Late Cretaceous–Cenozoic intraplate contractional deformation at the Norwegian continental shelf: timing, magnitude and regional implications

Contractional structures (large anticlines and synclines, reverse faults and inverted centres of deposition) of assumed Late Cretaceous–Cenozoic age are common in Cretaceous–Tertiary basins of the northwestern European margin. The similarities in style, orientation and timing of these structures are striking. The present detailed analysis of one anticline (the Ormen Lange Dome) of the mid-Norwegian continental shelf indicates that the total contraction is moderate (less than 2–3%), and that the analysed anticline has been growing almost continuously since its initiation in Eocene till Present. Inversion in the Barents Sea started already in the Late Cretaceous. This episode is suggested to be related to far-field effects of active plate-margin processes, and transfer of stresses across the plate as a consequence of the sub Hercynian and Paleocene ‘Laramide' event of the Alpine Orogeny. The development of co-axial structures was facilitated by stress focusing along pre-existing, high-relief N–S- and NE–SW-trending fault complexes. Far-field plate tectonic stresses originating mainly from the Alpine Orogeny seem to have been the most important cause of contractional deformation on the NW European shelf. In addition, ridge push from the North Atlantic spreading may have contributed significantly, particularly during the Neogene.     

Well-preserved garnet growth zoning in granulite from the Dabie Mountains, central China

Ultra-high pressure eclogites and granulites both occur in the Dabie Mountains, central China. A garnet porphyroblast from felsic granulite in the Dabie Mountains has been analysed for compositional zoning by electron microprobe. Two segments of the porphyroblast have opposite compositional variations. Segment I (from centre outward 9  mm to analytical point 18) has decreasing X_Sps and increasing X_Pyr, while Segment II (from analytical point 18, 1  mm outward to the rim) has increasing X_Sps and X_Alm and decreasing X_Pyr and X_Grs. The compositional zoning in segment I is considered as growth zoning and that in Segment II as diffusive retrograde zoning. Garnet growth zoning records a P–T  path prior to the peak granulite metamorphism. The minimum P – T  conditions are estimated to be 1.35  GPa and 850  °C for peak metamorphism, based on the highest Mg/(Fe+Mg) composition in the garnet (analytical point 18) and matrix hypersthene, biotite and plagioclase. A symplectitic corona surrounds the porphyroblast and appears to have formed at 0.6  GPa and 700  °C. The well-preserved growth zoning in garnet suggests a short residence time for the granulite at peak metamorphism and thus rapid tectonic uplift history. The P–T  path is consistent with that of ultra-high-pressure eclogite in the area. Tectonic movements during a collisional event could have brought both the granulite and the eclogite to their present positions.     

滨海城市环境工程地质问题发育特点分析

本文分析了我国滨海城市环境工程地质问题的主要类型,研究了环境工程地质问题的发育特点。     

优化偏最小二乘光度法同时测定铑铱钯的研究

采用局部加权、随机矩阵法等步骤,使建立的校准模型能充分反映未知样品的数字结构特征,达到优化的目的,从而改善偏最小二乘法在处理实际未知样品数据时的解析能力,以提高计算结果的精度。用该优化偏最小二乘法对模拟地质样品中痕量贵金属Ｒｈ、Ｉｒ、Ｐｄ进行多组分光度测定,其分析结果的相对误差均小于１０％;分别测定９．５μｇ／Ｌ、３５．０μｇ／Ｌ、６６．０μｇ／Ｌ含量的Ｒｈ、Ｉｒ和Ｐｄ７次,其标准偏差Ｒｈ为０．２;Ｉｒ为１．１;Ｐｄ为２．０。     

玻镁安山岩中辉石枝晶的形貌与晶体生长方式

川西乡城地区的玻镁安山岩基质中辉石微晶具有奇特的枝晶形貌。通过高倍率光学显微镜和扫描电镜观察,较详细地分析了辉石枝晶的形貌细节。辉石枝晶一般发育三级分枝,各分枝间以近于90°和110°交角沿单斜辉石结晶学主轴方位优先生长,各级分校具有整体一致的光学性质,如同单个晶体。玻镁安山岩浆流动性大,呈薄层状。快速冷凝作用和强的结晶能力是辉石枝晶发育的前提条件。初步探讨了在远离平衡态结晶时,辉石枝晶生长方式和界面稳定性对晶体形貌的控制作用。     

新矿物（1992.7—1992.12）

本文以表格形式列举了１９９２年７月至１９９２年１２月经《国际矿物学协会（ＩＩＭＡ）新矿物与矿物命名委员会（ＣＮＭＭＮ）》批准并在各国矿物学杂志上发表的５０个新矿物的中文英文名称、化学式及其他数据。数据依次为：矿物的晶系、空间群、晶胞参数、主要粉晶数据（Ｉ、ｈｋｌ）、物理性质（晶形、颜色、条痕、光泽、解理、发光、硬度、密度等）、光学性质（一、二轴晶、正、负光性,折光率,反射率,双反射,２Ｖ,色散,吸     

氧化物晶胞参数和配位多面体几何要素的关系

氧化物矿物中的化学键主要是离子键,结构可看成配位多面体以不同方式相连形成,因此,晶胞参数可用配位多面体几何要素表示,这样求得的晶胞参数与实测晶胞参数间的相对误差一般在百分之几。     

区域经济研究的几个理论问题

研究区域经济,首先要明确区域经济赖以存在的逻辑基础,好资源的稀缺性、人类经济活动的音空有限性和生产要素在空间上的非安全充分流动性。从这一逻辑推演,区域经济学是一门学多学科交叉的边缘学科。它所研究的主要内容是探索区域经济增长的一般规律并制定协同区域经济增长差异的政策。     

On the agricultural growth and structural changes in Suzhou Wuxi Changzhou region

ＳｕｚｈｏｕＷｕｘｉＣｈａｎｇｚｈｏｕ(ＳｕＸｉＣｈａｎｇ)ｒｅｇｉｏｎｉｎＪｉａｎｇｓｕＰｒｏｖｉｎｃｅｏｆＣｈｉｎａｃｏｖｅｒｓａｌａｎｄａｒｅａｏｆ17153ｋｍ2ｗｉｔｈａｐｏｐｕｌａｔｉｏｎｏｆ13.4ｍｉｌｌｉｏｎ,ｂｅｉｎｇ17.1ａｎｄ18.9ｐｅｒｃｅｎｔｒｅｓｐｅｃｔｉｖｅｌｙｏｆｔｈｅｔｏｔａｌＪｉａｎｇｓｕＰｒｏｖｉｎｃｅ.ＬｏｃａｔｅｄｉｎｔｈｅｆｅｒｔｉｌｅＣｈａｎｇｊｉａｎｇＤｅｌｔａｉｃＰｌａｉｎａｎｄｉｎｈｕｇｅｕｒｂａｎａｇｇｌｏｍｅｒａｔｉｏｎｗｉｔｈｃｅｎｔｒａｌｉｔｙｏｆＳｈ…     

贵州麻山冰洲石矿床成因的初步研究

贵州麻山冰洲石矿床成因的初步研究＊金志升朱成明刘钧蔡恩照（中国科学院地球化学研究所，贵州５５０００２）关键词方解石冰洲石成因晶体生长贵州省望谟县麻山地区分布有大小不等的方解石、冰洲石矿点数十处，是我国较重要的冰洲石产地之一。曹俊臣［１］曾对该地区冰洲...