Satellite Images: Invaluable Tools for Localizing and Mapping Miocene Calderas Prospected for Epithermal Au in Northeastern Mediterrenean Basin
Abstract
Remote sensing methods combined with field investigations have successfully localized two caldera structures in the 17 my volcanic complex of the island of Lesvos. The junctions of these structures with tectonic lineaments are very important for hydrothermal fluid circulation and deposition of epithermal Au. In the central part of Lesvos island a major caldera structure that of Vatoussa, is traced on SPOT-PAN imagery with an elliptical shape and with its major axis trending northwesterly. The northeastern part of this "nested" caldera, which is a much larger structure and encloses the caldera reported in the literature, is presently under sea level. The Vatoussa caldera is outlined and also encompasses volcanic domes, which are intensely hydrothermally altered. The western caldera wall displays well the radial caldera faults and is also marked by a megabreccia unit. The Stipsi caldera is smaller than reported in the literature with a circular outline intercepted by a major northeasterly trending tectonic zone. Volcanic domes invading the periphery and the caldera floor follow this direction. Remote sensing techniques have localized numerous intense hydrothermal alterations internal and external to the Stipsi caldera.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.V32F..10K
- Keywords:
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- 3665 Mineral occurrences and deposits;
- 8400 VOLCANOLOGY;
- 8494 Instruments and techniques