More than 50000 meteorite samples have been collected in Antarctica since 1969, making meteorite surveys a very important aspect of Antarctic expeditions. The Chinese National Antarctic Research Expedition has collect...More than 50000 meteorite samples have been collected in Antarctica since 1969, making meteorite surveys a very important aspect of Antarctic expeditions. The Chinese National Antarctic Research Expedition has collected more than 12000 meteorites in the Grove Mountains region, where has been confirmed as one of the richest meteorite concentration sites in Antarctica. China, therefore, possesses one of the world’s largest Antarctic meteorite collections and has made substantial contributions to this field of research. We summarize here the Chinese meteorite survey efforts in the Grove Mountains, as well as discuss progress of the classification and investigation of Grove Mountains meteorites. Outlooks are also proposed for the future of Antarctic meteorite work.展开更多
Meteorites provide an important window into the origins and evolution of the solar system. Since the first four meteorites were recovered in Grove Mountains, Antarctica, in 1998, a further total of 12665 meteorites ha...Meteorites provide an important window into the origins and evolution of the solar system. Since the first four meteorites were recovered in Grove Mountains, Antarctica, in 1998, a further total of 12665 meteorites have been collected over seven polar seasons in the Grove Mountains. All of these meteorites are owned and managed by the Chinese Antarctic Meteorite Depository (CAMD) at the Polar Research Institute of China (PRIC). In recent years, another 500 Antarctic meteorites have been classified and characterized based on mineralogy and petrology. In this work we examine four samples that have been identified as terrestrial, and a further 496 samples that have been confirmed as meteorites. These meteorites are further divided into different types:488 ordinary chondrites, one eucrite, one ureilite, one CM2 carbonaceous chondrite, one EH4 enstatite chondrite, one mesosiderite and three iron meteorites. The classification of meteorites not only provides an abundance of fundamental scientific data, but is also significant for introducing meteorites and related scientific knowledge to the publics particularly via the website of Chinese Resource-sharing Platform of Polar Samples for scientific research and education.展开更多
1 Introduction The howardite,eucrite and diogenite(HED)meteorites are ultramafic and mafic igneous rocks and impact-engendered breccias derived from a thoroughly differentiated asteroid 4 Vesta.Diogenites include duni...1 Introduction The howardite,eucrite and diogenite(HED)meteorites are ultramafic and mafic igneous rocks and impact-engendered breccias derived from a thoroughly differentiated asteroid 4 Vesta.Diogenites include dunites,展开更多
Lunar meteorites are fragments of the Moon that escaped the gravity of the Moon following high-energy impacts by asteroids, subsequently fell to Earth. An inventory of 165 lunar meteorites has been developed since the...Lunar meteorites are fragments of the Moon that escaped the gravity of the Moon following high-energy impacts by asteroids, subsequently fell to Earth. An inventory of 165 lunar meteorites has been developed since the discovery and identification of the first lunar meteorite, ALHA 81005, in 1979. Although the Apollo samples are much heavier in mass than lunar meteorites, the meteorites are still an important sample supplement for scientific research on the composition and history of the Moon. Apart from a small amount of unbrecciated crystalline rocks, the majority of lunar meteorites are breccias that can be classified into three groups: highland feldspathic breccia, mare basaltic breccia, and mingled(including fledspathic and basaltic clasts) breccia. The petrography of lunar rocks suggests that there are a series of rock types of anorthosite, basalt, gabbro, troctolite, norite and KREEP in the Moon. Although KREEP is rare in lunar rocks, KREEP components have been found in the increasing number of lunar meteorites. KREEP provides important information on lunar magmatic evolution, e.g., the VHK KREEP clasts in SaU 169 may represent the pristine lunar magma (urKREEP). Six launching pairs of lunar meteorites have been proposed now, along with ten possible lunar launching sites. In addition, symplectite is often found in lunar basalts, which is a significant record of shock metamorphism on the lunar surface. Furthermore, isotopic ages and noble gases not only provide information on crystallization processes in lunar rocks and the formation of lunar crust, but also provide insight into shock events on the lunar surface.展开更多
