Alaska starts scanning its drill core archive with light beyond what the eye can see

Alaska's state geologists have started scanning the state's archive of drill core with light the eye can't see. The goal is a digital record of the minerals in thousands of boxes of rock.

The scanner began operating in June at the Geologic Materials Center in Anchorage, according to a two-page circular the Alaska Division of Geological & Geophysical Surveys published this month.

The center holds more than 500,000 feet of core, about 95 miles, among more than 750,000 items the state says would cost more than $35 billion to replace.

The human eye sees light from about 400 to 700 nanometers. The scanner reads from 400 to 12,500, far into the infrared. Minerals show up as peaks and dips in the readings, which the circular likens to a "fingerprint." From those, geologists can estimate which minerals are in a sample and how much. Lined up core by core, the readings show how the rock changes with depth down a drill hole.

Industry and university researchers already use the center's samples. They've helped gauge Alaska's potential for lithium, rare earth elements and other critical minerals, the circular says, and could help with newer pursuits like underground carbon storage and natural hydrogen.

The state and a U.S. Geological Survey data preservation program have paid for the work. The agency bought the scanner in fiscal 2022, and its plan for fiscal 2025 called for scanning 7,000 boxes of core from holes with critical mineral and other resource potential.