GeoTek Multi-Sensor Core Logger Facility

Science Center Objects

The GeoTek Multi-Sensor Core Logger Facility houses two state-of-the-art loggers that collect high-resolution line-scan images and automated, non-destructive geophysical and geochemical measurements on whole and split soft sediment and rock cores as well as discrete subsamples and hand samples. The GeoTek Facility is available to USGS and non-USGS researchers. For more information, please contact Jessica Rodysill at


Line-scan imaging: The GeoTek MSCL has a GeoScan V Linescan Imaging system that can collect line-scan images at resolutions of 25 µm, 50 µm, and 100 µm pixel widths. The line-scan technology produces high quality images that do not exhibit “stitching” effects. Polarizing filters on the camera lens and the LED lamp lights reduce glare effects for wet samples. RGB color values are collected with each image.

Gamma density: A 137Cs gamma ray source and gamma detector are mounted on the GeoTek MSCL-S for measuring bulk density and based on gamma attenuation through core samples. Gamma density is typically measured on whole cores in a liner our unlined whole rock cores every 0.5 or 1 cm and calibrated to grams per cubic centimeter using an aluminum calibration piece mounted inside an empty scrap of the same liner material containing the core sample (if applicable). Gamma density can be measured on split cores under special circumstances.

Magnetic susceptibility: A 100 mm diameter Bartington MS2C loop sensor and an MS2E point sensor are used to collect magnetic susceptibility data on whole and split cores respectively. Magnetic susceptibility measurements are typically collected every 0.5 or 1 cm with 1 or 10 second dwell times.

P-wave measurement system: The GeoTek MSCL-S has two acoustic rolling transducers for measuring p-wave velocity on whole or split lined cores and two piston transducers for measuring p-wave velocity on whole or split bare rock cores. P-wave velocities are typically measured on whole cores every 0.5 o 1 cm.

Visible and near-infrared spectrophotometry: A Malvern Panalytical ASD LabSpec can collect measurements of visible (400 to 700 nm) and near-infrared (750 to 2500 nm) wavelengths of spectrophotometric data with measurements resolutions up to every 0.5 cm. Data can be exported in both 1 and 10 nm increments, as well as greyscale, L*a*b* and XYZ values on split core surfaces and bulk samples.

X-ray fluorescence: 34 elements, Mg to U, are detected and quantified in counts per second (cps) or parts per million (ppm) up to every 0.5 cm with a mounted Olympus Vanta M Series handheld XRF. X-ray energies of 9 and 40 keV are sequentially released from the XRF for a measurement time of up to 30 seconds per beam to maximize elemental counts for a variety of sediment core types and varying water and organic content.

Color spectrophotometry: Precise color measurements are collected on split core surfaces and subsamples using a Konica Minolta CM-700d spectrophotometer. Typical color measurements are collected every 0.5 to 1 cm, and data output includes percent reflectance at wavelengths between 400 and 700 nm, RGB values, L*a*b* values, XYZ values, and Munsell color values.