Showing papers in "Journal of Southeast Asian Earth Sciences in 1993"

TL;DR: In this article, 40Ar/39Ar radiometric age-dating results together with petrochemical studies of granitoid rocks from nearly all parts of Thailand strongly indicate that the granite belts (i.e. Eastern, Central and Western) form in different geological and geotectonic environments and show marked contrast in geochronological evolution.

TL;DR: Paleozoic and Early Mesozoic radiolarians are newly recovered from chert and associated fine-grained clastic rocks in Thailand as mentioned in this paper. But the age of these radiolarian rocks is unknown.

TL;DR: The Doi Inthanon complex as mentioned in this paper is composed of a dome-shaped orthogneissic core and mylonitic paragneisses, separated by detachment surfaces from a cover of low-grade to unmetamorphosed sedimentary rocks of mainly Early Paleozoic age.

TL;DR: In this paper, the source of gold is probably from the oceanic lithospheric or lower crustal materials, and the gold was extracted from these materials which were metamorphosed when they were subducted.

TL;DR: Isotopic age determinations were carried out on seven different localities along a cross section through northern Thailand as discussed by the authors, and the obtained data are consistent with the idea of a continuous transpressive regime since Permian/Triassic time resulting in thin-skinned tectonics in the eastern part and ramping, shearing and strong uplifting especially in Tertiary time in the western parts.

TL;DR: The Pearl River Mouth Basin (PRMB) is one of the largest offshore oil-bearing basins in the South China Sea as mentioned in this paper, and it covers an area of 175,000 km2 with the maximum sedimentary thickness of 12 km.

TL;DR: In this article, sedimentologic analysis of the potash-bearing Maha Sarakham Formation (Upper Cretaceous) shows that it is not of marine origin as previously thought.

TL;DR: Tectonic subsidence and subsidence rate analyses were conducted using a forward burial technique for the Cenozoic sediments of the northern Gulf of Thailand, a region presently bounded and intersected by major strike-slip fault systems as mentioned in this paper.

TL;DR: In this article, a dextral shear interacting with the inertia of the largely continental plate were the driving forces of basin genesis and development, setting in train a sequence of temporally and spatially variable tectonic events, diminishing in intensity away from the active plate boundary.

TL;DR: Within the Ratburi Limestone of Central Thailand, a sequence of supratidal to outer platform biofacies is recognized and subdivided on the basis of a particularly abundant and diverse fusuline and calcareous algal biota.

TL;DR: The Phetchabun Basin is a composite of several north-south trending half and full graben, which formed through transtensional dextral shear along the Mae Ping fault zone as mentioned in this paper.

TL;DR: In this article, the Eocene to Pleistocene paleomagnetic results from southeastern Borneo suggest the island has been at its present position with respect to Eurasia since Eocene.

TL;DR: Wang et al. as mentioned in this paper recognized four collision orogenic belts, formed in different geological times, in southeastern China, which constitute a complex tectonic framework and evolutionary history.

TL;DR: The structure, strain history, and metamorphism of a multiple deformed sequence of metagreywacke and phyllite in the Sirikit Dam area have been investigated in this article.

TL;DR: The earliest evidence consists of footprints of small dinosaurs from the Middle to Late Jurassic Phra Wihan Formation as discussed by the authors and the most varied dinosaur assemblage hitherto found in Thailand comes from the Late Jurassic Sao Khua Formation.

TL;DR: Wang et al. as mentioned in this paper classified the Pearl River Mouth Basin (PRMB) crude oils into two types: normal waxy type and cyclic type, which may be caused by minor biodegration and is restricted to the Liuhua District of Dongsha Massif.

TL;DR: Triassic limestone has been found at many localities in Peninsular Thailand and northwest Malaysia, shedding new light on the stratigraphy of the Gulf of Thailand region as discussed by the authors.

TL;DR: Paleomagnetic results from some of these Cenozoic sequences showed that many of the older rocks contain magnetizations which have the same direction as the Mesozoic rocks as discussed by the authors.

TL;DR: The structural history of the area since the Eocene is divided into four phases: Syn-Rift: Early Eocene-Mid-Oligocene Drift: Late Oligocene-mid-Miocene Collision: Mid-Late Miocene transpression: Latest Miocene-Present.

TL;DR: Paleomagnetic data collected from the Krabi, Phetchaburi, and Mae Moh intermontane basins of Thailand display rotations of both senses as discussed by the authors, and they interpret this inconsistency to indicate that the observed Tertiary deflections in these basins are controlled primarily by local rotations in discrete fault zones.

TL;DR: The Ratburi Limestone in Peninsular Thailand is a carbonate deposit formed in an extensive platform setting, suggesting that the Shan Thai craton occupied a subtropical-tropical position at this time.

TL;DR: In this article, preliminary paleomagnetic results from the Lower Triassic limestones in several representative localities of South China support the existence of displaced blocks proposed by Hsu et al.

TL;DR: In this article, an Indonesian-German technical cooperation project between the Directorate of Environmental Geology (Indonesia) and the Federal Institute for Geosciences and Natural Resources (Germany) has been conducting a study to improve the conservation and management of the natural resources for regional planning in the Bandung Basin.

TL;DR: Already, important modification of the geographic distribution of some species have been discovered which testify that during the Pleistocene, significative climatic changes have affected Southeast Asia.

TL;DR: In this article, the parent magma of the Balda leucogranite was fractionated and enriched in volatile contents at the end stage of its evolution, and the chemical variation within the two plutons studied support an in-situ crystal fractionation model combined with a variable degree of metasomatism of ERG after its emplacement.

TL;DR: The faunas contain fusulinids, smaller foraminifera, algae, some corals, bryozoa, echinoids and shell fragments as discussed by the authors.

TL;DR: In this paper, a microprobe analysis of clinopyroxenes from pyroxenites, metagabbros and amphibolites outcropping along the Bentong-Raub belt indicates that these rocks are alkaline to sub-alkaline.

TL;DR: In the early Permian, marginal buildups were formed mainly by fossiliferous grainstones with boundstones occurring only as small biostrome as mentioned in this paper, which are matrix rich with bryozoa, the main skeletal element and Tubiphytes, the main binding element.

TL;DR: The dismembered Angat Ophiolitic complex (DAOC) is made up of pillow basalts with associated sediments, sheeted diabase dike complex and massive/layered gabbros.

TL;DR: In this article, an overview of the physical and climatic setting, the geologic and geomorphic setting, and the weathered soil and colluvial material of this area are presented.