MIL090036 is a previously unknown meteorite (a feldspathic lunar breccia) that was discovered in Antarctica. The detailed petrography and mineralogy of this meteorite forms the subject of this paper. It has a typica...MIL090036 is a previously unknown meteorite (a feldspathic lunar breccia) that was discovered in Antarctica. The detailed petrography and mineralogy of this meteorite forms the subject of this paper. It has a typical clastic texture that consists of various types of rock debris (e.g. anorthosite, gabbroic anorthosite, gabbro, regolith breccia, troctolite, microporphyritic crystalline impact melt and compound clasts), mineral crystal fragments (e.g. pyroxenes, plagioclase, olivine and ilmenite) and feldspathic glass clasts. The ifne-grained recrystallized minerals and mineral clasts are cemented together in a glassy groundmass. The anorthite content of plagioclase in the gabbro (An81-83) and anorthosite (An88-93) both have relatively low calcium content compared to those from other breccias (An90-98). The pyroxene composition (Fs12-35 Wo3-44 En22-79) in the rock debris, crystal mineral clasts and anorthositic glass clasts are relatively iron-deifcient compared to those from gabbro debris with melt glass (Fs37-65 Wo10-29 En21-49) and groundmass (Fs18-69 Wo3-45 En14-50). In contrast, the pyroxene grains in the gabbroic anorthosite display a narrow compositional range (Fs24-27 Wo7-14 En59-69). Olivine grains in mineral fragments and the groundmass have a wider compositional range (Fo57-79) than those in the rock debris (Fo67-77). The Fe/Mn ratio in olivine is in the range of 47 to 83 (average 76) and 76 to 112 (average 73) in pyroxenes, and hence classify within the lunar ifeld. The characteristics of texture, mineral assemblage and compositions suggest that MIL090036 possibly originated from a region beyond that of the Apollo and Luna samples. Further study of MIL090036 is therefore likely to lead to a better understanding of the geological processes on the Moon and the chemical composition of the lunar crust.展开更多
Ureilites share the characteristics of differentiated meteorites and of primary chondrites. GRV 024237 is a ureilite, which was found in the 19th Chinese National Antarctic Research Expedition (CHINARE), at the No. ...Ureilites share the characteristics of differentiated meteorites and of primary chondrites. GRV 024237 is a ureilite, which was found in the 19th Chinese National Antarctic Research Expedition (CHINARE), at the No. 4 moraine, Grove Moun- tains, Antarctica. GRV 024237 consists mainly of coarse-grained olivine (60 vol%), pigeonite (30 vol%) and opaque minerals (10 vol% ). Tri-junction texture between olivine and pigeonite is common. Carbonaceous materials with minor amounts of troilite and nickel-iron metal were observed as interstitial phases. The Fa value of olivine composition varies from 6.2 to 16.8 from rim to core, but pyroxene is homogeneous in composition, with Fs 14.0 to 15.5. Both olivine and pyroxene have normal extinctions. Net-like iron or limonite veins filled in the fractures of olivine and pyroxene, and no diamond was observed. Based on petrographic and mineralogical features, GRV 024237 is a Type I and Group 2 monomict ureilite.展开更多
1 Introduction M16005 is a lunar meteorite found recently.Optical and microprobe examinations reveal that it is a well consolidated,polymict regolith breccia.M16005 is composed of abundant mineral fragments and a few
1 Introduction Generally,we can observe varying degree of ophitic texture or sub-ophitic texture in unbrecciated basaltic eucrites.However,a few unbrecciated basaltic eucritespossess the special characteristic of crys...1 Introduction Generally,we can observe varying degree of ophitic texture or sub-ophitic texture in unbrecciated basaltic eucrites.However,a few unbrecciated basaltic eucritespossess the special characteristic of crystalloblastic texture by high metamorphism,which are called as granoblastic textured basaltic eucrites(Mayne et al.2009,展开更多
