Geologic evolution of SE Asia related with Gondwana drift.

我们在泰国和马来西亚的以下地区进行了野外调查，收集了硅质、泥质和碳酸盐岩的微化石。我们还测量了新的地质剖面，查证了地层和地质构造。我们的室内工作才刚刚开始，但我们已经在泰国西北部采集的硅质和泥质岩石中获得了一些放射虫和牙形刺的新材料。我们从清迈北部暴露的方岩中采集样本，获得放射虫化石。这些放射虫代表晚二叠世至早三叠世，能够确定二叠纪和三叠纪的界线。我们的实地调查是在洛伊南部和王萨峰东部进行的。我们收集了许多样品，其中含有较小的有孔虫和毛藻纲，表明石炭系和二叠纪的界限。我们将能够在这些地区的灰岩中建立几乎完整的毛藻纲带。3)泰国半岛南部。在苏梅岛和哈代伊地区进行了古生物收藏。不幸的是，在这些地区暴露的Ratburi灰岩是被侵入的花岗岩变质的，但我们获得了新的岩相资料。4)西北马来西亚。我们在Alor Setar东部地区的Semangool组收集了许多燧石样品。虽然前人的研究认为Semangool组的地质年代为三叠纪，但这些燧石样品大多为中上二叠统。5)马来西亚中部。我们在本东-劳布缝合线一带新采集了大量燧石岩和泥质岩样品。微体古生物学研究将有助于确定西布马苏与东马来亚大陆块体碰撞的时间。6)马来西亚中东部地区。我们在甘榜阿华、珍卡山口和关丹东北部采集了石灰石样本。这些样本中的大多数产生较小的有孔虫和毛藻纲化石。少

We made field survey to collect microfossils from siliceous, argillaceous and carbonate rocks in the following areas of Thailand and Malaysia. We also measured new geologic sections and checked stratigraphy and geologic structure. Our indoor works are just started, but we already obtained some new materials of radiolarians and conodonts in siliceous and argillaceous rocks collected from northwestern Thailand.1)Northwestern part of Thailand. We collected samples to obtain radiolarian fossils from the Fang Chert exposed north of Chieng Mai. These radiolarians are indicating Late Permian to Early Triassic and enable to settle the boundary of Permian and Triassic.2)Northeastern part of Thailand. Our field survey carried out in the southern area of Loei and east of Wang Saphung. We collected many samples containing smaller Foraminifers and fusulinaceans indicating the boundary of Carboniferous and Permian. We will be able to establish almost complete fusulinacean zonations in the Upper Carb … More oniferous and Lower Permian in limestones in these areas.3)Southern Peninsular Thailand. Paleontological collections were made in Ko Samui and the Hatyai area. Unfortunately, Ratburi Limestone exposed in these areas are metamorphosed by intruded granite but we obtained new data concerning lithofacies.4)Northwestern Malaysia. We collected many chert samples of the Semangool Formation in the eastern area of Alor Setar. Although the geologic age of the Semangool Formation was considered to be Triassic by the previous works, most of these chert samples indicate Middle to Upper Permian.5)Central part of Malaysia. We newly collected many chert and argillaceous rock samples from the area along the Bentong-Raub suture line. Our micropaleontological study will contribute to settle the timing of the collision of Sibumasu and East Malaya continental blocks.6)Central and eastern part of Malaysia. We collected limestone samples from Kampong Awah, Jenka Pass and northeast of Kuantan. Most of these samples yield smaller foraminifers and fusulinacean fossils. Less