What is Highland Boundary Fault?
[[Image:Scotland (Location) Named (HR).png|thumb|The main geographical <br>divisions of Scotland]] The '''Highland Boundary Fault''' is a [[Fault (geology)|geological fault]] that crosses [[Scotland]] [[diagonal]]ly from [[Isle of Arran|Arran]] and [[Helensburgh]] on the west coast to [[Stonehaven]] in the east. It separates two distinctly different regions: the [[Scottish Highlands|Highlands]] from the [[Scottish Lowlands|Lowlands]].<ref name='scotgeol'>{{cite web | title=Loch Lomond–Highland Boundary Fault | date=2006-07-20 | publisher=Hunterian Museum and others | url=http://www.scottishgeology.com/outandabout/classic_sites/locations/loch_lomond_fault.html | work=Scottish geology | access-date=2006-12-13 | archive-date=2007-09-27 | archive-url=https://web.archive.org/web/20070927041135/http://www.scottishgeology.com/outandabout/classic_sites/locations/loch_lomond_fault.html | url-status=dead }}</ref><ref name=Worsley>Worsley, Harry ''Loch Lomond: the loch, the lairds and the legends'' {{ISBN|978-1-898169-34-5}} Lindsay Publications (Glasgow) 1988</ref> The geological history of Scotland can be understood as the result of two great [[tectonic]] events. The first was the formation of the global super-continent [[Pangaea]], the second was the break-up of Pangaea to form the continents we know today. The fault is the middle of three great faults which run from the south-west to the north-east across Scotland. In the north there is the [[Great Glen Fault]], and in the south the [[Southern Uplands Fault]]. Further south, just over the border with England, is the [[Iapetus Suture]], where the palaeo-[[Iapetus Ocean]] closed. These four major geological signs mark the ancient history of Scotland. [[Image:Scotland.central.geological.jpg|left|thumb|250px|Geological map of central Scotland. The fault divides the Old Red Sandstone and Devonian deposits (brownish, no. 23, at centre) from the Metamorphic and Archaean deposits (pinkish, no. 27, above the brownish).]] [[Image:Scotland.central.topo.jpg|right|thumb|250px|To