Petrological characteristics of bedded radiolarian cherts and different types of volcanic tuffs have been studied in the Ordovician of Weibei, Shaanxi.
通过对层状放射虫硅质岩的岩石学和火山凝灰岩岩石类型的特征研究，认为渭北奥陶系的放射虫硅质岩是由远源的火山喷发物提供了ＳｉＯ２的来源，造成有利于硅质生物大量繁殖的条件，死后堆积海底，最终转变为层状放射虫硅质岩。
Comprehensive research has shown that structure can make some conceal environments of formation of volcanic ash tuff in space.
构造能在空间形成一个隐伏的环境，而这种环境正是火山尘凝灰岩赋存的重要条件。
They were deposits of volcanic tuff in Nye County, Nevada;
3处场地分别是内华达州奈伊县的火山凝灰岩矿床层；
A volcanic rock formed by the welding together of tuff material from an explosive volcanic eruption.
熔结凝灰岩火山喷发后凝灰物质聚集后形成的一种火成岩
A rock composed of compacted volcanic ash varying in size from fine sand to coarse gravel.
凝灰岩致密火山灰构成的岩石，大小以细粒至粗砾石不等
The studies showed that (1) HFW are found in vocalnic tuff while the others in sedimentary rocks;
(1)前者产出层位是陆相火山爆发相的凝灰岩,后者是河湖相沉积岩;
The volcano ejected lava and ashes .
火山喷出熔岩和灰。
A volcano that vomited lava and ash.
喷出岩浆和火山灰的火山
Lava and ashes erupted from the volcano
熔岩和火山灰从火山中喷出来。
The volcano erupted lava and ashes
火山喷射出熔岩和火山灰。
Computation Method for Shale and Tuff Content in Reservoir with Pyroclastic Sedimentary Rock
火山碎屑沉积岩储层泥质与凝灰含量计算方法研究
volcanic ash and lava build the mountains that we call volcanoes.
火山灰和火山岩在喷射口堆积构成了火山。
Tuffite is formed by the combination of volcanic ashes and carbonate mud.
沈积凝灰岩主要为中远源的火山灰与碳酸盐灰泥混合而成，含石英团块，显斑点构造。
the commonest type of solidified lava; a dense dark gray fine-grained igneous rock composed chiefly of calcium-rich plagioclase feldspar and pyroxene.
最常见的凝固火山岩，是一种致密的深灰色火成岩，纹理细密，主要由富钙的斜长石和辉石组成。
The ash, cinders, and other fragments become a consolidated rock.
火山灰、火山渣和其它碎屑变成了固结的岩石。
Ash and bits of rock that were burnt black were falling onto the ship now .
烧黑色的火山灰和岩石落到船上。
A volcano emits smoke, lava and ashes.
火山喷射出烟、 熔岩和灰烬.
That volcano cast forth lots of lava and ashes.
那火山喷了出大量熔岩和灰烬。
The volcano began spewing out towering columns of ash and smoke on Monday.
火山星期一开始喷射出岩灰和浓烟。
portland pozzolan concrete
火山灰硅酸盐水泥混凝土