We propose that the level at which the conodont species Idiognathodus simulator (Ellison 1941) (sensu stricto) first appears be selected to mark the base of the Gzhelian Stage, because we believe that this is the ...We propose that the level at which the conodont species Idiognathodus simulator (Ellison 1941) (sensu stricto) first appears be selected to mark the base of the Gzhelian Stage, because we believe that this is the optimal level by which this boundary can be correlated. This taxon has a short range and a wide distribution, as shown by correlation of glacial-eustatic cyclothems across the Kasimovian-Gzhelian boundary interval among Midcontinent North America and the Moscow and Donets basins of eastern Europe, based on scale of the cyclothems along with several aspects of biostrati- graphy. Outside of these areas, I. simulator (sensu stricto) is known also from other parts of the U.S., and is reported from the southern Urals and south-central China in its expected position between other widespread taxa. Its first appearance is consistent with the current ammonoid placement of the boundary (first appearance of Shumardites cuyleri), and it is also compatible with certain aspects of the distribution of Eurasian fusulinid faunas (e.g., lectotype ofRauserites rossicus).展开更多
The accretionary complex related to the Paleo-Tethys subduction was developed along western margin of the Indochina Block in northern Thailand. The provenance,source rock compositions,and sediment supply system of the...The accretionary complex related to the Paleo-Tethys subduction was developed along western margin of the Indochina Block in northern Thailand. The provenance,source rock compositions,and sediment supply system of the accretionary展开更多
A rich foraminiferal assemblage,consisting of abundant Aulotortus sinuosus and A.tumidus in association with Lamelliconus multispirus,Endoteba ex gr.controversa,E.ex gr.badouxi,Endotebanella kocaeliensis,Endotriada ty...A rich foraminiferal assemblage,consisting of abundant Aulotortus sinuosus and A.tumidus in association with Lamelliconus multispirus,Endoteba ex gr.controversa,E.ex gr.badouxi,Endotebanella kocaeliensis,Endotriada tyrrhenica,Endotriadella wirzi,Malayspirina fontainei,Ammobaculites rhaeticus,Diplotremina astrofimbriata,Agathammina austroalpina,and others,was found in the Doi Long Formation of the Triassic Lampang Group,Northern Thailand.These foraminifers suggest that the formation is referable to the Carnian(early Late Triassic),which is consistent with the age estimated by ammonoids.In microfacies,peloidal grainstone,bioclastic grainstone,sponge-microbial boundstone,and oolitic grainstone were recognized in the Doi Long Formation.Based on microfacies,three depositional facies,the lagoon facies,reef facies,and shoal facies,are recognized in this formation.These lines of evidence are suggestive that the Doi Long Formation was deposited in a reef or bank setting rather than a ramp setting.展开更多
Tectonic subdivision of mainland Thailand has been discussed by means of Paleozoic and Mesozoic stratigraphy,micropaleontology represented by foraminiferal and radiolarian biostratigraphy and paleobiogeography,tectoni...Tectonic subdivision of mainland Thailand has been discussed by means of Paleozoic and Mesozoic stratigraphy,micropaleontology represented by foraminiferal and radiolarian biostratigraphy and paleobiogeography,tectonic settings of granitoids,展开更多
The Inthanon Zone of Northern Thailand,originally proposed by Barr and Macdonald(1991),is characterized by the occurrence of Paleo-Tethyan pelagic sediments including Carboniferous-Permian seamount-type carbonate asso...The Inthanon Zone of Northern Thailand,originally proposed by Barr and Macdonald(1991),is characterized by the occurrence of Paleo-Tethyan pelagic sediments including Carboniferous-Permian seamount-type carbonate associated with oceanic展开更多
文摘We propose that the level at which the conodont species Idiognathodus simulator (Ellison 1941) (sensu stricto) first appears be selected to mark the base of the Gzhelian Stage, because we believe that this is the optimal level by which this boundary can be correlated. This taxon has a short range and a wide distribution, as shown by correlation of glacial-eustatic cyclothems across the Kasimovian-Gzhelian boundary interval among Midcontinent North America and the Moscow and Donets basins of eastern Europe, based on scale of the cyclothems along with several aspects of biostrati- graphy. Outside of these areas, I. simulator (sensu stricto) is known also from other parts of the U.S., and is reported from the southern Urals and south-central China in its expected position between other widespread taxa. Its first appearance is consistent with the current ammonoid placement of the boundary (first appearance of Shumardites cuyleri), and it is also compatible with certain aspects of the distribution of Eurasian fusulinid faunas (e.g., lectotype ofRauserites rossicus).
文摘The accretionary complex related to the Paleo-Tethys subduction was developed along western margin of the Indochina Block in northern Thailand. The provenance,source rock compositions,and sediment supply system of the accretionary
文摘A rich foraminiferal assemblage,consisting of abundant Aulotortus sinuosus and A.tumidus in association with Lamelliconus multispirus,Endoteba ex gr.controversa,E.ex gr.badouxi,Endotebanella kocaeliensis,Endotriada tyrrhenica,Endotriadella wirzi,Malayspirina fontainei,Ammobaculites rhaeticus,Diplotremina astrofimbriata,Agathammina austroalpina,and others,was found in the Doi Long Formation of the Triassic Lampang Group,Northern Thailand.These foraminifers suggest that the formation is referable to the Carnian(early Late Triassic),which is consistent with the age estimated by ammonoids.In microfacies,peloidal grainstone,bioclastic grainstone,sponge-microbial boundstone,and oolitic grainstone were recognized in the Doi Long Formation.Based on microfacies,three depositional facies,the lagoon facies,reef facies,and shoal facies,are recognized in this formation.These lines of evidence are suggestive that the Doi Long Formation was deposited in a reef or bank setting rather than a ramp setting.
文摘Tectonic subdivision of mainland Thailand has been discussed by means of Paleozoic and Mesozoic stratigraphy,micropaleontology represented by foraminiferal and radiolarian biostratigraphy and paleobiogeography,tectonic settings of granitoids,
文摘The Inthanon Zone of Northern Thailand,originally proposed by Barr and Macdonald(1991),is characterized by the occurrence of Paleo-Tethyan pelagic sediments including Carboniferous-Permian seamount-type carbonate associated with oceanic