专业英语-地史古生物学

Historical geology examines the origin and evolution of Earth, including its continents, atmosphere, oceans, and life history. Historical geology is, however, more than just a recitation of past events. It is the study of a dynamic planet that has changed continuously during the past 4.6 billion years. In addition to determining what occurred in the past, geologists are also concerned with interpreting how and why past events happened.–––––“Historical Geology”, 2004, Reed Wicander & James Monroe① The Earth accreted from planetesimals and differentiated into a core and mantle, and at least some crust was also present.②Like the other terrestrial planets, the Earth was bombarded by comets and meteorites, and volcanic activities were ubiquitous.③Furthermore, a primitive atmosphere formed, although it was quite different from the oxygen-rich one we have today.①The oldest known organisms occur as fossil prokaryotes (anaerobic and autotrophic bacteria and cyanobacteria) from the 3.5-billion-year-old Warrawoona Group, western Australia.Other than the origin of life itself, the most significant biological event of the Archean was the development of photosynthesis. The oldest known undisputed stromatolites were found in 3.0-billion-year-old rocks in South Africa.②The Archean rock associations mainly consist of greenstone belts（绿岩带）and granite-gneiss complexes（花岗片麻杂岩）. Actually, granite-gneiss complexes have rocks varying form granite to peridotite to various sedimentary rocks, all of which have been metamorphosed.③Some primitive cratons or continental nuclei (including North China nucleus ) formed and grew by continental accretion during this Eon. By the end of the Archean, perhaps 30% to 40% of the present volume of continental crust existed.④Archean mineral resources: Gold is the mineral most commonly associated with Archean rocks.Though 92% of the Earth’s Banded Iron Formations (BIFs, from 3.8 to 1.8 Ga in age) were deposited during the Proterozoic (2.5~2.0Ga), the Archean is the most important period for China’s iron ore deposits (especially in Anshan, Benxi, eastern Hebei, etc.).Archean sulfide deposits of zinc, copper, and nickel are well known in Australia, Zimbabwe, and Canada. About one-fourth of Earth’s chrome reserves are in Archean rocks, esp. in Zimbabwe.① The appearance of eukaryotic cells（真核细胞）about 2.1 billion years ago marks a milestone in biological evolution comparable to the development of complex metabolic mechanisms such as photosynthesis（光合作用）during the Archean.Multicellular organisms also appeared in the Proterozoic. The most remarkable Ediacaran fauna was originally discovered as impressions of soft-bodied animals in the Pound Quartzite in the Ediacara Hills, southern Australia. The Ediacara-type faunas were found from all continents except Antarctica ca. 620Ma ago. But the great majority of these organisms did not survive the beginning of the Cambrian Period.②Deducing form the Grenville Orogenic Belt, the Proterozoic supercontinent known as “Rodinia” assembled between 1.3 and 1.0 billion years ago, consisting of all or at least much of the present continents, and then began breaking up ca. 750 million years ago.③V ast glacial deposits were found from Early Proterozoic localities. Two worldwide glaciers are most acceptable during the Neoproterzoic, i.e., the Sturtian glaciation (730~700Ma) and the Marinoan glaciation (665~635Ma), resulting in the coeval hypothetical “Snowball Earth”.④With gradual increase of free oxygen, the Proterozoic atmosphere evolved from a chemically reducing one to an oxidizing one. Two widespread types of Proterozoic sedimentary rocks serve as the evidence, i.e., Banded Iron Formations (BIFs) and Continental Red Beds.⑤Proterozoic mineral resources: Most of the world’s iron ore comes from Paleoproterozoic(2.5~2.0Ga) banded iron formations. Substantial nickel, copper and PGE are mined from Proterozoic rocks especially in Sudbury of Canada. The Bushveld Complex of South Africa yields most significant platinum and chromite. Economically significant oil and gas have been discovered in Proterozoic rocks in China and Siberia. The most important phosphorite was deposited during the Ediacaran (Sinian) of Neoproterozoic, esp. in Yunnan and Guizhou.