July 2020
Vol 6, Issue 31

About The Cover

Cover image expansion

ONLINE COVER While much attention has been paid to the origins of Stonehenge's "bluestones," which are made of various types of rock that clearly were not gathered locally, the monument's much larger sandstone boulders (called sarsens) have remained largely unexplored. Until recently, technology did not exist to determine the origins of the sarsens, which tower at up to 30 feet tall, weigh as much as 25 tons, and make up most of Stonehenge. To learn where the behemoth boulders came from, Nash et al. used portable x-ray fluorescence spectrometry (PXRF) to initially characterize their chemical composition, then analyzed the data statistically to determine their degree of chemical variability. Next, the researchers performed inductively coupled plasma mass spectrometry (ICP-MS) and ICP-atomic emission spectrometry (ICP-AES) of samples from a core previously drilled through one sarsen stone and a range of sarsen boulders from across southern Britain. After comparing these signatures, Nash et al. were able to point to West Woods as the sarsens' earliest home. The reason the monument's builders selected this site remains a mystery, although the researchers suggest the size and quality of West Woods' stones, and the ease with which the builders could access them, may have factored into the decision. [CREDIT: ENGLISH HERITAGE]