火山岩

Luzong area ; shoshonite series ; geochemistry ; rare earth element ; tectonic setting

庐枞地区；火山岩；地球化学；稀土元素；构造背景

Oligocene-Miocene volcanic rocks are shoshonite,late Miocene-Pleistocene volcanic rocks are High-k calc-alkaline.

渐新世-中新世火山岩以钾玄岩系列为主，部分为高钾碱性系列，火山活动强烈出露面积大而广泛。

Shoshonite ; high-K calc-alkaline ; volcanic cycle ; volcanic rocks Cenozic ; Hoh Xil Lake

钾玄岩系列；高钾钙碱性系列；火山旋回；新生代火山岩；可可西里湖地区

Yanbian region lies in the eastern segment of north margin of North China slab, situating on the intersect point of North China, Sibiric and the pacific slab. Space and boundary of these slabs controls the Mesozoic volcanic-subvolcanic rock distribution, which restricts the epithermal-porphyry gold metallogenic series. Though many research of deposits have been done individually, the synthesize works are few.

中文题名延边地区浅成低温热液－斑岩型金成矿系列副题名外文题名 The epithermal-porphyry gold deposit series in Yanbian region 论文作者梁俊红导师金成洙王建国教授学科专业矿产普查与勘探研究领域\研究方向学位级别博士学位授予单位东北大学学位授予日期2002 论文页码总数112页关键词成矿系列金矿床延边地区馆藏号BSLW /2003 /P618.51 /1 延边地区处于华北板块北缘东段，正好位于华北板块、西伯利亚板块和濒太平洋构造三大构造区域之间的三联点处，三者所处的空间位置和边界条件，对延边地区的火山—次火山岩及与之有成生联系的金成矿系列的形成和演化起着明显的控制作用。

There exist four layers of volcanic rocks in Sinian and Cambrian strata of Kuruktag area, Xinjiang.

在新疆库鲁克塔格地区的震旦纪和寒武纪沉积岩地层中，分布有四层火山岩。

Volcanic and intrusive rocks widely distributed, local there Sinian limestone, sandstone and shale.

火山岩和侵入岩广布，局部有震旦纪灰岩、砂页岩。

In contrast, the depth of mineral crystallization in the shallow part, which represents the condition of basaltic magma chamber, is in the range of 37~41 km, indicating that the basaltic magma might have been an mineral chemistry of the clinopyroxenes shows that the volcanic rocks in this area belong to subalkaline series and were probably formed in and island arc setting.

基于单斜辉石的成分和演化，确定了该地区火山岩属亚碱性系列，其构造背景为岛弧环境。

These subvolcanics, in which basalt, basaltic andesite and andesite are dominant, are petrochemically of calc alkaline affinity of subalkaline series and sodic type, and tend to have moderate low total REE, being LREE enriched.

岩石化学上属亚碱性系列、钙碱性火山岩系、钠质类型；稀土总量中低，属轻稀土富集型，稀土分布模式为右倾平滑曲线或略有正、负铕异常；过渡族元素球粒陨石标准化曲线形态呈&W&型，锶初始值为 0 。70 5398，反映物质来源较深。

The Paleoproterozoic Beidahe Group-complex remains as continental shivers in the interior of the North Qilian orogen. In its early stage of development, there occurred abundant amphibolite. The protolith of the amphibolite is basalts. The Alk-∑FeO-MgO plot, REE features and Rittmann index show that the protolith belongs to the calc-alkaline suite and exceptionally shows the subalkaline character. The rock is characterized by higher Al2O3 and ∑FeO and lower Mg#, indicating that it has a higher degree of compositional evolution and that the formation of volcanic rocks is related to activation of older crust. Highly fractionated REE patterns and amphibolite on the Ti-Zr-Y plot, Ni-FeO/MgO plot and Ta/Yb-Th/Yb plot all indicate the characteristics of volcanic arcs and active continental margins. On the geochemical diagram of basalt, the overall REE features are in the main analogous to those of calc-alkaline island-arc basalt, with Sr87/Sr86=0.71617–0.72033,Nd143/Nd144=0.512414–0.512495 and εNd=–2.79 to –4.37,εSr=245.78–305.3, showing that the magma was derived from the crust or subjected to contamination with the lower crust below the continent.

提要：以大陆碎块形式残存于北祁连造山带内部的古元古代北大河岩群早期发育有大量的斜长角闪岩，其原岩为玄武岩，Alk—∑FeO—MgO图解，REE特征，里特曼组合指数等均显示斜长角闪岩属钙碱性系列范围，个别显示弱碱性，斜长角闪岩具有较高的Al2O3，∑FeO和低的Mg#，这些特点反映其成分演化程度较高，表明火山岩的形成与古老地壳的活化有关，有较强分异的稀土元素分配模式，在Ti—Zr—Y图，Ni—FeO/MgO图解和Ta/Yb—Th/Yb图解上斜长角闪岩均显示火山弧或活动大陆边缘的特点，在玄武岩的地球化学形式图，稀土元素整体特征与钙碱性岛弧玄武岩基本相同；87Sr/86Sr=0.716 17～0.720 33， 143Nd/144Nd=0.512 414～0.512 495，εNd=-2.79～-4.37。

The volcanic facies in study area include 12 subfacies in 5 volcanic facies.

松辽盆地东南隆起区营城组火山岩岩相类型涵盖5种岩相中的12种亚相。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。