The mineral thermobarometry proposed in literature is used to calculate the equilibrium temperature and pressure of garnet Iherzolite and websterite xenoliths within the Cenozoic kama-fugite from west Qinling, Gansu P...The mineral thermobarometry proposed in literature is used to calculate the equilibrium temperature and pressure of garnet Iherzolite and websterite xenoliths within the Cenozoic kama-fugite from west Qinling, Gansu Province, China. The results show that the equilibrium temperature and pressure of garnet Iherzolites and websterite and 1127-1266℃, 2.9-3.6 Gpa and 1169 -1248℃, 2.8-3.2 Gpa respectively. The equilibrium peressures reach or exceed the equilibrium peressure of spinel Iherzolites (2.0-3.0 GPa), and fall into the stability range of garnet peridotite. The equilibrium temperature of the xenoliths reach or exceed the ocean geotherm, identical with the melting temperature of kamafugite magma determined by experiments under the conditions of post-orogenic lithosphere extension. So the thermal state of Cenozoic mantle of the west Qinling may be fit to generate the kamafugite magmatism. The research on petrology-mineralogy and geobarothermometry of the xenoliths shows that both garnet Iherzolite展开更多
Cenozoic basalts in the eastern part of Liaoning-Jilin contain abundant mantle-derived inclusions. The rock types of the ultramafic inclusions are composed mostly of spinel lherzolite and a few websterites. In order t...Cenozoic basalts in the eastern part of Liaoning-Jilin contain abundant mantle-derived inclusions. The rock types of the ultramafic inclusions are composed mostly of spinel lherzolite and a few websterites. In order to study the origin of inclusions, the concnetrations of several trace elements have been measured in samples by NAA. According to geochemical characteristics of trace elements, there are two types of spinel Iherzolite inclusions. The first type is refractory residues left after partial melting of the upper mantle and the second type is metasomatizing refractory residues. The websterites inclusions formed by segregation of basaltic melt derived from high degree of melting of mantle source rocks.展开更多
基金the Major State Basic Research Development Program(G1998040800), the National Natural Science Foundation of China (Grant No. 49973014) and Qinghai-Xizhang Plateau Special Project of Ministry of Land and Resources (200101020404).
文摘The mineral thermobarometry proposed in literature is used to calculate the equilibrium temperature and pressure of garnet Iherzolite and websterite xenoliths within the Cenozoic kama-fugite from west Qinling, Gansu Province, China. The results show that the equilibrium temperature and pressure of garnet Iherzolites and websterite and 1127-1266℃, 2.9-3.6 Gpa and 1169 -1248℃, 2.8-3.2 Gpa respectively. The equilibrium peressures reach or exceed the equilibrium peressure of spinel Iherzolites (2.0-3.0 GPa), and fall into the stability range of garnet peridotite. The equilibrium temperature of the xenoliths reach or exceed the ocean geotherm, identical with the melting temperature of kamafugite magma determined by experiments under the conditions of post-orogenic lithosphere extension. So the thermal state of Cenozoic mantle of the west Qinling may be fit to generate the kamafugite magmatism. The research on petrology-mineralogy and geobarothermometry of the xenoliths shows that both garnet Iherzolite
文摘Cenozoic basalts in the eastern part of Liaoning-Jilin contain abundant mantle-derived inclusions. The rock types of the ultramafic inclusions are composed mostly of spinel lherzolite and a few websterites. In order to study the origin of inclusions, the concnetrations of several trace elements have been measured in samples by NAA. According to geochemical characteristics of trace elements, there are two types of spinel Iherzolite inclusions. The first type is refractory residues left after partial melting of the upper mantle and the second type is metasomatizing refractory residues. The websterites inclusions formed by segregation of basaltic melt derived from high degree of melting of mantle source rocks.
