四川省石棉县草科地区大雪山花岗岩体强力就位特征

位于石棉县草科地区的花岗岩体,普遍发育渗透性叶理。经对其按岩石谱系单位划分方法解体,并重点对叶理、岩体与围岩接触关系,围岩变形变质等进行了详细研究,认为该岩体为典型的强力就位花岗岩体热轻气球膨胀模式,渗透性叶理为强力就位机制所造就。     

超高压变质岩的全球分布与地球演化节律

高压、超高压变质作用不是一个局部的孤立的地质现象，而是一个时空跨度大、范围广、影响构造观的重要科学问题。文中讨论了世界上三类（１３个）典型超高压变质地区的地质学岩石学特点，从全球构造的角度研讨了超高压变质的时空分布，从而得到下列认识：（１）所有高压、超高压变质岩均分布于全球活动带及其次级褶皱带内，超高压变质岩常常保存于多期变质和变形的基底片麻岩块体中，与深位壳型剪切带关系密切。（２）现有的年代学资料说明大部分超高压变质带出现于显生宙不同时代的褶皱带（造山带）内。（３）超高压变质演化的多阶段性，说明了地球从收缩到膨胀的节律现象。（４）从欧亚大陆范围看来，从北而南，从陆到洋超高压变质有逐渐变新的趋势，可能说明欧亚大陆从中生代以来，有从大陆向大洋方向增生的总趋势。     

Thermal structure and uplift of the Cretaceous Shimanto Belt, Kii Peninsula, Southwest Japan: An illite crystallinity and Mite bo, lattice spacing study

Abstract Illite crystallinity (IC) and illite b, lattice spacing were measured across the Cretaceous Shimanto Belt, Kii Peninsula, Southwest Japan. For the IC survey, 103 samples of argillaceous rocks were analyzed from the central area and the western area of the belt. Values of IC (Kubler Index) vary between 0.28 and 0.71 Δ°2θ and indicate diagenetic and anchizone metamorphism respectively. The IC distribution reveals two contrasting patterns of thermal maturity. The Hanazono Formation, exposed in the northern area of the belt, generally dips north, but IC values increase systematically from 0.28 Δ°2θ in the north to 0.54 Δ°2θ in the south and indicate an inverted thermal structure. Values in other formations vary widely in the southern area of the belt ranging between 0.45 and 0.71 Δ°2θ, but the values do not show any systematic change from north to south and on average remain almost constant. Illite b_o, lattice spacing values for 56 samples vary between 9.006 and 9.041 Å corresponding to intermediate pressure conditions of the metamorphic facies. These values, combined with paleotemperatures estimated from IC, indicate paleogeothermal gradients of 22 and 31°C/km for the northern and southern areas of the belt, respectively. The inverted thermal structure of the Hanazono Formation, together with a lower paleogeothermal gradient, possibly is a result of the subduction of a relatively cold oceanic plate during the Late Cretaceous. The higher geothermal gradient could be a product of late thermal overprinting caused by the later subduction of a comparatively younger and hotter oceanic plate during the Eocene.     

高压、超高压变质岩形成深度讨论

根据硅酸盐矿物压缩系数的实测值与一些地质现象结合，提出岩石圈中壳幔边界处可能存在负荷压力与来自地幔的压力结合而形成一种复合的压力状态，可以在莫霍面附近造成形成含柯石英和金刚石的超高压变质岩的地质环境，其前是造成来自地幔向上压力过程的速率要大于地壳释放压力的地质过程的速率，并同时提出地深增压率的概念和在地质上的一些表征．最后结合桐柏—大别高压、超高压变质岩的地质事实提出一个高压、超高压变质成因的模型     

辽河群镁质碳酸盐建造及其非金属矿产

辽河群镁质碳酸盐岩系，含矿岩石组合有黑尔峪组镁质碳酸盐含矿建造和大石桥组镁质碳酸盐含矿建造。其中由区域变质作用形成的白云石－滑石－菱镁矿、滑石－菱镁矿－透闪石、滑石－菱镁矿－水镁石－蛇纹石和硼矿物－蛇纹石－菱镁石－水镁石－滑石－金云母－透辉石等４种矿床组合形式，构成规律明显，经济价值大的非金属成矿系列。     

剪切带研究的某些进展

简要介绍了一般剪切带的成分变异、体积变化、流体流动的研究进展、着重讨论了榴辉岩相剪切带流体流动与变形变质作用的关系，认为剪切带应变不均匀性、变质作用不均一性和流体存在状态及流体超压是榴辉岩形成和保存的3个主要制约因素。     

丹巴地区变质岩的矿物化学特征及其p－T轨迹的构造意义

丹巴地区变质岩的矿物化学特征及其ｐ－Ｔ轨迹的构造意义钟宏（中国科学院地球化学研究所．贵阳５５０００２）关键词动热变质作用，Ｐ－Ｔ轨迹，构造环境，丹巴地区丹巴地区位于扬子地台西缘与松潘一甘孜造山带过渡带的中段，丹巴弧形构造带之西侧。该区变质岩分布很广，...     

A review of the In Ouzzal granulitic terrane (Tuareg shield, Algeria): its significance within the Pan-African Trans-Saharan belt

The In Ouzzal terrane (IOT) or In Ouzzal granulite unit (IOGU) is an elongated Palaeoproterozoic block within the Neoproterozoic Pan-African belt of north-west Africa. The granulites derive from Archaean protoliths that include a large volume of metasediments which were deposited on a 3.2-Ga gneissic basement. Near-peak granulite facies conditions between 2.17 and 2 Ga were estimated at P=10 kbar and T rising from 800 to 1000°C. Premetamorphic orthogneisses were intruded at 2.5 Ga, and followed by the emplacement of syn- to late-kinematic charnockites, syenites and carbonatites at around 2 Ga. Cooling of the granulites occurred till 1800 Ma. Shortly after its exhumation coeval with crustal extension and related alkaline magmatism in adjacent areas, the IOT was buried beneath late Palaeoproterozoic and Neoproterozoic cover sequences, and then behaved as a rigid block. Both margins are lithospheric faults, as evidenced by the occurrence of shear-zone-related mafic and felsic plutons. Pan-African tectonothermal events were negligible in the north, but granulites in the south were significantly reworked under lower greenschist facies conditions during the northern motion of the block with respect to both the western and the eastern Pan-African terranes. The Cambrian molasse, associated with widespread alkaline volcanism and subvolcanic granites, is horizontal in the north. The IOT, which was part of a larger continental mass including its counterpart in northern Mali, is interpreted as an exotic terrane which may have docked during Pan-African plate convergence and lateral collision. The unchanged pediplain since c. 1.7 Ga in the north suggests that the IOT is underlain by thick Palaeoproterozoic lithospheric mantle, whereas its southern part is probably allochthonous and overlies Pan-African structural units.     

五台山地区原金刚库组中含蓝晶石组合的变质作用及其意义

本文对山西五台山地区与超镁铁质岩密切共生的含蓝晶石的各类片岩进行了研究。研究发现，在蓝晶石铝直闪石片岩中存在一种特殊的冠状体结构，即蓝晶石和铝直闪石被它们之间内圈的十字石十刚玉十绿泥石和外圈的堇青石所包绕。这种特殊的反应边结构，说明岩石曾处于较高的压力条件下（０．９～１．４ＧＰａ），然后经历了明显的近等温的减压过程。其它类型的含蓝晶石片岩，也包含了高压变质矿物组合，并经历了同样的变质演化过程。这种演化历史与该区经历了古洋壳俯冲，消减，弧陆碰撞和伴随的迅速折返和抬升是密切有关的。