Chronology of fluvial erosion. - A scenario of quaternary geodynamics from the model region Baza/Guadix.

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The basin of Baza/Guadix in the northeastern part of Andalusia with a size of about 6000km2 was until the Middle Pleistocene an endorheic depression, into which sediments of all grain sizes originated from the framing mountains were deposited. Deposition started shortly before the Pliocene. Later the basin was captured by the head-waters of the Rio Guadalquivir, which have incised into the sediments to a depth of 300 meters until today. Since the time of capturing, the regressive erosion has reached a river length of more than 90 km. When the capture took place is still subject of intensive scientific discussion, although the assumptions on this vary between 1000 ka and 43 ka. However, it can be assumed that the time of capture was hardly less than 500,000 years ago.In geomorphological research, the concept of backward erosion still leaves many questions unanswered. How, and above all at what velocity, backward erosion takes place has not yet been investigated for the time period under consideration.The aim of the proposed project is to approximate the rate of erosive incision and regressive erosion in this model region and to better delimit the time of capturing. Suitable time markers are the valley fillings of the rivers in the form of terrace deposits, but also the travertine and sinter formations of different generations, which were formed after river incision on the valley flanks as a result of crop-out of springs. We will be able to model the backward erosion by mapping and recording of the valley fillings and by extensive dating. With this approach, the proposed project will significantly expand the ideas and the state of knowledge on the phenomenon of backward erosion and make an important contribution to the quaternary landscape development of this model region.