中文摘要：

伦坡拉盆地是目前青藏高原唯一获得工业油气流的一个盆地，然而目前有关该盆地古近系主要沉积地层的地层格架划分尚较薄弱且鲜有探讨。选择伦坡拉盆地西伦2井自然伽马测井曲线为研究对象，运用频谱分析、滤波分析以及Fischer图解等方法，建立了井下牛堡组和丁青湖组天文年代标尺，进行了牛堡组和丁青湖组旋回地层层序划分，初步探讨了该盆地可容空间变化、旋回叠加模式以及层序成因机州。结果显示，伦坡拉盆地丁青湖组和牛堡组地层中主要地层旋回周期之比与米兰科维奇地球轨道周期参数之比一致，表明天文轨道周期旋回对伦坡拉盆地陆柏地层的沉积过程具有明显影响。其中，丁青湖组对应于405ka周期保存了约37个长偏心率周期旋回，对应于124.5ka周期发育120个短偏心率旋回，旋回堆积平均速率约为4.75cm／ka，沉积时限约为14.985Ma左右；牛堡组对应于405ka周期发育46个长偏心率旋回，对应于131.5ka周期发育142个短偏心率旋回，旋回堆积平均速率为7.71ca／ka，沉积时限约为18.63Ma左右。丁青湖组与牛堡组均经历了两次较大规模的长周期可容空间上升以及下降的过程，可容空间均呈快速上升一快速下降至缓慢上升一缓慢下降的变化趋势。丁青湖组可划分出2个二级旋回层序、6个三级旋回层序、37个四级旋回层序、120个五级旋回层序及270个六级旋回层序，牛堡组可划分出2个二级旋回层序、8个三级旋回层序、46个四级旋回层序、142个五级旋回层序乖489个六级旋回层序，其中四级旋回层序的发育受长偏心率周期405ka控制，五级旋回层序主要受短偏心率周期控制，而六级高频旋回层序主要受天文轨道轴斜率周期控制。该研究成果为伦坡拉盆地今后油气勘探工作中的地层分析，建立区域内高频层序单元格架等研究提供一种新的方法和手段

英文摘要：

Lunpola basin is the best petroliferous basin in the world with average elevation of about 4600 meters in central Tibet Plateau, however, the paleogene stratigraphic frames in the Lunpola basin is rarely discussed. Natural gamma data of the well Xilun 2 of the Lunpola Basin which possess clearly top and bottom and continuous layers have been analyzed by spectral analysis, filter analysis and Fischer plots. A high- resolution astronomical timescale of each formation is established, the sequence stratigraphy of high-frequency cycles in the Niubao and Dingqinghu Formations is divided, the curve of accommodation and the high-frequency sedimentary cycle Superposition type is identified. The results revealed the production of lacustrine depositional cycles in Lunpola Basin was controlled by the Milankovitch cycles. The Dingqinghu Formation is divided into 37 fourth-order sequence units and 120 fifth-order sequence units using eccentricity cycle curve, and the sedimentary rate is 4. 75 cm/ka during 14. 985Ma. The Niubao Formation is divided into 46 fourth-order sequence units and 142 fifth-order sequence units using eccentricity cycle curve, and the sedimentary rate is 7. 71 cm/ka during 18. 63 Ma. By using Fischer plots, the result indicates that both the Dingqinghu and Niubao Formations represent two long cycles of accommodation changes, which from rapidly rising-rapidly falling to slowly rising- slowly falling. The Dingqinghu Formation can be divided into 2 second-order sequence units, 6 third-order sequence units, 37 fourth order sequence units, 120 fifth-order sequence units and 270 sixth-order sequence units; the Niubao Formation can be divided into 2 second-order sequence units, 8 third-order sequence units, 46 fourth-order sequence units, 142 fifth-order sequence units and 489 sixth-order sequence units. The investigation provides a new effective approach to build the correlating framework of high-resolution sequence in the Lunpola basin.