The Delaware Geological Survey's Atlantic Outer Continental Shelf (OCS) Sample and Data Repository is a large collection of cores and samples from oil and gas exploration wells and deep research boreholes drilled offshore the U.S. Atlantic Coast 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 Atlantic OCS Sample and Data 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 1975 and 1984. Samples include cores, unwashed cuttings, rock thin sections, vials containing samples processed for micropaleontology and palynology, and micropaleontology and palynology slides and splits. The inventory of materials from these oil and gas exploration wells is extensive:

• 489 boxes of core material (348 boxes holding 2,470 linear feet of slabbed core; 141 boxes holding 200 core slices and 2325 core chips).
• 19 boxes of sidewall cores (277 samples).
• 391 boxes of unwashed cuttings containing approximately 10,500 individual samples.
• 1981 boxes of washed cuttings containing approximately 88,400 individual samples.
• 308 boxes of vials containing approximately 26,000 individual prepared material residues.
• 690 boxes of slides containing approximately 62,000 slides (including 5,700 thin sections).
• geophysical logs, micropaleontology summaries, and other data from many of the wells.

The collection also includes piston cores, biostratigraphic slides and preparations from 17 of the 18 holes drilled for the 1967 Atlantic Slope Project, including:

• 18 boxes of piston core (474 samples).
• 10 boxes of slides (969 slides; 690 palynology slides, 279 nannofossil slides).
• 1 box of biostratigraphy residue (1 vial).

Source of Material

The Bureau of Ocean Energy Management (formerly Minerals Management Service, MMS) of the U.S. Department of the Interior was a major contributor to and supporter of the DGS Outer Continental Shelf (OCS) Core and Sample Repository as it was assembled. 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 sources in the energy industry, 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 Core Labs was added to the collection. The 1967 Atlantic Slope Project materials included in the collection were acquired from the U.S. Geological Survey.

Inventory Summary

A summary of holdings in the DGS Atlantic OCS Sample and Data Repository is available as a PDF download below. Sample type abbreviations are as follows:

• SWCore-sidewall core
• CT-washed cuttings
• UCT-unwashed cuttings

Spreadsheets with detailed inventories of all sample holdings are available upon request. For more information on holdings, access, and sampling policies, or to arrange a visit, please contact Pete McLaughlin at ppmclau@udel.edu or Kelvin Ramsey at kwramsey@udel.edu.