Geomorfología y sedimentología del sistema de cárcavas en el borde costero al suroeste del Castillo de Araya, Estado Sucre, Venezuela

Abstract

The study area is located in the south-west coast of Araya in Sucre State, between 10° 33’30” N, 10°33’59” N y 64°15’32” W, 64°15’36” W, which it is affected by erosion processes impacting the population center that sits there. Hence the research is to analyze the geomorphological processes developed, based on a model no-experimental and design field, in descriptive and explanatory levels, operationalized in three phases: a) field, to collect 21 samples of surface sediment (0-20 cm) distributed in 12 samples in the first badlands and 9 samples in the second and lift the morphometry of these landforms erosion; (b) image analysis, three stages such as the development of thematic maps from the Topographical maps of Cumana, Geological Araya Peninsula and The Cadastral Charter covered: Punta Caracare; followed by drawing sketches of gullies, from the data collected in the field, refer to height, length and width of the land. Corresponding to the last two variables data were corrected by the equation suggested by Wolf and Ghilani (2008), for data collected on slopes using measuring tape; and finally drawing the sketch of the apical cliff line drawn from the interpretation of the captured images of Google Earth for the years 2003, 2006, 2009 and 2011, based on the proposal of Soriano (2009) and (c) laboratory, to analyze the comportamientode physical properties such as: hygroscopic water content, determined by gravimetric method, based on the arguments presented by Rivera, et al. (2006) and Toledo (2009); size distribution of the particles (Method Bouyoucos) following the protocol reported by Lara (1985); Percentage of dispersion and soil (double hydrometer method) based on the specifications referred by porters and Alva (1999). As for the chemical-mineralogical properties, it was determined from 10 samples analysis of total rocks and clay mineralogy, for both analyzes samples were prepared, processed and analyzed in the laboratory Diffraction x-ray (xrd), assigned to the Departmental Management Exploration pdvsa-intevep. Being used for analysis brand panalytical diffractometer X’Pert model equipped with a curved crystal monochromator graphite (Cu Ka radiation) and operated by the X-Pert Data collector ltu pw3240 / 92 (version 2.2b) software, applying a range scanning of 5 ° θ 45 ° θ. For all rock and 0 2 ° to 35 ° θ clay minerals for less than 2 microns (<2μ) fraction. As to biochemical properties, the organic carbon were analyzed on the floor (COs) using in method Wlakley and Black, reported by Arrieche and Pacheco (sf) and Toledo (2008), and content of organic matter (mo) by the conventional factor Vammelen, referred to by Navarro (2007) and Toledo (2008) and checked against the proposal by palmaven (1992) qualitative scale In general, you have to cliff erosion affected by the retrograde type badlands, It consists of a material silt loam, total analysis rocks which shows an abundance of clay (52%), silicon oxide (28%), calcium carbonate (18%), plagioclase (5%), iron sulfide (5%) and iron carbonate (2%), meanwhile, clays analysis lesser fraction two microns shows as predominant: Kaolinite (47%), Illite (39%), Chlorite (14%), and Smectic (1%). This is a dispersive and expansive regolith, with very low organic matter content, which favors the occurrence of current washout, soil and collapse of rock, possibly detonated from the slight increase in rainfall recorded between July and November, as well as the steep terrain, which has generated a decrease of apical contour, estimated at 1.31 m * year-1.