塔斯曼海构造特征及其演化过程研究

塔斯曼海位于西南太平洋地区，处于印度-澳大利亚板块和西兰板块之间，大地构造背景复杂。该地区是全球油气资源勘探的重点海域之一，但是国内对该地区的研究相当匮乏。本文根据塔斯曼海海域的自由空气重力异常对塔斯曼海海域的构造单元进行了划分，前人关于塔斯曼海的研究主要集中在Resolution海岭北部，我们认为塔斯曼海的范围应包括Resolution海岭以南，麦夸里海岭以西，塔斯曼断裂带以东的区域（即南部次盆）。结果显示，塔斯曼海域及邻区包括3个一级构造单元:东澳大利亚陆缘、西兰板块和塔斯曼海盆，且塔斯曼海盆可进一步划分为西部次盆、东部次盆和南部次盆。本文基于塔斯曼海域90 Ma以来的洋壳年龄数据编制了构造演化图，将塔斯曼海的形成演化过程分为4个阶段:（1）中生代陆内裂谷期（90~83 Ma BP）；（2）塔斯曼海扩张阶段（83~61 Ma BP）；（3）塔斯曼海北部扩张停止阶段（61~52 Ma BP）；（4）塔斯曼海南部改造阶段（52 Ma BP至今）。

Study on structural characteristics and evolution process of the Tasman Sea

Tasman Sea lies in the Southwest Pacific, among the Pacific Plate, Indo-Australia Plate, and Antarctica Plate, where geotectonic background is intricate. It is one of the most important waters for global oil and gas resource exploration, but research on the region is rare in domestic. We identify tectonic elements around the Tasman Sea Basin based on the free air gravity anomaly published on the International Gravimetric Bureau. Predecessors'' research about the Tasman Sea usually focused on the part north of the Resolution Ridge, but we suggest that the Tasman Sea is supposed to include region south of the Resolution Ridge, west of the Macquarie Ridge and east of the Tasman Fault Zone. This region is transformed by intrusion and spreading of the Southeast Indian Ocean Ridge along boundary between the Southwest Pacific Plate and Indo-Australia Plate (the Macquarie Ridge) since about 50 Ma BP. Results show that three class-ltectonic elements in this region and adjacent area are as follows: Eastern Continental Margin of Australia, Zealandia and Tasman Sea Basin (including Western Sub-Basin, Eastern Sub-Basin, and Southern Sub-Basin). In addition, we make 11 evolution process maps of the Tasman Sea by using global crustal age data supplied by the Professor Dietmar Müller of Sydney University. The process shows that evolution of Tasman sea can be divided into four phases: Mesozoic intra-continental rift phase (90-83 Ma BP); expansion phase of the Tasman Sea (83-61 Ma BP); stop expansion phase of north of the Tasman Sea (61-52 Ma BP), transformation of southern sub-basin (52 Ma BP to present).