Hydrothermal alteration and main structures mapping using TM images in La Primavera geothermal field (Mexico)

Landsat TM images of the La Primavera geothermal field area were used to identify the main structures within the field, andto locate areas that show hydrothermal alteration. The methods used in the processing of the images include univariate andmultivariate statistical analysis, spectral and spatial...

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Detalles Bibliográficos
Autores: T. Fernández de la Vega Márquez, G. Orozco, Rosa María Prol Ledesma
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2001
País:México
Institución:Universidad Nacional Autónoma de México
Repositorio:Redalyc-UNAM
OAI Identifier:oai:redalyc.org:56840301
Acceso en línea:https://www.redalyc.org/articulo.oa?id=56840301
Access Level:acceso abierto
Palabra clave:Ciencias de la Tierra
Mexico
TM images
Geothermal
alteration
remote sensing
Descripción
Sumario:Landsat TM images of the La Primavera geothermal field area were used to identify the main structures within the field, andto locate areas that show hydrothermal alteration. The methods used in the processing of the images include univariate andmultivariate statistical analysis, spectral and spatial enhancement. Vegetation in the area is not composed by wide leaf plants;however, there is interference between the spectra of vegetation and hydrothermal alteration. In order to overcome this interference,the Crosta technique and the Loughlin method were used (Crosta and Moore 1989; Loughlin 1991). As a result, iron oxidesand hydroxyl minerals were detected in the area. The resulting images were displayed in gray tones and false color composites toenhance main structures and the altered rocks respectively.The identified alteration zones were correlated with the discharged flows from the geothermal reservoir, and with the mainstructures that control the permeability of the reservoir and the cap rock; therefore, locating hydrothermally altered rocks in thesurface will help to determine the presence of upflows from the geothermal reservoir.