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The Geology of D-Day (June 6, 1944)

June 6, 1944 – in planning for D-Day – also geology was considered, as aerial photographs of the shores of Normandy were studied to find suitable landing sites for the invasion.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


June 6, 1944 - in planning for D-Day - also geology was considered, as aerial photographs of the shores of Normandy were studied to find suitable landing sites for the invasion.

The confluence of larger rivers with the English Channel between the harbors of Le Havre and Cherbourg created sandy shorelines were a landing with amphibious vehicles was possible. In January 1944 British divers risked their lives to collect samples from selected sites; geologists had to determine if the sandy shores could in fact support the heavy equipment and modified tanks needed to overrun the local German coastal fortifications.

44 years later, June 1988, Earle F. Mc Bride and M. Dane Picard, geologists and passionate sand collectors, collected some sand from one of the most contested landing sites - "Omaha Beach". Studying the sand at first they didn´t find something unusual: the sand reflects the catchment area of the rivers and the marine environment - and is composed of grains of quartz, feldspar, limestone and fragmented shells. However the geologists found also magnetic grains and small spheres of iron and glass, realizing that those are particles generated from the battles during D-Day: fragments of the metallic shells and quartz sand melted by the heat of explosions.


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In September 2013 artists Andy Moss and Jamie Wardley, with the help of many volunteers, used the same sand to create a memorial to the fallen soldiers.

The landing of the infantry at D-Day was accompanied by a bombardment to create a breach in the coastal artillery. One of the most strategic important locations was Pointe du Hoc, a rocky peninsula overlooking the Omaha Beach sector, supposedly fortified with heavy artillery.

The scars left there by the bombs and grenades are still visible today. In 2006 geographers Joseph Hupy and Randy Schaetzelintroduced the term "bombturbation" to describe this modern trace fossil.

Also the geology of the inland proved to be of strategic importance. The Calvados plateau, located northwest of the city of Caen, is formed by limestone of Jurassic age covered by a layer of loess deposited there during the last Ice Age. This flat and dry terrain was an ideal surface to build there the airfields to ensure the fast transport of troops by the British air force. After the successful invasion of Normandy, the military geologists had to identify suitable rocks for buildings and construction works. New boreholes were drilled to get to the local aquifers and provide the ever growing number of soldiers with enough drinking water.

Geology didn´t play only a role in the past. Maybe the tiny metallic and glass particles in the sand and the bomb craters in the ground will survive some centuries or millennia before disappearing - the fragments worn away by the incessant motions of the waves and tides, the craters filled with new sediments, maybe some will even become part of the geological record - the rocks as silent testimonies of human warfare…

My name is David Bressan and I'm a freelance geologist working mainly in the Austroalpine crystalline rocks and the South Alpine Palaeozoic and Mesozoic cover-sediments in the Eastern Alps. I graduated with a project on Rock Glaciers dynamics and hydrology, this phase left a special interest for quaternary deposits and modern glacial environments. During my research on glaciers, studying old maps, photography and reports on the former extent of these features, I became interested in history, especially the development of geomorphologic and geological concepts by naturalists and geologists. Living in one of the key area for the history of geology, I combine field trips with the historic research done in these regions, accompanied by historic maps and depictions. I discuss broadly also general geological concepts, especially in glaciology, seismology, volcanology, palaeontology and the relationship of society and geology.

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