CONSIDERAÇÕES SOBRE A DINÂMICA PALEOAMBIENTAL A PARTIR DA ANÁLISE DE DEPÓSITOS DE TANQUE NO SÍTIO PALEONTOLÓGICO JIRAU, MUNICÍPIO DE ITAPIPOCA (CE).

The tank deposits are small sedimentary bodies of quaternary age that fill natural tanks in rocky outcrops, especially granite plains (lajedos) and domes, in the semiarid region of Northeastern Brazil. These deposits are, in most cases, stratified siliciclastic sediments and, eventually, fossiliferous, preserving remains of a diverse prehistoric megafauna that inhabited the area during the Late Pleistocene - Early Holocene. In the present work, the deposit that fills the interior of the fossiliferous natural tank Jirau 01, in the Paleontological Site Jirau - municipality of Itapipoca (CE), corresponds to the main target of investigation. The analysis of samples collected in the field indicates that the depositional dynamics is related to the action of several factors that influenced the surface processes and the transport of sediments in different space-time scales. There is evidence of erosive-depositional pulses, above all, events related to the remobilization of alteration mantles - resulting from physical-chemical weathering around the paleontological site - and flakes of desquamation in a saprolitic state on the side wall of the tank that provided part of the material sediment from the tank deposit. This discussion subsidizes, even at the local scale level, the understanding of the geologicalgeomorphological and paleontological reconstitution of the northeastern semi-arid region. Thus, the theme associated with filling in natural tanks constitutes an important chapter on Quaternary Geomorphology, especially in the Brazilian semiarid region, since such relief features, when completely filled in tend to preserve information about the dynamics of the landscape and its environment. surroundings, helping to reconstitute part of the paleoenvironmental scenario. [ABSTRACT FROM AUTHOR]