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Title: Upper Carboniferous reef mounds and climate change

Conference · · Geological Society of America, Abstracts with Programs; (United States)
OSTI ID:5907016
;  [1]
  1. Kansas State Univ., Manhattan, KS (United States)

Tetractinomorph demosponges (chaetetids) are a minor component of extant tropical reefs, but they were the major framebuilder of reef mounds during the Westphalian (Carboniferous). These chaetetids were confined to tropical latitudes during the Carboniferous, reached an abundance peak in the Westphalian, and then declined suddenly until the Upper Triassic. After their decline, red and green algae became the dominant reef builders of the Stephanian. The marked decline of chaetetids corresponds with the disappearance, and/or decline of other marine benthic invertebrates, as well as some terrestrial plants and is the basis for the biostratigraphic boundary between the Westphalian and Stephanian (Desmoinesian and Missourian). This biostratigraphic boundary coincides with a minor extinction event and a major'' climatic change. The Westphalian climate was wetter than that of the Stephanian, and in the midcontinent this change is recorded by a gradual decline in coals and siliciclastic lithologies and a corresponding increase in carbonate lithologies. A rise in water temperature might be expected in a drier tropical climate, and if extant chaetetids are any clue, elevated water temperature may have been detrimental. Extant chaetetids are associated with tropical coral reefs that are confined to a narrow temperature range. It is not unreasonable to suggest that elevated seawater temperatures were responsible, in part, for the disappearance of chaetetid reef mounds. Red and green algae, presumably more tolerate of higher water temperatures, became the major framebuilders of reef mounds in the Stephanian. Thus, the demise of chaetetid reef mounds, and other organisms at the end of the Westphalian, may be the result of global warming.

OSTI ID:
5907016
Report Number(s):
CONF-921058-; CODEN: GAAPBC
Journal Information:
Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
Country of Publication:
United States
Language:
English