Cretaceous

[S] chalk Ji (Cretaceous Period Cretaceous) mesozoic The last century, began 145 million 500 thousand years ago, at the end of the 65 million 500 thousand years ago, after 79 million 500 thousand years.
Cretaceous
During this period, the ocean continent is separated, the earth became warm and dry. Flowering plants, the largest dinosaur period, many new kinds of dinosaurs began to appear, the dinosaurs ruled the land, pterosaurs in the sky gliding, huge marine reptiles dominated shallow water. The earliest snakes, moths, bees, and many new small mammals also appeared.
Cretaceous ( English : Cretaceous Period ) is Geologic Age in mesozoic The last century, 80 million years, is Phanerozoic The longest one stage. Cretaceous Because of the Western Europe in the Cretaceous strata are mainly sedimentary named. Cretaceous Be located Jurassic Period and Paleogene Between about 145 million 500 thousand years (the error is 4 million years) and 65 million 500 thousand years ago (the error is 300 thousand years). happen to Cretaceous The extinction event at the end of the Mesozoic, and Cenozoic era The boundary.
Cretaceous The weather is warm, sea level The big change. Living dinosaurs, marine survival marine reptiles , Ammonites And rudists. New Mammals , birds Appear, Flowering plants For the first time. The third century - <b> Cretaceous</b> extinction event yes Geologic Age One of the most serious mass extinction events in most species, including dinosaurs, perish.
Cretaceous During this period the formation of the strata is called "Cretaceous", abbreviated as K That is German The Cretaceous (abbreviation Kreidezeit).
Cretaceous During the period of the atmosphere oxygen The content is 150% today, Carbon dioxide The content is industrial age 6 times before, the temperature is higher than 4 DEG C today.
Cretaceous In 1822 by the Belgium Geologist Jean d'Omalius of d'Halloy Paris Basin When the proposed. In the name of Latin Meaning "clay" refers. Cretaceous The formation of common Cretaceous The non marine. vertebrate The body of the carapace Calcium carbonate Deposited, especially coccolith. The chalky clay layer in Europe With the mainland British Isles (especially famous White Cliffs of Dover Found).

Cretaceous Age determination

Like other ancient geological age, Cretaceous The rock signs are very obvious and clear, accurate time it started but not very accurate is determined, the error is in the millions of years. In the Jurassic and Cretaceous No extinction events or biological evolution characteristics, can be clearly separated from the two's.. Cretaceous The end of the time will be relatively accurate, in 65 million 500 thousand years to the end of the 65 million 900 thousand years ago, when the earth rock layer containing large amounts of iridium . The general thought, then there is a huge Meteorite To hit earth In this. Mexico Yucatan Leaving a large crater. This meteorite caused massive extinction, called The third century - Cretaceous extinction event . But this theory is now controversial.

Cretaceous Cretaceous sub layer

Early scientific literature Cretaceous Is divided into three periods according to the time, sooner or later: Newcombe's world (Neocomian), high (Gallic), Lu Shi Senonian (Senonian). The current scientific literature generally Cretaceous As of late, as early as two points, a total of 12, with the Europe The formation of the name follows from the late earliest subdivision:
Late Cretaceous  
Maastricht period: 70.6 + 0.6 - 65.8 + 300 thousand years
Campanian: 83.5 + 0.7 - 70.6 + 600 thousand years
Santo period: 85.8 + 0.7 - 83.5 + 700 thousand years
Coniacian period: 89.3 + 1 - 85.8 + 700 thousand years
Turonian: 93.5 + 0.8 - 89.3 + 1 million years
Sen Norman period: 99.6 + 0.9 - 93.5 + 800 thousand years
   
Early Cretaceous  
Albian: 112 + 1 - 99.6 + 900 thousand years
Aptian: 125 + 1 - 112 + 1 million years
Balem period: 130 + 1.5 - 125 + 1 million years
Haoteliwei period: 136.4 + 2 - 130 + 1 million 500 thousand years
Where the blue: 140.2 + 3 - 136.4 + 2 million years
Berria period: 145.5 + 4 - 140.2 + 3 million years
  

