中文摘要：

油气成藏年龄是石油地质学和同位素年代学共同面临的科学难题之一。本文探讨砂岩储层自生伊利石^40Ar-^39Ar阶段加热技术获得油气成藏年龄的可能性。样品采自南海珠江口盆地第三纪珠海组砂岩储层,采用冷冻加热循环技术缓慢碎裂样品,以减少碎屑长石混入量。释出气体首先经过专门研制的纯化装置,有效地除弃有机杂质气体,然后经过2个NP10Zr/Al泵进一步纯化。06ZJ26I伊利石40Ar-39Ar激光阶段加热分析获得了阶梯状上升的年龄谱。开始3个最低激光能量阶段加权平均年龄（12.1±2.2）Ma（2σ）解释为自生伊利石的最小年龄,可能代表了油气成藏的最大年龄;而较高激光能量阶段坪年龄（98.0±0.9）Ma则代表了砂岩中陆源碎屑长石的年龄。与传统K-Ar法相比,^40Ar-^39Ar法可以揭示伊利石样品更多的年代学信息。

英文摘要：

Timing of petroleum emplacement is one of the important scientific problems in petroleum geology and isotope chronology. This study investigates the possibility of determining the age of petroleum emplacement by an authigenic illite^40Ar-^39Ar laser stepwise heating technique. The sample is from the reservior sandstone of the Tertiary Zhuhai Formation in the Pearl River Mouth Basin. The sandstone was gently disaggregated by repeated freezing-heating in order to reduce the detrital feldspar content. The released gases were first cleaned up through the specific apparatus, and then further purified by two Sacs NP10R Zr/A1 getters. An increasing ladder-shaped age spectrum is obtained for illite 06ZJ26I by ^40Ar-^39Ar laser stepwise heating. The weighted mean age （12. 1±2. 2） Ma （2a） of the three initial lowest laser- power steps is interpreted as the minimum age of authigenic illite, indicating the maximum age of petroleum emplacement. A plateau of （98. 0 ± 0. 9） Ma is determined in high laser-power steps. The plateau age may represent the age of terrestrial detrital feldspar in the sandstone. Compared with the traditional K-Ar method, ^40 Ar^39 Ar stepwise heating provides more precise age dates from illite samples.