GSA Bulletin 121, 688–697 (2009)

The rough surface of Israel's Negev Desert has the slowest rates of erosion ever measured, according to Ari Matmon of the Hebrew University of Jerusalem and his colleagues. His team calculated the speed of erosion there by measuring the concentration of the radioactive isotope beryllium-10 in chert clasts — little stones — collected from sites in the Negev. This isotope is formed when cosmic rays hit rocks and soils, so its concentration can indicate how long an object has been exposed to the sky.

This technique, along with others, suggests that the bits of chert covering parts of the Negev, Sinai, Sahara and Arabian deserts have been sitting there for upwards of 2 million years, making this landform the longest-lived one on Earth according to current measurements.