白垩纪

The prints are believed to have been made during theCretaceousperiod of the Mesozoic Era, Kim said in a statement.

这些足迹被认为是在中生代白垩纪时期由当时鸟类留下的。

The Lower/Upper Cretaceous boundary in Songliao Basin is,therefore,between the Quantou and Denglouku formations,instead of between the Quantou and Qingshankou formations.2.The dark mudstones and shales in the Member 1 of Qingshankou Formation are of high organic carbon and low diasteranes contents.Organic geochemical characters are illustrated by biomarkers of 28,30-bisnorhopane and gammacerane,and positive excursion of kerogen isotopes.It is suggested that the dark mudstones and shales in the Member 1 of Qingshankou Formation are the products of lake anoxic period.It corresponds to the oceanic anoxic event at Cenomanian-Turonian boundary in Cretaceous.3.Based on the study of biostratigraphy,chronostratigraphy,magnetostratigraphy and event stratigraphy,a correlation of the lacustrine sequence to marine standard has been proposed,i.e.,the Quantou Formation corresponds to Cenomanian stage,Qingshankou Formation correlates to Later Cenomanian-Early Turonian,Yaojia Formation to Later Turonian-Coniacian,Nenjiang Formation to Santonian-Campanian.Sifangtai and Minshui Formations to Maastrichtian. 4.Analysis of lithology,lithofacies and microfossils of Cretaceous in Songliao Basin, shows that shore and shallow lake facies yield the most abundant microfossil groups,and the predelta and deltaic distributary plain facies rich in fossils as well.In the shore and shallow lake areas during the high level periods(such as Qingshankou and Nenjiang sedimentary periods),the lacustrine biota are of high diversity and high abundance.

因此，松辽盆地上、下白垩统的界线应在泉头组的底界，即泉头组与登娄库组之间，而不是泉头组的顶界。2、青山口组一段黑色泥岩、页岩具有有机碳含量高、重排甾烷含量低，生物标志物出现28，30—双降藿烷和伽马蜡烷，干酷根碳同位素具有正向偏移等有机地球化学特征，表征为青山口组一段黑色页岩、油页岩是古湖泊缺氧事件的产物，它对应于白垩纪古海洋Cenomanian—Turonian期界线附近缺氧事件，二者具同步性。3、通过生物地层学、年代地层学、磁性地层学和事件地层学研究，认为泉头阶大体相当于Cenomanian阶，青山口阶相当于晚Cenomanian—早Turonian阶，姚家阶对应于晚Turonian—Coniacian阶，嫩江阶对应于Santonian—Campanian阶，四方台阶和明水阶相当于Maastrichtian阶。4、通过对松辽盆地上白垩统的岩性、岩相及微体化石分析，认为滨浅湖相是微体生物群最为发育的相带，其次为三角洲前缘相和三角洲分流平原相。

According to structural analysis and sediment comparison ,we judge the western of the basin is outside of west-edge thrust nappe belt .

盆地现今的西界为西缘逆冲推覆带所限，而西缘逆冲推覆带主要形成于晚侏罗世一白垩纪。

The composi-tion of the seawater has changed rapidly since Phanerozoic, and the prolonged mineralogical changes of marine non-skeletal limestone and potash evaporates occurred in a phase on a 100-200 Ma.

结果表明：显生宙以来海水组分发生变化，经海相非骨骼灰岩和钾盐蒸发岩矿物学研究，发现这两种沉积岩长期以来连续变化，在"文石海"是MgSO4型蒸发盐，在"方解石海"是KCl型蒸发盐，从白垩纪晚期、第三纪早期的底部石盐溴含量及矿物学特征表明，此时处于"方解石海"，古海水组分的特点是造成缺硫酸盐型钾盐矿床形成的物化基础；通过NaCl-KCl-MgCl2-H2O和NaCl-KCl-MgCl2-CaCl2-H2O两个体系相图的分析认为，当时所形成的成钾原始体系母液是高镁、低钾氯化物型的卤水，在母液蒸发过程中，由于原始海侵母液与残余高镁母液的掺杂作用，致使结晶路线直接从氯化钠区到E点母液或光卤石与氯化钠共饱线上，而没有通过氯化钠和氯化钾的共饱线，因而在矿体中氯化钾相很少或几乎不存在，由于外界CaCl2型水体的掺杂，使成钾母液进入光卤石相区，随着蒸发的进行，最终形成溢晶石矿物。

Assuming a relatively constant rate of orchid evolution, the oldest common ancestor of the orchid family probably lived at least 76 million years ago, in the Late Cretaceous period.

