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Hidetoshi HARA Koji WAKITA Jun-ichiro KURODA Toshiyuki KURIHARA Katsumi UENO Yoshihito KAMATA Ken-ichiro HISADA Punya CHARUSIRI Thasinee CHAROENTITIRAT Pol CHAODUMRONG 《地球学报》2009,30(Z1):12-12
The Paleo-Tethys formed a large ocean basin that existed between Laurasia and Gondwana during Late Paleozoic to Early Mesozoic times. It opened in the Early Devonian by the rifting of Gondwanaland and closed at around latest Triassic time by the collision of the Cimmerian continent to Laurasia (Metcalfe, 1999). We reconstructed opening and closing process of the Paleo-Tethys in Northern Thailand. 相似文献
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Ken-ichiro Aoki 《Contributions to Mineralogy and Petrology》1970,25(4):284-288
Andesine megacrysts up to 3 cm in size occur sporadically in certain alkali basalts and allied mafic rocks in southwestern Japan. They are sometimes accompanied by megacrysts of mafic minerals and ultramafic and mafic inclusions. Nine andesines have been chemically analysed.From the petrography and chemistry and the results of high pressure experimental work, it is suggested that andesine megacrysts crystallized from alkali basalt magma under dry conditions at a depth of about 30 to 60 km. 相似文献
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K. HISADA L. L. PERCHUK T. V. GERYA D. D. VAN REENEN B. K. PAYA 《Journal of Metamorphic Geology》2005,23(5):313-334
Metapelites, migmatites and granites from the c. 2 Ga Mahalapye Complex have been studied for determining the P–T–fluid influence on mineral assemblages and local equilibrium compositions in the rocks from the extreme southwestern part of the Central Zone of the Limpopo high‐grade terrane in Botswana. It was found that fluid infiltration played a leading role in the formation of the rocks. This conclusion is based on both well‐developed textures inferred to record metasomatic reactions, such as Bt ? And + Qtz + (K2O) and Bt ± Qtz ? Sil + Kfs + Ms ± Pl, and zonation of Ms | Bt + Qtz | And + Qtz and Grt | Crd | Pl | Kfs + Qtz reflecting a perfect mobility (Korzhinskii terminology) of some chemical components. The conclusion is also supported by the results of a fluid inclusion study. CO2 and H2O ( = 0.6) are the major components of the fluid. The fluid has been trapped synchronously along the retrograde P–T path. The P–T path was derived using mineral thermobarometry and a combination of mineral thermometry and fluid inclusion density data. The Mahalapye Complex experienced low‐pressure granulite facies metamorphism with a retrograde evolution from 770 °C and 5.5 kbar to 560 °C and 2 kbar, presumably at c. 2 Ga. 相似文献
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Yoshihito KAMATA Hidetoshi HARA Katsumi UENO Apsorn SARDSUD Thasinee CHAROENTITIRAT Punya CHARUSIRI Ken-ichiro HISADA 《地球学报》2012,33(S1):36-37
The Inthanon Zone of Northern Thailand, origi-nally proposed by Barr and Macdonald (1991), is characterized by the occurrence of Paleo-Tethyan pe-lagic sediments including Carboniferous–Permian seamount-type carbonate associated with oceanic ba-saltic rocks and Middle Devonian–Middle Triassic radiolarian chert (Ueno, 1999; Ueno and Hisada, 2001; Ueno and Charoentitirat, 2011). These pelagic rocks have been mainly studied from the viewpoint of bio-stratigraphy to clarify the duration of their deposition. These studies concluded the Paleo-Tethys to be a vast ocean basin once existed between the Indochina and Sibumasu continental blocks during Devo-nian–Triassic times. 相似文献
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Wirote Saengsrichan Thasinee Charoentitirat Assanee Meesook Ken-ichiro Hisada Punya Charusiri 《Gondwana Research》2011,19(1):47-60
The Thung Yai Group extends over a large area of peninsular Thailand, along the eastern margin of the Shan Thai block. Bound by angular unconformities 300 m thick dominantly detritic brackish to non-marine deposits with few intercalated limestone beds between Triassic marine and Tertiary non-marine sediments, represent the Thung Yai Group that comprises four formations: Khlong Min, Lam Thap, Sam Chom, and Phun Phin Formations. In the Ao Luk–Plai Phraya (ALPP) area, the Khlong Min and Lam Thap formations yield marine, brackish-water and non-marine fossil assemblages. These include trace fossils and for the first time in peninsular southern Thailand, the bivalve Parvamussium donaiense Mansuy, 1914. Based on fossil determinations, the Thung Yai Group has a late Early Jurassic to Early Cretaceous age.Our new observations help unravel the tectonic history of Mesozoic Peninsular Thailand. After the complete closure of the Paleotethys in the Late Triassic, renewed inundation, from the late Early Jurassic to the early Middle Jurassic, brought a regime of shallow to open marine and lagoon sedimentation over northwestern, western and southern peninsular Thailand, in the eastern part of Sundaland bordering the Mesotethys to the west. 相似文献
