摘要
新疆含油气盆地的主要生油层是古生界,研究盆地的古地温显得尤为重要。 为进一步研究盆地的热史,引进了裂变径迹法,即磷灰石裂变径迹退火带上—下限温度为70～125℃。同石油主要形成于60～140℃之间相接近。此方法还可解决沉积盆地热历史及某些基础地质问题。裂变径迹年龄代表抬升剥蚀以后的地质年龄,可推断抬升剥蚀作用发生的时间。提出了用包裹体溫度认识地热过程。 准噶尔盆地地溫演化可分为三个主要阶段:地槽期(石炭纪时期)古地温梯度8～5℃/100m:山前坳陷期(二叠—三叠纪末)古地温梯度5～3℃/100m:地台期(侏罗—早第三纪)古地温梯度3～2℃/100m。盆地中几个主要凹陷内石炭、二叠系生油岩在二叠、三叠纪时就进入了生油高峰期,因之应特别重视寻找古生新储的油气藏。
The major source beds in the oil— bearing basins of Xinjiang are Paleozoic formations, therefore, it is rather important to study the paleogeothermal regimes of the basins.For the further study of the geothermal histories of the basins, the method of fission scar tracks in apatite is adopted, which suggests that the annealing temperatures (70～125℃) of fission tracks in apatite are within the temperature range (60～110℃) of substantial oil generation. Besides, the method is also used for solving the thermal history and some basic geological problems of sedimentary basins. The age of fission tracks represents the geological age of uplifting and erosion, s(?) it can be used for the timing of uplifting and erosion. The authors suppose a method of reconstructing geothermal history using enclosure temperature.The geothermal evolution of the Junggar Basin is divided into three major phases: a) the geosynclinal phase (Carboniferous Period) with paleothermal gradients, of 8～5 C/100m, b) the foredeep phase (Permian to the end of Triassic Period) with paleothermal gradients of 5～3℃ 100 m, and c) the platform phase (Jurassic to Paleogene) with paleothermal gradient of 3～2℃ 100 m. The Carboniferous and Permian source beds in a few major depressions of the basin reached the oil generation peak stage during Permian and Triassic Periods,therefore, the authors suggest that emphasis should be placed on finding Cenozoic reservoirs coupled with Paleozoic source beds.
出处
《新疆石油地质》
CAS
CSCD
北大核心
1989年第3期67-74,共8页
Xinjiang Petroleum Geology
