下扬子区地温场和大地热流密度分布

DISTRIBUTIONS OF GEOTEMPERATURE AND TERRESTRIAL HEAT FLOW DENSITY IN LOWER YANGTZE AREA

根据下扬子区５０余口井温测量资料，从中选取能代表地层温度的井温数据计算地温梯度，在实验室中测量中、新生界的１１０余块砂岩和泥岩热导率及古生界碳酸岩和砂岩１００余块露头样品的热导率．在此基础上，确定了４１口井的大地热流密度值．地温梯度和大地热流密度分布表明，下扬子大部分地区中生代构造热事件伴随的热异常已不明显，而新生代时期岩石层拉张地区─－苏北盆地和郯庐断裂带是高热流密度和高地温梯度区．

Lower Yangtze area is an important region bearing hydrocarbon resources of China. Research on the distributions of geotemperature and terrestrial heat flow density possesses considerable significance in the evaluation of hydrocarbon resources and also in the description of thermal evolution of the lithosphere in this area. In this paper, the authors collect all continuous temperature measurements at more than 50 boreholes and select the temperature measurements which may present the formation temperature to determine gradients of geotemperature. Heat conductivities of over 110 core samples Mesozoic-Cenozoic sandstone or mudstone and over 100outcrop samples of Palaeozoic carbonate or sandstone are measured. Based on these data, values of terrestrial heat flow dinsity are determined at 41 boreholes in this are. The distributions of geotemperature gradients and heat flow densities show that Northern Jiangsu basin and Tanlu fault belt with extension and basaltic eruption in Cenozoic are characterized by high heat flow densities and high geotemperature gradients, and that no obvious thermal anomalies exists in the areas where tectonothermal processes. occurred dominantly in Mesozoic.