The shock metamorphism of 47 H group chondrites (H-chondrites) from the Grove Mountains including undulatory extinction, planar fractures, mosaic extinction, shock veins and pockets, and dendritic eutectic metal-sul...The shock metamorphism of 47 H group chondrites (H-chondrites) from the Grove Mountains including undulatory extinction, planar fractures, mosaic extinction, shock veins and pockets, and dendritic eutectic metal-sulfide, is observed through optical microscope. The textures and assemblages of shock veins in these H-chondrites are examined by the scanning electron microscope. Based on observations of the above shock effects, the shock stages of the 47 H-chondrites are classified into S1(5), S2(19),S$3(14), S4(8) and S5(1). Of these H-chondrites, GRV 022469 has the highest(S5) shock stage. The comparison of shock stages in these H-chondrites with L group chondrites(L-chondrites) indicates that the shock metamorphism of H-chondrites is relatively low (except for GRV 022469, they are all lower than $5). A scenario for the history of the H-chondrite parent body is proposed that suggests the duration of the shock events in the H-chondrite parent bodies was much shorter than those in L-chondrite parent bodies. Also, the pressure may have been released more quickly, and consequently, the high-pressure phases should be easily preserved. However, the parent bodies of the H-chondrites may have been exposed to high temperatures for a longer time after the shock event, so the high-pressure phases formed by solid transformation might have retro-metamorphosed to low-pressure ones; its peak pressure is estimated to be less than 15 GPa. Wadsleyite was found in a shock vein in GRV022469, as confirmed by the Raman spectrometer. Petrological and mineralogical characteristics support the idea that the wadsleyite was formed by solid-state transformation.展开更多
基金funded by the National Natural Science Foundation of China (Grant nos.41776196 and 41173077)the National Infrastructure Natural Resource Platform for Science and Technology (Grant no.2005DKA2146)
文摘More than 50000 meteorite samples have been collected in Antarctica since 1969, making meteorite surveys a very important aspect of Antarctic expeditions. The Chinese National Antarctic Research Expedition has collected more than 12000 meteorites in the Grove Mountains region, where has been confirmed as one of the richest meteorite concentration sites in Antarctica. China, therefore, possesses one of the world’s largest Antarctic meteorite collections and has made substantial contributions to this field of research. We summarize here the Chinese meteorite survey efforts in the Grove Mountains, as well as discuss progress of the classification and investigation of Grove Mountains meteorites. Outlooks are also proposed for the future of Antarctic meteorite work.
基金supported by the National Natural Science Fund of China (Grant no. 41173077)the Scientific Research Project of Guangxi Colleges (Grant no. KY2015LX119)+1 种基金the National Science and Technology Infrastructure Platform Project (Grant no.2005DKA21406)the Key Laboratory of Geological Fluid and Geological Process at Universities of Guangxi Province
文摘Meteorites provide an important window into the origins and evolution of the solar system. Since the first four meteorites were recovered in Grove Mountains, Antarctica, in 1998, a further total of 12665 meteorites have been collected over seven polar seasons in the Grove Mountains. All of these meteorites are owned and managed by the Chinese Antarctic Meteorite Depository (CAMD) at the Polar Research Institute of China (PRIC). In recent years, another 500 Antarctic meteorites have been classified and characterized based on mineralogy and petrology. In this work we examine four samples that have been identified as terrestrial, and a further 496 samples that have been confirmed as meteorites. These meteorites are further divided into different types:488 ordinary chondrites, one eucrite, one ureilite, one CM2 carbonaceous chondrite, one EH4 enstatite chondrite, one mesosiderite and three iron meteorites. The classification of meteorites not only provides an abundance of fundamental scientific data, but is also significant for introducing meteorites and related scientific knowledge to the publics particularly via the website of Chinese Resource-sharing Platform of Polar Samples for scientific research and education.
