念青唐古拉山前断裂系周围地区的居里等温面与热流分析

CURIE ISOTHERMAL SURFACE AND HEAT FLOW ANALYSIS OF THE ADJACENT REGION OF THE NIANQING TANGGULA PIEDMONT FAULTED ZONES

西安地质学院

念青唐古拉山前断裂系周围地区,包括雅鲁藏布江以北,纳木湖以南,麻江县以东,桑日县以西的整个地区。该区具有独特的地壳构造。本文用航磁异常计算出该地区居里等温面的深度。计算结果表明,在当雄——南木林断裂带(或称念青唐古拉山前大断裂)的西侧为居里等温面的隆起区。该区的居里等温面深度约16公里,地温梯度达40℃/公里以上,热流值达2.5HFU以上。可以认为,这是羊八井地区热田的深部热源。 由航磁异常可以同时推断出念青唐古拉山前断裂带的位置。此断裂带恰好通过居里等温面隆起区的东侧,成为深部热源上涌的通道。因此在此断裂带上,分布有该地区内主要的热田和沸泉,此带的地温梯度达100℃/公里。在此断裂带的西部边界有可能找到有意义的热田。

The adjacent region of Nianging Tanggula Piedmont faulted zones covers the whole area to the north of Yaluzangbu (Yalu Tsangpo) River, the south of Namu Lake, the east of Majiang County and the west of Sangri County. The crust construction of the earth in this area has its own uniqueness. The depth of the Curie isothemal surface of this area has been calculated from the aeromagnetic anomalies. Results show that the west flank of Dangxiong-Nanmuling faulted zone (i. e., the major Nianging Tanggula Piedmont faulted zone is the upwarping region of the Curie isothermal surface. Its depth is about 16 kms, the geothermal gradient is more than 40℃/km and the valves of the heat flow is more than 2.5 HFU. It is considered to be the heat-origin at depth in the region of well Yang No 8.The correct inferences of the location of Nianqing Tanggula piedmont faulted zones can be drawn simultaneously from the aeromagnetic anomalies. It is just passing through the east side of the upwarping area of the Curie isothermal surface and a funnel is being made up for the gushing of the heat at depth. Just for this reason, the heat fields and the boiling springs are mainly distributed in these zones, the geothermal ra-dient there is up to 100℃/Km. From the above analysis, hopefully, some industrial heat fields will be found within the boundary west of the faulted zones.