where did the cambrian period get its name from
Cambrian The Cambrian Period ( /ˈkæmbriən/ or /ˈkeɪmbriən/) was the first geological period of the Paleozoic Era, of the Phanerozoic Eon.[6] The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago (mya) to the beginning of the Ordovician Period 485.4 mya.[7] Its subdivisions, and its base, are somewhat in flux. The period was established (as “Cambrian series”) by Adam Sedgwick,[6] who named it after Cambria, the Latinised form of Cymru, the Welsh name for Wales, where Britain's Cambrian rocks are best exposed.[8][9][10] The Cambrian is unique in its unusually high proportion of lagerstätte sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biology surpasses that of some later periods.[11]
Europe The geological history of Europe traces back to the formation of the Baltic Shield (Fennoscandia) and the Sarmatian craton, both around 2.25 billion years ago, followed by the Volgo–Uralia shield, the three together leading to the East European craton (≈ Baltica) which became a part of the supercontinent Columbia. Around 1.1 billion years ago, Baltica and Arctica (as part of the Laurentia block) became joined to Rodinia, later resplitting around 550 million years ago to reform as Baltica. Around 440 million years ago Euramerica was formed from Baltica and Laurentia; a further joining with Gondwana then leading to the formation of Pangea. Around 190 million years ago, Gondwana and Laurasia split apart due to the widening of the Atlantic Ocean. Finally, and very soon afterwards, Laurasia itself split up again, into Laurentia (North America) and the Eurasian continent. The land connection between the two persisted for a considerable time, via Greenland, leading to interchange of animal species. From around 50 million years ago, rising and falling sea levels have determined the actual shape of Europe, and its connections with continents such as Asia. Europe's present shape dates to the late Tertiary period about five million years ago.[184]