Researchthe quaternary periodThe science of environmental development and evolution during the period, includingcrustal movement、climate change、depositional environment , stratigraphic division and correlation, biological succession, etc.Andgeology、Geomorphology、climatology、Paleogeography, paleontology, paleoanthropology, archaeology and other disciplines are closely linked.In the early 19th century, European geologists studied loose sediments and put forward the proluvial theory and glacier theory successively.[1]
At the end of the 19th century and the beginning of the 20th centuryEuropeEstablishedthe quaternary period4 timesGlaciationTheory, rightGlaciation, climate change, etc.YugoslaviamathematicianMilankovic(M. Milanko vich) put forward the astronomical theory of climate change in 1920,Earth orbitThe cycle has become an important theoretical basis for discussing the Quaternary climate change and the formation of ice age.In 1899, Austrian geologist E. Suess establishedSea level changeTheory, after continuous enrichment and developmentAmerican scholarR. Daly proposed that glacier sea surfacecybernetics。
Three types
In 1961, R.W. Fairbridge classified the sea level changes into three types: ① tectonic eustatic movement; ②Sedimentation -Eustatic movement；③Glacier - eustatic movement.
Continuous development
Since the 1950s,Radiocarbon, potassium argon methoduraniumTie FaFission track methodDating and oxygenisotopeThe application of temperature measurement and other technologies has brought the research of Quaternary geology to a new level.In 1963, A. Cox establishedPaleomagnetic chronologyIt provides a basis for the division and correlation of Quaternary strata.The study of continental and oceanic sedimentary sequences has updated the traditional concept of four ice ages and supported Milankovitch's astronomical theory of climate change.In 1977, G. Kukla and others studied the Brno loess in the Czech Republic, which proved that 17 times had occurred in 1.7 million years since the Olduwe paleomagnetic eventInterglacial periodOn average, there is one ice age every 100000 years -Interglacial climateCycles.Indian Ocean, Equatorial Atlantic OceanCaribbeanOfMarine depositThe study also draws similar conclusions.Quaternary loess in ChinaThe research reveals that there have been 13 climate cycles in the last 700000 years.Many international research projects implemented since 1960s, such as DSDP（Deep sea drilling program）, CLIMAP (long-term climate research, mapping and prediction plan), IGCP (international geological correlation plan), etcGlacial climateFeaturesmarine environmentThe changes and other aspects have made important achievements, thus promoting the development of Quaternary geology.
A brief history of research
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From the very beginning, human beings had an indissoluble bond with Quaternary geology, but the real research on it started very late.At first, people divided the development history of the crust into the first period (primitive period), the second period andTertiary3 major stages.In 1829, the French scholar J. de Nuoye putthe tertiaryThe upper loose sediment is divided intoQuaternary And its age is Quaternary.along withGeoscienceThe first and second periods were abandoned because they were subdivided into several periods, and only the names of the lower tertiary period and quaternary period were retained. These two periods are collectively calledCenozoic era。In 1839, the famous British geologist C. Lyle (1797-1875) divided the Quaternary intothe pleistoceneAnd the Holocene.
terrain
Quaternary geology is mainly studied in EuropeThe AlpsAnd the Scandinavian glacial relics.In China, since the end of the 19th century, some foreign scholars have observed the huge thick loess widely distributed in the Yellow River basin.At the beginning of the 20th century, the study of Quaternary geology in China had made great progress.There are many specialized research units and large professional research teams.In 1957, the China Quaternary Research Committee was established and has now joinedinternationalQuaternary Union.[2]
Quaternary sediments
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What people observeQuaternary sedimentsIt is mainly continental strata.Continental strata are widely distributed on the surface, mostly loose, with large thickness changes, intense phase change and complex composition.Therefore, in the Quaternary periodGeologic AgeandStratigraphic divisionA variety of signs are generally used in, such asBiomarker, ancient human and cultural signs, climate signs, landform signsAbsolute age determinationEtc.
Quaternary sediments can be divided into eluvium, diluvium, diluvium, alluviumLacustrine sediment, glacial depositsMarine sediment, biological sediment, aeolian depositVolcanic deposits, cave deposits, artificial deposits, etc.In 1948, geologistYang ZhongjianQuaternary sediments in China were divided into four categories, namely cavesStacking, gravel andpiedmontAccumulation, river lake accumulation and earthy accumulation.
