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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 67 (1983)

Issue: 3. (March)

First Page: 477

Last Page: 478

Title: Larger Foraminifera as Depth Indicators in Carbonate Depositional Environments: ABSTRACT

Author(s): Pamela Hallock

Article Type: Meeting abstract


Studies of living larger foraminifera have provided several breakthroughs pertinent to the use of their ancient analog in paleoenvironmental interpretation. The first of these insights is that modern larger foraminifera are nutritionally dependent upon algal symbionts and are morphologically adapted to house those symbionts. The second is that algal symbiosis is energetically highly advantageous under nutrient-deficient conditions such as those prevalent in well-developed modern coral reef environments. In addition, experimental evidence demonstrates that the availability of light and water turbulence in the environment

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influences shapes and sizes of modern foraminifera.

By analogy, assemblage composition, including the presence and abundance, or absence, of planktonic and smaller benthic species, along with shapes and size distributions of the larger foraminifera, can be used in paleodepth analysis and to supplement other petrographic evidence in carbonate facies interpretation.

Among the current limitations of the use of larger foraminifera as paleodepth indicators are the complications caused by taxonomic heterogeneity of both the larger foraminifera and their algal symbionts. Nevertheless, the potential for use of larger foraminifera in paleoenvironmental analysis is tremendous, as is the potential benefit of further studies of both modern and ancient assemblages of larger foraminifera.

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Copyright 1997 American Association of Petroleum Geologists