State geologists are scanning Alaska's archived drill core into a digital library

The Alaska Division of Geological & Geophysical Surveys is scanning drill core from its sample archive to build a digital library that researchers and industry can use, according to a two-page information circular the agency published in October.

The work happens at the agency's Geologic Materials Center, which holds the state's collection of rock samples. The center runs the scanner "to enhance the digital accessibility of this collection," the circular says.

The scanner uses hyperspectral imaging, which reads light across many wavelengths. It shines light on each sample and records the reflected light from 400 to 12,500 nanometers, a range that covers visible and infrared light. Different minerals reflect light differently, so the readings identify minerals and rock properties in each sample. A 3D laser profiler measures the surface of the rock.

The system combines the infrared readings, high-resolution photographs and the surface measurements into a single digital record. That data can estimate the type and amount of mineral in each pixel of an image and show how rock types and mineral amounts change with depth down a drill hole.

Rock samples at the center have already been used to assess Alaska's potential for lithium, rare earth elements and other critical minerals, the circular says.

The state and the U.S. Geological Survey's National Geological and Geophysical Data Preservation Program have jointly paid for the scanner and the scanning work. The agency describes the project in phases: buying the scanner in fiscal 2022, then installing and testing it, developing a workflow and moving to production scanning. Its plan for fiscal 2025 called for scanning 7,000 core boxes chosen for critical-mineral and other resource potential.