| Abstract: | Geotemperature and heat flow patterns in a large-scale Meso-Cenozoic basin such as the North China Basin are strongly affected by the relief of the basement, and controlled by the contrast of thermal conductivity between basement rock and sedimentary cover. Usually, heat flow observed at the surface of a basement uplift is greater than that of a basement depression. Calculation revealed, that the ratio of the former and the latter is determined by the uplifted height (H) of the bed-rock roof of the basement and the thickness (h) of the sedimentary cover. The relief of the basement also disturbs the geotemperature and, hence, the heat flow patterns at shallow depth. Consequently, the more or less “uniform” one dimensional heat flow from the deep interior of the Earth becomes two dimensional at shallow depth with great lateral and vertical variations. The extent of the disturbed zone is also controlled by the contrast of the thermal conductivity between basement rock and sedimentary cover as well as the uplifted heigh (H) of the bed-rock roof of the basement. Numerical computation demonstrated that the disturbed depth (Ze) is usually about 3–6 times of the uplifted height (H) of a basement uplift. |
