Scientist Uses Sand Grains to Sift Through History

A Desert Research Institute scientist is sifting through the sands of time for a history lesson on past climate changes, earthquake dates and a chronology of when humans lived where.

Nick Lancaster studies samples of sand grains to determine how long they have been in the ground. This gives researchers a better idea of when various events occurred in the area.

The process, called luminescence dating, complements carbon-14 dating because it works with desert materials that do not contain carbon.

Lancaster has worked with British colleagues for four years, scouting local spots rich in samples. The grains are returned to Great Britain for analysis.

Lancaster will be able to analyze his own samples at the institute within a year. A $50,000 grant from Reno’s E. L. Cord Foundation will pay for a machine to make the studies and the institute will remodel an existing lab to set up the fourth such facility in the country.

The machine measures the amount of light given off by the sand, then feeds information into a computer that determines its age.

Lancaster said one of the richest spots the scientists have found is among the sand dunes of the Mojave Desert in California.

He hopes to concentrate much of the Desert Research Institute’s studies on granules in earthquake faults and in terraces formed around ancient Lake Lahontan as water receded over the centuries.

Thermoluminescence dating has been used since the 1960s and has been used extensively to authenticate dates of pottery and artwork.

The local lab will concentrate on an infrared dating process that is more sensitive than thermodating and works on feldspar granules.

A third technique using green light shows promise of working on quartz, one of the most common grains found on Earth.