Uplift of Qinghai-Tibet Plateau and Its Influence

Since 1980s, the Qinghai-Tibet Plateau has gradually become a hot spot in earth science research, and new theoretical breakthroughs are brewing. On the one hand, because the Qinghai-Tibet Plateau is the most typical continental collision area on the earth, it is an ideal place to test and develop plate theory, which is helpful to establish a new geodynamic theory; On the other hand, the strong uplift of the Qinghai-Tibet Plateau in the late Cenozoic greatly changed the atmospheric circulation in Asia and even the whole northern hemisphere, and had a great impact on the chemical weathering of continental rocks, the evolution of marine strontium isotopes, and the environment, climate and terrestrial ecosystems around the plateau.

In this paper, the time, process, environmental and climatic effects of Qinghai-Tibet Plateau uplift and its influence on the evolution of marine strontium isotopes are summarized, in order to understand the importance of Qinghai-Tibet Plateau uplift in global climate change and have a clear understanding of the evolution characteristics and influencing factors of marine strontium isotope composition.

1 uplift of Qinghai-Tibet Plateau and its climatic and environmental effects

The Qinghai-Tibet Plateau is the highest step on the global continent. The uplift of the Qinghai-Tibet Plateau has greatly changed the shape of the earth's surface and had an important impact on global change.

1. 1 stage of plateau uplift

The uplift of the Qinghai-Tibet Plateau is a multi-stage and non-uniform complex process. Scholars at home and abroad have different views on this. Scholars in China believe that from the middle Eocene to the early Miocene, after the collision between the Asian plate and the Indian plate, the crust of the Qinghai-Tibet Plateau was almost twice as thick as the normal crust, but at this time, only the Gangdise Mountain and the Himalayas had obvious uplift, and the vast plateau headquarters only passively made corresponding stress adjustment and deformation, but after long-term erosion, it was leveled twice, and the strong uplift of the Qinghai-Tibet Plateau began in the late Pliocene and/or early Quaternary [/kloc-

The Qinghai-Tibet Movement, the Kunlun Yellow River Movement and the * * * Movement, which started at 1. 1.6 and 0. 15, finally brought the plateau to its present height. The Qinghai-Tibet movement is divided into three stages (3.6, 2.5 and 1.7).

), by stage B of about 2.5, the Qinghai-Tibet Plateau has been uplifted to half of its present height (about 2

000 m), which is considered as the critical height of plateau uplift-loess accumulation. * * * and the movement period, the Himalayas generally exceeded 6.

000 meters has become the main obstacle to stop the Indian Ocean monsoon. Since the 1990s, many foreign scholars have questioned this view and put forward the time when the Qinghai-Tibet Plateau rose strongly. Coleman [3] thinks that as early as 14.

In the past, the Qinghai-Tibet Plateau reached its maximum height, collapsed in the east-west direction, and then its height decreased. The evidence is that the age of 14 was found on the north-south normal fault in the Himalayas.

New minerals. Kroon et al. [4] think that Himalayas and Qinghai-Tibet Plateau are in 8.

It has reached the present height before, mainly based on the discovery of upwelling in the Arabian Sea at 8: 00.

When it is greatly enhanced, it indicates the emergence of the Indian Ocean monsoon. Quade et al. [5] revealed that the carbon isotope of carbonate in the soil of northern Pakistan is about 7.4 ~ 7.0.

At that time, C 3 plants changed sharply into C 4 plants, which marked the formation or significant strengthening of the Asian monsoon at that time. Harrison

Through the study of stratigraphic chronology, sedimentary petrology, oceanography and paleoclimatology, it is shown that the rapid uplift and decapitation of the southern Qinghai-Tibet Plateau began at about 20.

In the past, the height of the modern Qinghai-Tibet Plateau benefited from the plateau uplift about 8 years ago. Wang Yanbin et al. [7] proposed that the whole southern Himalayan orogenic belt was a rapid uplift period from Pliocene to Quaternary according to the fission track analysis results of apatite in granite samples in Nyalam area of Himalayas. Zhong Dalai and others [8] made a systematic study on the fission tracks of minerals: 45 ~ 38.

After the collision between the Indian plate and the Eurasian plate, the Qinghai-Tibet Plateau experienced three uplift events (25 ~17

,13 ~ 8,3 till now). Shi Yafeng and others [9] also support this view and think that at 40.