Hadean Archean Proterozoic Phanerozoic
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Paleoproterozoic Mesoproterozoic Neoproterozoic The Paleozoic Era mesozoic Cenozoic era
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Invasion
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junction
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Jurassic
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Paleogene Neogene The Quaternary Period  
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Cretaceous formation

During this period the formation of the Cretaceous strata called" Cretaceous "By hand can be grated, abbreviated K as the Cretaceous (Kreidezeit) is the German abbreviation. Chalk is a very fine powder and pure limestone, is biogenic Marine sediment , mainly by a Coccolithes (Coccoliths). calcareous nannoplankton Planktonic and fossil composition in Britain and France On both sides of the Straits The formation of beautiful white cliffs. Chalk not only developed in Europe, North America and Western Australia have distribution. The chalk is limestone A type is mainly composed of calcite Uniform and fine particle. The Cretaceous temperature is about 4 degrees Celsius is higher than today.

Cretaceous Geological structure

The lower Cretaceous is famous Weldon The group of continental strata, including Hastings The two part layer and Weldon mudstone; the upper part of Lower Cretaceous is green sandstone layer, including sedimentary and two Aptian Albian period; Upper Cretaceous chalk is narrow, ranging from the game of the Norman period to the early Campanian strata, the late Campanian and top loss in Maastricht During the period of deposition. North America has abandoned the past some of the lower Cretaceous separate division called "comache system" approach, to the international standard. But in the Rocky Mountains, Cretaceous transgression From the beginning of the late cretaceous, General lack of early and middle deposition. Japanese scholars believe that the Japanese islands from Western Europe, are different Biogeographic zone With the establishment of the European system, on the basis of the international standard in order to direct comparison, independent division of the marine Cretaceous K1 ~ K66 units in different phase, using different stratigraphic names.
Continental Cretaceous is well developed in the hinterland of East Asia, rich in oil, coal And other mineral salts and a variety of freshwater and terrestrial animal and plant fossils. People's Republic of China Tibet, Xinjiang Kashgar In the eastern part of Heilongjiang Province, and Taiwan Island Only Marine facies Cretaceous sedimentary and other areas are developed in different degree. Continental strata . The eastern coast is the circum Pacific active zone, with red and mottled rock clip Volcano clastic rock And lava; Northwest Inland basin The main sedimentary rocks by c.; Southwest And China is mainly red rock. Northeast of the lower Cretaceous coal bearing strata is upper. Lake facies With a little. oil shale ; the upper Cretaceous is famous oil-bearing rocks, and North America, the coal bearing strata rarely. The Cretaceous system in People's Republic of China BIOSTRATIGRAPHY The study, since 1950s, has made great progress, but due to the continental strata, on the basis of relatively weak, has not yet completed construction of regional and hierarchical order, has been established in various areas is not perfect compared with marine standard layer. The Jurassic Cretaceous boundary into a long debate, it seems in the short term is difficult to be solved properly.