①There are six major continents (Gongdwana, Laurentia, China, Siberia, Baltica and Kazakhstania) existed at the beginning of the Paleozoic.②Animals with skeletons, the so-called Small Shelly Fossils (SSFs), appeared abruptly at the beginning of the Paleozoic Era and experienced a short period (less than 5 Ma) of rapid evolutionary diversification, i.e., the evolutionary “Big Bang” or the Cambrian Explosion represented by the Chengjiang Biota, the Burgess Shale Biota, and the Sirius Passet Biota.The Cambrian Period was a time of many evolutionary innovations during which almost all the major modern invertebrate phyla appeared and evolved. Remarkably, the earliest vertebrates, agnathous (jawless 无颌) fish, emerged from the Early Cambrian in South China, whereas the well-known jawless fish ostracoderms (甲胄鱼) were found in the Upper Cambrian.③The Ordovician Period witnessed striking changes in the marine community, resulting in a drastic increase in the diversity of invertebrates (无脊椎动物), esp. corals (珊瑚), trilobites (三叶虫), brachiopods (腕足类), cephalopods (头足类), and graptolites (笔石), followed by a mass extinction (集群绝灭) at the end of the Ordovician.Bryozoans (苔藓动物) and tabulate and rugose corals (横板珊瑚和皱襞珊瑚) rose in Ordovician and acted as major reef builders.④The earliest jawed fish (acanthodians 棘鱼) and first seedless vascular land plants (psilophytes 裸蕨类) appeared in the Early and Late Silurian respectively.⑤ The Lower Paleozoic rocks contain a variety of important mineral resources. The Early Cambrian is also an important time for the deposition of phosphorite (磷灰岩) in China. Industrial limestone and sandstone, strata-bound lead and zinc deposits, rock salt and rock gypsum etc. areyielded from rocks of this Era throughout the world.① Extensive glaciers covered vast areas of the southern continents, esp. Gondwana, during the Late Paleozoic. In contrast, the continents such as Laurasia, China etc. located at low paleolatitudes were tropics or subtropics. Movement and collision of the six major continents during the Paleozoic resulted in the formation of the supercontinent Pangaea (联合古大陆) at the end of the Paleozoic.② Some marine invertebrates, esp. graptolites and trilobites thriving during the Early Paleozoic greatly declined or became extinct, whereas fusulinids ( ), corals, brachiopods and ammonoids (菊石) flourished during the Late Paleozoic.③All major groups of fish were present in the Devonian seas. The earliest amphibians evolved from fish during the Late Devonian. Primitive reptiles evolved from amphibians by the Late Mississippian, which was critically attributed to the evolution of the amniotic egg (羊膜卵).④ By the end of the Devonian, forests with tree-sized plants had evolved. The Late Devonian also witnessed the evolution of flowerless seed-bearing plants (gymnosperms 裸子植物). Seedless vascular plants (lycophytes 石松and sphenophytes 节蕨) flourished during the Carboniferous Period, whereas the gymnosperms came to dominate the Permian landscapes.⑤ A mass extinction occurred near the end of the Devonian (Frasnian-Famennian Age, ca. 375 Ma), resulting in a worldwide near-total collapse of the massive reef communities.⑥The greatest recorded mass extinction in the Phanerozoic took place by the end of the Permian, causing the catastrophic extinction of roughly 50% of all marine invertebrate families and about 90% of all marine invertebrate species. Fusulinids, rugose and tabulate corals, trilobites, most brachiopods, and ammonoids did not survive the end of the Permian.⑦The Carboniferous and Permian are among the most important periods for coal accumulations. Significant strata-bound polymetallic mineral deposits are yielded from Devonian rocks. Bauxite, petroleum and natural gas are also recovered from the Late Paleozoic rocks.①The breakup of the supercontinent Pangaea began with rifting between Laurasia and Gondwana during the Triassic, which profoundly affected geologic & biologic events during the Mesozoic. The breakup also influenced global climatic and atmospheric circulation patterns.