大别-胶南高压地体变质杂岩中流体包裹体特征和形成的热动力条件

在中国陆内南北板块之间古缝合线内大别-胶南高压地体中。分布着一套变质程度不一的杂岩系,我们将其划分出三期高峰变质作用形成的不同性质变形变质岩相带,并阐述了各自所代表的矿物流体包裹体特征,计算出它们形成时的温度、压力、氧逸度、差异应力等热动力参数,为揭示地体变形变质环境和构造演化特点,提供了可靠(?)数值根据。     

Discovery of Eoarchean Meta-Dioritic Rocks in Anshan Area, China and Its Geological Significance

INTRoDUCTIONThe3.8GaBeijiafentrondhjemiticrockwasformedbypartialmeltingofsomeoldercontinentalmaterialintermsofgeochemicalresearches(Waneta1-,l999).Soitisveryim-portanttofindthemoreancientrocksintheAnshanarea.Therecentdiscoveryofthemeta-dioriticrockofEoarchaeanintheDongshanScenicSpotisspecificallyimportantsignifi-canceforit'GEOLOGYANDPETROGRAPHYlntheDongshanScenicSpotoftheAnshancity,thereis.anancientrockbeltbeingmorethanlomwideandstrikingapproximatelyNNW-SSE.Inthebelttherear…     

PETROCHEMISTRY AND MINERALOGY EVIDENCES FOR THE WEATHERING PROCESS OF THE WEATHERING PITS ON ROCK SURFACES OF MOUNTAIN LAOSHAN,CHINA

2011年5月对崂山山顶风化坑进行考察和采样,通过对风化坑内碎屑和坑外岩石的粉晶X射线衍射矿物分析、X射线荧光光谱化学全量分析,研究了风化坑内外的矿物风化及各元素迁移特征,对风化坑的成因过程进行探讨.研究结果表明:1)崂山山顶风化坑碎屑的英长比总是大于其周边岩石的英长比,说明风化坑的形成是花岗岩造岩矿物差异风化的结果;2)风化坑风化过程中被风化的岩石矿物主要是条纹长石和钾长石;3)风化坑中大量的Mg和Ca主要是外部加入的;4)崂山山顶风化坑内碎屑,坑外岩石面均受到化学风化的作用;5)崂山山顶风化坑内外的风化指数CIA值并不反映崂山当地的气候,山上山下CIA值的差异是风化时间长短不同造成的;6)LOI能很好地反映崂山风化坑内外风化强度的差异,说明长石主要在水解作用下发生分解,也说明了风化坑的积水成因.     

某些磷灰石矿物的红外吸收光谱

本文讨论了各种磷灰石矿物的光谱特征,氟磷灰石和羟磷灰石的光谱-结构关系及磷灰石中CO_3~(2-)和OH~(-1)离子的存在形式。在结构资料基础上,对氟磷灰石和羟磷灰石中的PO_4~(3-)离子进行了相关分析,给出了内模式的分配数目。碳氟磷灰石中的CO_3~(2-)离子的光谱与简单无水碳酸盐和氟磷灰石混合物光谱之间的差异表明,C0_3~(2-)离子以类质同象形式进入磷灰石结构中。磷灰石中的P_2O_5含量随CO_2含量的增加而降低,PO_4~(3-)离子的v_4带随CO_2的增加或减少而变化,这表明PO_4~(3-)与CO_3~(2-)离子之间存在密切的相关关系,CO_3~(2-)-PO_4~(3-)取代是类质同象置换的一种形式。羟磷灰石OH-OPO_3中的O-O距离和它的高温光谱证明,OH~(-1)离子以氢键形式存在。     

云南老王寨金矿区煌斑岩中碳酸盐的化学成分及其意义

本文报道了云南老王寨金矿区非矿化、矿化煌斑岩中不同产状碳酸盐的化学成分，结果表明本区煌斑岩中为次生碳酸盐，原生碳酸盐含量不超过１％；煌斑岩蚀变、矿化为不同阶段的产物；碳酸盐脉活动发生在成矿作用之后。     

Geochemical process of fluorine in soil

Fluorine is in the dynamic balance of two geochemical processes, enrichment and leaching, reflecting the adsorption and desorption of fluoride by clay minerals, respectively. The two geochemical processes of fluorine in soil are influenced by factors including geochemical characteristics of soil and clay minerals, pH and sanity of soil solutions, climate, grazing and agriculture activities. Main factors controlling enrichment and leaching process of fluorine in soil can be found with interaction consideration.     