Before and after, the Qinghai-Tibet Plateau was uplifted for the first time, but the mountains formed at that time had been completely eroded, and the height was difficult to estimate and the scope was small. The second uplift of Qinghai-Tibet Plateau occurred in 25 ~ 17 years.

. The evidence is that the 87 Sr/ 86 Sr variation of turbidite fan deposits in the Bay of Bengal indicates that the age range of Himalayan metamorphic rocks is 20- 18.

In a strong rising period (Harris, 1995). Cui Zhijiu [10] used the study of planation plane and paleokarst to prove the correctness of the view that the Qinghai-Tibet Plateau experienced three uplifts and two levelings. Wang Fubao et al. [1 1] based on the research data of sedimentology, magnetostratigraphy, paleontology and oxygen and carbon isotopes, restored the structural and climatic events since the late Miocene, and pointed out that the rise of Himalayas began at 7.0.

Before, but the strong rise occurred between 2.0 ~ 1.7 and 0.8, and between 4.3 and 3.4.

Occasionally, there is an obvious uplift, but the second two uplifts are the strongest, and the differential uplift movement between mountains and basins is obvious.

Up to now, the time, process, amplitude and speed of Qinghai-Tibet Plateau uplift are still inconclusive, which needs further study and confirmation by scholars at home and abroad.

1.2 environmental and climatic effects of plateau uplift

The relationship between the uplift of the Qinghai-Tibet Plateau and global and regional environment and climate change has aroused widespread concern among scientists all over the world. Especially in recent years, with the hypothesis that tectonic uplift drives climate change, various physical and chemical processes and their climate effects caused by tectonic uplift, such as the Qinghai-Tibet Plateau, have become the focus of domestic and foreign scholars' research to explain the arrival of the Great Ice Age and global climate change. Since the 1950s, scientists have noticed the thermal and dynamic effects of the Qinghai-Tibet Plateau on atmospheric circulation, and conducted a series of observations and studies. As early as more than 20 years ago, the numerical simulation results of Zhenguo et al. (1974) showed that, considering the existence of the large terrain of the Qinghai-Tibet Plateau, 10/00.

The atmospheric circulation pattern on the K-Pa isobaric surface is basically consistent with the actual observed values at present. When the Qinghai-Tibet Plateau does not exist, the existing Siberian high will not exist [12]. Mintz and others [13] all agree that Siberian high only exists in winter in Eurasia because of the existence of the Qinghai-Tibet Plateau. The numerical simulation results of Kutzbach et al. [14] show that the existence of the Qinghai-Tibet Plateau is the decisive factor for the formation of the Asian monsoon, especially the East Asian monsoon. Birchfield and others [15] think that the uplift of the Qinghai-Tibet Plateau has increased the thickness of snow in winter and changed the local or even global albedo, which may have a significant impact on the global climate. Recently, Ruddiman et al. [16] attributed the cooling of the late Cenozoic earth and the enhancement of regional heterogeneity to the uplift of the Qinghai-Tibet Plateau and the western North American Plateau through theoretical analysis and numerical simulation. Jincon [16] discussed the evolution of Cenozoic climate and topography in the western Qaidam basin from the aspects of the differentiation and evolution of sporopollen plants, the distribution of drought debris and gypsum and salt deposits. The results show that there are two extremely dry climatic periods (gypsum salt development period) from Eocene to Oligocene and Pliocene to Quaternary respectively. The former is related to the subtropical arid zone controlled by Paleogene planetary circulation, while the latter is related to the uplift of the Qinghai-Tibet Plateau.

Shi Yafeng and others [9] have studied the Qaidam Basin, and the results show that the Qinghai-Tibet Plateau is between 25 and17.

The second intense uplift is equivalent to the second Himalayan movement, and its height and width are enough to change the circulation situation. Combined with the warming of tropical Pacific Ocean, the increase of cross-equatorial airflow of Antarctic ice sheet, the expansion of marginal basins in eastern and southeastern Asia, the westward extension of Asian continent, and the shrinkage of subtropical Tethys Ocean, the thermal difference and dynamic action between the mainland and the ocean have been strengthened, and an Asian monsoon system dominated by summer monsoon has been bred.

Teng Jiwen and others [17] studied and discussed the relationship between plateau uplift and global change from the perspectives of thick crust and thin lithosphere model, characteristics of potential field and wave field, plate structure, deep process and dynamic mechanism. They believe that the material movement in the earth's interior (crust, mantle and core) is closely related to climate change, and point out that the unique crust-mantle structure of the plateau, the formation of a series of large-scale strike-slip faults and their overall uplift have all affected the transmission mode of solar energy in the atmosphere, which increased the efficiency of atmospheric heat engines, led to the strengthening of planetary westerly winds and the increase of polar equatorial temperature difference, and finally formed the Quaternary Great Ice Age.