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Advanced argillic (AA) alteration is developed over a vertical interval of 500 m, above (and enclosing) Late Devonian quartz
monzodiorite intrusions that accompany porphyry-style Cu–Au mineralization at the Hugo Dummett deposit. The AA alteration
is mainly in basaltic rocks and locally extends into the overlying dacitic ash-flow tuff for about 100 m. The AA zone overprints
porphyry-style quartz veins associated with quartz monzodiorite intrusions, but at least partly precedes high-grade porphyry-style
bornite mineralization. Mineralogically, it consists of andalusite, corundum, residual quartz, titanium oxides, diaspore,
alunite, aluminum phosphate-sulfate (APS) minerals, zunyite, pyrophyllite, topaz, kaolinite, and dickite, as well as anhydrite
and gypsum, but is dominated by residual quartz and pyrophyllite. Alteration zonation is not apparent, except for an alunite-bearing
zone that occurs approximately at the limit of strong quartz veining. Whole-rock geochemistry shows that the AA alteration
removes most major elements except Si, Al, Ti, and P, and removes the trace elements Sc, Cs, and Rb. V, Zr, Hf, Nb, Ta, U,
and Th are relatively immobile, whilst light REEs (La to Nd), Sr, Ba, and Ga can be enriched. Middle REEs (Sm to Gd) are moderately
depleted; Y and heavy REEs (Tb to Lu) are strongly depleted except in two unusual samples where middle to heavy REEs are enriched. 相似文献
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Morishita Tomoaki Ghosh Biswajit Soda Yusuke Mizukami Tomoyuki Tani Ken-ichiro Ishizuka Osamu Tamura Akihiro Komaru Chihiro Aari Shoji Yang Hsiao-Chin Chen Wen-Shan 《Mineralogy and Petrology》2018,112(4):521-534
Mineralogy and Petrology - We examine ultramafic and olivine-rich troctolite blocks of the East Taiwan Ophiolite (ETO) in the Lichi Mélange. Although ultramafic rocks are extensively... 相似文献
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Phase analysis in the model K2 O-poor aluminous rock system (FMASH) illustrates the following sequence of reactions during retrograde metamorphism in the Botswanan Limpopo Central Zone:
Opx+Sil+Qtz=Crd ,
Opx+Sil=Spr+Crd ,
Grt+Qtz=Opx+Crd ;
Opx+Crd+W=Ged+Qtz ,
Grt+Opx+Crd+W=Ged ;
and
Grt+Qtz+W=Ged+Crd .
A quantitative petrogenetic grid with phase relations shows that sapphirine results from nearly isothermal decompression in the quartz-undersaturated portions of the grid, and that gedrite formation by reactions (4)–(6) records isobaric cooling from high temperature ( c . 800° C) after the decompression. Conditions for hydration in the western part of the area were 700–800° C and c . 6 kbar, based on microthermometric data and the available garnet–cordierite geothermometer. On the basis of these conditions and predicted thermodynamic properties of gedrite, phase relations in T–XMg space were constructed to investigate the isobaric cooling event. The results are in good agreement with the hydration P–T path. Further, the T–X Mg topologies show that hydration of orthopyroxene in the central part of the area (reaction 4) occurred at about 800° C and c . 5 kbar. Therefore, we conclude that the Botswanan Limpopo Central Zone has suffered isothermal decompression, similar to the Central Zone in South Africa and Zimbabwe, followed by isobaric cooling. The isobaric cooling event in the western (at c . 6 kbar) and central (at c . 5 kbar) parts of the area commenced at nearly the same temperature ( c . 800° C), and appear to be consistent with a tectonic model that involved westward movement (thrusting) of the Central Zone. 相似文献
Opx+Sil+Qtz=Crd ,
Opx+Sil=Spr+Crd ,
Grt+Qtz=Opx+Crd ;
Opx+Crd+W=Ged+Qtz ,
Grt+Opx+Crd+W=Ged ;
and
Grt+Qtz+W=Ged+Crd .
A quantitative petrogenetic grid with phase relations shows that sapphirine results from nearly isothermal decompression in the quartz-undersaturated portions of the grid, and that gedrite formation by reactions (4)–(6) records isobaric cooling from high temperature ( c . 800° C) after the decompression. Conditions for hydration in the western part of the area were 700–800° C and c . 6 kbar, based on microthermometric data and the available garnet–cordierite geothermometer. On the basis of these conditions and predicted thermodynamic properties of gedrite, phase relations in T–X