Helium and argon isotope geochemistry of natural gases in China’s petroliferous basins

The age-accumulation effect of 40Ar in hydrocarbon source rocks was discussed in accordance with the decay law of radioactive elements. In terms of the mean values of 40Ar/36Ar, the old Sinian gas reservoirs (mean values of 40Ar/36Ar: 7009) were definitely distinguished from the Permian gas reservoirs (mean values of 40Ar/36Ar: 1017) in Weiyuan, Sichuan Province, and the gas source of the Permian gas reservoir (mean values of 40Ar/36Ar: 5222) in well Wei-7 with the Weiyuan structure is defined as the Sinian system. Based on the values of 40Ar/36Ar, the coal-type gases (The source rocks are of the C-P system; mean values of 40Ar/36Ar: 1125) are definitely distinguished from the oil-type gases (The source rocks are of the Tertiary system; mean values of 40Ar/36Ar: 590) in the Tertiary reservoirs of the Zhongyuan Oilfield. Besides, 40Ar/36Ar values also have a positive effect on the oil-source correlation of oil reservoirs in ancient hidden mountains. According to the crust-mantle interchange information reflected by 3He/4He values, petroliferous provinces in China can be divided into three major tectonic regions. (1) The eastern active region: The crust-mantle volatile matter exchanges actively, and the 3He/4He values are mainly around 10-6, partly around 10-7. (2) The central stable region: The 3He/4He values are all around 10-8. (3) The western sub-stable region: The 3He/4He values are mainly around 10-8, and around 10-7 on the edges of the basins. Helium contents of some gas wells in China’s eastern petroliferous region reach the industrial abundance (He≈0.05%–0.1%), the 3He/4He values reach 10-6, and the equivalent values for the mantle-source components in helium gas can reach 30%–50%. As viewed from this, a new type of crust-mantle composite helium resources has been proposed. Geneses of some CO2 gas reservoirs in the east of China and some issues concerning mantle-source methane were discussed in the light of the helium and carbon isotopes of CO2 and CH4 in natural gases. In the discussion on helium isotopic characteristics of inclusions in the reservoirs, it was discovered that the 3He/4He values are close to those in natural gases. That is to say, this phenomenon is related to regional tectonism. The 3He/4He, CO2/3He and CH4/3He data were used to discuss the tectonic activities of fault zones in a certain number of regions in China.     

大别山榴辉岩一片麻岩杂岩的成因

大别山榴辉岩由辉长岩、大陆拉斑玄武岩和少量泥灰质经高压变质作用形成。大别地块可划分出四个形成条件不同的榴辉岩区,它们代表一种构造－岩石组合体。片麻岩杂岩中各种高压变质岩类的发现证明它们与榴辉岩一起经历了原地高压变质过程。二者变质作用Ｐ－Ｔ参数的差异归因于抬升过程中退变质反应速度的不同。不同地区榴辉岩退变质组合及Ｐ－Ｔ条件与围岩的一致性表明,大别杂岩现今所展示的“递增”变质带是由榴辉岩相退变质作用形成的。高压榴辉岩－片麻岩杂岩的产生是印支期扬子与华北两个大陆板块碰撞的结果。     

Magma type and genesis of the basic-ultrabasic layered intrusions in Panzhihua-Xichang area,Southwest China

The layered intrusions in the Panzhihua-Xichang area may be grouped into two types: basic rock masses represented by the Panzhihua rockbody and basic-ultrabasic rock masses represented by the Hongge rockbody. Their major difference lies in that the former has poorly developed ultramafic facies, while the latter is characterized by well developed mafic facies and ultramafic facies. There exists apparent rhythmic stratification in the rock masses, which can be basically divided into four grades in terms of superimposition relationship and multicycle characters. Both direct and indirect evidence suggest that the magma responsible for the layered intrusions in this area should be a transition-type alkaline olivine basalt magma derived directly from partial melting of the upper mantle. In rhythmic cycles of various grades, the magmatic evolution is characterized obviously by periodicity and early enrichment of Fe and Ti, which is evidently different from the evolution of the Skaergaard magma in which Fe and Ti are enriched at the late stage. The FCA diagram can be used to describe the unique evolutionary trend of magma in this area. It is demonstrated in this diagram that the enrichment of Fe and Ti is consistent with the increase of basicity. In the upper magmatic chamber, the evolutionary trend of magma is conditioned by the difference in pressure, and this enables magma to form different types of rock assemblage. In the Fo-Di-An system, when the pressure exceeds 5 x 18⁸ Pa, forsterite is incompatible with anorthite, and the rock facies sequence of Hongge type might form; when the pressure is lower than 5 x 10⁸ Pa, forsterite can coexist with anorthite, and the rock facies sequence of Panzhihua type is likely to form if the magma is relatively rich in Mg and Fe components.     

冀西北赤城-宣化盆地土城子组沉积特征及盆缘构造分析

为了揭示华北北部晚侏罗世沉积盆地性质,对赤城-宣化盆地中土城子组沉积特征及盆缘构造进行了研究。通过对土城子组沉积特征研究表明,土城子组中-下部为一套河湖相沉积,上部为一套冲积扇粗碎屑沉积;土城子组砾岩成分系统统计分析显示,赤城盆地与宣化-下花园盆地具有相似岩屑岩性相旋回,反映源区具有相同或相近的蚀顶过程。研究区晚侏罗世盆地中土城子组充填特征及盆缘构造特征表明,土城子组形成于挤压构造背景,土城子组沉积时期盆地受控于盆缘逆冲断层。大地构造背景暗示,赤城-宣化盆地晚侏罗世-早白垩世期间,古太平洋板块向NW方向的俯冲作用与尚义-赤城断裂向南逆冲并伴随右旋走滑作用是土城子组沉积时期盆地格局形成的重要控制因素。