基金funded by the National Natural Science Foundation of China (Grant No. 41173077)Chinese science and technology basic conditions platform project of Ministryof Science and Technology (2005DKA21406-9)Science and technology plan projects in guangxi(AD16450001)
文摘1 Introduction The howardite,eucrite and diogenite(HED)meteorites are ultramafic and mafic igneous rocks and impact-engendered breccias derived from a thoroughly differentiated asteroid 4 Vesta.Diogenites include dunites,
基金funded by the National Natural Science Foundation of China(Grant nos.41173077 and 40673055)the National Natural Resources Platform Project of China(Grant no.2005DKA21406-1)the Director Fund Project of Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration(Grant no.13A-01-02)
文摘Lunar meteorites are fragments of the Moon that escaped the gravity of the Moon following high-energy impacts by asteroids, subsequently fell to Earth. An inventory of 165 lunar meteorites has been developed since the discovery and identification of the first lunar meteorite, ALHA 81005, in 1979. Although the Apollo samples are much heavier in mass than lunar meteorites, the meteorites are still an important sample supplement for scientific research on the composition and history of the Moon. Apart from a small amount of unbrecciated crystalline rocks, the majority of lunar meteorites are breccias that can be classified into three groups: highland feldspathic breccia, mare basaltic breccia, and mingled(including fledspathic and basaltic clasts) breccia. The petrography of lunar rocks suggests that there are a series of rock types of anorthosite, basalt, gabbro, troctolite, norite and KREEP in the Moon. Although KREEP is rare in lunar rocks, KREEP components have been found in the increasing number of lunar meteorites. KREEP provides important information on lunar magmatic evolution, e.g., the VHK KREEP clasts in SaU 169 may represent the pristine lunar magma (urKREEP). Six launching pairs of lunar meteorites have been proposed now, along with ten possible lunar launching sites. In addition, symplectite is often found in lunar basalts, which is a significant record of shock metamorphism on the lunar surface. Furthermore, isotopic ages and noble gases not only provide information on crystallization processes in lunar rocks and the formation of lunar crust, but also provide insight into shock events on the lunar surface.
基金was supported by the Natural Science Foundation of China(Grant no.41173077)the Director Fund of Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration(Grant no.13-A-01-02)
文摘MIL090036 is a previously unknown meteorite (a feldspathic lunar breccia) that was discovered in Antarctica. The detailed petrography and mineralogy of this meteorite forms the subject of this paper. It has a typical clastic texture that consists of various types of rock debris (e.g. anorthosite, gabbroic anorthosite, gabbro, regolith breccia, troctolite, microporphyritic crystalline impact melt and compound clasts), mineral crystal fragments (e.g. pyroxenes, plagioclase, olivine and ilmenite) and feldspathic glass clasts. The ifne-grained recrystallized minerals and mineral clasts are cemented together in a glassy groundmass. The anorthite content of plagioclase in the gabbro (An81-83) and anorthosite (An88-93) both have relatively low calcium content compared to those from other breccias (An90-98). The pyroxene composition (Fs12-35 Wo3-44 En22-79) in the rock debris, crystal mineral clasts and anorthositic glass clasts are relatively iron-deifcient compared to those from gabbro debris with melt glass (Fs37-65 Wo10-29 En21-49) and groundmass (Fs18-69 Wo3-45 En14-50). In contrast, the pyroxene grains in the gabbroic anorthosite display a narrow compositional range (Fs24-27 Wo7-14 En59-69). Olivine grains in mineral fragments and the groundmass have a wider compositional range (Fo57-79) than those in the rock debris (Fo67-77). The Fe/Mn ratio in olivine is in the range of 47 to 83 (average 76) and 76 to 112 (average 73) in pyroxenes, and hence classify within the lunar ifeld. The characteristics of texture, mineral assemblage and compositions suggest that MIL090036 possibly originated from a region beyond that of the Apollo and Luna samples. Further study of MIL090036 is therefore likely to lead to a better understanding of the geological processes on the Moon and the chemical composition of the lunar crust.
