Geodiversity assessment of the Xingu drainage basin

Abstract

Geodiversity is a recent concept that refers to the abiotic variety of nature. It is defined as the range of geological (rocks, minerals, fossils), geomorphological (landforms, processes) and soil features, including their assemblages, relationships, properties, interpretation and systems. In this work, a method of quantitative assessment of geodiversity was applied to the Xingu drainage basin (Amazônia – Brazil). The method is based on the quantification and integration of abiotic features represented on thematic maps at scales ranging from 1:250,000 to 1:2,500,000, overlaid by a 1:25,000 systematic grid. In order to calculate the final geodiversity index, five partial numerical indices representing the main components of geodiversity were drawn compiled: geology, geomorphology, soil, palaeontology and mineral occurrences. The resulting Geodiversity Index map is presented in the form of five isoline classes. The objective of this method is to present such a mapping technique as a tool for environmental planning, particularly for the identification and definition of priority areas for conservation.