西昆仑阿卡孜达坂绿片岩：受大陆地壳混染的板内玄武岩

形成于震旦-早寒武纪的西昆仑阿卡孜达坂变质火山岩是一套绿片岩相的中基性岩石,其构造性质对于西昆仑的构造演化历史具有重要的制约意义。这些变质火山岩具低到中的SiO2(42.3%-64.7%),MgO(2.69%-7.54%),宽的TiO2(0.94%-3.05%)和Fe2O3T(7.64%-18.47%)含量,显示出玄武质或安山质的母岩特征。这些岩石富含高场强元素(Nb,Ta,Zr,Hf)和稀土(∑REE=-407μg/g),并具有相对高的Ti/Y(183-673),Th/Yb(0.5-3.9)以及较低的Hf/Ta(1.6-8.6)比值。它们相对富集轻稀土(La/Yb=5.4-20),除了两个具有Nb正异常的样品外多数样品具有不同程度的负Nb异常(Nb/Nb*=-0.2)并呈现介于板内和消减带有关岩浆之间的过渡特征。这些变质火山岩所具有的消减带特征排除了其来自大洋中脊,洋岛,板内海山和大洋台地玄武岩的可能性,而岩石所具有的板内特征以及两个具Nb正异常的样品表明这些变质火山岩并非形成于破坏性的板块边缘环境(如岛弧或活动大陆边缘)。它们相对高的Gd/Yb比值(1.4-2.9)明显不同于典型的岛弧拉斑玄武岩,同时其较高的Zr/Y(3.1-12),Ta/Yb(0.27-0.73)和较低的Zr/Nb(多数小于12)显示出强烈的大陆板内特征。这些特征表明阿卡孜达坂变质火山岩的原岩是受陆壳物质混染的板内玄武岩,很可能形成于一个陆内裂谷环境。阿卡孜达坂变质火山岩与东昆仑和北祁连所发育的同时代的板内火山岩一起,可能反映了塔里木克拉通从冈瓦纳大陆的裂解事件。在上述研究的基础上,结合已有资料对震旦纪至早古生代期间的西昆仑构造演化历史进行了讨论。     

A WAVELET PACKET ENERGY DIAGNOSIS OF SOUTH ASIAN SUMMER MONSOON INFLUENCING ON THE WEST PACIFIC SUBTROPICAL HIGH

1 INTRODUCTION An important constituent in the Asian summer monsoon system, the West Pacific subtropical high (simplified as the 揌igh) is closely related with the activity of summer monsoon via the changes in intraseasonal intensity and progression[1 - 8]. Zhang et al[5]. discuss the relationship between seasonal jumps and anomalous location of the Highs ridge and onset of low-latitude westerlies and tropical convection in summer, with the finding that the northward jump of the High is …     

多元地学数据信息处理及解译在西秦岭地区金矿找矿中的应用

多元地学数据信息处理及其在综合找矿中的应用，以其信息量大、多方位、立体化、快速高效等特点，近年来受到普遍重视。作者在秦岭成矿带甘肃段（西秦岭地区）约５万ｋｍ２范围内，利用最新的地质、矿产、物化探、遥感等方面资料，开展金矿多元地学数据信息处理和综合分析解译，研究多元地学信息特征及其与金矿的关系和成矿地质环境，查明了深部构造和岩浆活动规律，建立三维空间的金矿找矿模型，寻找金成矿有利区。实践表明，该研究方法在金矿资源调查和分析研究区域地质构造方面有着显著的地质效果。     

粤西小片云母资源及其开发利用

粤西有着丰富的小片云母资源，其开发利用对广东的经济发展有着十分重要的意义。本文介绍了粤西小片云资源概况，并论述了开发利用途径和前景最后，对粤西小片云母资源的开发利用提出了建议。     

查湾岩体的识别及其区域地质意义

通过对安徽舒城查湾地区“大别群未分部分”的各种界面关系、包体特征及岩石化学等的观察研究，发现该“部分”实属燕山期沿磨子潭断裂上侵的Ⅰ型加里东期花岗岩类，并认为这一事实的区域地质意义有：岩体侵入前的磨子潭断裂可能沿１２５°方向延至官庄，查湾岩体可能为目前“大别群”与“芦镇关群”①的界线。     

新疆哈密三道岭地层新知

在三道岭原石炭系中采到大量腕足类化石,其上部灰岩的时代应为D_1—D_2,其下部泥岩的时代应为S_3—D_1.     

