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沂源龙泉石膏矿是近几年山东省内勘查评价的几处寒武纪—奥陶纪海相碳酸盐岩系型石膏矿之一 ,这类矿床的发现及勘查评价 ,为省内石膏矿资源勘查与开发规划部署提供了新线索。沂源县龙泉石膏矿产于寒武纪长清群朱砂洞组丁家庄段 ,自下而上分 3个矿层 ,呈不规则的层状、似层状 ,以第Ⅰ矿层规模最大 ,最大厚度 13 98m。矿石自然类型以块状、网脉状—块状石膏为主 ,其次为网脉状—浸染状石膏、硬石膏和纤维状石膏。沂源龙泉石膏矿含矿层位及矿层分布比较稳定 ,矿床规模较大。 相似文献
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Anne Nédélec Jean-Louis Paquette Jean-Luc Bouchez Philippe Olivier Bruno Ralison 《Geodinamica Acta》2013,26(1):48-56
AbstractStratoid granites constitute a major feature of the Precambrien basement of Madagascar. A detailed structural study was carried out NNW of Antananarivo. New zircon isotopic data on a typical alkaline granite ascertain their Panafrican age (585 Ma). The sheets of granites metric to kilometric of thickness, are interlayered with migmatitic gneisses and amphibolites. Their internal structures, determined by anisotropy of magnetic susceptibility measurements, everywhere yield foliations gently dipping to the west, and lineations striking WSW-ENE. These structures were mostly acquired at the magmatic stage in the granites, in the country-rocks they resulted from high-temperature plastic deformation.The very constant structural pattern, interpreted in terms of shear deformation of a section of the crust, as well as the low P (P = 4 - 5 kb) - high T (T # 750°C) conditions, suggest that the emplacement of the stratoid granites was coeval with a late-orogenic stage in the Panafrican Mozambique belt, and possibly linked to the thinning of the lithosphere. 相似文献
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