GEOTHERMAL STATE OF DSDP HOLE-395A AND HOLE-534A - RESULTS FROM THE DIANAUT PROGRAM
GEOTHERMAL STATE OF DSDP HOLE-395A AND HOLE-534A - RESULTS FROM THE DIANAUT PROGRAM
复制标题
DOI：
10.1029/92gl00333
复制
发表时间：
1992-03-03
影响因子：
5.2
通讯作者：
BECKER, K
中科院分区：
文献类型：
--
作者：
GABLE, R;MORIN, RH;BECKER, K
从DIANAUT程序确定的热流值提供了深入了解位于大西洋中脊西侧的三个DSDP孔的地热状态。非常低的值（最大20 mW/m2）在3.5百万年中观察到，孔333 A的老地壳随深度而减少，表明由于上洋壳多孔层的冷水循环，基底持续冷却。寒冷的海洋底层水继续侵入断裂的7.3百万年的上层。395 A孔的古老基底，但温度与时间记录显示大规模的温度波动，可能与钻孔对流有关，在500 mbsf和稳定的温度，可能表明缓慢恢复到热平衡，在600 mbsf。534 A孔的老地壳表现出相对稳定的热状态，热流接近传导冷却板的理论值;在该井中记录的热梯度的微小变化可能代表钻孔流体的非常缓慢和微妙的运动。这些最新的结果与几年前获得的结果进行了密切的比较，证明了相对稳定的热制度的存在。
Heat-flow values determined from the DIANAUT program provide insight into the geothermal state of three DSDP holes situated on the western flank of the Mid-Atlantic Ridge. Very low values (20 mW/m2 max.) observed in 3.5-m.y.-old crust at Hole 333A decrease with depth and indicate persistent basement cooling due to cold water circulation in the porous level of the upper oceanic crust. Cold ocean bottom water continues to invade the upper level of fractured 7.3-m.y.-old basement at Hole 395A, but temperature v. time records show large-scale temperature fluctuations, probably associated with borehole convection, at 500 mbsf and stable temperatures, probably indicating a slow return to thermal equilibrium, at 600 mbsf The 154-m.y.-old crust at Hole 534A exhibits a relatively steady thermal state with a heat flow close to theoretical values for a conductively cooling plate; small variations in the thermal gradient recorded in this well probably represent very slow and subtle movement of borehole fluids. The close comparison of these latest results with those obtained several years previously, demonstrates the presence of relatively stable thermal regimes.