Remote Sensing Analysis of Lacustrine Carbonates, Namibe

Abstract

This thesis involves analysis of multispectral (Aster images) and field data to identify hydrothermal rocks such as travertines associated with two stages of volcanism from (Precambrian 122ma) and from (Cenomanian-Turonian88ma) in the Namibe basin, southern part of Angola. The images are Aster 8-3-2 false colour high resolution.

A complete aster scene consists of 14 bands. Three bands in the visible and near infrared (VNIR) part of the Electromagnetic spectrum have 15m resolution and an 8 bit unsigned integer data type. Six bands in the short wave(SWIR) have a 30m resolution and also have an 8 bit unsigned integer data type. Finally there are five thermal bands (TIR) with a 90m resolution and have a 16- bit unsigned integer data type. For this work were used image from SWIR bands because of spectral high resolution.

Study of the nature and spatial distribution of specific hydrothermal alteration at hot springs using multispectral remote sensing provides insight into hydrothermal alterations of these systems, and the occurrence and characteristics of hot springs systems, potentially leading to new and/or improved exploration methods for hydrothermal carbonate rocks. Hydrotermal deposits identified by the integrated analysis are consistent with detail published geological map of the study area.