胶东半岛构造-岩相形式及玲珑-焦家式金矿的构造动力成岩成矿地质特征研究

玲珑-焦家式金矿是指胶东前寒武变质岩系内中生代花岗岩含金剪切带石英脉-绢英质蚀变岩金矿类型。由于赋矿及成矿构造性质不同,该类矿床可分为明显有别的两种典型矿床类别。区域成矿作用受中生代“N”形断陷构造-岩相形式与基底反“S”弧形断褶-变质岩相形式的复合控制。成矿是沉积→变质→交代和重熔作用发生发展的综合结果。开展矿源岩系(序)列研究,划分成矿花岗岩类为剪切、挤压及引张构造-岩浆岩相,并提出了室内外鉴别标志。 作者在对各层次岩石结构、形变与成分、相变等相关的地质事实研究基础上进一步探讨了成因,侧重以“构造作用力影响成岩成矿静水压力”的观点建立了理论、数学模型,实测了古应力、古压力及其它成矿物理化学参数,从而论证了构造附加静水压力是变形岩石发生相应相变的主要动力因素,构造附加静水压力不仅是使变形岩石体变的物理量,而且是影响、制约其中成岩成矿化学过程的物理化学参变量。

ON THE TECTONO-PETROFACIES FORMS AND LINGLONG-JIAOJIA-TYPE GOLD DEPOSITS IN THE JIAODONG PENINSULA, CHINA

Linglong-Jiaojia-type gold deposits in this paper deff erent from main research types of the world mean the pyrite quartz vein-phyllic altered cataclasite type occurring in shear zone of granites of Mesozoic. The material base of alteration-remelting of the granites comes mainly from a Precambrian sedimentary-metamorphic series containing intermediate-basic volcanics. Because of different properties of ore-containing and ore-forming structures, these deposits show two main forms or subspecies of mineralization. The Linglong-subtype (quartz vein-type) and the Jiaojia-subtype (veinlet-disseminated phyllic altered rock-type) appear to possess a horizontal zoning mainly.In the research field of deformation in combination with petrofacies change of rock, this paper deals with the following, defines a reversed"S"-shape for the arcuate fault-fold metamorphic petrofacies form extending in the E-W direction in the Jiaodong basement and a "N"-shape for the fault-basin tectonic petrofacies form, and puts forward that the compounding of their both formed the basic tectonic frame of regional minerogenesis; the granitoid related to gold mineralization is respectively assigned to the com-presso-shear structural petrofacies Linglong-type granite, the compressive structural petrofacies Guojialing-type granite and the tensile structural petrofacies Luanjiahe-type granite, whose these characteristics are coordinated with Indosino-Yanshanian movement in this area; according to research of geology, chemical composition, isotope and REE etc., classifies the Precambrian metamorphic rocks chiefly of the Jiaodong Group as the intermediate source series whose original submarine intermediate-basic volcanics and elastics are initial ore source series, and the granitoid formed by metasomatism and remelting of them is the direct ore source rocks; minerogenesis is related to shear zone and its subordinate component, as a general rule, Linglong-Jiaojia-type belongs to gold-bearing shear zone-type gold deposit (M. emaison et al. 1986). Studying their genesis of above phenomena of relationship close between structure and petrofacies, author sets up the theoretical and mathematical model, measures the palaeostress, The palaeopressure and other physicoche-mical parameters, emphatically on basis of viewpoint of "the affect of tecto-nodynamics on hydrostatic pressure", and demonstrates that the tectonic additional hydrostatic pressure is basic dynamic factor causing the change of chemical progress and element properties in petrofacies change during deformation of rock. Forthermore, puts forward that the tectonic additional hydrostatic pressure is regarded not only as the physical variable causing the change of rock volume, but also as a physicochemical parameter affecting chemical progress in the deformational rock.