Aeolian deposit is a typical atmospheric deposit, which is particularly sensitive to the change of atmospheric circulation pattern and intensity, so it can be indirectly used as an important geological evidence that tectonic uplift drives climate change [18]. Therefore, the Loess Plateau, which is related to the weather and geographical location of the Qinghai-Tibet Plateau, can well explain the uplift of the Qinghai-Tibet Plateau. The aeolian sedimentary sequence on the Loess Plateau truly records the formation and evolution of the East Asian monsoon.

It is not only a reflection of the climate change during the Great Ice Age in the northern hemisphere, but also a response to the tectonic uplift of the Qinghai-Tibet Plateau [19,20]. According to stratigraphic records, Wu Xihao and others [20] compared the tectonic climate cycle reflected by loess-paleosol sequence in the Loess Plateau with the uplift process reflected by moraine-paleosol sequence in the Qinghai-Tibet Plateau, indicating that their eccentricity in the earth orbit is quasi-0.4.

The periodic variation of Ma has a roughly synchronous phase relationship. Liu Dongsheng et al [2 1] also discussed the origin and development of Asian monsoon system and its coupling with polar ice sheets and tectonic movements. Wang Fubao et al. [22] further explained that the Qinghai-Tibet Plateau has the function of "starting area" and amplifier for global climate change by using sporopollen analysis, sedimentology and 14 C dating data.

In addition, the East Asian winter and summer monsoon reflected by the magnetic susceptibility curve and oxygen isotope curve is from 3.4.

At the same time, the global ice volume began to increase significantly, roughly 3.4 ~ 2.6.

The relationship between the acceleration and uplift of the Qinghai-Tibet Plateau is by no means a coincidence. In addition, the periodic uplift of the Qinghai-Tibet Plateau has a certain internal relationship with the multiple climatic abrupt changes of the East Asian monsoon [20, 23].

Raym et al. (1992) proposed that the large-scale uplift of the Qinghai-Tibet Plateau accelerated the weathering rate of global continental silicates in the past 40 Ma, which led to the decrease of atmospheric CO 2 content and global temperature, and called it "icehouse effect".

Effect) ".But this view has been challenged by many scholars [24 ~ 26]. Cristran

[27] It is pointed out that the main influence of Himalayan weathering and denudation on carbon cycle is to increase the buried amount of organic carbon in sedimentary rocks, not to increase the weathering rate of silicate. In addition, it is worth mentioning that the loess-paleosol sequence covering about 10% of the earth's land surface contains about 10% of carbonate [19] on average, that is, a considerable amount of carbon is fixed and buried, which may also be a factor to reduce the atmospheric CO 2 concentration.

The importance of the uplift of the Qinghai-Tibet Plateau in the study of global climate change has been recognized by many scholars. Recently, however, Lu Yanlong and others [28] pointed out that since the convergence of the Indo-Eurasian plate in the early Cenozoic, the Tethys Sea has subsided and the Pacific plate has shrunk in the eastern and southeastern margins of the Asian continent, leading to the expansion of back-arc basins (such as the Sea of Japan, the East China Sea and the South China Sea) and continental basins (such as the Yellow Sea and the Bohai Sea). This point has been proved in the AGCM digital simulation test results of Ramstein et al [29].

At present, the mechanism of global change, especially the Quaternary climate change, is deeply studied, but the research on the influence of Qinghai-Tibet Plateau on global climate change is not enough, and a clear understanding has not been reached. & ltfont size="3 " >& ltstrong & gt& lt/p & gt；

& LTPAlign = "left" >< font color = "# 0000a0" >< font size = "4" > 2 Evolution of strontium isotope composition in the ocean

At present, the average concentration of strontium in seawater is about 8 mg/L, and the value of 87 Sr/86 Sr is 0.7093 0.0005 [30], which is one of the most abundant trace elements in seawater. The residence time of strontium in seawater is 3.

Ma(Richter et al., 1993) is much longer than the mixing rate of seawater (about 10 3 a) [30]. Strontium in seawater mainly exists in the form of marine authigenic carbonate and some salt minerals such as phosphate and sulfate. The 87 Sr/ 86 Sr value of marine authigenic carbonate minerals reflects the characteristics of strontium isotopic composition in seawater at the time of mineral deposition, and truly and continuously records the evolution process of marine strontium isotopic composition. Many research results show that.

