火山喷发碎屑

On August 26-27 1883, Krakatoa erupted and continually sent enormous plumes of ash and dust into the sky.

1883年8月26－27日，喀拉喀托火山喷发并且激起了冲天的火山灰和碎屑的柱体。

Sub-volcanic rocks include andesitic porphyrite, rhylitic porphyry, cryptoexplosive breccia as well as autobreccia etc.(2) Volcanic lithofacies——through the observation of cores, identification of thin sections and interpretation of well logs and seismic data, there are 8 kinds of lithofacies for the volcanic rocks of Yingcheng Formation are identified: fallout facies, effusion facies, pyroclastic flow facies, base surges facies, lahar facies, eruption-sedimentary facies, subvolcanic facies and extrusion facies.(3) Three types of eruption——i. e. explosion, effusion and surge.(4) Two kinds of eruptive environments——Subaerial (e. g. volcano in Well Shangshen 3) and subaqueous .(5) Three remarkable volcanic apparatus in Shengping-Wangjiatun area——layered, micro-shield and cone volcanoes according to volcanic processes and lithofacies distribution.

次火山岩有安山玢岩、流纹斑岩、隐爆角砾岩及自碎角砾岩等；(2)火山岩相——通过岩芯观察、镜下鉴定、测井与地震资料解释，营城组火山岩中发育8种岩相类型，即爆发空落相、溢流相、火山碎屑流、基底涌流相、喷发沉积相、火山泥石流相、侵出相和次火山相等；(3)火山喷发的形式——有爆发、溢流和涌流三种；(4)火山喷发环境——有陆上(如尚深3井火山)和水下两种；(5)火山机构类型——根据火山作用特点和岩相分布特征，在升平—汪家屯地区识别出三类截然不同的火山机构，即层火山、微型盾火山和渣锥火山。

The author deals with mainly the sequence and distribution of the pyroclastic deposits of the 800 a. B. P. eruptions.

主要论述了这次大爆发的火山喷发碎屑堆积物的层序和分布。

This paper demonstrates the results of grain-size sieve analyses of the millennium pyroclastic flow deposits from Tianchi volcano.

文中对长白山区天池火山千年大喷发火山碎屑流堆积进行了粒度分析。

Volcanologist examining tephra horizons in south-central Iceland.

火山学家在冰岛中南部观察火山喷发碎屑。

The eruptive pattern of the Chifeng phase is: Plinian column (the Chifeng pumice fall deposits)→pyroclastic flow (the Changbai pyroclastic flow deposits)-lahar mainly triggerd by pyroclastic flow. The eruptive pattern of the Yuanchi phase is from Plinian column (the Yuanchi pumice and ash fall deposits)→pyroclastic flow (the Bingchang pyroclastic flow deposits).

赤峰期喷发模式为：普林尼式喷发柱－火山碎屑流－火山泥流，主要由火山碎屑流诱发火山泥流；园池期火山喷发模式为：普林尼式喷发柱－火山碎屑流。

Over one hundred sixty volcanic cones,pyroclastic sheet,river valley lava and eight maars with phreatomagmatic eruption genesis distribute of Longgang volcano,Jilin Province.The volcanic rock of Longgang volcano is trachybasalt with very similar chemical composition(SiO2=48-50%).

龙岗火山区分布160多个玄武质火山渣锥，以及火山碎屑席、河谷熔岩和8个射气岩浆喷发的低平火山口－龙湾，所有火山岩为单一钾质粗面玄武岩(SiO2变化于48-50%)。

The mendous thick ore body was formed by sea floor volcanic eruptive sedimentation during the Devonian Period; the stringer ore body by Yanshanian magmatic hydrothermal fluid filling and overprinting. The reduction of old terrigenous detritus and some organic materials has important effect on the late ore fluids.

其中层状矿体为泥盆纪海底火山喷发沉积作用所致，脉状矿体可能来自燕山期岩浆热液充填迭加形成，古大陆碎屑物质和部分有机质的还原对后期成矿流体具有较大的影响作用。

Many lives have been lost to the volcano's frequent eruptions, which are accompanied by high-speed pyroclastic flows and mudflows called lahars.

许多人的生命已经丧失由于火山频繁喷发，这是伴随着高速的火山碎屑流和泥流所谓的火山泥流。

Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra, rock and lava samples.

火山学家经常去火山区，尤其是活火山，观察火山喷发，收集火山喷发碎屑、岩块和熔岩之类的喷发物。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。