Sands Of Time: The Geology of D-Day

The Rant Foundry Presents: A Special D-Day 75th Anniversary Edition
By JF Dowsett

The June 6, 1944 Allied invasion of France – known as D-Day – was a turning point in the European theater of the Second World War. Upon landing on a 50-mile stretch of Normandy coastline, 150,000 American, Canadian and British soldiers faced the Atlantic Wall, a complex defensive system of fortifications, bunkers, minefields and trenches. Between 1942 and 1944, Nazi Germany had reinforced her European coastal flanks, stationing thousands of troops along the way.

Tschechenigel (Czech hedgehog) at Pas de Calais (image via bunkervliegtuigarcheo.com)

Now 75 years in the past, nearly 10,000 men died that day.

In 1988, American scientists Earle F. McBride and M. Dane Picard visited the infamous Omaha Beach section of the Normandy coast and sampled the sands for microscopic analysis. As they were to write later, “there is more to the legacy than just the memorials: The sand at Omaha Beach retains remnants of the devastation.” When they returned to the lab at the University of Texas at Austin, they were to uncover the legacy that fateful day was to have on the natural environment: a study of the sands “revealed bits of shrapnel, and iron and glass beads that have been reworked by the English Channel’s waters over time, a microscopic record of the battle.”

Magnetic grains discovered in the Normandy beach sediments are the fragments of metallic shells and ammunition, in addition to glass spherules created from melted sand particles caused by the heat from explosions on the shore. Geologists believe that the particulate evidence of the battle will remain locked in the French sands for another 1,000 years.

Omaha Beach sand seen through a binocular microscope. Pastel grains are carbonate rock fragments, carbonate skeletal grains, and iron-oxide-coated quartz grains. Rust coated shrapnel grains are visible in the center of the photo. (image: McBride & Picard)

During the Second World War, the German SS (Schutzstaffel) had a special military geology unit known as the Wehrgeologen which was tasked in 1943 with supervising the construction of the coastal defences or Hindernisbau along the Normandy coast. The obstacles consisted of anti-vehicle as well as anti-personnel devices, featuring an array of concrete, steel, wire, timber and explosives.

Once the United States had been drawn into the conflict, the Allied forces also began using specialized civilian and then later military geologists. In the preparation for the June invasion, British and American geologists studied nearly one million aerial photographs of the Normandy shores, scouring the images for the ideal landing site. British divers had risked their lives in January 1944 collecting soil samples from potential sites, allowing Allied scientists and cartographers to make classified maps of the coast and beaches, displaying the various sediments, currents and other important environmental detail. These maps enabled military planners to select beaches with geological features best suited to a landing, and allowing them to consider such details as the fineness or coarseness of the sand grain, an important factor in maneuverability.

The geologists found what they had been looking for on the beaches between Le Havre and Cherbourg. The Permian-Triassic metamorphic rocks found inland at Normandy turn into the medium-grained sands the invasion planners needed to literally support the landing. The seabound cliffs erode and the rivers and currents deposit their quartz and feldspar on these beaches, delineating a 50-mile stretch of coast. This was divided into five sectors. Three Canadian divisions would land at the Gold, Juno and Sword sectors. Two American divisions would land at the sections of beach named Utah and Omaha.