Biological models for Mesozoic reef evolution

Journal Article · Thu Nov 01 00:00:00 EST 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5901230

Kauffman, E G ^[1]

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1. Univ. of Colorado, Boulder (USA)

Throughout the Mesozoic, shallow-water carbonate ramps and platforms of the circumequatorial Tethyan Ocean were characterized by extensive development of reef ecosystems, especially during times of eustatic highstand, expansion of the Tropics, and warm equable global climates. The greatest reef development was north of the paleoequator in the Caribbean and Indo-Mediterranean provinces. These reefs and associated debris facies comprise major petroleum reservoirs, in some cases with remarkable porosity and permeability normally attributed to a combination of sedimentologic, tectonic, and diagenetic factors. The biological evolution of Mesozoic reefs also has had an important, and in some cases dominant, role in determining reservoir quality. Three major biological factors are critical to mesozoic reef-associated reservoir development: (1) the replacement/competitive displacement of coral-algal dominated, highly integrated reef ecosystems by loosely packed rudistid bivalve-dominated reef ecosystems in the Barremian-Albian; (2) the evolution of dominantly aragonitic, highly porous shells among framework-building rudistids in the middle and Late Cretaceous; and (3) competitive strategies among rudistids that effectively prevented widespread biological binding of Cretaceous reefs, leading to the production of large marginal fans that comprise major carbonate reservoirs. Detailed studies of these evolutionary trends in reef/framework development and of the distribution of different groups of bioconstructors on reefs lead to predictive modeling for primary and secondary porosity development in mesozoic carbonate reservoirs. The competitive displacement of coral-algal communities by rudistids on Cretaceous reefs was so effective that, even after Maastrichtian mass extinction of rudistids and other important groups comprising Mesozoic reef/carbonate platform ecosystems, coral-algal reef-building communities did not evolve again until the late Eocene.

• OSTI ID: 5901230
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:11; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
PETROLEUM DEPOSITS
RESERVOIR ROCK
REEFS
ORIGIN
CARBONATE ROCKS
CRETACEOUS PERIOD
DIAGENESIS
DISTRIBUTION
GEOLOGIC HISTORY
PERMEABILITY
POROSITY
PRODUCTION
TECTONICS
TERTIARY PERIOD
CENOZOIC ERA
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MESOZOIC ERA
MINERAL RESOURCES
RESOURCES
ROCKS
SEDIMENTARY ROCKS
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences