Neogene integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The remarkable uplift of the Tibetan Plateau in the Neogene had great impacts on the climate and environment of East Asia and even the world.Therefore,establishment of the Neogene stratigraphic framework of the Tibetan Plateau is of great significance to research in various fields of geosciences.Based on marine sediments,the international chronostratigraphic system of the Neogene is divided into six stages in the Miocene and two stages in the Pliocene.Since the beginning of the Cenozoic,the shar...     

Paleogene integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The Paleogene is a crucial period when terrestrial and marine ecosystems recovered from major disruptions and gradually approached their modern states. In the Qinghai-Tibetan Plateau and its surrounding regions, the Paleogene also represents a significant phase of tectonic evolution in the Qinghai-Tibetan Plateau-Himalaya orogeny, reorganization of Asian climates, and evolution of biodiversity. Due to limitations in research conditions and understanding, there are still many controversies regard...     

Preface to integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

<正>The Qinghai-Tibetan Plateau(QTP) is well known as the Roof of the World, the Third Pole and the Asian Water Tower. It spans a vast area from the Pamir Plateau in the west to the Longmenshan-Hengduan Mountains in the east, from the Himalaya Mountains in the south to the Kunlun-Qilian Mountains in the north. It stretches approximately 1,200 km from north to south and 2,500 km from east to west. When did the QTP start to uplift? This is still controversial between early and late Cenozoic s...     

The Qingzang Movement: The major uplift of the Qinghai-Tibetan Plateau

Thirty-five years ago, the idea of a young Qinghai-Tibetan Plateau was proposed based on a comprehensive investigation on the Qinghai-Tibetan Plateau. This hypothesis suggested that the plateau began to rise from a planation surface(relict surface) that was less than 1000 m high formed during the Miocene to Pliocene. The fast uplift, i.e., the Qingzang Movement, began since ~3.6 Ma, evidenced by massive molasse deposits around the plateau margin and the synchronous occurrence of faulted basins within the plateau. However, later studies challenged this idea and suggested earlier(8, 14 or 35 Ma) formation of the huge plateau topography. Here we reevaluate the Qingzang Movement on the basis of our previous results and in light of new studies in the recent decades. The plateau margin has been subjected to intensive incision by very large drainages and shows the landscape characteristics of an "infant" stage of the geomorphological cycle. However, these drainages were not formed until 1.7–1.9 Ma; headwater erosion has not yet reached the hinterland of the plateau, so the interior of Tibet is free of significant erosion despite its lofty elevation, and remains an "old stage" landform. If the mean erosion rate is equivalent to the sum of clastic and soluble discharges of the modern rivers draining the Tibetan Plateau, it should have been worn down to a lowland within 8.6 Ma, ignoring tectonic uplift and isostasy. The massive conglomerate around the plateau margin began to deposit at about 3.6 Ma, indicating an increased relief after that time. Furthermore, the Hipparion fauna sites were widely distributed, and elephants, giraffes, and rhinos were abundant in the Qaidam Basin until the early Pliocene. Cenozoic climate change alone is not able to account for the dense occurrence of Hipparion fauna, unless the paleo-elevation of Tibet was lowered. The rise of Tibet since the Qingzang Movement has had a great influence on the Asian interior aridification.     

Cambrian integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The Qinghai-Tibetan Plateau and its surrounding areas have a long and complex tectonic evolutionary history.Cratons and blocks, such as northern India, Lhasa, Qiangtang, Qaidam and Central Qilian, and their in-between orogenic belts constitute the main part of the Qinghai-Tibetan Plateau. During the Cambrian Period, most of these cratons and blocks were on the northwestern periphery of Gondwana, and were associated with the surrounding blocks, e.g. Arabian, Central Iran, Afghanistan, Tarim, Alxa...     

Carboniferous integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

During the Carboniferous Period, the Qinghai-Tibetan Plateau and its surrounding areas were located in quite different paleogeographic positions with various sedimentary and biological types. It is important to systematically compile and summarize the Carboniferous strata and biotas of the Qinghai-Tibetan Plateau and its surrounding areas, to establish an integrated stratigraphic framework for correlation, and to reconstruct the paleogeography for correctly understanding the breakup of the Gondw...     

Cretaceous integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The Cretaceous Period is a vital time interval in deciphering the evolutionary history of the Neo-Tethys Ocean and the convergence of different plates and blocks across the Qinghai-Tibetan Plateau. A detailed stratigraphic framework and paleogeographic patterns are the basis for understanding the evolution of the Neo-Tethys Ocean and the formation of the QinghaiTibetan Plateau. Here, the Cretaceous stratigraphy, biota, paleogeography, and major geological events in the Qinghai-Tibetan Plateau ar...     

