Cart-ruts in Spain

Abstract

The Padul sector is situated in the south-east of the Granada Basin in the transitional area to the depressed sector of the Alpujarran Corridor, to the east, and the Guadalfeo River which connects to the coast. This sector is formed by rocks of the Betic Internal Zone and others corresponding to the sedimentary infilling of the Betic Neogene basins. The Betic Internal Zone is formed by three superimposed tectonic complexes, which:' from bottom to top are the Nevado-Filabride, the Alpujarride, and the Malaguide. In the Padul area the Malaguide Complex is not conserved, while the Nevado-Filabride Complex forms the higher relief of the Sierra Nevada; which relief is bordered by limestone-dolomitic mountains belonging to the Alpujarride Complex. Therefore, the older rocks of the Padul area correspond to the Alpujarride Complex. In very limited areas there are schist and phyllites attributable to the Paleozoic and to the Triassic, but the more abundant rocks are limestone, dolomite, and limestone-dolomitic marbles, which are more than moo m thick. They date to the middle and late Triassic, that is to say, older than 200 million years ago. They form the high relief of the Silleta and Manar sierras, situated to the north of the Padul and Durcal towns, and they are also present in great measure in the relief of lesser importance situated to the south of Padul where are the cart-ruts. Over the Alpujarride rocks, in much more recent times (9 to 6 million years ago, during the Tortonian and Messinian, both of the late Miocene) were deposited conglomerates, sands and detritic limestones (calcarenites) with shallow marine rests. Over these deposits followed silts and marls, marine, and later lacustrine. From the late Miocene to the present, younger deposits were formed in a smaller area in what is defined as the graben of Padul-Durcal. These sediments correspond to conglomerates, silts, clays, and peat. This peat is nowadays extracted in several areas. In the south border of the Silleta and Manar sierras significant alluvial fans have formed. Their earlier age may date to the Pliocene, but mostly date to the Pleistocene age, and many of them have been active also during the Holocene (the last IO, ooo years) to the present.