Quaternary climate
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After the beginning of the Quaternary, taking the Northern Hemisphere as an example, the cold climate zone on the earth moved southward, making ice sheets or glaciers widely developed in high latitude and high mountain areas, resulting in an ice age.During the ice age, the northern edge of the subtropical arid area in the Northern Hemisphere fell into the westerlies, and the precipitation increased.The interval between two glacial periods is called interglacial period.During the interglacial period, due to the temperature rise,Glacial ablation, Northern Hemisphere VicePolar high pressure zoneMoving towards the pole,Northern HemisphereRainfall in arid areas decreased.
Geological picture
Many people in Europe have done a lot of work on the changes of the Quaternary climate, especially in the Alps and Northwest Europe.It is generally believed that there are 5 glacial periods, 4 interglacial periods and 1Post glacialThe last ice age was subdivided into 2 or 3 ice segments.In China, geologist Li Siguang based on theMoraineAnd glacial erosion landform, three glacial periods of Poyang, Dagu and Lushan were divided, and later some people included the Dali and Longchuan glacial periods determined by research in Yunnan.In this way, there are five ice ages in China that can correspond to those in Europe.Except for a few mountains in Africa where glaciers have developed, most of the ground is not affected by glaciers, but the climate change is still obvious.In Africa, the Ice Age is called because of the rainy and humidRainy seasonorProluvial period；The interglacial period is called because of lack of rain and droughtInterrainy periodorInterdiluvial period。
The Minde Rhys interglacial period is called the "Great interglacial period", which lasted for about 300000 years.The climate was warmer then than it is now, but it was still colder during the interglacial period.During the ice age with the largest glacier activity, 32% of the earth's land surface was covered by glaciers. As the precipitation stagnated on the continent, the sea level dropped significantly, sometimes 130 meters or more.During the ice age, the annual average temperature is generally 3~7 ℃ lower than today.
Quaternary organisms
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Introduction to microorganisms
Quaternary ismammalIn the era of highly developed angiosperms, the emergence of human beings is the most prominent event in this era.Therefore, some people also call the Quaternary as the life period or the spiritual life period, and some people even separate it from the Cenozoic and list it as the life generation or the spiritual life generation.Quaternary mammals have obvious characteristics of modernization.During the early Pleistocene, many families in the Tertiary horse fauna, such as the weasel hyena (Ichtheriidae), the hornless rhinoceros (Aceratheriinae), and the giraffe (Giraffeidae), were extinct.Some Tertiary remnant species, such as Machairodontinae, Hyracoidea, Mastodontidae, Stegodontinae, Hipparion, Chalicotheriidae, and Mimomys, are almost in the process of extinction.Standard Quaternary species and genera are abundant, such as Ailuropoda, Elephantine, oelodonta, Elasmotherium, Bos, Bison, Bubalus, Leptobos, Elaphurus, etc.
Early Pleistocene representative
topographic features
The representative fauna of the Early Pleistocene in northern ChinaNihewan faunaOr Xihoudu fauna, which is found in the southYuanmou fauna , Europe hasVillafranchian fauna ；There are Blanco fauna in America.Middle PleistoceneDuring the period, some of the remaining species of the Tertiary period, such as saber tooth tiger and saber tooth elephant, continued to exist,MastodonThe three toed horse only existed in a few areas for a short time.A considerable part of the species that appeared in the early Pleistocene have survived, and the elements of modernization are increasing. Real big horned deer (Megaloceros), red deer (Cervus elaphus), and donkeys (Equus hemionus) have begun to appear, and pandas are very prosperous in South China.Fauna of this period, China hasGongwangling Fauna。Zhoukoudian faunaYanjinggou fauna;In Europe, there are Val Fauna, Cromer Fauna, Holstein Fauna, Ilford Fauna, etc;There are Owenton fauna in America.Late PleistocenePeriod,Middle PleistoceneThe composition of the fauna has greatly decreased, and the number of living species has increased. Donkeys, red deer, and primitive cattle (Bos primigenius) have been greatly developed, and mammoths (Mammutus) are widely distributed in high latitudes of the Northern Hemisphere.The representative fauna of this period areDingcun fauna 、Salawusu Fauna, mountain top cave fauna, etc. (see Paleolithic archaeology in China);Europe has Em fauna, etc;In America, there are Ranchola Brea fauna, etc.[3]
Holocene fauna
The Holocene fauna is dominated by living species, and there are fewer fossil species than ever before. Only the woolly rhinoceros (Coelodonta antiquatus) and mammoth have survived for some time, and the donkey and red deer have lived until now.In addition, during the Quaternary period, molluscs and microfauna were widely distributed with various types, and a variety of plants were found in all corners of the world. With the changes of climate and geographical environment, they were constantly changing.
