火山岩

The volcanic rocks of eastern China belong to quatz andesite ...

一、火山岩空间展布、分带及基本特征广泛发育于中国东部的中生代陆相火山岩是印支旋回以来亚洲大陆东部发展成为滨太平洋构造域的产物，总体呈北北东向展布，是环太

In this paper, we research the imaging problems beneath volcanic area. We sort common asymptotic conversion point gathers and perform velocity analysis to establish the initial velocity which will be used in PSTM. By scanning migration velocity and V p/ V s, we get the optimum migration velocity and

本文针对火山岩地震屏蔽层的转换波成像问题，通过对转换波共近似转换点道集进行速度分析，建立了转换波叠前时间偏移的初始速度场，通过速度扫描和纵、横波速度比值扫描确定最佳的偏移速度场和纵、横波速度比值，实现了在火山岩高速层覆盖区域的转换波偏移成像。

The volume proportion of basalts is less than 30% even in bimodal volcanic rocks.

即使是双峰式火山岩也以酸性岩为主，玄武岩仅占全部火山岩体积的30％以下。

Research finds out that Carboniferous-Early Permian volcanic rocks system that largely distributing in Tianshan and its adjacent regions are continental rift volcanic rock system, it originated from mantle plume, they may be the surface response of the deep Geodynamics of paleo-Tethys extension effect in central Asian region.

5研究查明天山及其相邻地区广泛分布的石炭纪—早二叠世火山岩系为大陆裂谷火山岩系，其源区起源于地幔柱，它们可能是古特提斯拉伸裂解作用的深部地球动力学在中亚地区的地表响应

The border of Ehuling group and Daguding group was renewed.it concluded that volcano rocks of former subcycle and latter subcycle volcanic activities all came from the same source of magma,according to their chemical compositions and their chondrite normalized REE patterns.

对如意亭剖面鹅湖岭组与打鼓顶组的界线进行了重新厘定，对早晚两个火山活动旋回火山岩的化学成分、稀土配分特征进行了比较，得出了两旋回火山岩系属同一岩浆源的不同阶段演化产物的认识。

Firstly, the volcanics and shaly sand were separated with FMI static images and conventional logging data. Then, the image characteristics of all typical volcanics were analyzed with the dynamic FMI images to establish the FMI image patterns of volcanic lava (including rhyolite, dacite, andesite, and basalt) and volcaniclastic rock (including volcanic breeds and tuff).

首先利用FMI静态图像和常规测井曲线将砂泥岩与火山岩区分开来；然后利用FMI动态图像分析了火山岩各种岩性的图像特征，归纳总结出火山熔岩类（流纹岩、英安岩、安山岩、玄武岩）和火山碎屑岩类的FMI图像模式。

The study shows that volcanic magma origin has relatively no change, and comesfrom mantle source areas, which have similar geochemical characteristic, the volcanicrock erupted during the depositional period of Dongying division 2 contrasts withother period, so the relative hasty mantle diapir penetration in this period is relatedwith intensive basin extending and chasmic stage.

研究认为，本区火山岩浆来源于相对较为固定，较为类似地球化学特点的地幔源区，东营组二段沉积时期所喷发的火山岩与其他时期的火山岩成分形成对比，推断该时期盆地强烈伸展裂陷与相对快速的地幔底辟上隆相联系。

There occur different genetic types of granitic subvolcanie rocks in nature as well as different genetic types of volcanic rocks.

与花岗质火山岩具不同的成因类型相似，自然界也存在着不同成因类型的次火山岩。

In the second formation of the Langshan group in the Dongshengmiao polymetallic pyrite deposit, metamorphic basic volcanic rock s have been discovered,except quartz keratophyre, with a blastoporphyritic texture containing albite and oligoclase and minor, pyroxen and hornblende.

东升庙硫－多金属矿床狼山群二组含矿地层中，除已发现的变质石英角斑岩之外，又找到具有变余斑状结构（斑晶主要为钠质斜长石，另有少量辉石和角闪石）的变质基性火山岩和变质凝灰岩夹层以及火山岩屑与晶屑。

Those formed during the flare-up period, i.e., the Pana Formation, however, show significant geochemical variations from low-K tholeiitic through calc-alkaline to shoshonitic compositions coupled with increasing enrichment in LREEs. Therefore, the volcanic successions are divided into four suites, namely, calc-alkaline suite, low-K suite, high-REE suite and shoshonitic suite.

在大喷发时期产生的火山岩最不均质，组成从低钾拉斑质、钙碱质变化到钾玄质，并且呈现不同程度的轻稀土元素富集，我们据此可将本期林子宗火山岩区分为钙碱质系列（calc-alkaline suite）、低钾系列（low-K suite）、高稀土系列（high-REE suite）和钾玄系列四类。

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。