| Abstract |
There are numerous hot springs in Mongolia, and many are utilized for heating, bathing and medicinal purposes, but there is presently no geothermal electric power utilisation. Feasibility studies for small-scale energy development projects, however, have been conducted by domestic and foreign developers as Mongolia presently depends on non-renewable sources of energy for almost all of its electrical power requirements. National Sanatoriums, which directly utilise thermal waters by shallow (typically <100m) drilling, have been constructed at Tsenkher, Shargarljuut, Khujirt, Zaart, Shivert, Khalzan Uul, Eruu and Tsagaan Khundii; whilst the springs at Tsenkher, Shargarljuut and Khujirt, in particular, have become popular tourist sites. Regional surveys have identified 5 areas (including 43 hot spring fields) with anomalous heat flow characteristics and geothermal resource potential, in the (i) Mongolian Altai (54±24 mW/m2); (ii) Khangai region (52±6 mW/m2); (iii) Khentii region (65±10 mW/m2); (iv) Khuvsgul nuur region (60±12 mW/m2); and (v) Dornod Mongolian region (44±6 mW/m2), which are all associated with Late Cenozoic volcanism and faulting - of these, the Khangai region has attracted most interest for future geothermal development. The Khangai region is subdivided into the Tarbagatai-Uliastai (low flow (0.1-1.5 l/min), <60 ?C, low-Rn, SO4-HCO3 and SO4-Cl springs) and more southerly Baidrag-Tamir/Orkhon-Taats (high flow (up to 50 l/min), 50-98 ?C, high-Rn, HCO3-Na, low salinity/low-Cl springs) area, with many hot spring systems coincident with the intersection of NE-SW and cross-cutting WNW Paleocene faults. There is no obvious heat source for thermal manifestations in the Khangai region (i.e. no active volcanoes), although solute geothermometry indicates reservoir temperatures up to 150 ?C (e.g. at Shargaljuut, Baidrag-Tamir area). The high temperature, high flow springs at Shargaljuut and Tsenkher (Orkhon-Taats) are "high-fluoride" waters, which point to the source of geothermal energy in southern Khangai being conductive heat from magma associated with the Khangai Batholith, linked with the N-S trending Baikal rifting system, and transferred through metamorphosed Palaeozoic rocks to heat meteoric waters that are channeled to the surface via intersecting faults and fractures. |