USGS INL Project Office

Core Logger Project

The United States Geological Survey (USGS) has conducted research and performed ground water monitoring at the INL since 1949 when it was asked to characterize water resources before nuclear-reactor testing facilities were built. Since that time, the USGS has maintained and expanded a network of ground-water quality and water-level measurement wells and other facilities at and near the INL. (Use the INL History link on the right for further explanation regarding the relationship between the INL and USGS.)

In order to better understand the subsurface geology that hosts the eastern Snake River Plain aquifer, many wells and boreholes were and are cored as they are drilled. The USGS INL Project Office has its own drilling rig and crew to drill and core monitoring and research wells, and the INL contractor also drills and cores wells. All core from these projects is stored at the Lithologic Core Storage Library. The Lithologic Core Storage Library (CSL) currently houses more than 90,000 feet of core and several suites of cuttings from boreholes drilled at the INL; more cores and cuttings are added every year. The Lithologic Core Storage Library also houses two suites of core and cuttings from the western Snake River Plain. Many entities collect core from drilling activities, but core from extrusive igneous rocks is rare, because such rocks seldom host hydrocarbons, precious metals or other economically valuable material.

The USGS INL Project Office Corelogger Program began the summer of 2003 in an effort to provide better access to materials stored at the Lithologic Core Storage Library to the subsurface science research community. Our first corelogger, Reuben Johnson, designed and implemented the Corelogger protocol, using commercially available software and equipment. The intent of the program was to create a standardized, web-accessible, efficient method for logging and photographing core stored at the Lithologic Core Storage Library. The protocol was designed to develop standardized core logs that included photographs, maximum description and minimum interpretation, to provide researchers with an overview of material to aid in choosing the most productive material for their purposes. Also, digital logging with photographs will help provide a permanent record in case of loss or consumption of core.

Lithologic and geophysical corelogs will be made available as .pdf or ASCII-DAT files for ease in downloading and printing. Large format, high resolution photographs are also available; unfortunately, photographs and .pdf corelogs are very large files.

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Method for logging core

Core is organized by well name and depth. Core to be logged is laid out on tables, where it is dusted off, and re-marked if necessary to preserve up markings (red line on the right) and depth numbers. Core is then photographed, using a specially designed jig to control lighting and layout. The corelogger moves the rolling logging table along the laid out core, recording data as he or she goes through the core from top to bottom. Data includes lithologic description, lithology symbol, vesicle size and relative abundance estimates, fracture frequency, structure information and photographs.