Since Ma, the strontium isotope ratio in the ocean has obviously increased [3 1 ~ 34].

2. Geochemical Properties of1Sr Isotope

Strontium has four stable isotopes: 88 Sr, 87 Sr, 86 Sr and 84 Sr, of which 87 Sr is the product of natural decay of 87 Rb, with a half-life of 48.8.

The chemical properties of Ga .Rb and K crystals are similar, and they often enter silicate minerals such as potash feldspar and biotite in the form of isomorphism. The crystal chemical properties of Sr and Ca are similar, and they often replace Ca [35] in calcium-containing minerals such as plagioclase, apatite and carbonate. The 87 Sr/ 86 Sr values in geological bodies depend on their Rb/Sr values and ages. Due to the difference of Rb and Sr properties, different rocks, minerals and their weathering stages have different Rb/Sr values, and different Rb/Sr ratios or/and ages determine their specific 87 Sr/ 86 Sr values [49]. In addition, unlike isotopes such as H, C, O and S, Sr isotopes will not be fractionated due to physical and chemical weathering and biological processes [36].

2.2 Evolution Characteristics of Marine Strontium Isotopic Composition

As early as 1948, wickman suggested that the composition of strontium isotopes in seawater should increase monotonically with time due to the decay of 87 Rb in the crust, and it is only a function of time. However, in 1955, Gast determined the strontium isotope of marine carbonate rocks of known age. The results showed that the change rate of 87 Sr/ 86 Sr value in seawater was much less than that estimated by Wickman, and it was pointed out that Wickman overestimated the Rb/Sr value in the crust. Palmer et al. [33] measured the 87 Sr/ 86 Sr value of the whole Phanerozoic marine limestone, and found that the obtained results did not increase systematically, but showed an irregular curve change, reaching the maximum value in Precambrian and now, with an obvious minimum value from the end of Permian to the beginning of Triassic. Martin et al. [37] conducted 87 Sr/ 86 Sr on seawater from Middle Permian to Triassic.

In the Late Permian, the ratio increased at the rate of 0.000097/Ma, which was about 40% higher than in the past.

The average growth rate of Ma is 2.5 times larger, which is roughly equal to the maximum growth rate of the whole Cenozoic era, and this growth only occurs in a short time. Edmund [34] pointed out that in the past 500 years,

In Ma, the evolution of marine strontium isotope composition with time presents an asymmetric trough shape. Its highest value is in Cambrian and present (0.709 1), and its lowest point is in Jurassic (0.7067), with some small shocks superimposed on it, in the past 100.

In horses, its value shows an obvious monotonous growth trend.

Richter et al. [38] 1992 studied the evolution of ocean 87 Sr/ 86 Sr value since 100 Ma, and the results showed that 100 ~ 40.

The value of ocean 87 Sr/ 86 Sr changed little or decreased slightly. However, since 1940, the Marine Corps 87 Sr/ 86 Sr

The value of 87 Sr/ 86 Sr in the ocean keeps rising, and the fastest rising period is about 20 ~ 15, which is attributed to the increase of Sr flux from mainland rivers to the ocean due to the collision of India-Asia plate. Palmer et al. [39] drilled 75 holes in DSDP No.21and 375.

The 87 Sr/ 86 Sr value of foraminifera showed an upward trend, which was about 10 ~ 20.

The change rate is the largest (4× 10 -5 /Ma). In 199 1 year, Hodell et al. [40] changed from 24.

The strontium isotope ratio is up to now 26 1. Its change curve can be regarded as a series of linear parts with different slopes, with the maximum slope of 6× 10 -5 /Ma and the minimum slope close to zero. They believe that the strontium isotope ratio of seawater rose from 0.7082 to 0.7092 in the late Tertiary, but the rate of change was not constant, but a series of changes. Among them, the early Miocene (24 ~ 16

), which grew rapidly in late Miocene (5.5 ~ 4.5) and late Pliocene-Pleistocene (2.5 ~ 0); Middle Miocene to Early Late Miocene (16 ~ 8

), the isotope ratio has increased moderately; However, the isotopic ratios of 8 ~ 5.5 and 4.5 ~ 2.5 have little or no change. Hodell et al [4 1] on Late Tertiary (9 ~ 2

The research results of strontium isotope composition change in the ocean are as follows: the strontium isotope composition in the ocean is on the rise, with several different slopes between 9 and 2. 9~5.5

The value of 87 Sr/ 86 Sr is almost constant, about 0.708925. 5.5~4.5 mA

The value of BP, 87 Sr/ 86 Sr increases linearly at a rate of about 1× 10 -4 /Ma. At 4.5 ~ 2.5

In the meantime, the change rate of 87 Sr/ 86 Sr value gradually decreased to zero, and the final ratio remained at 0.709025. Capo et al. [42] measured marine carbonate samples and showed that in the past 2.5 years.

