青海当金山口-四川黑水大地热流研究

Heat flow Study of Dangjinshankou-Heishui Profile

在青海当金山口—四川黑水剖面（GGT）区带内大地热流测量的基础上,采用布拉德数值分析法对地温梯度进行了三维地形校正,对中—新生代孔隙岩石热导率样品进行了饱水校正,取得了满意的效果,获得了10个可信的大地热流值。青藏高原北部平均热流值为51mW·m^（-2）,变动于35～78mW·m^(-2)之间,其中柴达木盆地最低,平均为38mW· m^(-2);东昆仑构造带最高,平均为72mW·m^(-2);柴达木北缘构造带和巴颜喀拉构造带处于二者之间,平均为49mW·m^(-2).这种分布不均一性与各构造单元自身发展及演化过程的差异有关,但更主要的原因来自挽近期构造活动的影响。

Based on borehole temperature logging and thermal conductivity measurement, 10 reliable heat flow values have been determined for the profile from Danjinshankou in Qinghai Province to Heishui in Sichuan Province. The terrain correction of thermal gradient was made by employing three dimensional Bullard method, while the thermal conductivities of porous rocksamples from Mesozoic- Cenozoic sediment were corrected through water saturation experiments. The paper focuses its attention on the heat flow determination along this profile. Results show that the heat flow in the Qinghai area varies from 35 to 78 mW·m-2 with an average of 51 mW·m-2. The Qaidam Basin (QB)is characterized by the low heat flow with an average of 38 mW·m-2. The highest heat flow is observed in the Eastern Kunlun Tectonic Zone (EKTZ). The average heat flow for EKTZ is 72 mW·m-2. The heat flow in the north margin of Qaidam and Bayangela Tectonic Zone lies bettween that of QB and EKTZ. The average heat folw for this part is 49 mW· m-2. From this we can see that the crosswise distribution of the heat flow of Qinghai - Xizang plateau isn't uniform. This kind of un - uniformity is, of course, connected with the development of each structural element itself and the difference of evolutionary pro-cess, but the main reason is from the effect of tectonic movement during the neoid period.