Cretaceous Climate and environment

The Cretaceous Sea level change A large, warm climate, showed a large area of the land is covered by a warm shallow sea. The Cretaceous is chalk layer to the common European name, but in other parts of the world, mainly by the Cretaceous strata Marine facies A lime rock, the marine limestone is warm in shallow water environment. Sedimentation sea level will cause a large range, so the formation of thick Sedimentary layer . Because of the Cretaceous strata thickness, age is near, all over the world are often found Cretaceous strata outcrop.
The common component in the Cretaceous strata of cretaceous. The chalk is by the sea Coccolithes The calcareous shell particles (coccolith) deposited; Cretaceous is a common algae coccolith.
In northwest Europe, often found in Cretaceous sedimentary layer, Upper Cretaceous includes: the south coast of England Dover The white cliffs, the coast of Normandy, France and The Low Countries In northern Germany, Denmark Coast。 Chalk texture is not firm, so these Sedimentary layer The loose texture. These include limestone, Sandy Rock strata. These strata can be found in the sea urchin, Belemnite And the ammonites, and marine reptiles (e.g. Mosasaurs The fossil).
The Cretaceous strata in southern Europe for marine strata, mainly composed of limestone, marl and minority composition. At the end of the Cretaceous period, the Alps Orogeny It hasn't happened yet, so the Cretaceous strata of southern Europe was more Tethys Around the ocean Continental shelf .
In the mid Cretaceous, marine low layer flow is slow, the marine environment caused by hypoxia. Many around the world Black shale That is in the hypoxic environment, this period of formation. The shale layer is an important source of oil and natural gas, The North Sea Is this.
Barremian period of cold climate change since the trend. Jurassic Period The last period began. High latitude snowfall increased, whereas in the tropics than The Triassic Period The Jurassic, more humid. However, the ice appeared only in high latitude regions of mountains, and more Low latitude The snow is still visible seasonal.
In order to Balem at the end, the temperature began to rise, until the end of the cretaceous. Why the temperature rise is an intensive volcano, producing large amounts of carbon dioxide into the atmosphere. The ridge The formation of many plumes, caused by rising sea levels, Continental crust Many of the areas covered by shallow water. In equator In the Tethys ocean, contribute to global warming. stay California Alaska and Greenland Found Fossil plants The Cretaceous, and found 15 degrees south latitude area dinosaur fossil The temperature is warm, that the cretaceous.
The temperature gradient between the tropics and the polar ocean flat, may be due to stagnation of flow and caused the weak planetary wind system. Widely distributed oil shale strata, and anoxic events, can confirm that the ocean flow stagnation. according to Sedimentary layer The study pointed out that the tropical sea surface temperature About 42 degrees Celsius, higher than the current about 17 degrees centigrade; while the average surface temperature is 37 degrees centigrade of global ocean. The ocean bottom temperature is higher than our current 15 degrees Celsius to 20 degrees.

Cretaceous Topographic features

 The Cretaceous period of global land distribution The Cretaceous period of global land distribution
In the early cretaceous, gondwana Not split, and South America, Antarctica, Australia have been from India and Africa. Madagascar Even in Africa. south Atlantic Began to appear with the India ocean. These ones here Plate movement , resulting in a large number of The undersea mountains Then, causing a global sea level rise . The North African Tethys in narrowing. Western Interior Seaway The North America is divided into two things, the seaway in the late Cretaceous narrow, thick leaves Marine sediment Layer mixed coal bed. At sea level the highest during the Cretaceous, 1/3 land surface immersed The ocean Under the. Because the famous Cretaceous clay layer, clay layer formed during this period more than Phanerozoic The other time. The ridge of the volcano activity, or Submarine volcano The water flow in the vicinity of the ocean, rich in calcium, close to saturation, but also makes the calcium Micro plankton The increase in the number of. Wide distribution of carbonate and other Sedimentary layer The Cretaceous rock record, particularly. The famous formations in North America include: The state of Kansas The Marine facies The smoke are clay and late Continental facies Haier group. Other famous Cretaceous strata include: Europe Wilder ( Weald ), Asia Yixianformation . At the end of the Cretaceous to the early Paleocene, India massive volcano formation Deccan Traps .
During the Cretaceous, between South America and Africa, the formation of the South rift spread quickly Atlantic To the end, has been widened to about 3000 km. The North Atlantic Rift is located in the east of Greenland and North America, with the North America The westward drift, expanding rift. Tethys Separated from Eurasia and Africa, and in southern Europe In the Near East Many countries all the time in the transgression In. During the Cretaceous climate is warm, no Polar region Ice signs. At that time, most areas of abundant rainfall, humid climate, offshore and coastal areas rich in oil formation, coal Natural gas and oil shale deposits, such as the United States Texas Mexico, The Persian Gulf Many large, North Africa and Russia oil field Again, such as China Songliao Plain The upper Cretaceous. Daqing Oilfield Inner Mongolia, the northeast and the lower Cretaceous large coalfield. In some hot dry climate regions, such as South China late Cretaceous West South Lake And group Yun-mengLakes Water, with thick salt deposit. In addition, in Yunnan in the Cretaceous red bed copper ore, high grade, large scale, easy mining and smelting, copper is Chinese famous township.