The 87 Sr/ 86 Sr value of Ma seawater increased by 14× 10 -5, and the growth rate was different in different periods. Such a high average change rate shows that the weathering rate of the mainland is quite high. The inconsistency of growth rate reflects the fluctuation of weathering rate (the change rate is as high as 30% compared with today's value).

Dia et al. [3 1] analyzed the marine Sr isotope ratio records of nearly 30 Ma, and found that a period of 10 was superimposed on this gradually increasing Sr isotope change.

Ma oscillates at high frequency, and this periodic change is consistent with the periodic change of earth orbit parameters. Clemens et al [32] identified 45

Sr isotope ratio of seawater since Ma, and points out that its maximum and minimum are consistent with the minimum and maximum of continental ice volume, respectively. But these high-frequency changes are related to Sr.

The contradiction of staying in the sea for a long time is difficult to explain. If these glacier-interglacial Sr

If isotope changes are global, then we must reconsider Sr.

Dynamic mechanism of ocean circulation.

In addition, it should be pointed out that the obtained Sr isotope ratio may be different due to different test samples or different seabed test locations. Hodell et al. [43] studied the different positions (289 holes, 558 holes and 747 holes) of deep seabed drilling, and found that due to the different deposition rates at different positions on the seabed, the curves of strontium isotope composition in seawater reflected by them are different, for example, Hodell.

It is considered that the Sr isotope change curve of hole DSDP 289 has an inflection point around 20, but for DSDP,

747 hole, osric and others think that the curve is a straight line from 22.5 to 15.5. For DSDP 558 hole and DSDP

747 holes, from 14 ~ 9, also have the same inconsistency, and the 87 Sr/ 86 Sr value reflected by the former is lower than that of the latter, and there is no linear correlation. & ltstrong & gt& lt/p & gt；

& LTPAlign = "left" >< font color = "# 0000a0" size = "3" > 3. Influencing factors of strontium isotope composition change in the ocean.

Sr in the ocean mainly comes from the following aspects [33, 44]: ① The average value of 87 Sr/ 86 Sr of surface runoff input is 0.7119; ② The average strontium isotope composition of groundwater input is similar to that of surface runoff; ③ The interaction flux between oceanic crust and seawater, including the action of high-temperature hydrothermal area in mid-ocean ridge and the low-temperature water-rock reaction between both sides of mid-ocean ridge and cold oceanic crust, has an average Sr isotope composition of about 0.7035 0.0005; (4) The average Sr isotope composition of the sediments released from the seabed by recrystallization or in the form of pore water is 0.7084, which is close to the 87 Sr/ 86 Sr value of seawater. In this way, the Sr isotopic composition of seawater is mainly influenced by the Sr flux of continental rivers and the Sr flux of submarine hydrothermal solution.

Palmer et al. [39] drew the following conclusion by studying the quantitative geochemical cycle model of strontium: Although the cycle of submarine hydrothermal solution and marine carbonate plays a very important role in the change of strontium isotope ratio in seawater, the weathering of terrestrial silicate became the main factor to control its change during the whole Cenozoic. The study on the controlling factors of the change of 87 Sr/ 86 Sr value shows that rivers are the main source of marine strontium, of which about 75% strontium comes from the weathering of uplift limestone and the rest from silicate weathering. Marine carbonate provides a certain amount of circulating strontium for bottom seawater through pore water, and a small part of strontium in seawater comes from the dissolution of sedimentary carbonate. In addition, strontium isotope exchange also took place between seawater and submarine basalt through submarine hydrothermal solution, but the strontium content did not change obviously during this process.

