Northern Thailand resembles the Great Basin of the western

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USA in that it occupies an area of late Cenozoic, north-trending grabens and half-grabens, with a very high geothermal gradient, near the western margin of a continent. Similarities in the tectonic setting of the two regions include their location east of an inactive magmatic arc, the presence of a late Cenozoic transform fault to the west, a marginal basin to the southwest, and existence to the southeast of a major plateau, uplifted in the late Cenozoic. These similarities suggest plate boundary events in and west of northern Thailand, comparable to those in the Great Basin region. Mineral deposits of probable late Cenozoic age in northern Thailand are confined largely to fluorite and antimony; comparison with the Great Basin suggests a possible lineament control on their location. A sence in northern Thailand of the late Cenozoic silver-gold deposits, so widespread in the Great Basin, may reflect the lack of late Cenozoic basaltic and rhyolitic flows forming potential source rocks, although the large basaltic bodies postulated at depth in the region suggest that subsurface precious metal or mercury deposits could be present.

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