Since the discovery of cosmic dust from Suzhou A-type granite, a following new problem is whether cosmic dust is preserved in only one type granite or in different types. In order to make the problem clear, the author...Since the discovery of cosmic dust from Suzhou A-type granite, a following new problem is whether cosmic dust is preserved in only one type granite or in different types. In order to make the problem clear, the authors carried out many field and room investigations on I-type granite of western Suzhou, and found out that Suzhou I-type granite also could retain microspherules. Studies about these microspherules indicate that they are of ablated cosmic dust.展开更多
Several of the known over 3000 minerals possess great typomorphic implication and experienced twists and turns of their discovery. Ringwoodite is the most outstanding of them. In 1931, Goldshmidt suggested that the cr...Several of the known over 3000 minerals possess great typomorphic implication and experienced twists and turns of their discovery. Ringwoodite is the most outstanding of them. In 1931, Goldshmidt suggested that the crystal structure of Mg<sub>2</sub>GeO<sub>4</sub> could show two polymorphs for olivine and spinel. Based on this, in 1936, J. D. Bernal put forward his bold assumption that the increase of seismic velocity in mantle is caused by展开更多
A large number of microspherules have been extracted from Suzhou A-type granite bymeans of heavy placer.Both natural surfaces and part sections of 539 microspherules have been observed bySEM.457 microspherules have be...A large number of microspherules have been extracted from Suzhou A-type granite bymeans of heavy placer.Both natural surfaces and part sections of 539 microspherules have been observed bySEM.457 microspherules have been determined by EDX,with some of them by EPMA,XRD and INAA.The results suggest these spherules are of ablated cosmic dust.Among them silicate glassy microspheruleshave been highly enriched in REE and other lithophile refractory trace elements,and REE abundance patternfavors a meteoritic origin as a roughly flat distribution.Ringwoodite has been first found in these glassy mi-crospherules.The composition of these iron spherules is similar to those of the ablated cosmic dust from deepsea and polar ice.Some Fe-Ni spherules and spherules composed of troilite have also been found.This isprobably the first report on various types of cosmic dust extracted from granite.展开更多
The thick loess strata in the Loess Plateau of China, which have not been essentially reformed by internal and external agents, are one of the optimum continental deposits preserving the extraterrestrial materials in ...The thick loess strata in the Loess Plateau of China, which have not been essentially reformed by internal and external agents, are one of the optimum continental deposits preserving the extraterrestrial materials in the last 2.5 Ma. Thus, combining the records with the detailed data of the loess-paleosol sequence, the ages and environmental impacts of the astrogeologic events can be determined.展开更多
基金the National Natural Science Foundation of Chinathe Analytical Foundation of Center for Modern Analysis, Nanjing University.
文摘Since the discovery of cosmic dust from Suzhou A-type granite, a following new problem is whether cosmic dust is preserved in only one type granite or in different types. In order to make the problem clear, the authors carried out many field and room investigations on I-type granite of western Suzhou, and found out that Suzhou I-type granite also could retain microspherules. Studies about these microspherules indicate that they are of ablated cosmic dust.
基金Project supported by the National Natural Science Foundation of China
文摘Several of the known over 3000 minerals possess great typomorphic implication and experienced twists and turns of their discovery. Ringwoodite is the most outstanding of them. In 1931, Goldshmidt suggested that the crystal structure of Mg<sub>2</sub>GeO<sub>4</sub> could show two polymorphs for olivine and spinel. Based on this, in 1936, J. D. Bernal put forward his bold assumption that the increase of seismic velocity in mantle is caused by
基金the National Natural Science Foundation of China
文摘A large number of microspherules have been extracted from Suzhou A-type granite bymeans of heavy placer.Both natural surfaces and part sections of 539 microspherules have been observed bySEM.457 microspherules have been determined by EDX,with some of them by EPMA,XRD and INAA.The results suggest these spherules are of ablated cosmic dust.Among them silicate glassy microspheruleshave been highly enriched in REE and other lithophile refractory trace elements,and REE abundance patternfavors a meteoritic origin as a roughly flat distribution.Ringwoodite has been first found in these glassy mi-crospherules.The composition of these iron spherules is similar to those of the ablated cosmic dust from deepsea and polar ice.Some Fe-Ni spherules and spherules composed of troilite have also been found.This isprobably the first report on various types of cosmic dust extracted from granite.
基金Project sponsored by the foundation of Xi'an Laboratory of Loess and Quaternary, Academia Sinica and by the foundation of the Laboratory of Geomechanics Ministry of Geology and Mineral Resources PRC
文摘The thick loess strata in the Loess Plateau of China, which have not been essentially reformed by internal and external agents, are one of the optimum continental deposits preserving the extraterrestrial materials in the last 2.5 Ma. Thus, combining the records with the detailed data of the loess-paleosol sequence, the ages and environmental impacts of the astrogeologic events can be determined.
