Jurassic subduction of the Paleo-Pacific plate in Southeast Asia: New insights from the igneous and sedimentary rocks in West Borneo

Abstract. The non-marine Mesozoic sedimentary rocks of Thailand, which consist of the Indochina block and the Sibumasu block, have yielded several terrestrial and aquatic vertebrate fossils, but only few amphibian remains have been reported. Here, we present an overview on the Thai amphibian palaeo-diversity based on the literature, re-examination of published material, new findings, and unpublished material. Thai amphibian fossil remains are assigned to Stereospondyli (Cyclotosauridae, Plagiosauridae, and Brachyopoidea) and Anura and were discovered from four formations, ranging from the Upper Triassic to Lower Cretaceous of Thailand. The occurrence of Brachyopidae in Thailand, which are related to Chinese forms, supports the previous hypothesis of physical connections between the Indochina blocks and the Sibumasu block during the Mesozoic era.

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On The Possibility of an Autonomous History of Modern Southeast Asia

Journal of Southeast Asian History ◽

10.1017/s0084255900007944 ◽

1961 ◽

Vol 2 (2) ◽

pp. 73-105 ◽

Cited By ~ 2

Author(s):

John R. W. Small

Keyword(s):

Southeast Asia ◽

Contemporary History ◽

The Past ◽

History Of

It is generally accepted that history is an element of culture and the historian a member of society, thus, in Croce's aphorism, that the only true history is contemporary history. It follows from this that when there occur great changes in the contemporary scene, there must also be great changes in historiography, that the vision not merely of the present but also of the past must change.

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Direct Observation of Crystalline Ordering In Naturally Graphitized Carbon Produced by Low Grade Metamorphism

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078377 ◽

1977 ◽

Vol 35 ◽

pp. 162-163

Author(s):

Thomas R. McKee ◽

Peter R. Buseck

Keyword(s):

Crystallite Size ◽

Sedimentary Rocks ◽

Carbonaceous Material ◽

Low Grade ◽

X Ray ◽

Graphitized Carbon ◽

Transmission Electron ◽

Heat Treated ◽

Commercial Carbon ◽

Metamorphic Zone

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).

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Stabilizing pyritic material

The Paleontological Society Special Publications ◽

10.1017/s2475262200005207 ◽

1989 ◽

Vol 4 ◽

pp. 244-248 ◽

Cited By ~ 2

Author(s):

Donald L. Wolberg

Keyword(s):

Significant Contribution ◽

Organic Materials ◽

Sedimentary Rocks ◽

Iron Sulfides ◽

Decomposition Products ◽

Iron Minerals ◽

Pyrite Formation ◽

Organic Sediments ◽

Freshwater Environments

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.

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