A REGIONAL MODEL STUDY OF THE VARIATIONS AND DISTRIBUTIONS OF OZONE AND ITS PRECURSORS ON EASTERN ASIA AND WEST PACIFIC OCEAN REGIONS*

A simulated study of mechanism for variations and distributions of ozone and its precursors was made by using the three-dimensional regional Eulerian model.The results showed that the ozone production was controlled by NO_x,but there is a complicated nonlinear relation between them.The photochemical reactions controlled by solar radiation are the determinative factors affecting the variations of the surface ozone and its precursors.The relations of ozone and CO,PAN were studied.We compared the simulated and observed results during the PEM-WEST A in order to better understand the photochemical processes of ozone and its precursors.     

Ductile normal faulting along the West Bohemian Shear Zone (Moldanubian/Tepla-Barrandian boundary): Evidence for late Variscan extensional collapse in the Variscan Internides

Structural and kinematic investigations of the West Bohemian Shear Zone (WBS) clearly indicate late Variscan orogen-parallel (WSW-ENE) extension within the Variscan internides. Along the WBS the western part of the Tepla-Barrandian (TB) was downthrown to the east against the adjacent Moldanubian. According to seismic data, the steeply east-dipping WBS flattens with depth, forming a prominent detachment zone. The western part of the TB was tilted along this zone, producing the patterns of metamorphic isograds, the age of which is probably Cadomian. Cross-cutting relationships of WBS mylonites and Carboniferous granites, as well as the overall cooling ages of hornblende and mica, suggest that ductile normal faulting along the WBS was active from about 330 to 310 Ma.Geothermobarometric data, derived from WBS mylonites, prove that during the extensional movements relatively cold crust of the TB (medium pressure greenschist facies) was juxtaposed to relatively hot Moldanubian crust (low pressure amphibolite facies). Thus mylonites which originate from TB rocks show a first-stage prograde development reaching the lower amphibolite facies under medium pressure conditions. This stage was followed by further (uplift-related) retrograde shearing under low pressure greenschist facies conditions.Extensional movements and the emplacement of granitoids along the WBS, as well as the strong low pressure/high temperature metamorphism of the Moldanubian rocks are remarkably similar in age (Middle Carboniferous). Therefore, a close relationship and mutual dependence of all these features is suggested. Rapid advective thinning of the deeper part of the previously thickened lithosphere and associated rapid crustal uplift are the most probable processes to explain the high Middle Carboniferous heat flow as well as magmatism and extension.     

西秦岭地区二叠—三叠系界线地层研究

在西秦岭地区南秦岭带广泛发育碳酸盐岩型二叠、三叠系。本文以选部益哇沟剖面为例，对该区界线地层进行研究，从岩石地层划分、生物地层划分以及地球化学元素最优分割研究出发，确定了二叠、三叠系界线点，证明牙形石Ｈｉｎｄｅｏｄｕｓｐａｒｖｕｓ可作为三叠系开始的标志，并且二叠、三叠系是连续的。沉积环境分析表明，三叠纪初期相对于二叠纪末发生了一次海侵。     

西南极利文斯顿岛中部中－新生代火山岩的岩相学和矿物学特征

出露在利文斯顿岛中部的中－晚白垩世火山碎屑岩为多源的角砾凝灰岩、角砾岩和集块碎屑岩，成分以安山质为主。橄榄玄武岩主要在史莱夫角出露，为全晶质斑状构造；主要出露在中利文斯顿和汉那角的安山岩、玄武安山岩多具细晶微斑构造。更新世至现代的火山岩为全晶质斑状的橄榄玄武岩和火山碎屑岩。熔岩的基本矿物组合大致相似，均为斜长石＋辉石（＋橄榄石）＋铁的氧化物，但矿物的含量比例因岩性不同而有所区别。岩石中的斜长石斑晶多具正环带；随着岩石ＳｉＯ２含量的增加，斜长石中Ｏｒ和Ａｂ组分增加而Ａｎ含量下降，斑晶边缘成分一般与基质里长石的成分相近。安山岩和玄武安山岩含有中长石－拉长石斑晶，玄武岩主要含拉长石斑晶，但橄榄玄武岩和粗玄岩中斜长石斑晶的核部为富钙的倍长石。更新世－现代的橄榄玄武岩，其所含斜长石斑晶和基质长石亦比较富钙。玄武安山岩中的辉石多为普通辉石，橄榄玄武岩和玄武岩中含有透辉石斑晶。辉石的Ｔｉ含量低，这是钙碱性火山岩的共同特点。史莱夫角的橄榄玄武岩含有贵橄榄石斑晶。粗玄岩中橄榄石成分与史莱夫角基质橄榄石成分相近。更新世至现代的橄榄玄武岩中既有正常结晶的橄榄石斑晶，还见到高Ｆｏ组分的深源捕掳晶。上述玄武岩中矿物组合的基本特征证明