Using geophysical methods in lateritic systems for modeling of landscape evolution in tropical environments

Abstract

The ferricretes, ferruginous laterites are usually found in tropical landscapes commonly occurring in flattened surfaces at different altitude levels and they may present ages ranging from Cretaceous to the Quaternary period. Their genesis can also be initiated at different levels of relief, or by setting up a sequence with different erosion stages generating local formations, stable to the ferricretes formation in a landscape. It is assumed that hot and humid paleoclimatic conditions were ideal for the development of lateritic systems in stable cratons in the tropics. In this context, we seek to study the relationship between the ferricretes levels, stratigraphy and geomorphology of the landscape from shallow geophysical techniques for understanding the vertical and lateral variations in subsurface on Critical Zone Observatory (CZO) in Western Australia that will help build a model of evolution for landscape in the Serra do Espinhaço Meridional (SdEM), Minas Gerais state and to establish possible links between the pedogenetic processes and the old planning surfaces of the South American continent. It is an initiative of using pedogenic materials of preterit origins, dating back beyond the Quaternary period, to study the SdEM landscape. The geomorphological study in the SdEM will include the delimitation of compartments and planning surfaces, addressing possible gaps of these for tectonic movements (neotectonic). Analyses include macro and micromorphological images, chemical and mineralogical composition of the materials. A better understanding of the general composition and development of the SdEM landscape will be achieved by comparing with an overseas area (Western Australia) where the formation history is well understood and documented. This overseas study will help to produce a general concept of the genesis of the deeper subsurface studied within the new CZO of the University Western Australia. Concepts learned and understood in the CZO context will be used in the generating the model of evolution of the landscape in the SdEM. (AU)