基金supported by the Pilot Project of Knowledge Innovation Program of the Chinese Academy of Sciences (Grant no.kzcx2-yw-Q08)the National Natural Science Foundation of China (Grant no.40873054)+1 种基金the China Program for International Polar Year 2007-2008the Polar Research Strategic Research Foundation of China (Grant no.20100208)
文摘Ureilites share the characteristics of differentiated meteorites and of primary chondrites. GRV 024237 is a ureilite, which was found in the 19th Chinese National Antarctic Research Expedition (CHINARE), at the No. 4 moraine, Grove Moun- tains, Antarctica. GRV 024237 consists mainly of coarse-grained olivine (60 vol%), pigeonite (30 vol%) and opaque minerals (10 vol% ). Tri-junction texture between olivine and pigeonite is common. Carbonaceous materials with minor amounts of troilite and nickel-iron metal were observed as interstitial phases. The Fa value of olivine composition varies from 6.2 to 16.8 from rim to core, but pyroxene is homogeneous in composition, with Fs 14.0 to 15.5. Both olivine and pyroxene have normal extinctions. Net-like iron or limonite veins filled in the fractures of olivine and pyroxene, and no diamond was observed. Based on petrographic and mineralogical features, GRV 024237 is a Type I and Group 2 monomict ureilite.
基金supported by the National Natural Foundation of China (No. 41173077)Science and Technology Program of Guangxi (No. AD16450001)
文摘1 Introduction M16005 is a lunar meteorite found recently.Optical and microprobe examinations reveal that it is a well consolidated,polymict regolith breccia.M16005 is composed of abundant mineral fragments and a few
基金supported by the National Natural Foundation of China (No. 41173077)
文摘1 Introduction Generally,we can observe varying degree of ophitic texture or sub-ophitic texture in unbrecciated basaltic eucrites.However,a few unbrecciated basaltic eucritespossess the special characteristic of crystalloblastic texture by high metamorphism,which are called as granoblastic textured basaltic eucrites(Mayne et al.2009,
基金supported by the Pilot Project of Knowledge Innovation of Chinese Academy of Sciences (Grant no.KZCX2-YW-110)the National Natural Science Foundation of China(Grant nos. 40673055 and 40473037)the Open Foundation of Key Laboratory of Geological Engineering Centre of Guangxi Province (Grantno. Gui Ke Neng 07109011-K024)
文摘The shock metamorphism of 47 H group chondrites (H-chondrites) from the Grove Mountains including undulatory extinction, planar fractures, mosaic extinction, shock veins and pockets, and dendritic eutectic metal-sulfide, is observed through optical microscope. The textures and assemblages of shock veins in these H-chondrites are examined by the scanning electron microscope. Based on observations of the above shock effects, the shock stages of the 47 H-chondrites are classified into S1(5), S2(19),S$3(14), S4(8) and S5(1). Of these H-chondrites, GRV 022469 has the highest(S5) shock stage. The comparison of shock stages in these H-chondrites with L group chondrites(L-chondrites) indicates that the shock metamorphism of H-chondrites is relatively low (except for GRV 022469, they are all lower than $5). A scenario for the history of the H-chondrite parent body is proposed that suggests the duration of the shock events in the H-chondrite parent bodies was much shorter than those in L-chondrite parent bodies. Also, the pressure may have been released more quickly, and consequently, the high-pressure phases should be easily preserved. However, the parent bodies of the H-chondrites may have been exposed to high temperatures for a longer time after the shock event, so the high-pressure phases formed by solid transformation might have retro-metamorphosed to low-pressure ones; its peak pressure is estimated to be less than 15 GPa. Wadsleyite was found in a shock vein in GRV022469, as confirmed by the Raman spectrometer. Petrological and mineralogical characteristics support the idea that the wadsleyite was formed by solid-state transformation.