Cretaceous Species distribution

Early Cretaceous terrestrial gymnosperms and Fern Pine and cypress are still dominant, Cycas , ginkgo, ferns and class composed of flora. Angiosperms arose in the early Cretaceous, the mid to late in large increases Terrestrial plants In the dominant, beech, Banyan , Magnolia, maple, oak, poplar, camphor, walnut, Plane tree Have appeared, close to the new generation Flora Look. Starting from the Jurassic Nannofossil With its characteristics, produce different layers and change, has important significance in stratigraphy. The stone There are already extinct, Micro cone (stone Nannoconus Wedge, stone () Sphenolithus Etc.).
The vertebrate reptile from prosperity to decline, the main representatives Rex ( Tyrannosaurus Rex ), Anhanguera , Qingdao Dragon Etc.. Before the Jurassic Ganoid cover Teleostomes Instead. ocean Invertebrate In planktonic foraminifera has become an important basis for dividing the A new force suddenly rises., compared with in middle and late Cretaceous marine strata, large benthic foraminifera also appeared in many Standard fossils . Ammonites and belemnites evolved rapidly and obviously, widely distributed, is the standard order and the traditional division of fossil zone. Benthic groups Clam. Class (Rudistids) can form a reef, is typical of the warm water animal group, found in People's Republic of China and southern Tibet in the Cretaceous strata are on. The sea urchin is quite prosperous in the Tethys Sea, there are a few standard species. Coral and From animal In the second place in the cretaceous. Freshwater invertebrates are also very rich, such as crustaceans and ostracods Conchostraca The rapid evolution of snails and mussels, the distribution of software in animal widely, and insects and fresh water CHAROPHYTES Many species, which can be divided into contrast Continental strata The standard in fossils. Geological mapping And play an important role in oil and coal and other mineral resources exploration.
Chinese Early Cretaceous Plant geography The partition is very obvious, according to a study of spores and pollen, the territory has at least two obvious differences. Palynoflora .
The seamless double bag powder - no rib pattern (spore Disacciatrileti-Cicatricosisporites Flora). Located in the northern region, including Northeast and North china. Here lush plants, especially the pinaceae, Podocarpaceae and Lygodium Of plants, the formation of rich coal deposits. Also described here is warm and humid Climatic zone .
The CLASSOPOLLIS - schizaeaceae (spore Clas-sopollis-Schizaeoisporites Flora). Located in the Southern District, located in the red strata containing salt deposits, reflects the relatively hot and dry Climate and environment . Between latitude 40 degrees to 50 degrees, there is a strip of transition is north west south east direction, North and South Flora Mixed phenomenon occurred. From the global distribution, People's Republic of China north and south two plant area and arid zone and wet subtropical quite.

Cretaceous Botany

From the early Cretaceous to Gymnosperms Plant communities mainly still flourish, and Angiosperm There is The evolution of plants Another important event in the history of. The Cretaceous is the reliable Early angiosperm To the late Cretaceous, angiosperms rapidly, instead of gymnosperm dominance, formed the continuation of angiosperm groups, such as A magnolia Liu feng, Poplar Birch, palm, etc., all over the ground. The emergence and development of angiosperm, is not only The plant kingdom A big change, but also to the animal with great influence. Angiosperms for some animal, such as insects, birds, Mammals And provide a lot of food, allowing them to breed; on the other hand, the role of animal spread pollen and seed dispersal, also contributed to the flourish and development of angiosperms.
Flowering plants (angiosperms) in the Cretaceous, began to spread, but until Campanian Jiecai became the dominant plant. Bees, contribute to the evolution of flowering plants; flowering plants and insects are common examples of evolution. Banyan、 Plane tree Magnolia, and other large plants began to appear. Some of the early gymnosperms continue to exist, for example Pinopsida . Araucaria With other conifers flourish and widely distributed, and Bennettitales At the end of the Cretaceous extinction.
Early Cretaceous to gymnosperms in cycads, The Cycads Class, ginkgo and conifers, Filicinae Still prosperous. Rise from the late Early Cretaceous to the late Cretaceous angiosperms have developed rapidly, and gradually replaced the dominance of gymnosperms. This occurred at the beginning of the angiosperms, after a gradual development. The ammonites and dinosaurs, pterosaurs, ichthyosaurs, plesiosaurs etc. by the prosperous gradually become extinct mammals and birds become the emerging animal groups.

