STRUCTURAL GEOMORPHOLOGY OF MAMANGUAPE RIVER GRABEN AND ADJACENT AREAS – STATE OF PARAIBA, BRAZIL - DOI 10.5216/bgg.v35i1.35482

Abstract

This present work is based on the morphostructural characterization of Mamanguape River graben, located in  the north portion of the eastern border of the State of Paraíba, northeast of Brazil. By using detailed mapping, we aim to produce quantitative and morphological information, conditioned by the present structural framework of  Mamanguape River graben and its adjacencies. For the elaboration of the cartographic products, three topographic maps, with scale 1:25.000 and 10m equidistance interval of the contour-lines, which covers the whole area  at issue, were entirely digitalized and vectorized. With this scale, it was possible to make an inedited detailed  mapping of Mamanguape River graben and its adjacencies. By using the cartographical products generated, it was  possible to observe and quantify the morphological and morphostructural aspects in the area, such as: discrepant  altimetricdifferencies between its north and south sectors, that run along the adjacency of the graben, abrupt  slopes with more marked declivity on the north sector, hogbacks on shoulders, drainage network assimetric  patterns and anomalous orientations and abrupt inflexions of various fluvial canals and accelerated backings of  drainage headwaters. These characteristics point to the existence of a morphostructural control in the area, once  only the climatic factor would make it impossible the formation of the morphological pattern found on it.

Key words: Mamanguape river graben, Barreiras Formation, coastal tableland.