A survey of the packing density in oolitic grainstone from surface and subsurface samples shows compaction ranging from zero in unburied Pleistocene Bahamian oolite to nearly 90% for parts of the Late Jurassic Smackover Formation at a depth of about 10,000 ft in the Haynesville field, northern Louisiana. Mississippian oolitic grainstone which crops out has been compacted as much as 59% in the Greenbrier Formation of West Virginia, contrasted with only 10% in the Ste. Genevieve (Levias Member) of Indiana. Commonly, Smackover thin sections show amounts of compaction between 50 and 70%.

Grain fracturing, cementation of broken grains, stylolitization, partial dolomitization, and authigenic quartz formation can be related to the degree of compaction in favorable circumstances. Noteworthy is the observation that authigenic quartz apparently formed after as much as 60% compaction had taken place in Smackover oolite. In addition, final calcite cementation apparently occurred in a Smackover sample after grain compaction of 61% and fracturing, an example of very late cementation.

End_of_Article - Last_Page 713------------