Cretaceous Terrestrial animal

The Cretaceous dinosaur species reached its zenith, at this time the most famous dinosaur is Tyrannosaurus Rex That is the largest carnivorous animal on land appeared, and then the ocean huge ferocious reptiles is not less than the Tyrannosaurus Rex, which mixed the dragons on the sea and Lizard The Cang long length can be more than 15 meters, than we know the orcs whale and Great white shark Are large. The Cretaceous ocean reef rudists reached its zenith, replaced become the main coral reef building organisms, make modern types Coral reef Interrupted for nearly seventy million years. About sixty-seven million years ago at the end of the Cretaceous period, the land and the ocean animal extinction, only a few remaining.
The many popular and dominant categories, such as Gymnosperms , reptiles, ammonites and belemnites, later after the decline or extinction of birds, mammals and angiosperms, emerging Gastropods , Bivalve Other development, indicates a new stage of the new generation of the advent of biological evolution. Reptiles in vertebrates from Late Jurassic to early Cretaceous to the peak, on behalf of Rex , Pterosaur , Qingdao Dragon Then, the decline. At the end of the Cretaceous, dinosaurs, ammonites and other large extinct taxa. The causes of the mass extinction of organisms, there is a lot of debate. Some people think that the universe is a great meteor Caused by the body hit the earth, it is based on the Cretaceous and third lines on the line of iridium in the clay rocks unusually high.
The animal kingdom, mammals is still relatively small, only a small part of the land animal. The advantage of land animal
 Velociraptor Velociraptor
Still The main Dragon Reptiles, especially dinosaurs, they are a more diversified period. Pterosauria In the late Cretaceous, but they gradually adapt to the competition facing the radiation of birds. At the end of the Cretaceous pterosaurs, only two families around. The birds are vertebrates to air the biggest success. Early Cretaceous birds began to differentiate, and the ability to fly and arboreal than Archaeopteryx Greatly improve. Paleontologists discovered in China famous" Confuciusornis Is the early Cretaceous birds represent molecular.
At the end of the Cretaceous, the creatures of the earth experienced a major extinction event: the disappearance of a large number on the surface of dominant reptiles, dinosaurs became extinct; more than half of the plants and the other Terrestrial animal At the same time. What is the cause of the sudden extinction of dinosaurs and a large number of organisms? This problem is always in the geologic history of a mystery. Commonly accepted view is Meteorite impact that . Notably, mammals are the biggest beneficiaries of the mass extinction event, they through the crisis, and in the Later Cenozoic occupied the ecological environment by the exit of dinosaurs and other reptiles, the rapid evolution of development for the new rulers on earth. Liaoning province Chinese Chaomidian group found a large number of small early Cretaceous dinosaurs, birds, and mammals. Here it was found that a variety of Maniraptora That is regarded as the link between dinosaurs and birds, which contains a number of Feathered dinosaurs .
The insects in this period began to diversify, and found the oldest ants, termites, Lepidoptera (butterflies and moths). Bud worm, Grasshopper , Gallwasps Also began to appear.

