Barrandian in the southwest part of Prague and surroundings

Geological history of Prague and the area spreading from here to south west to the town of Pilsen is exceptionally diversified.  A basin occupying the area, known in geological literature as Barrandian, is mostly in-filled with unmetamorphosed rocks of Proterozoic and Palaeozoic age. Enormous number of fossils have been discovered in these rocks, documenting marine environments and orogenic processes which built Barrandian. During the Asynth orogenesis which took place in the end of Proterozoic and the Variscian orogeny which begun in Early Palaeozoic and finished in Devonian a large mountain chain developed there, which was later completely denudated. Later orogenic processes affected Barrrandian only little by tectonical faults, which resulted in movements of its particular blocks. In areas which subsided, peat swamps and lakes formed during Late Palaeozoic. The last marine transgression affected Barrandian during Late Cretaceous.

The left part of the bank of Vltava River west of the Prague City exposes numerous geological profiles in the Barrandian. Prague – Zlíchov, in the locality called Na Dívčích Hradech is where Joachim Barrande first discovered fossils, which he spent then spent the remaining fifty years of his life studying. Most of the area is exposed near to the central part of the Prague Basin, where the youngest fossils crop out.  The axis of the basin is exposed in the railway-cut under the bridge of Buštěhrad Railway in Prokopské Valley. Fossils of the youngest – Srbsko Formation come from there. They contain numerous terrestrial fossil plants which were moved in there.  To the west from here other localities of the Prokopské and Dalejské Valleys are exposed.  In numerous places there variously coloured limestones and shales of Lower Devonian age are exposed. During Silurian near today’s Butovice there was an underwater volcanic center. 420 million years ago there were numerous lava flows on the bottom of the sea and volcanic ash accumulated there. Diversity of life in the Silurian sea, which was situated in the subtropical climate of the Southern hemisphere, is documented by numerous finds of fossil fauna. Prevailing groups were molluscs, brachiopods, trilobites, echinoderms and semichordata. The world known profile – the stratotype of Požáry Formation – is located near Řeporyje. North of Prague-Butovice, there is a table mountain Vidoule. It represents a remnant of Mesozoic sediments – sandy marlstones, sandstones and claystones, which sedimented during Late Cretaceous roughly 90 million years ago. Shells of ammonites, rare finds of fish bones and fossil flora are known from there.

The rock section between the Barrandov Bridge and Velká Chuchle documents classical exposures of Devonina limestones. By sieving of yellowish weathered limestones rich Devonian fauna of corals, bryozoa, brachiopods and echinoderms was gathered from the U Kapličky Quarry. Its diversity mirrors the existence of very dense population of various forms of life on the shallow Devonian sea bottom. The gold-lettered plaque on the Barrande cliff, bearing Barrande's name is a memorial to one of history's best-known palaeontologists. His work publicized the fossils from this area all over the world. The Lochkov limestones deformed into sharp flexures are a result of the Variscian Orogeny, which took place during Middle Devonian. Further against the flow of the Vltava River older rock crops out, like - graptolite shale and diabases (Palaeozoic basalts). They sedimented in Silurian age. The bedding is broken here with numerous faults. In south east wing of Barrandian in Velká Chuchle Late Ordovician sediments – sandstones and shales crop out.  Also there is known rich fossil fauna, with famous trilobites. Old quarries between Velká Chuchle and Slivenec are remarkable geological profiles and palaeontological localities showing Silurian and Early Devonian rocks. The Radotín Valley and adjacent locality Černá rokle are very important from palaeontological point of view. In Černá rokle near Kosoř the black Lochkov Limestone was mined through first half of the 2Oth century for Prague mosaic pavements. In that quarry workers discovered numerous fossils molluscs, trilobites and brachiopods and also fish remains. Nearby in the Orthoceras Quarry near Lochkov, there existed dark limestones overfilled by shells of orthoceras cephalopods, oriented by sea currents. These limestones have been mined since the 18th century in the vicinity of Zadní Kopanina for purposes of decoration.  Also the quarries Na Cikánce are known for their special ping marble, used for decoration. Today, early Devonian limestones on both sides of the Radotín Valley are intensively mined for cement. Further north, in a northern wing of Barrandian Silurian sediments crop out again. Diversified Silurian fauna comes from grey limestones U Zmrzlíku. It consists particularly of cephalopods, molluscs and trilobites; it was intensively collected in the 19th century.