Hodell et al. [40] have measured the strontium isotope ratios of 24 samples up to now, which is 26 1 sample. It shows that the factors affecting the change of isotope ratios cannot be attributed to simple geological phenomena, but may be the result of the comprehensive action of structural and climatic factors. The combined effect of these two factors affects the abundance and proportion of strontium transported from the mainland to the ocean. The obtained marine strontium isotope records are consistent with the gradual increase of the rate of chemical weathering in the mainland in the Late Tertiary, and may also be related to the increase of the denuded area of the mainland caused by the ice age cycle, the decline of sea level and the strengthening of the mainland topography caused by the rapid tectonic uplift.

Raymo et al. [45] put forward that there are two reasons for the obvious increase of marine Sr isotope ratio: ① the radioactive Sr flux emitted by continental rivers increases; ② The submarine hydrothermal activity decreased. At present, the Sr flux of submarine hydrothermal solution is 1.0× 10 10.

The average value of mol/a and 87 Sr/ 86 Sr is 0.7035; The annual strontium flux of continental rivers into the sea is 3.3× 10 10.

The average value of mol/a and 87 Sr/ 86 Sr is 0.7 1 19. In this way, the annual Sr flux of hydrothermal alteration of submarine basalt is about 1/4 [33] of the Sr flux of continental rivers entering the sea.

There is a speculation accepted by most people that hydrothermal activity on the seabed is a function of the expansion rate of the seabed. If the change of the total amount of Sr entering the ocean by hydrothermal alteration is in direct proportion to the rate of the formation of the new ocean crust, the total amount of Sr entering the ocean by hydrothermal alteration of submarine basalt has decreased by 40% every year since Cretaceous, but this change is not enough to explain the accumulation in the past 40 years.

The apparent increase of strontium isotope ratio in the ocean since Ma (Richter et al., 1992) [38]. So, 40

The increase of marine Sr isotope ratio since Ma can only be attributed to the increase of radioactive Sr flux emitted by mainland rivers. In order to further demonstrate this conclusion, Richter

[38] The following four points are proved: ① The sum of Sr fluxes of Yarlung Zangbo River, Ganges River, Indus River and Qinghai-Tibet Plateau is 40.

The increase of strontium concentration and 87 Sr/ 86 Sr value in seawater since Ma is consistent in order of magnitude. (2) Before the India-Asia continent collision, the strontium flux of the river changed little, but it began to increase immediately after the collision; ③ The erosion of Himalaya and Qinghai-Tibet Plateau has provided sufficient strontium since the collision, which explains the increase of river strontium flux since the collision; (4) The remarkable feature of the river strontium flux change is that it starts at 20.

The increase of short-term pulse coincides with the high-speed erosion in Himalayan region in time. Copeland et al. [46] determined the 40 Ar/ 39 Ar age of clastic potash feldspar in the fan-shaped area of Bangladesh, showing that in the middle Miocene, the Himalayan collision area suffered from intense pulse uplift and erosion, and the rapid erosion in some areas ran through the whole Late Tertiary, similar to Quxu of Richter et al. [47] in the Gangdise belt in southern Tibet.

Pluton's research revealed a rapid erosion period (about 20 ~ 15). Zeitler [48] found that the increase in the rate of top removal in the western Himalayas began at about 20.

. Therefore, it can be considered that the fastest rise of ocean 87 Sr/ 86 Sr value from about 20 to 15 is a response to the rapid erosion of the Qinghai-Tibet Plateau in a short time.

Through the above analysis and demonstration, we can get the following understanding: before the India-Asia continental collision, the radioactive Sr flux entering the ocean did not change much, but after the India-Asia continental collision, the radioactive Sr flux entering the ocean increased greatly, and the 87 Sr/ 86 Sr value continued to rise. During this period, the strong uplift and rapid erosion of the Qinghai-Tibet Plateau provided enough radioactive Sr for the rise of the 87 Sr/ 86 Sr value in the ocean.

conclusion

In recent 40 years, the isotopic ratio of strontium in the ocean has obviously increased, and scholars at home and abroad have studied and explored its triggering mechanism in many aspects, but so far there is no conclusion. Under the hypothesis that tectonic uplift drives climate change, the uplift of the Qinghai-Tibet Plateau is closely related to global climate change, the rate of continental chemical weathering and the evolution of marine strontium isotope composition, which provides a good idea and method for further understanding and clarifying the age, amplitude and form of the uplift of the Qinghai-Tibet Plateau. With the further application and deepening of this idea and method, we believe that the scientific problems about the mechanism and process of Qinghai-Tibet Plateau uplift and the evolution law of marine strontium isotopes will gradually become clear, and can provide good methods and means for solving the current debate about silicate and carbonate weathering.