摘要
我国地热资源丰富,分布广泛,尤其在一些中新生代沉积盆地中蕴藏着储量相当可观的中低温地下热水资源。通过重点整理分析华北大量油田、矿区及部分地热田的测温资料写成本文。试图通过地温分布规律的研究指出华北地区地热远景区,为进一步勘探开发提供依据。
The Meso-Cenozoic Sedimentary Basins of North China contain abundant geothermal water resources of medium and lower temperature.Since 1979 researches on geotemperature distribution have been carried out in order to study the distribution and formation of geothermal resources and predict their prospects.Including Liaoning,Hebei,Shandong,Henan,Anhui Jiangsu provinces and the Shaanxi-Gansu-Ningxia border region in the west,the Meso-Cenozoic Sedimentary Basins of North China are tectonically located in the eastern part of the China Continent of the Eurasian Plate and belong to part of the North China Block.In Palaozoic this region had the characteristics of a stable platform.Since Mesozoic era the region under study had undergone such a differentiation:the Ordos Basin in the west had been continuing to subside to form a large platform-type depressed basin;meanwhile the North China Basin in the east began to reactivate.A faulted basin of the graben-type consisting of a series of faulted depressions and faulted uplifts was formed.Both the history of geological evolution and the tectonics of the region under study have controlled the geotemperature distribution in this area.On the basis of more than 1300 temperature data measured in the boreholes of the oil and geothermal fields,maps of isotherms at depths of 1000 m and 2000 m respecfively and a geothermal gradient map of the covering strata for the Meso-Cenozoic Sedimentary Basin of North China have been compiled and attached to this paper.These maps show that the Ordos Basin has a temperature of 35-40℃at depth of 1000 m and 65-70℃at depth of 2000 m and a temperature gradient of 2.9℃/100m in the covering strata and that those of the North China Basin are 40-45℃,70-80℃and 3.2-3.3℃/100 m,respectively,that is,the temperature at the same depth and temperature gradient in the covering strata for the later is higher than those for the former.The above-mentioned geotemperature distribution may be explained by the facts that the structures of Ordos Basin are relatively simple and the geotemperature is uniformly distriputed;and in the North China Basin the structures are more complicated with a number of fracture systems,and the temperature distribution is characterized by low-high-low variation corresponding obviously to the depressions and uplifts of the basement.In addition,32 geothermal anomalous areas have been identified in this paper according to a geothermal gradient of more than 4.0℃/100 m.Most of them have an area greater than 50-100km^(2),the maximum being about 700 km^(2).The gradient values of geothermal anomalous areas are usually between 4.0-6.0℃/100m,the highest being up to 8.0-11.0℃/100 m.Studied in this paper are also the main factors controlling the geotemperature distribution of given regions such as the deep structures of the Earth’s Crust,the structural configuration of the basement,the deep-seated structures and the thermal water convection.At the same time,two types of the mechanism for the occurrence of the temperature distribution can be distinguished:the conduction type and the convection type.The later has been considered as the main type in forming geothermal anomaly areas with the development prospects.Based on discussion of the regional geotemperature distribution,and taking into account the favourable condition for the development and utilization,the geothermal water resources have been preliminarily assessed.
作者
王钧
黄尚瑶
黄歌山
汪集旸
Wang Jun;Huang Shangyao;Huang Geshan;Wang Jiyan(Institute of Geology,Academia Sinica;Institute of Geomechanics,Chinese Academy of Geological Sciences)
出处
《地质学报》
1983年第3期304-316,共13页
Acta Geologica Sinica