Triassic integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

Rocks of the Qinghai-Tibetan Plateau(QTP) host abundant Triassic fossils. So far, the well established marine fossil sequences based on ammonoids, conodonts, bivalves, brachiopods, radiolarians, and terrestrial spora-pollen sequence have become standard for biostratigraphic correlation of the QTP. For much of Triassic time, the QTP occupied a marine setting as suggested by the dominance of marine deposits. The main sedimentary types represented in the Triassic successions include littoral to sha...     

青藏高原陆相介形类的分布特征及其对生态环境的响应

统计分析了青藏高原不同区域水体环境表层沉积物陆相介形类的属种分布特征,探讨了介形类在不同水环境下（盐度、pH值及水深）对生态环境的响应.结果显示,青藏高原现生介形类共计21属67种,其中Candona candida、Ilyocypris bradyi、Eucypris inflata、Limnocythere dubiosa、Limnocythere inopinata、Paracypricerus angulata、Leucocytherella sinensis和Leucocythere mirabilis为青藏高原地区的常见种.湖泊、河流、洼地和湿地4类水体环境中,湖泊中介形类最为丰富,达19属62种;青藏高原东北部（祁连山和柴达木盆地）、北部（昆仑山）、西部和南部不同区域的介形类常见种存在较大差异,可能是区域海拔、pH值和盐度综合作用的结果.淡水和微咸水环境介形类属种数量较咸水及盐湖中丰富,分别有17属41种和13属42种,Limnocythere dubiosa （0.52~90.6 g/L）和Leucocythere mirabilis（0.51~174.63 g/L）在淡水、咸水及盐湖中均有出现,适应盐度范围较广;pH值在8.0~10.0范围内介形类属种多样性最丰富,表明大部分介形类具有嗜碱性的特征;青藏高原陆相介形类属种多样性随水深的增加而降低,浅湖（0~15 m）中介形类属种最为丰富,达到17属52种,其中Candona candida（0.2~80 m）和Leucocythere dorsotuberosa（0.3~110 m）从滨湖至深湖区均有分布,二者均具有较大的水深适应范围.     

Pre-Cryogenian integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The composition and geological evolution of pre-Cryogenian material in the Tibetan Plateau and its surrounding areas have played an important role in studying the formation and evolution of early supercontinents on Earth. This paper systematically summarizes the characteristics of pre-Cryogenian sedimentation, paleontology, magmatism, and metamorphism in the Tibetan Plateau and its surrounding areas. Based on existing data, the records of pre-Cryogenian sedimentation and paleontology are mainly ...     

Jurassic integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The Qinghai-Tibetan Plateau experienced a unique geological evolution during the Jurassic, driven by the termination of the Palaeotethys and the reduction of the Neotethys. The Indian Plate separated from the northern margin of Gondwana and drifted northward from the Southern Hemisphere. Given that the timing of strata serves as the basis for reconstructing geological history, the present work aimed to develop a new multiple stratigraphic and chronologic framework for the Jurassic strata of the ...     

Ordovician integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The Ordovician rocks on the Qinghai-Tibetan Plateau represent the oldest non-metamorphic strata, and are critical to understanding the history of regional geology and biotic evolution of the entire plateau. Strata of Floian, Darriwilian, Sandbian,Katian and Hirnantian are represented in the plateau with a hiatus of variable duration occurring underneath the basal Ordovician across the area. Five stratigraphical regions, including the Himalaya, Gangdise-Zayu, Qiangtang-Qamdo, Songpan-Garze, and K...     

The earliest prehistoric pottery in the Qinghai-Tibetan Plateau and its archaeological implications

Remains of prehistoric human activity in the Qinghai-Tibetan Plateau (QTP) were often found exposed in the surface due to strong erosion. Thus, archaeological sites containing continuous and integral cultural remains within stratigraphic layers are rare in the plateau. The Jiangxigou site, located in the south of Qinghai Lake basin and in the northeastern margin of the plateau, are such a site with ages ranging from the early to late Holocene, i.e. from the Paleolithic to the Neolithic. Our excavation disclosed remains including more than 700 pieces of microliths, 14 pottery pieces, and other cultural relics. The oldest pottery fragments were found at the depth of 75 cm in the section, and in particular, a painted pottery piece was found at the depth of 61 cm. In this study, both luminescence (TL and OSL) and radiocarbon dating were employed to establish the chronology for these remains. Two pieces of pottery were dated using thermoluminescence (TL), another two pieces of pottery were dated by OSL, and three charcoal samples by AMS ¹⁴C. TL age of pottery piece P14 from the depth of 75 cm is 7.06 ± 0.51 ka, making it the earliest pottery in the Tibetan Plateau. The AMS ¹⁴C age of charcoals from the same depth of 75 cm is 6805 ± 95 Cal a BP, in agreement with TL age of P14. OSL age of pottery P12 from the depth of 60–70 cm is 6.50 ± 0.47 ka, and OSL age of pottery P9 from 54 cm is 4.97 ± 0.25 ka. Thus, the age of the painted pottery piece at the depth of 61 cm should be ∼5.50 ka by interpolation, making it the earliest painted pottery in the QTP. The pottery P14 has many common features similar to that of the Yangshao culture in China. We suggest that, before 7 ka, hunters using microlithic had been living in the northeastern margin of the QTP. Since 7 ka, these native microlithic hunters had been affected by the Neolithic Yangshao culture from the Loess Plateau, which was characterized by well-developed pottery. Agricultural growers migrated from the lower elevation of the Loess Plateau to the east of the QTP, leading to profound cultural exchanges with highland native microlithic hunters.     

