Therefore, hydrothermal alteration
reserves (sericite, biotite, K-feldspars and several K-bearing clay minerals) can be identified and mapped by using spectrometric data .
These features includes : Thickening (25 to 200 m) of the rhyolitic units; Hydrothermal alteration
of the rhyolites (Ishikawa Index > 80 %); Existence of favorable horizons (exhalites); Existence of massive sulphides grading: 11.
Episyenitization is a hydrothermal alteration
process during which quartz is dissolved by fluid-rock interaction.
MONITORING HYDROTHERMAL ALTERATION
IN ACTIVE VOLCANOES USING REMOTE SENSING: THE CASE OF TURRIALBA VOLCANO (COSTA RICA)
In addition, celadonite is a typical hydrothermal alteration
product of marine basalts in the field veinlets (Andrews, 1980; Delmont, 1985; Staudigel et al.
The project hosts two large hydrothermal alteration
systems that are the focus of exploration.
Most samples indicated widespread hydrothermal alteration
consisting of argillic and potassic alteration and the formation of extensive quartz breccias.
More detailed examination of a single plutonic-volcanic complex allows testing for local versus regional patterns of hydrothermal alteration
The present study reports the laboratory simulation of the hydrothermal alteration
of Neogene sedimentary and pyroclastic rocks exposed around the Sochagota Lake (Paipa, Boyaca) to zeolites to understand the geological conditions controlling their formation.
All the surveys have returned anomalous gravity lows, typically located at the intersections of structural trends and potentially indicative of hydrothermal alteration
related to uranium deposits in the area.
plagioclase-augite-hypersthene-opaque (FIGURE 3) Ancient lava flows usually show hydrothermal alteration
, while young lava flows are usually unaltered; however, young lava flows show locally thin exudation layers in cooling fractures where sulfur, sulfates and salts have been deposited (FIGURE 4).
Resistivity is the geophysical technique of choice in the Athabasca Basin due to its ability to image hydrothermal alteration
systems, which form resistivity "chimneys", often associated with fault zones and unconformity-type uranium deposits.