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Geology 106 Laboratory

Studies in the geologic history of deep ocean basins

For this exercise you will work with sections of core obtained for the Ocean Drilling Program (ODP) by the drillship JOIDES Resolution, as part of fundamental scientific exploration and investigation on the geology of the Earth's ocean basins. Cores contain stratigraphic records of ocean sedimentation on the ocean floor and samples of oceanic crust.  The cores to be examined show two characteristic suites, which include both shallow and deep marine deposits.One is a suite of deposits associated with the sinking of a continental shelf, such as occurs along the margins of newly formed continental blocks after continental breakup. During subsequent continental drift, the newly formed continental margins and oceanic crust gradually cool, subsiding and becoming covered with ocean waters.  Rates of sedimentation on the continental shelf determine shelf water depths.  These deposits and rocks are a characteristic suite of the rifting phase of the Wilson cycle. The other is a suite of deposits associated with the drowning of a carbonate platform, such as found in the mid Pacific Ocean basin.  Newly formed volcanic islands and plateaus are soon colonized with carbonate-producing organisms. As volcanism ceases, the volcanic mass and ocean crust slowly subside, while carbonate-producing organisms generate reefs with large quantities of sediment, typically as an atoll reef complex. The outward growth of reefs produces a characteristic suite of carbonate platform sediments.

The following core sections are available for study (click on a link to view the cores):

Print the following pages to use for the lab excercise


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Modified on Friday, 26-Sep-2008 12:37:14 CDT.