Old Red Sandstone

The Old Red Sandstone (English: Old Red Sandstone ), short and Old Red or ORS, is a rock formation of considerable importance to paleontology and historical geology. Of those in England and Scotland widespread rocks, the terms Old Red facies and Old -Red - continent derive that have a far beyond the UK reaching significance in the regional geology of Europe.

History of exploration

The name was used in the geological literature for the first time in 1822 by William Daniel Conybeare and William Phillips.

The fossil content of the rock sequence has been studied intensively by Hugh Miller, Henry Thomas de la Bèche, Roderick Murchison and Adam Sedgwick, and a large part of the stratigraphic debates that time revolved around these rocks. Sedgwick was in 1839 the one who placed the Old Red Sandstone in the Devon. 1841 appeared Hugh Miller's classic work Old Red Sandstone. He described the occurrence in the north along the coast of Scotland, explained the sequence of the various distinguishable rocks and enclosed a detailed description of the fossils contained in it, especially the abundant fish.

Sedimentology and dissemination

The Old Red Sandstone is a predominantly named after its red sandstones and arkoses Gesteinsfazies that was deposited after the Caledonian orogeny in the late Silurian, during the Devonian and lower Carboniferous.

The Old Red facies is dominated by sediments such as sandstones, arkoses, siltstones and conglomerates. You can assign two deposition areas: firstly, the core area in England, Scotland and western Norway showing exclusively marine remote deposits, on the other a vast, bordering on the sea in Devon belt of predominantly red-colored sediment that extends from the south-west England, France, Belgium and Germany can be traced up to the eastern Baltic.

In the core area of the Old Red, the deposits accumulated primarily in sedimentary basins, which were deposited in the area of ​​young mountains after the Caledonian orogeny. The poured into this basin material mostly came from the immediate area, the deposits reached thicknesses of up to 7,000 m. The sequences of the Old Red are divided by unconformities that permit here a rough tripartite division of the Old Red Sandstone. Signs of deposition conditions are cross-bedding, wave ripples and desiccation cracks, which show for the older part of the Old Red along with the low and concentrated to a few spots Fossil guide a formation in rivers and lakes under semi-arid climate. Dune deposits and ventifacts in connection with the formation of extensive soil crusts are the signs that the younger part of the Old Red was deposited in wüstenhaftem climate.

The common red color is caused by iron oxide. Not all rocks of the Old Red Sandstone, however, are colored red, gray mudstones and conglomerates are also not rare. The conglomerates form the often remarkable rock formations, such as the cliffs of Fowlsheugh nature reserve in Kincardineshire.

In older geological publications prior to the formulation of the theory of plate tectonics, the rocks of the so-called Catskill Delta were considered in the Catskill Mountains of the United States as part of the Old Red Sandstone. It is now known that the two stratigraphically not related, but just about the same age and are designed to be very similar due to similar deposition conditions.

Old Red Sandstone as a building material

In areas where the rocks of the Old Red Sandstone are open near or at the surface, the material used as building material for many stone houses. Notable examples can be found in the area around Stirling, Stonehaven, Perth and Tayside. The inhabitants of Caithness at the north-eastern tip of Scotland used the block also to a greater extent.

Famous buildings of Old Red Sandstone

Radiolarite Stratigraphy Perth, Scotland Orcadian Basin
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