medieval-atlas/introductory/8

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Land-and sea-level changes The last major valley glaciers in Scotland melted around 10,000 bc (by uncalibrated radiocarbon dating). For several millennia, a race ensued. Sea level rose sporadically, as ice masses elsewhere melted. and restored their water to the world's oceans. The earth's crust in Scotland was also rising, but not equally in all places: recovery tended to be greater where the ice loading had caused the most depression. Towards the periphery ofScot land, the overall result tended to be submergence, but every-~ where the sequence was complex and raised beaches are wide-~ spread. Often their sands have improved land use potential, by J) lightening glacial tills (for example, in the Fringe 0' Gowd round 'J the East Neuk of Fife). The carse clays (which are shown in the last map) are another kind of legacy of agricultural importance: rich estuarine muds largely emerging above sea-level from around 4000 bc (radiocarbon dating). For example, the carselands flanking the meanders east of Stirling were highly regarded: "The links 0' Forth are worth an Earldom in the North." This potential was not always realised, however. Thus west of Stirling the deep peat that had colonised the carse surface was not cleared until the eighteenth century and even now Lochar Moss still covers much of the carse by Dumfries. The first map shows the distortion over the last six thousand years or so: this is shown by the uplift contours derived from the main post glacial shore lines. The two remaining maps show the Dumfries area as an example of the extent to which parts of Scotland's coastline have changed during the period of known human occupation. Scotland: uplift cOlllltours Dumfries area CarseClay ~ Before deposit of carse clay After d.eposit of carse clay lAM

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