Ordovician period

Study on the sedimentary characteristics and sedimentation of the strata in Ordovician period in Southeastern Hubei

鄂东南奥陶纪地层沉积特征及沉积作用研究

The soluble rocks in this area are the carbonate rock constructions of the Sinian , the Cambrian and the Ordovician period .

区内可溶岩地层为震旦纪、寒武纪及奥陶纪碳酸盐岩建造。

Hot Water Karst Characteristics of Ordovician Period in Ordos Basin

鄂尔多斯盆地奥陶系热水岩溶特征

Study of the Fluctuation of Sea Level During Ordovician Period in Tarim Basin

Hypermecaspis（三叶虫）的蜕壳塔里木盆地奥陶纪海平面变化

New Fossils in Shanghai Silurian & Ordovician Period and Their Stratigraphic Significance

上海志留纪、奥陶纪地层新发现化石及其地层意义

Stratigraphic classification of the Ordovician period of Guilin

桂林奥陶纪地层的划分

Enrichment of Au during the Ordovician period ;

奥陶系富集Au；

Carbonate Gravity-Flow Sedimentation from Middle Cambrian Period to Lower Ordovician Period in Sandu-Danzhai Region

三（都）&丹（寨）地区中寒武世至早奥陶世碳酸盐重力流沉积

At the end of Ordovician Period , a differential elevation occurred in the central Shanganning Basin due to the Caledonian Movement .

陕甘宁盆地中部气田的主要储气层段为奥陶系马五段的古岩溶层。

There was a deposit of carbonate gravity flow from Middle Cambrian Period to Lower Ordovician Period in Sandu & Danzhai area .

三（都）&丹（寨）地区在中寒武世至早奥陶世发育了一套别具特色的碳酸盐重力流沉积。

It is believed that there are three sea level change cycles during the Ordovician period in the study area : the first one occurred from early to late Lianghekou age ;

认为研究区奥陶纪存在三个海平面变化旋回，第一个旋回发生于两河口期早期至晚期；

Horseshoe crabs are considered " living fossils . " The earliest horseshoe crab fossils are dated to the Ordovician period .

马蹄蟹素有“活化石”之称，最古老的马蹄蟹化石可追溯到奥陶纪。

Comprehensive researches have concluded that the Heishan ophiolite was formed in Nanhua Ordovician period and its structural location in Silurian period early Middle Devonian epoch .

综合研究得出黑山蛇绿岩形成于南华奥陶纪，构造就位于志留纪早中泥盆世。

Volcanism and tectonic setting during Ordovician Period on north margin of Qaidam deep water carbonate debris flow in the Middle Ordovician Pingliang Formation of fuping , shaanxi

柴达木北缘奥陶纪火山作用与构造机制陕西富平中奥陶统平凉组的深水碳酸盐碎屑流

FLOURESCENT IN SITU HYBRIDIZATION OF ENRICHED SFA-DNA ON PACHYTENE CHROMOSOMES IN MOUSE enrichment of Au during the Ordovician period ;

小鼠富集着丝粒DNA在小鼠减数分裂粗线期染色体上的原位杂交奥陶系富集Au；

Many coal mine in our country suffers from the Ordovician period Karst containing water inrush frequently due to the complex geology condition , Water inrush is a serious disaster in coal mining .

我国煤田地质条件复杂，许多煤矿不同程度的受奥灰岩含水层的威胁，突水是采矿过程中常常面临的一种严重灾害。

The palaeo-geotherm gradient is 3.2 ~ 3.5 ℃ / 100m in early Ordovician Period and Cambrian Period , and it decreases distinctly from then on .

早古生代塔中地区古地温梯度较高，寒武纪&早奥陶世地温梯度为3.2～3.5℃/100m，此后地温梯度显著下降；

Southeast margin of middle Yangtze Block was situated in passive continental margin slope of Yangtze block form later Sinian to early Ordovician period , and various sedimentary facies alternated frequently .

中扬子区东南缘震旦纪-早奥陶世处于被动大陆边缘坡折带附近，各种相带频繁交替，生储盖组合配置良好。

Five past extinctions : Some event near end of the Ordovician period , 440m years ago , wiped out almost all corals and fish , and25 % of all families of creatures .

历史上曾发生过的5次物种大灭绝：4.4亿年前奥陶纪将要结束时的一些事件使几乎所有的珊瑚和鱼类以及25%的物种灭绝；

The natural geography of the Ordovician period is that : the Hannan paleocontinent and the Bashan Mountain rise at the north , and the wide epicontinental sea basin lies in the south .

奥陶纪时期，本区处于北为汉南古陆与巴山隆起，南为广阔的陆表海盆地的古地理环境。

The study area is a stable deposition of micro-plate in the early Cambrian , from the Ordovician period it experience a plate crack , entered a period of tectonic activity , this event end in the late Ordovician .

研究区在寒武纪为一稳定的微板块内沉积，从奥陶纪开始发生了一次板内裂解，步入了一个构造活动期，到奥陶纪末期板内活动结束。

The technique is suitable to explore the aquifuge thickness , the lower coal group construction , the interface of Ordovician period , the boundary of upper flooding sandstone , and so on , in the underworkings of the multi coal beds , inclined coal beds mining area .

该技术适用于在多煤层、急倾斜煤层开采矿区，井下探测隔水层厚度、下组煤构造、奥灰界面、上部充水砂岩界面等。

The early ordovician ( nanjinguan period ) bioherms of Northwestern Hunan and its forming environment

湘西北早奥陶世南津关组生物丘（礁）及其形成环境

In the Ordovician , Silurian Period , the Devonian , Carboniferous , the advent of low amphibians and ancient ancient reptiles .

在奥陶纪、志留纪、泥盆纪、石炭纪，相继出现低等鱼类、古两栖类和古爬行类动物。

The basin-forming period of rifting and extension from the Sinian to the middle Ordovician : the orogenic period of dip slip compression from the late Ordovician to the S ü urian ;

震旦纪至中奥陶世裂陷拉伸成盆期；晚奥陶式至志留纪倾滑压缩造山期；

Ordovician is the key period for transformation of the Paleozoic basin in Kuruktag . The rift basin of Cambrian - early Ordovician was transformed into the foreland basin of late Ordovician-Silurian through middle Ordovician .

奥陶纪是早古生代盆地发生盆地类型转化的关键时期，即从寒武纪-早奥陶世的裂陷盆地，经中奥陶世的过渡，转化为晚奥陶世-志留纪的前陆盆地。