庐枞地区安粗岩系

Volcanic rocks discussed here are distributed in the Lujizng-Zongyang region, Anhui province, covering an area of about 100 km^2, where a set of potash-rich intermediate series is developed which is particularly referred to as “Latitic Series”. The characters of the latitic series are as follows: (1) It was formed during middle Yenshanian (108--132 m.y.) ; (2) Spatially, it occurs frequently on the continental side of closing slab boundary stretching along the deep rift zone; (3) It is mainly composed of latite, trashybasalt and trachyte; (4) It contains sanidine coexisting with augite, plagioclase (labradonite, andesine and oligoclase) and magnetite, and clinopyroxene, formed under high pressure conditions, as well as pseudoleucite with no orthopyroxene and quartz; (5) The chemical composition is characterized by high alkalis, especially potasinm,with the ratio of K2O/Na2O≥1 and high alnminium but low titanium. The formation of latitis magma could be related with the slab movement. It has been shown that volcanic activities during middle Yenshanian were rather weak in intensity and small in scale as compared with those during late Yenshanian. The rather slow movement of Pacific slab during middle Yenshanian could not provide sufficient water and rubbing heat energy to the slab boundary, and therefore, partial melting could proceed only at the upper mantle depth (100-200km). It is believed that the partial melting of phlogopitelberzolite in some local regions of the continental mantle along the dosing slab boundary was responsible for the formation of potash- and aluminium-rich latitic magma,     

内蒙兴和石墨矿含矿建造特征与矿床成因

兴和石墨矿赋存于上集宁群深变质的孔兹岩系中,含矿的原岩建造主要为一套富铝的粘土质和半粘土质浅海相沉积物,岩系的基本特征与印度马德拉斯地区的孔兹岩系类似。前人认为石墨是由碳酸盐经变质作用转变而成,属无机成因。作者据新资料的综合分析认为石墨是大量原始藻类遗体堆积后经成岩作用和变质作用而成,乃属有机成因。     

浙江中生代晚期火山—沉积岩系层序和时代

浙江中生代晚期火山—沉积地层由上、下两个岩系组成,上岩系包括横山组、永康群、衢江群及天台群,下岩系包括建德群和磨石山群。这两个岩系的同位素年龄范围分别在１１０～９０Ｍａ和１３５～１２０Ｍａ。根据同位素地质年代结合该区火山—沉积地层的古地磁和古生物研究资料,我们提出上岩系的形成时代为早白垩世晚期至晚白垩世早期,下岩系为早白垩世早期     

东北地区新生代火山作用-深部作用与大陆裂谷型盆地

新生代火山岩含有丰富的上地幔岩包休和高压巨晶，火山岩系列、岩石类型、痕量元素等特征以及空间分布特征和与俯冲作用有关的中生代火山岩截然不同，其岩石学特征及热力学研究等表明它们形成于大陆裂谷构造环境。根据出露地表的古老的变质岩系和新生代玄武岩中的上地幔岩包体的岩石学特征以及热力学计算，建立了陆壳一上地幔结构岩石学剖面，新生代岩石圈拉伸，软流圈上隆，为一减薄的陆壳结构，形成了下辽河等一些大陆裂谷型盆地。     

蚀变作用的多原岩系统及质量平衡

介绍了造成岩石地球化学不均匀性的原因，主要有测量误差、闭合问题及岩石学方面的控制等。各有其不同的研究和解决方法。对于蚀变岩的多原岩系统，常用不相容高场强元素（HFSE）来描述岩石性质，用其作为监视器，可作出各相容元素（或成分）的分异线；用不活动元素蚀变线与分异线的产点来确定原始成分，并在此基础上进行蚀变岩质量变化的计算。     

北山窑洞努如—公婆泉岛弧火山岩岩石地球化学特征(摘要)

北山窑洞努如—公婆泉岛弧火山岩岩石地球化学特征（摘要）冯铁全左国朝金松桥（甘肃省地勘局研究所兰州７３００００）窑洞努如—公婆泉岛弧火山岩呈东西向分布于甘肃省肃北县马鬃山地区，属于塔里木板块东北大陆边缘的岛弧带（地质图略）。岛弧主要由中、下志留统及部分...     

河北平山晚太古代阜平群中主要变质岩类及其深熔产物的稀土地球化学初步研究

河北平山小觉地区晚太古代阜平群含有三种主要表壳岩性质的变质岩类，即钾长浅粒岩类，黑云变粒岩－片麻岩类和角闪质岩石类。它们所经历的初期深熔作用产物，其岩石化学成分分别与钾长花岗岩，奥长花岗岩和花岗闪长岩相当，并在很大程度上继承了原岩（母岩）的总体岩石化学特征，可能由于深熔产物中富含稀土的一些副矿物含量的降低，它们的稀土总量都不同程度地较原岩为低，但两的稀土分布模式却很相似，这从另一角度说明了它们的成因关系。