"The Core Research Center is a dramatic example of the value of geoscience sample and data rescue that has real benefit to a wide variety of users on a daily basis. The U.S. Geological Survey rock core and drill sample repository is similar in many respects to a book library, and the Center has adopted many of the philosophies, techniques, and services of modern book libraries."
Tom Michalski, Curator, U.S. Geological Survey
Preservation of rock cores and drill samples represents an enormously valuable resource for the entire earth sciences community.
The CRC houses about 1.4 million feet of core in the general collection of petroleum exploration and development holes as well as in specialized collections. These cores come from 31 States and about 95 percent were donated by petroleum and mining companies, State geological surveys, other Federal agencies, and by universities; about 5 percent are special scientific cores drilled by the USGS. In addition, the CRC maintains about 15,000 thin sections taken from catalogued cores. Cuttings from over 50,000 wells in 27 States are also housed at the repository. This unique collection of cuttings represents nearly 235 million feet of drilling at a replacement cost over $10 billion.
Duplicate portions of cores that are not kept as part of the collection are offered at no cost to interested people and organizations, such as researchers, universities, State agencies, and school teachers. Restrictions placed on this offering are that the receiver of the excess core slabs assume responsibility for shipping and that the core be made available to other users.
The core collection is used extensively by workers in industry (65 percent), Federal and State agencies (25 percent), and academia (10 percent). Up to 2,000 scientists per year from around the world access the collection, although the largest portion of users is from the U.S. Over the past two decades, the CRC staff has provided library service to over 35,000 people. In addition, the CRC facilities are available to high-school and college students for a variety of academic needs.
Most industry core studies attempt to correlate in-place borehole surveys, such as for porosity, with rock taken from known depth intervals. Such borehole "truthing" is a crucial step to implementing future petroleum drilling strategies in a potentially productive area. However, increasing interest is also being given to the environmental functions drillholes can perform when used, for example, as disposal sinks for unwanted fluids such as salt water produced with oil.
The National Ice Core Laboratory, a cooperative with NSF and the University of Colorado, retains, curates, and makes available over 30,000 feet of ice cores taken from ice sheets around the world. Work conducted on these ice cores supports global climate-change research by providing detailed annual records of climate and weather variations for the past 250,000 years. Recent results of ice core studies indicate that large natural swings in temperature and precipitation, sufficient to initiate global changes in ice distribution, occur in a matter of a few tens of years. USGS scientists have not yet determined whether human activity can trigger such rapid and widespread climate change, but climate records in the ice suggest that natural events, such as volcanic eruptions, are sufficient to cause major shifts in the Earth's climate.
Email: tmichalski@sedproc.cr.usgs.gov
This USGS Fact Sheet can be found at <URL:http://energy.usgs.gov/factsheets/Core/crc.html>
In 1974, the U.S. Geological Survey (USGS), in cooperation with the Rocky Mountain Association of Geologists, established a permanent free-access core repository in Denver. The purpose of the repository is to rescue rock cores threatened with destruction or disposal. The Core Research Center (CRC) accepts donated cores, prepares them for curation, and makes them available to the interested public. The diverse collection has grown significantly over the past two decades due to national recognition of the USGS facility. Recently, core donations have increased dramatically from around 50,000 feet of core per year to 200,000 feet per year. Today, the Center is the largest public core repository in the country and has cultivated a high degree of trust and integrity with its donors and users. Conservative estimates, based on the value of cores housed at this facility, indicate that the public cost of storage is only about 0.5 percent of the original cost of drilling, and one-tenth of that percentage if the cores were drilled today. The USGS can store the cores, which are used for educational and research purposes, for at least 200 years before reaching the original cost of drilling.
The USGS maintains the most diverse public-access core collection in the country.
A variety of core sub-collections are available in the repository including those from oil shale development; Eniwetok Atoll; Cajon Pass, California; Yellowstone Park; and offshore wells. In addition, CRC curates one of the country's larger collections of "cuttings", rock chips brought to the surface during drilling operations which are invaluable for constructing geologic concepts of an area. The core and cuttings collection is also accompanied by a large collection of thin sections that are used to examine microscopic details of the rocks. Photographs of cores are also available to researchers. A file is maintained that contains chemical and physical analyses, core descriptions, stratigraphic charts, and other analyses performed by daily users of the collection.
The USGS curates one of the country's larger collections of drill-hole material.
USGS workers have processed 400,000 feet of rock core that are available for immediate use.
The backlog of full-diameter cores requiring processing for complete curation is about 1 million feet, and the priority for processing these cores is defined by user needs. The principal step in processing cores is cleaning and slabbing, which involves slicing lengthwise and retaining about one-third of the full-diameter core, and placing core slices in their proper stratigraphic order in special storage boxes. Once reboxed, cores are photographed for posterity, and the photographs are archived elsewhere. Photographs perform three functions: they allow users to preview selected portions of the collection; they provide a means for reconstructing the order of core fragments; and, they offer some tangible product in the event of permanent loss of the core.
The unique collection is available to users worldwide.
USGS workers transport core-testing capabilities to the drill site.
A number of science holes are drilled and cored every year by the USGS and other science agencies, and the CRC makes its field core-testing equipment and expertise available to these important projects. Because many physical and chemical properties of cores can change quickly after being removed from the ground, the CRC often tests and processes core samples on-site soon after they reach the surface. Most of these scientific drill-hole projects have been conducted as part of a cooperative effort by the USGS, the National Science Foundation (NSF), and the Department of Energy. Recent projects include drilling at Cajon Pass, California; Creede, Colorado; Escalante, Utah; Canyon City, Colorado; and, Hilo Hawaii.
The USGS recently established a highly-specialized ice-core storage facility as part of the CRC.
For More Information:
Tom Michalski
U.S. Geological Survey
MS 975
Denver Federal Center
Denver, CO 80225
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Maintained by L. Friedrich Last updated 22-Jan-1997