellid and serpulid polychaetes, calcareous sponges), borers (the sponge borings Entobia, the worm borings Maeandropolydora and Caulostrepsis, the barnacle borings …