Abstract

 

Identifying Areas of Hydrothermal Alteration in Tropical Vegetation Using Remote Sensing

 

By

 

David Velez

 

Remote sensing has become an essential tool for the identification of potential targets for mineral exploration.  Landsat and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images can potentially identify geochemical and/or mineralogical anomalies quickly and at low cost over a wide area, and can thereby focus and enhance the efficiency of ground-based exploration techniques.  In tropical and sub-tropical environments where soil and vegetation may be very thick, spectra in remotely sensed images may reveal information about vegetation and plant stress patterns related to hydrothermal alteration and mineralization of the underlying rock.  This therefore could potentially provide a non-invasive technique for exploration in very remote and unexplored regions.  The new Terra platform and the resulting ASTER imagery provide these new potential capabilities, both in terms of spatial and spectral resolution.

 

My research will focus on a region of the Dominican Republic, the southern Santiago Rodriquez-Jicomé (SSRJ) area, which is currently being explored by Unigold Dominicana, S.A.  Landsat 7 and ASTER images will be compared against each other, and compared with alteration zones which have been identified on the ground by Unigold.  Detailed ground surveys will be conducted to look for variations of vegetation types and vegetation stress related to the alteration zones.  These variations will be compared with the remote sensing imagery (Landsat 7 and ASTER) and with pre-existing airborne radiation surveys.  The goal is to identify spectral signatures indicative of vegetation stress or plant homogeneity derived from hydrothermal alteration and mineralization, which may then be applied over a broader area, and to determine which of the image types is most effective for this type of exploration.

 

 

Date:            October 10th , 2003                             Department:               Earth Science

Time:  3:30 pm                                           Major Professor:            Andrew Macfarlane

Place:            University Park, PC 432