Another claim to fame: including Manicouagan Reservoir and Trinity Site in our travels made Rietje and me fairly unique in having trod all five generic types of terrestrial rock (igneous and sedimentary and metamorphic as usual, but also impactite and trinitite). Impactite must have been abundant in the Earth's early phase of bombardment (leaving the many scars still seen on Mercury and the moon), but by now Isle René Levasseur is its major manifestation. Trinitite hopefully remains limited to its site in New Mexico.
Of course we collected this record by traveling abroad. Holland has almost no indigenous rock at or near its surface, and no impactite or trinitite yet (hopefully never). Holland consists of sedimentary sand and clay, except for an outcrop of limestone defining "Maastrichtien" as the last phase of the Cretaceous, some older sandstone, and one Carboniferous site, all in the Southern tip of Limburg. Beyond Winterswijk a layer of Trias limestone ("Muschelkalk") is mined just below the surface. Elsewhere, all rocks were imported. Pebbles were imported by rivers, especially the Maas, along their beds. Granite boulders were imported by ice-age glaciations from Scandinavia; the largest were assembled into about 50 burial monuments by the neolithic Hunebed people ("trechterbekercultuur") about 5000 years ago. Blocks of columnar basalt (a million or so) were imported more recently by the Dutch per barge from Germany to cap river levees and sea dikes. They came from along the Rhine between Mainz and Bonn; their sources are now depleted, manual placement is no longer warranted. Their volcanic origin was identified in 1771 by geologist Rudolf Erich Raspe who later wrote "The Surprising Adventures of Baron Münchhausen". Our claim to fame is based on less extraordinary travel.
Basalt quarry, Vulkaneifel, December 2010 Limestone quarry, Winterswijk, January 2011
Rob Rutten 2017-11-19