The Delaware Geological Survey's Outer Continental Shelf (OCS) Core and Sample Repository is a large collection of cores and samples from oil and gas wells drilled offshore the Atlantic Coast of the U.S. during the 1970s and 1980s. This collection was assembled from the contributions of federal agencies, other state agencies, and private institutions that have recognized the value of having a centralized repository for this material.

One of the missions of the DGS is to understand the geology of the lands under the ocean adjacent to our state, providing information that can provide the basis for planning decisions involving potential offshore deposits of oil and gas, as well as other mineral resources. As part of this mission, the DGS strives to maintain an understanding of the regional context of the offshore geology of the state, with interests in the geologic evolution of the U.S. Atlantic seaboard. The DGS Outer Continental Shelf (OCS) Core and Sample Repository is an important resource for ensuring access to sample material related to these interests as other core and sample repositories for these materials have been closed, consolidated, or reduced in size.

Summary of Holdings

The Repository contains samples from all 51 oil and gas wells drilled in the U.S. North Atlantic, Middle Atlantic, and South Atlantic offshore regions between 1977 and 1984. Samples include cores, unwashed cuttings, vials containing samples processed for micropaleontology and palynology, and thin sections of core, cuttings, and micropaleontology and palynology splits.

• 465 Boxes of core material
• 245 boxes of unwashed cuttings containing approximately 5000 individual samples
• 1959 boxes of washed cuttings containing approximately 40,000 individual samples
• 32 boxes of vials containing approximately 6500 individual samples
• 88 boxes of thin sections containing approximately 6300 slides
• geophysical logs, micropaleontology summaries, and other data from many of the wells

Source of Material

The Minerals Management Service (MMS) of the U.S. Department of the Interior has been a major contributor to and supporter of the DGS Outer Continental Shelf (OCS) Core and Sample Repository. When the Atlantic Region Office of the MMS was consolidated with the Gulf Coast Office, samples then housed by the MMS in Reston, VA, were transferred to the Delaware Geological Survey to form the repository. Since that time, samples have been acquired from several petroleum exploration sources, including Occidental, and Shell, as well as from the U.S. Geological Survey and the Texas Bureau of Economic Geology. In August, 2000, new material acquired from CoreLabs was added to the collection.

Inventory Summary

The table below is a summary of Atlantic OCS oil and gas exploratory wells and sample holdings in the DGS OCS Sample Repository. The sample types available are indicated using the following codes:

• CR-core
• CT-washed cuttings
• UCT-unwashed cuttings
• V-vials
• TS-thin sections and slides (including rock thin sections, kerogen slides, paleo slides and palynomorph slides)

Spreadsheets are available from the Delaware Geological Survey with detailed inventories of all sample holdings. For more information, please contact Kelvin Ramsey at kwramsey@udel.edu or Pete McLaughlin at ppmclau@udel.edu.