假定兰花的进化过程一直保持一种相对稳定的水平，那么兰花家族最古老的共同祖先可能生活在距今至少7600万年前，即白垩纪晚期。

It underwent the collision event of the Southern China plate with the North China plate at early Triassic, overthrust napping event of continental, and continental spread structure event beginning at Cretaceous. I...

它已经历三迭纪早期华南陆块与华北陆块的碰撞事件、大陆逆掩推覆构造事件及后期白垩纪早期开始的大陆伸展构造事件，是我国华南陆块与华北陆块之间的重要过渡单元。

The Santee Coastal Reserve core, a 545 ft deep borehole in northeastern Charleston County, South Carolina, recovered sediments of Late Cretaceous, Paleocene, Eocene, and Quaternary age.

Santee海岸储藏岩心是从加州南部的查尔斯顿的545英尺深的钻井中采集的，代表白垩纪晚期、古新世、始新世和第四纪的沉积物。

The generic distributions in both modern and fossil times were outlined, and their distribution center, place and time of origin and the way of dispersal were discussed. An attempt was made to discuss early differentiation, geographical radiation and morphological evolution of the family on the background of paleogeography and paleoclimatology, tracing back as far as the Late Cretaceous and Early Tertiary.

作者试图回到遥远的晚白垩纪和旱第三纪，从描绘桦木科植物起源和早期分化的古地理和古气候背景入手，分析了在这种背景下桦木科植物所发生的空间辐射以及植物体本身所产生的形态进化，以求得对桦木科植物起源、散布和分化作出比较合理的解释。

The tectonic evolution history of Tianshan is an example. In the Triassic, it was once uplifted to form the mountains with thick molasse accumulation on both its sides, Junggar and Tarim Basins. Then it became a peneplain by the exposion and deplanation in the Jurassic, forming the widespread coal-bearing strata which can be correlated. From the Cretaceous to the Early Cenozoic, it was uplifted again, until the Quaternary to build huge mountains with two large sedimentary basins on both sides.

如天山山脉的构造演化，三叠纪天山曾经一度隆起成山，两侧的准噶尔和塔里木盆地中堆积了巨厚的磨拉石；侏罗纪时由於剥蚀夷平成为一个准平原，形成了广泛分布且可以对比的含煤岩系；从白垩纪到早新生代，它再度隆升，直至第四纪时形成雄伟的高大山系，两侧形成相应的大型沈积盆地。

The tectonic evolution of southern Junggar basin can be classified into seven stages: stage of intracontinental rift from middle Periman to late Late Carboniferous; stage of weak extension and peneplane from late Permian to early Triassic; stable depression stage in middle-late Triassic; maximal basin formation phase in the setting of weak extension in early-middle Jurassic; inactive depressed basin formation phase in thrust setting in middle-late Jurassic; stable depression stage in Cretaceous and Eogene; foreland depressed basin formation phase in thrust setting in Neocene and Quaternary.

准噶尔盆地南缘晚石炭世以来盆地构造演化可划分为七个演化阶段：晚石炭世—中二叠世陆内裂谷作用阶段；晚二叠世到早三叠世处于弱伸展-稳定坳陷作用阶段；中、晚三叠世准平原化作用阶段；早、中侏罗世为弱伸展背景下广盆形成阶段；中、晚侏罗世冲断背景下的坳陷盆地形成阶段；白垩纪到古近纪弱伸展背景下的稳定坳陷盆地形成阶段；新近纪—第四纪为冲断背景下的前陆坳陷盆地形成阶段。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。