The remote prehistory of Scotland Prehistoric Scotland

scotland geologically alien europe, comprising lost sliver of ancient continent of laurentia (which later formed bulk of north america). during cambrian period crustal region became scotland formed part of continental shelf of laurentia, still south of equator. laurentia separated continent of baltica (which later became scandinavia , baltic region) diminishing iapetus ocean. 2 ancient continents moved toward 1 through cambrian , ordovician periods, tectonic folding during silurian pushing first scottish land above water. final collision occurred during devonian period, scottish segment of laurentian plate smashing avalonia (which contained of england , wales), motile subcontinent had joined baltica. impact threw massive chain of mountains (at least tall present-day alps) , saw formation of granitic west highland , grampian mountain chains , (through carboniferous) period of volcanic activity in central , eastern scotland. during permian , triassic periods, iapetus ocean entirely closed, scotland lay near centre of pangaean supercontinent. @ start of tertiary, constructive plate boundary (at tectonic plates move apart) became active between laurentia , eurasia, pushing 2 apart (and parting scotland laurentia). recession opened atlantic ocean first time, , consequent subduction zone @ western plate margin led renewed period of volcanism, time on scotland s west coast, producing fresh mountains on skye, jura, mull, rùm, , arran.

this tectonic activity produced basis of scotland s topography: ancient mountains in north , south of country, partially eroded 400 million years of water , ice wide fertile valley between them, , newer, wilder western terrain. scotland in northern temperate zone, subjected numerous glaciations in neogene , quaternary periods, ice sheets , attendant glaciers carving landscape typical postglacial one, overdeeping river valleys characteristic u-shape , leaving upland areas covered glacial corries , dramatic pyramidal peaks. in lowland areas ice deposited rich fields of fertile glacial till , eroded softer material surrounding extinct volcanoes (particularly older carboniferous ones), leaving many crags.