在系统分析华北克拉通南部地区现今地温场数据的基础上,对该区现今地温场特征进行了系统的研究,对其控制因素及其油气地质意义进行了探讨。该区现今地温梯度平均为2.69℃/100m,大地热流平均为56.54mW/m^2,地温场特征表现为北高南低,东高西低,与中国东部热盆、西部冷盆相比,华北克拉通南部地区属于一种过渡类型。现今地温场主要受岩石圈厚度、构造特征和地下水活动的影响。华北克拉通南部不同地区热演化过程及其结果不同,开封坳陷、周口坳陷中部局部凹陷带现今地温场代表了该区最高的热演化状态并影响着古生界烃源岩成烃。其他地区现今地温则小于古地温,古地温决定了这些区域古生界烃源岩成烃。
Based on relatively plentiful temperature data, the characteristics of present geothermal field in southern area of the North China Craton are studied systematically, and the controlled factors of the present geothermal field as well as its effect on hydrocarbon generation of the Paleozoic source rocks are discussed. It is showed that the present geothermal gradient and heat flow are 2.69 ℃/100m and 56.54 mW/m^2 , the geothermal field in the northern and eastern areas are higher than the south and west. The geothermal field of studied area belongs to the transitional type between the hot basin in eastern and cold basin in western China. The present geothermal field is controlled by thickness of lithosphere, structural features as well as groundwater activity. Different areas have the different thermal evolution processes and results. The present geothermal temperature is considered as the higher compared with its paleo-temperature in the middle areas of Zhoukou depression and Kaifeng depression, which play an important role in Paleozoic hydrocarbon generation. However, the present geothermal temperature is lower than paleo-temperature in other areas, and the paleo-geothermal field is the key factor for the Paleozoic hydrocarbon generation of the Paleozoic source rock.