某锡矿区矽卡岩形成过程的特征

锡矿区位于某中生代拗陷带内。区内三迭纪地层(以石灰岩为主,白云岩次之)广泛发育,并普遍受到不同程度褶曲作用。锡矿区一级褶皱构造有背斜与向斜,褶皱轴方向为北东。一级背斜构造又为次一级背斜构造(走向北西)所复杂化。同时在隐伏花岗岩体之     

石灰岩介质中地下核试验熔岩的矿物研究及其形成过程

The melt rocks produced during an underground nuclear explosion in the limestone medium may be classified into three types in the light of thin-section examinations and chemical compositions. One of them is the carbonate melt rock which is distributed widely and very large in quantities. About 20 kinds of monominerals were identified by X-ray powder and electron microprobe techniques. Some minerals, such as moissanite, brownkillerite, Ca12Ah14O33, etc., are rare or have not yet been discovered in nature. In addition, this paper presents the four stages of formation of the melt rocks, i.e., the vaporization-liquefaction stage, the initial crystallization-cavity stripping stage, the crystallization stage, and the chimney formation-thermal metamorphism stags. Furthermore, preliminary theoretical analysis was carried out of the physico-chemical process of mineral formation.     

南极陨石研究的启示Ⅴ：南极铁陨石的化学组成及其分类

报道了５２个南极铁陨石的１３个元素的浓度，并根据其构造和Ｇａ，Ｇｅ，Ｎｉ，Ｉｒ及其它向量元素的含量进行了分类，５２个铁陨石油１６个ＩＡＢ，１２个ＩＩＡＢ，１个ＩＩＥ，３个ＩＩＩＡＢ，１个ＩＩＩＣＤ，１个ＩＶＡ及１８个未分解的化学群组成。ＩＡＢ，ＩＩＩＣＤ及ＩＩＥ为非岩浆成因的铁陨石群，它们是由球粒陨石质母体近表面区冲击产生单独的熔体池形成的，ＩＩＡＢ，ＩＩＩＡＢ及ＩＶＡ显示金属岩浆分离结晶作用的特     

橄辉无球粒陨石的矿物-岩石学特征及其分类

本文主要综述单矿和复矿碎屑橄辉无球粒陨石的矿物-岩石学特征及冲击变质效应,并依据Δ17O,δ13C,mg#[MgO/(MgO+FeO)mol%],稀有气体,辉石丰度及辉石类型讨论橄辉无球粒陨石的分类和成因模式。橄辉无球粒陨石为超基性的岩浆岩,既显示原始无球粒陨石,又显示分异无球粒陨石的一些特征,并认为是来自球粒陨石质母体的部分熔融,大多数典型的橄辉无球粒陨石具单矿碎屑岩的结构,复矿碎屑岩质橄辉无球粒陨石较少,其角砾岩碎片含单矿碎屑岩橄辉无球粒陨石的石屑碎屑及其它物质。橄辉无球粒陨石为原始和分异特征的混合物,其成因模式主要是超基性火成堆积岩或部分熔融的残余。     

Petrology of ureilites from Grove Mountains, Antarctica：Constraints on the origins

Ureilites are a common group of achondrites with a high abundance of carbon. They probably have a genetic relationship with chondrites, hence provide an insight into origin and evolution of terrestrial planets. A new meteorite-rich region, Grove Mountains (GRV), was found by the Chinese Antarctic Research Expedition, with discovery of 9834 meteorites. Of 2433 meteorites classified, 9 ureilites have been identified. In this paper, we report petrography of 6 of these ureilites. Four ureilites contain graphite and exhibit triangle conjunction and common reduced margins of olivine. GRV 052382 probably experienced heavy shock metamorphism followed by fast cooling, as indicated by mosaic texture or fine-grained granular texture of olivine. GRV 022931 was highly reduced of these ureilites, with olivine as isolated grains in abundant carbonaceous matrix. All 9 ureilites are monomict, and are classified into subtype II (with medium FeO content, Fa15-18) and subtype I (with high FeO content, Fa>18) based on compositions of the cores of olivine. The diverse mineral compositions and petrography of these ureilites suggest that they are not paired and reveal a multi-event history of the parent body. Partial melting of the parent body produced carbon-rich magma, followed by crystallization of graphite and silicates. Later, graphite was partially inverted to diamond by shock events. Reburial of the shocked debris experienced various degree of thermal metamorphism. Finally, these rocks were excavated from the parent asteroid and ejected into Earth-cross orbit by another impact event.     

我国铁陨石研究

本文总结回顾了我国铁陨石研究的现状和特点，对比国际研究水平分析了不足和差距。近10年来，我国在单块体铁陨石元素面分布、分类参数、铁陨石母体成因、特殊构造集合体和大气剥蚀消融作用等方面取得了可喜的进展。     

普通球粒陨石的物理和岩石学性质及其分类参数

不同球粒陨石群的物理和岩石学性质,包括球粒的平均大小、球粒结构类型、复合球粒、带火成边球粒及含硫化物的比例、化学组成及矿物学特征等可用以划分球粒陨石的化学-岩石类型和小行星类型,这些性质提供了不同球粒陨石群有用的分类参数及其形成环境的信息.由于不同球粒陨石群的△17O与日心距离存在有相关关系,因此,依据不同球粒陨石群形...     

清镇顽火辉石球粒陨石的矿物学特征及其成因

清镇陨石以具有高度还原的矿物组合为特征。普通球粒陨石和碳质球粒陨石中的亲石元素在顽火辉石球粒陨石内显示亲铜或亲铁的性质。在该陨石中发现的矿物有陨硫钙石。硫镁矿、钾的硫化物——硫铜钾矿,含Si的铁纹石及Ni的硅化物——硅磷镍矿等。顽火辉石和斜顽火辉石具有低的FeO含量,其FeO/(FeO+MgO)比值范围为0.004—0.01。在未完全熔融的球粒中发现具尘粒状贫Ni金届包裹体的残余橄榄石颗粒。本文首次报道陨石中含Ga的闪锌矿和发现陨石中稀少的碱硅镁柱石。金属-硫化物组合显示再加热和熔融的结构特征,金属发生硫化作用并被硫化物所取代。清镇陨石(EH_3)的化学成分与EH_(4,5)球粒陨石很相似,其La/Sm比值比平均EL高,Co/Ni则比EL低。清镇陨石的形成部位比任何其他球粒陨石群更靠近太阳,可能形成于水星-金星区。     

铁陨石及中铁陨石的稀有气体同位素丰度和放射性核素活度

测定了两个铁陨石及两个中铁陨石的稀有气体同位素丰度和＾１０Ｂｅ、＾２６Ａｌ和＾３６Ｃｌ的放射性核素活度。在所研究的４个陨石中,东乌珠穆沁旗（类型Ⅰ）、渭源（类型Ⅲ）中铁陨石及宁波铁陨石（ⅣＡ）是在中国回收的,另一个无结构铁陨石Ｒａｆｒｕｔｉ是于１８８６年在瑞士发现的。根据＾１０Ｂｅ－＾２１Ｎｅ、＾２６Ａｌ－＾２１Ｎｅ和＾３６Ｃｌ－＾３６Ａｒ计算了两个铁陨石的产率及宇宙射线暴露年龄。其中Ｒａｆｒｕｔ