Please Note: The McCracken Core Library and Research Center is open by appointment during normal working hours. If you have any questions, would like to visit the facility or examine the library holdings, please contact the McCracken Facility Operator by email or call 573-368-2100.

McCracken Core Library and Research Center Open House

Thanks for helping us celebrate 30 years | Phelps County Focus newspaper article

We provide examination and sampling of subsurface geologic materials for research purposes to interested individuals, businesses and organizations at the discretion of the state geologist. To request core or cutting samples, reference the following policy and procedures and sample request form:

Images--Core Samples

McCracken Core Library and Research Center Documents

Patrick on the Ladder in the McCracken Core Library in Rolla

Staff manage McCracken Core Library and Research Center, a repository for more than 2 million linear feet of subsurface geological materials (rock core and cuttings) that have been donated to the state. The 21,000 square-foot facility is named in honor of geologists Earl and Mary McCracken, whose service to the geological survey spanned more than three decades. Study and examination room facilities were made possible through donated funds in the memory of Clark. S. Rhoden. Mr. Rhoden donated some of his core that was used when exploring and drilling for oil in Missouri.  His North and South Rhoden leases produced more than $5.7 million dollars of oil between 1980 and 1987. McCracken is one of the largest such collections in the nation and is open to the public, by appointment.

Images--Core Samples

Core is cylinder-shaped segment of rock obtained by using a hollow-stem drill and drill bit.  This method of collection allows for continuous samples through the bedrock zones of interest.  Core typically collected for research is 1.375 inches in diameter and stored in 2-foot segments.  Cuttings are small grouped up pieces of rock that are pushed to the surface as a solid stem drill bit is advanced. Samples of cuttings are collected as they are flushed out of the borehole.  The samples are then washed to remove and fine particles and placed into small vials for storage and later examination.

The collection and archiving of core and cuttings helps to preserve geological history, lead to a better understanding of Missouri geology and hydrology, and yield data useful in solving environmental, industrial and engineering problems. By archiving core and cuttings, they can be saved for future research and exploration.

Core and cuttings available for study come from many different sources. Drilling projects from quarries, oil and gas exploration, mineral exploration, landfills, hazardous waste sites and highway department construction have contributed to the holdings at McCracken.

McCracken Core Library and Research Center article in the Spring 2014 Missouri Resources magazine.

Download Core Library Core and Cuttings Holdings List September 2019
Note: Click to open or right-click to download and save the list to your computer.