I have frequently noted my pleasure in regularly receiving “out of the blue” comments and e-mails – I find myself in contact with all kinds of people from around the world with whom I would never have otherwise intersected, on an amazing range of topics, many of which are completely new to me. All of this because of a mutual interest in all things arenaceous.
Here’s a case in point – together with a question for anyone who might be able to shed light on this. The unique nature of any particular family of sand grains from a specific location, be it a river sand bank or a coastal beach, has long provided forensic science with a tool for location identification. This has not only been applied to any number of cases of criminal forensics, but also, for example, to archaeological and military investigations. I described the classic military example in Sand:
In late 1944, balloons 9 meters (30 ft) in diameter appeared in the skies above the United States. Landing from the West Coast to Michigan, they carried a deadly cargo: incendiary bombs. Although the only casualties over the following months were, tragically, members of a Sunday school group attempting to retrieve one that had landed, the potential danger to life, towns, and forests was considerable. It was apparent that the weapons had blown in from the Pacific, but where had they been launched? The devices had an automatic altitude-regulation system, releasing hydrogen or ballast to maintain height. The ballast bags were filled with sand. The U.S. Geological Survey’s Military Geology Unit, established in 1942, was tasked with identifying the sand. The family of grains was consistent from one retrieved ballast sample to the next, and unique. Distinctive forams and other microscopic shells, together with small amounts of unusual mineral grains in among the granite debris, correlated precisely with beach sands described in prewar geological reports from two locations on the east coast of Japan. Air photographs identified hydrogen production plants at these locations, which were then targeted and destroyed.
Recently, a reader of this blog, a self-confessed “WWII history buff” sent me a series of photographs and asked for my views on whether there was any chance of figuring out the provenance of the sand grains shown at the head of this post. And where did these grains find themselves used as a military application? As camouflage on a German helmet: