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
Nan suture in northern Thailand,representing a complex zone with complex geology and structures, has been selected for airborne geophysical investigations.The suture has been widely accepted as an early Triassic colli...Nan suture in northern Thailand,representing a complex zone with complex geology and structures, has been selected for airborne geophysical investigations.The suture has been widely accepted as an early Triassic collision zone between Shan-Thai and Indochina microcontinental blocks.Our field data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
Two ruby-related basaltic fields were recently discovered in the southeast region of Kenya, exposed in the Nguu and Ngulai Hills vicinities. These fields host abundant deep-seated xenoliths, including corundum-bearing...Two ruby-related basaltic fields were recently discovered in the southeast region of Kenya, exposed in the Nguu and Ngulai Hills vicinities. These fields host abundant deep-seated xenoliths, including corundum-bearing granulites. The basalts are alkaline affinity having compositions from foidrite to basanite. The Ngulai basalts have a wider range of SiO2（38.2 wt.%-44.8 wt.%） covering those of the Nguu basalts（38.7 wt.%-42.3 wt.%）. This overlapping behavior also holds for other major oxides and trace elements, e.g., Al2O3, Na2 O, K2 O, Cr, Ni, Rb and Ga. The overall OIB-like incompatible patterns with strong K depletion and slight spike of Ti enrichment signatures imply low degrees of partial melting of the upper mantle region source induced under a mantle plume-related process. The K-depletion signature indicates a residual K-bearing phase still retained in the source domain. Chondrite-normalized REE patterns exhibiting strong LREE enrichment without Eu anomalies suggest that plagioclase fractionation is insignificant. New 40Ar/39 Ar ages indicate eruption events occurred during the Pleistocene times, which are around 2 Ma for the Ngulai basalts and 0.9 to 1.6 Ma for the Nguu basalts. Clinopyroxene-basalt thermobarometric calculations yield the equilibrium P-T ranges of -8-29 kbar and 1 200-1 450 ℃.展开更多
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Nan suture in northern Thailand,representing a complex zone with complex geology and structures, has been selected for airborne geophysical investigations.The suture has been widely accepted as an early Triassic collision zone between Shan-Thai and Indochina microcontinental blocks.Our field data
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
基金financially supported by the Gem and Jewelry Institute of Thailand (public organization) for fieldwork expensesthe 90th Anniversary of Chulalongkorn University Fund (ratchadaphiseksomphot endowment fund) for laboratorial
文摘Two ruby-related basaltic fields were recently discovered in the southeast region of Kenya, exposed in the Nguu and Ngulai Hills vicinities. These fields host abundant deep-seated xenoliths, including corundum-bearing granulites. The basalts are alkaline affinity having compositions from foidrite to basanite. The Ngulai basalts have a wider range of SiO2（38.2 wt.%-44.8 wt.%） covering those of the Nguu basalts（38.7 wt.%-42.3 wt.%）. This overlapping behavior also holds for other major oxides and trace elements, e.g., Al2O3, Na2 O, K2 O, Cr, Ni, Rb and Ga. The overall OIB-like incompatible patterns with strong K depletion and slight spike of Ti enrichment signatures imply low degrees of partial melting of the upper mantle region source induced under a mantle plume-related process. The K-depletion signature indicates a residual K-bearing phase still retained in the source domain. Chondrite-normalized REE patterns exhibiting strong LREE enrichment without Eu anomalies suggest that plagioclase fractionation is insignificant. New 40Ar/39 Ar ages indicate eruption events occurred during the Pleistocene times, which are around 2 Ma for the Ngulai basalts and 0.9 to 1.6 Ma for the Nguu basalts. Clinopyroxene-basalt thermobarometric calculations yield the equilibrium P-T ranges of -8-29 kbar and 1 200-1 450 ℃.