Cretaceous Sea Animals

In the ocean, we know Skate , Shark And the other. Teleost fish Also common. Marine reptiles include: living in the early to mid Ichthyopterygia Early to late Plesiosaurs Class, Late Cretaceous Mosasaur .
Baculites Have straight carapace, belong to Ammonoidea , and reef building Rudist with prosperous marine animal. Hesperornithiformes Is a group of primitive birds cannot fly, can swim in the water, like a modern podicedidae. Foraminifera The intercepted beetles (Globotruncanidae) and Echinoderm animal (e.g. Sea urchin , Starfish Alive). In the Cretaceous, the earliest in the ocean diatom (for siliceous diatom, diatom and non calcareous); Miocene diatoms live in fresh water until only appeared in. For the cause Biological attack The marine species, is an important stage of the Cretaceous evolution of these species.

Cretaceous Extinction event

Violent crustal movement And the sea changes, led to great changes in the field of biology, many Mesozoic Cretaceous, prevailing and dominant categories (such as gymnosperms, reptiles, ammonites and belemnites etc.) later after decline and extinction, emerging angiosperms, birds, mammals and gastropods, bivalves have been developed, heralding a new biological evolution the advent of new generation stage.
Reptiles from the late Jurassic to early Cretaceous reached its zenith, continued to occupy the sea, land and air. Birds continue to evolve, which constantly close to modern birds. Mammalian development appeared slightly. Marsupial Original and placental Eutheria . The fish has been completely to Teleost fish The main.
Marine invertebrates of the most important categories of the Cretaceous still chrysanthemum stone outline, shell size, shell shaped ammonites, shell ornaments and suture type than the Jurassic diversity. The Cretaceous of ancient southern continent continues to disintegrate, north of the ancient continent rising gas When cold, clear seasonal changes. Omnivorous, insectivorous, carrion and animal survival in the extinction event, probably because more changes in their diet. At the end of the Cretaceous seems not fully herbivorous or carnivorous mammals. Mammals and birds by insects, Earthworm , Snail ... Such as animal feed and live in the K-T event, and the animal to plant and animal death for food. Scientists hypothesize that these organisms in biological organic detritus for students, so to be in the Flora The collapse of the survival of the extinction event.
In the river Biological community In only a few animal perish; because the river biological community on biological organic debris washed down the land for a living, less directly to the living plants. The ocean has a similar situation, but more complex. Live in the pelagic zone of the animal, which affect the survival than in seabed Is a large animal. Live in the pelagic zone of animal almost to living phytoplankton, and the animal is on the seabed there, organic detritus organisms for food, or can be converted into bio organic detritus for food.
Survived the extinction event in this species, the largest land animal is crocodile and Choristodera That is a semi aquatic animal, and can Biodetritus For students. Modern crocodiles can carrion for students, and can not eat for several months; juvenile crocodiles are small, slow growth, in the first few years in invertebrates, dead creatures for food. These characteristics may be able to survive the crocodile key at the end of the Cretaceous extinction event.
The earth is Shanghai land distribution and biological change sharply, the Atlantic rapid cracking and volcano activity era, has extensive low-lying late transgression. Late Cretaceous Angiosperm Instead of gymnosperms in land advantage, is a great change in the plant kingdom. The animal kingdom was a major change in the late Cretaceous period, the dinosaurs, ammonites and many other biological group A mass extinction, indicates that the new generation is about to begin. The causes of the mass extinction, in the international scientific community launched a heated debate. Popular "extraterrestrial events" theory thinks that some places on earth, the Cretaceous mudstone in third on the line of the iridium anomaly of high content, is a giant meteor hitting the earth in the universe is similar Nuclear winter Effect, accordingly, determine the Cretaceous boundary in the third lines all over the world, Iridium anomaly Is an important principle. However, the "extraterrestrial incident" doubts and objections to a lot of people, they think, at the end of the Cretaceous mass extinction occur gradually, ecological change results, and is not caused by a simple extraterrestrial disaster hit the earth.
Cretaceous (english: Cretaceous Period ) is Geologic Age In the last period of the Mesozoic era, as long as 70 million years, is Phanerozoic The longest one stage.
In the western part of the main strata Cretaceous Named after the deposition. Located between the Jurassic Cretaceous and Paleogene, about 137 million years (the error is 4 million years) and 65 million years ago (the error is 300 thousand years). The Cretaceous The third century The extinction event is one of the most serious mass extinction events in geological time, most species including dinosaurs, perish.
Like other ancient symbol of the Cretaceous rock geological era, obvious and clear, accurate time it started but not very accurate is determined, the error is in the millions of years. In the middle Ji no extinction event or biological characteristics and evolution of the Cretaceous, can be clearly separated from the two's.. The end of the Cretaceous time comparison, is about 65 million 500 thousand years ago (65 million 900 thousand years ago scientists estimate), then the whole earth rock layer containing large amounts of iridium. The general thought, there was a huge meteorite hit the earth, there was a big hole in the vicinity of the Yucatan Peninsula, Mexico. This caused a lot of meteorites Extinction Called. The third century Cretaceous extinction event . But this controversial theory.

