the British area formed part of a vast and mountainous northern continent. To the south, a marine trough extended across Central Europe, the northern limit of this sea being from the north of Devon to the extreme south-east of England. Gower lay on the southern fringe of the northern land, and powerful rivers poured great thicknesses of sand and mud over Gower and the rest of South Wales. These sediments were predominately red in colour, and subsequently hardened to form the now familiar "Old Red Sandstone", seen today on Cefn Bryn and Rhosili Down. The foundations of Gower were beginning to be laid. On top of the Old Red Sandstone was deposited, in early Carbon- iferous times, some 3,000 feet of light-grey calcareous muds which consolidated to form the Carboniferous Limestone. These deposits were formed in a very shallow and warm sea which had spread northwards into South Wales. This sea abounded in life-corals, crinoids and brachiopods. The fossil remains are visible today in almost all the limestone layers of Gower. At the commencement of Upper Carboniferous times, im- portant changes took place. Appreciable uplift of land to the north resulted in rivers again pouring mud and silt over South Wales, and great deltas were pushed out into the Carboniferous sea. The resulting Millstone Grit is "coarse" and siliceous in areas such as Brynamman and Glynneath, but in Gower it is mainly shaley. As Upper Carboniferous times progressed, the vast deltas and mud flats were periodically clothed with dense vegetation, which accumulated on decay to form the seams of coal in these Coal Measures. Further south, over Devon and Cornwall, violent earth-movements were building up high mountain ranges. Rapid erosion of these mountains resulted in great thickness of sand and silt being carried northwards into South Wales, forming the now familiar Pennant Sandstone (the present foundation of Town- hill). These earth-movements were the preliminary phases of the Armorican Earth Storm which affected many British areas at the close of Carboniferous times. The Devonian and Carboniferous strata were thrown into numerous folds and the beds were also severely upset by fractures or "faults." The displacement of beds often amounted to many hundreds of feet. In the Gower area, the main folds were an intense Cefn Bryn upfold and a downfold in the Gowerton area. Other downfolds included the Oxwich ind Port Eynon synclines, separated by an Oxwich Anticline. Gower became part of a high mountainous mass, and a long period )f active erosion, under mainly desert-like conditions, commenced. [t lasted throughout Permian and much of Triassic times, and, by ate Triassic times, the Gower surface was deeply eroded to almost ts present form. A tremendous thickness of strata had been re- noved from some areas. From the top of Cefn Bryn, for example,
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