② A global rise in sea level during the Cretaceous resulted in worldwide transgressions onto the continents, which left about one-third of the present land area inundated by epeiric seas.③Drastic tectonic and magmatic activites took place in eastern China, which were triggered by westward subduction of paleo-Pacific plate during the Jurassic Period. In contrast, the western China was characterized by vast stable continental basins.During the Jurassic Period, drastic tectonic and magmatic activites took place in ancient eastern China, which were triggered by westward subduction of paleo-Pacific plate.In contrast, the western China was characterized by vast stable continental basins.④ The collision of the South China Block and the North China Block took place during the Triassic. Subsequently, several terrains and microplates moved northward and were accreted to the continental margin of the South China Block. Thus, the ancestral united continent of China eventually came into being.⑤ Marine invertebrates that survived the Paleozoic extinctions diversified and repopulated the Mesozoic seas. Ammonoids, belemnites (箭石类), and bivalves (双壳类) are most abundantthroughout the Mesozoic. Conodonts (牙形石), the enigmatic fossil invertebrates, went extinct by the end of the Triassic.⑥Reptile diversification that began during the Mississippian continued throughout the Mesozoic Era.⑦ Dinosaurs evolved from Mesozoic reptiles by the Late Triassic and then soon colonized and dominated the Mesozoic landscapes. The first birds evolved from reptiles during the Jurassic. Mammals evolved from cynodonts (犬齿兽) by the end of the Triassic.⑧Gymnosperms continued to flourish during the Mesozoic. Land plant communities changed considerably when flowering plants (angiosperms 被子植物) evolved during the Cretaceous Period.⑨Dinosaurs, flying reptiles and marine reptiles, some important marine invertebrates (including ammonoids, rudists and most planktic foraminifera 有孔虫类) became extinct at the close of the Cretaceous. The most popular hypothetical explanation for the terminal Mesozoic extinction is a calamitous meteorite impact.⑩The Triassic, Jurassic and Cretaceous are also most important periods for coal accumulations known from America, Canada, China, Australia and Russia. Large concentrations of petroleum and natural gas formed in many areas of the world during the Mesozoic Era. The Cretaceous and Jurassic are the most significant periods for the accumulation of oil and gas in China.Substantial endogenic metallic mineral deposits of copper, iron, lead, zinc, Tungsten, tin, molybdenum, bismuth, etc. originated along the Circum Pacific Orogenic Belt during the Mesozoic (esp. the Jurassic and Cretaceous). Important accumulations of Gold, Uranium, and Diamond were also formed in the Mesozoic rocks.①The breakup of Pangaea that began during the Mesozoic continued, giving rise to the present distribution of land and sea.②Cenozoic orogenies were concentrated in two belts, one nearly encircling the Pacific Ocean basin (Circum-Pacific Orogenic Belt), whereas the other trending east-west through the Mediterranean basin and on through southeast Asia (Alpine-Himalayan Orogenic Belt).③ The India plate that drifted northeastward during the Cretaceous eventually collided with Asia ca. 40 million years ago, resulting in the Himalayan orogen as Roof of the World.④A widespread continental glaciation was present on the Northern Hemisphere continents during the Pleistocene.⑤Angiosperms continued to diversify and to dominate land plant communities during the Cenozoic Era (the Age of Angiosperms). The present-day invertebrates evolved.⑥ The Cenozoic is also referred to as the Age of Mammals. With the demise of dinosaurs and their relatives, mammals experienced a quick and remarkable diversification through the Cenozoic.⑦ The marine invertebrates that survived the Mesozoic extinctions diversified throughout the Cenozoic. Bivalves, gastropods, corals and foraminifera proliferated.⑧Tertiary-age coal deposits are also most abundant throughout the world. Huge quantitative of oil shale and evaporates were found in Tertiary rocks in many countries.。