Division of Quaternary System
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Basic Introduction
The Quaternary is a very short period in the geological history and has not yet ended.There is no consensus on when the Quaternary began.In the past, it was generally believed that its age was only about 1 million years.In recent years, due to ancient anthropology andPaleolithic archaeologyAndDating techniqueIt is generally believed that its age is much older, some think it is 1.8 to 2 million years, others think it is 2.48 million years, and others think it has exceeded 3 million years.
Quaternary geology
For a long time, people have been trying to find the standard stratum of the Quaternary system that is universally applicable, but it has not been achieved.Because the Quaternary sediments have a strong regional character, different strata can be formed in different natural environments and different geomorphic units at the same time;In different periods, similar strata can be formed in similar natural environment and on the same geomorphic unit.Therefore, it is impossiblesimpleQuaternary strata are divided according to the nature of rocks.
Division of climate change
Quaternary is usually divided into glacial and interglacial periods, or rainy and interrainy periods based on climate change.However, there are many places in the world that lack evidence of paleoclimate change, so vertebrates andMarine mollusks The paleontological method of the paleontology is used to determine the stage and stratigraphic division of the Quaternary.In areas rich in ancient human and cultural materials,Applied anthropologyAnd the effect of archaeological methods is relatively obvious.
the quaternary periodmarine animalThe group changes slowly, especially in the ocean, and there is almost no change. Only some high latitude inland sea areas, such as the Mediterranean Sea, the Caspian Sea and other places, have group migration. When the ice age comes, the species under the cold living conditions in the north migrate to the south, and when the interglacial period comes, they return to the north.However, vertebrates, especially terrestrial mammals, have a fast evolutionary speed, and the fauna in a certain physical geographical region at a certain stage has a relative consistency.In the Quaternary spineanimal fossilAmong them, the most collected are Quaternary mammals, and their research is also relatively detailed.Therefore, Quaternary mammals not onlyContinental strataIt is of great significance to divide and contrast, and plays a particularly important role in restoring the paleoclimate and paleogeographic environment at that time, and in exploring the survival era and living conditions of ancient humans.
evaluate
There is no consensus on the division of Quaternary strata in the world.According to the draft discussed at the 1959 National Stratigraphic Conference, the Quaternary strata in China include the Lower Pleistocene, Middle Pleistocene, Upper Pleistocene andHolocene seriesIts age is different from that of the early PleistoceneMiddle Pleistocene, Late Pleistocene andHoloceneEach stage corresponds.
Topographic map
The relationship between Quaternary geology and archaeology is an essential part of Paleolithic archaeological research.Because mankind itself is the product of geological history, and the relics of early humans are usually used asGeological phenomenonBuried in the stratum.Since the survival of early humans almost completely converged to the natural environmentruinsThe distribution in the stratum is regular.[4]
significance
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Paleolithic AgeThe field investigation of archaeology requires the application of Quaternary geological knowledge, such as restoring the Pleistocene paleogeographic environment and determining the Quaternary strata formed under the conditions suitable for the survival of ancient humans.The excavation work can be carried out smoothly only on the basis of full understanding of the Quaternary strata, especially for those buried in the river lake faciesSedimentary layerThe ancient human cultural sites in the area are meaningful only if we adopt the working method of Quaternary geology.The determination of the age of ancient human cultural relics, the division and correlation of Quaternary strata and the analysis and judgment of mammals are still the main methods today.Of course, cultural relics of ancient humans are also an important basis for Quaternary stratigraphic division.[5]
