The Highland Boundary Fault traverses Scotland from Arran to Stonehaven. It separates two distinctly different physiographic regions: the Highlands from the Midland Valley, but in most places it is only recognisable as a change in topography. Transport in Scotland Timeline of Scottish history Caledonia List of not fully sovereign nations Subdivisions of Scotland National parks (Scotland) Traditional music of Scotland Flower of Scotland Wars of Scottish Independence National Trust for Scotland Historic houses in Scotland Castles in Scotland Museums in Scotland Abbeys and priories in Scotland... Arran shown within Argyll The Isle of Arran (Scots Gaelic: Eilean Arainn) is the largest island in the Firth of Clyde (430 km2). ... Dunnottar Castle Location within the British Isles Stonehaven (Steenhive in the Doric dialect of Scots ) is a town on the North-East coast of Scotland. ... The Scottish Highlands are the mountainous regions of Scotland north and west of the Highland Boundary Fault. ... The Scottish Lowlands, although not officially a geographical area of the country, in normal usage is generally meant to include those parts of Scotland not referred to as the Highlands (or Gàidhealtachd), that is, everywhere due south and east of a line (the Highland Boundary Fault) between Stonehaven and...

Aligned southwest to northeast, from Lochranza on Arran it crosses the Firth of Clyde, via Helensburgh, Loch Lomond, Aberfoyle to Callander, Comrie and Crieff, then forming the northern boundary of the Vale of Strathmore before reaching Stonehaven. To the north and west lie hard Precambrian and Cambrian metamorphic rocks: marine deposits metamorphosed to schists, phyllites and slates. To the south and east are Old Red Sandstone conglomerates and sandstones: softer, sedimentary rocks of the Devonian and Carboniferous periods. Lochranza is a village located on the Isle of Arran in the Firth of Clyde, Scotland. ... The Firth of Clyde is the estuary of the River Clyde, from its upper tidal limit in Glasgow city centre to the outer firth in Argyll and Ayrshire, Scotland. ... Helensburgh (Baile Eilidh in Gaelic) is a Scottish town historically part of Dunbartonshire, but since local government reorganisation in 1995 in Argyll and Bute, on the north shore of the Firth of Clyde. ... Looking south from Inveruglas Bay Loch Lomond (pronounced LOW-mond) is a Scottish loch (or lake) located in both the western lowlands of Central Scotland and the southern Highlands. ... Aberfoyle (Scottish Gaelic: Obar Phuill) is a village in the region of Stirling, Scotland, 27 miles northwest of Glasgow. ... Callander is a burgh in the region of Stirling, Scotland, on the River Teith. ... Comrie is a town in Perthshire, Scotland. ... Crieff is second largest town in the central region of Perthshire Scotland. ... The Precambrian is an informal name for the eons of the geologic timescale that came before the current Phanerozoic eon. ... The Cambrian is a major division of the geologic timescale that begins about 542 million years before the present (BP) at the end of the Proterozoic eon and ended about 490 million years BP with the beginning of the Ordovician period. ... Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means change in form (from the Greek words meta, change, and morphe, form). The protolith is subjected to extreme heat (greater than 150 degrees Celsius) and pressure causing... Categories: Mineral stubs | Metamorphic rocks ... Phyllite Phyllite is a type of metamorphic rock primarily composed of quartz, sericite mica, and chlorite; the rock is intermediate in grade between slate and mica schist. ... Slate Slate is a fine-grained, homogeneous, sedimentary rock composed of clay or volcanic ash which has been metamorphosed (foliated) in layers (bedded deposits). ... The Old Red Sandstone is a rock formation of considerable importance to early paleontology. ... A mineral conglomerate In geology, a conglomerate is a rock consisting of other stones that have been cemented together. ... Sandstone near Stadtroda, Germany Sandstone is an sedimentary rock composed mainly of feldspar and quartz and varies in colour (in a similar way to sand), through grey, yellow, red, and white. ... Two types of sedimentary rock: limey shale overlaid by limestone. ... Disambiguation: Devonian is also an adjective relating to the English county of Devon or the people there. ... The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359. ...

The Highland Boundary Fault was active during the Caledonian Orogeny, a plate tectonic collision which took place from Mid Ordovician to Mid Devonian periods (520 to 400 million years ago), during the closure of the Iapetus Ocean. The fault allowed the Midland Valley to descend as a major rift by as much as 4000 metres and there was subsequently horizontal movement. The Caledonian orogeny is a hypothetical series of events in geologic history explaining a group of highland formations that are very similar in composition, stratigraphy and fossils: the mountains and hills of northern England, Wales, Scotland, Ireland and west Norway. ... Plate tectonics (from the Greek word for one who constructs, τεκτων, tekton) is a theory of geology developed to explain the phenomenon of continental drift, and is currently the theory accepted by the vast majority of scientists working in this area. ... The Ordovician period is the second of the six (seven in North America) periods of the Paleozoic era. ... Disambiguation: Devonian is also an adjective relating to the English county of Devon or the people there. ... Old fault exposed by roadcut near Harrisburg, Pennsylvania. ... USGS image In geology, a rift is a place where the Earths crust and lithosphere are being pulled apart. ... Old fault exposed by roadcut near Harrisburg, Pennsylvania. ...