Cretaceous Geological classification

The Cretaceous division in Europe Marine strata According to the first ammonites as standard of 6 ~ 7 order (period), then some sub order upgrades, increased to 12 order (period), but people are still accustomed to the 4 order of the lower Cretaceous are collectively referred to as the Volgian stage (or Newcombe's order). The upper Cretaceous in the middle of Connie yake, Thornton And the 3 order are collectively referred to as the Campanian senonian. In the 12 stage can be divided into 53 zones and the ammonites, planktonic foraminifera and calcareous nannofossils as Cretaceous stage, zoning as well as an important basis for Intercontinental comparison.
There are 2 kinds of opinions about the Cretaceous
The division between the Albian and Norman order of upper and lower Cretaceous
Late Cretaceous
(Maastricht period Maastrichtian ): 70.6 + 0.6 - 65.8 + 300 thousand years
 The Cretaceous Dinosaur: the golden age (Zhao Chuang painted) The Cretaceous Dinosaur: the golden age (Zhao Chuang painted)
Campanian ( Campanian ): 83.5 + 0.7 - 70.6 + 600 thousand years
( Santonian ) Santo period: 85.8 + 0.7 - 83.5 + 700 thousand years
Coniacian period ( Coniacian ): 89.3 + 1 - 85.8 + 700 thousand years
Turonian ( Turonian ): 93.5 + 0.8 - 89.3 + 1 million years
Norman ( Cenomanian ) Sen period: 99.6 + 0.9 - 93.5 + 800 thousand years
Early Cretaceous
Albu S ( Albian ): 112 + 1 - 99.6 + 900 thousand years
Aptian ( Aptian ): 125 + 1 - 112 + 1 million years
Balem ( Barremian ) period: 130 + 1.5 - 125 + 1 million years
Haoteliwei period ( Hauterivian ): 136.4 + 2 - 130 + 1 million 500 thousand years
Where the ( Valanginian ) blue: 140.2 + 3 - 136.4 + 2 million years
( Berriasian ) Berria period: 145.5 + 4 - 140.2 + 3 million years
The claim three points, draw a unification, as the middle of the top and bottom boundary to determine, there are different opinions.
 Sichuan Cretaceous dinosaur footprint map Sichuan Cretaceous dinosaur footprint map
From 1974 to 1982, there is a "Middle Cretaceous event" international organization activities, very active, mainly on the Cretaceous period of biological stratigraphy , transgressive regressive and anoxic event, Field reversal The form, salts and Cretaceous in southern the Atlantic and Mozambique The canyon and crack. Indian Plate from Gondwana The separation of subject. The Middle Cretaceous is not a precise concept of geological time, people from the Aptian date to the Thornton period, the majority of people from Albuquerque. During the play Connie Yake period. In the Cretaceous division except In the Middle East Outside, rarely used internationally. The Cretaceous dichotomy has been used for decades, and a large number of publications in geological maps, not to change the current.

Cretaceous archaeological discovery

In September 15, 2014, Zigong Dinosaur Museum and China University of Geosciences experts on the territory of Xuyong County of Luzhou City, Da Shi Xiang Xin Yang, Longjing two village of dinosaur footprints found in field investigation, the conclusion is that the three species of dinosaur footprints in the Cretaceous period about one hundred million years ago.