Permian integrative stratigraphy,biotas, paleogeographical and paleoclimatic evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The Permian Period was a critical time interval during which various blocks of the Qinghai-Tibetan Plateau have experienced profound and complex paleogeographical changes. The supercontinent Pangea was formed to its maximum during this interval, hampering a global east-to-west trending equatorial warm ocean current. Meanwhile, a semi-closed Tethys Ocean warm pool formed an eastward-opening oceanic embayment of Pangea, and became an engine fostering the evolutions of organisms and environmental c...     

Cryogenian and Ediacaran integrative stratigraphy,biotas, and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

The complex evolutionary history of the Qinghai-Tibetan Plateau and its surrounding areas, including the continental blocks(Indian, Lhasa, South Qiangtang, Tarim, Olongbuluk, Central Qilian, Alxa, North China, Yangtze, Central Iran and Oman) and the orogenic belts between them, has long been the frontier in Earth science research. The Cryogenian and Ediacaran strata are extensively distributed in these blocks. Specifically, relatively complete Cryogenian and Ediacaran successions have been disco...     

Factors contributing to the oxygen concentration over the Qinghai-Tibetan Plateau and its contribution rate calculation

A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming. The Qinghai-Tibetan Plateau is located at a high altitude, and thus, it faces a hypoxia challenge; however, knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking. Here, we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteo...     

Characterizing the dynamics of soil organic carbon in grasslands on the Qinghai-Tibetan Plateau

Carbon dynamics of grasslands on the Qinghai-Tibetan Plateau may play an important role in regional and global carbon cycles. The CENTURY model (Version 4.5) is used to examine temporal and spatial variations of soil organic carbon (SOC) in grasslands on the Plateau for the period from 1960 to 2002. The model successfully simulates the dynamics of aboveground carbon and soil surface SOC at the soil depth of 0-20 cm and the simulated results agree well to the measurements. Examination of SOC for eight typical grasslands shows different patterns of temporal variation in different ecosystems in 1960-2002. The extent of temporal variation increases with the increase of SOC of ecosystem. SOC increases first and decreases quickly then during the period from 1990 to 2000. Spatially, SOC density obtained for the equilibrium condition declines gradually from the southeast to the northwest on the plateau and showed a high heterogeneity in the eastern plateau. The results suggest that (i) SOC den-sity in the alpine grasslands shows remarkable response to climate change during the 42 years, and (ii) the net carbon exchange rate between the alpine grassland ecosystems and the atmosphere increases from 1990 to 2000 as compared with that before 1990.     

Fungal spore record of pastoralism on the NE Qinghai-Tibetan Plateau since the middle Holocene

Pastoralism is considered a crucial factor in the eventual year-round occupation of high-altitude regions(3000 m asl) of the Qinghai-Tibetan Plateau, and the northeastern Qinghai-Tibetan Plateau(NE-QTP) was an important corridor for early human occupation. We analyzed fossil fungal spore records for the last 8500 years from a high resolution aeolian section at Langgeri(LGR) on the NE-QTP. Thirty-two fungal spore types were identified in the LGR section, including seven coprophilous types. We combined analysis of coprophilous fungal spores, Cyperaceae, Artemisia, and Hippophae pollen, and the charcoal50 μm fraction to explore the timing and controls of pastoralism on the NE-QTP since the middle Holocene. Pastoralism commenced at LGR shortly before ca. 5.5 ka and gradually increased between ca. 5.5–3.5 ka, but markedly intensified after ca.2.2 ka, with three periods of growth at ca. 2.1–1.9, 1.4–1.2, and 0.6–0 ka, and a decline at ca. 1.1–0.6 ka. The timing of changes in pastoral activity on the NE-QTP based on the coprophilous fungal spore record is supported by regional archeology and historical documents. Technological and political developments, rather than climate change, played key roles in the long-term fluctuations of regional pastoralism on the NE-QTP in the late Holocene.     

青藏高原东缘重力观测及对芦山M7.0地震的反映

介绍了青藏高原东缘地区相对重力与绝对重力的观测情况,系统分析了该区域2010以来的区域重力场变化及其与2013年4月20日四川芦山7.0级地震发生的关系。结果表明:(1)芦山7.0级地震前青藏高原东缘重力变化剧烈,芦山地震发生在沿龙门山断裂带南段的重力变化高梯度带的转弯部位;(2)芦山地震距2008年汶川地震不到100km,芦山震中及汶川地震震中均处于重力变化四象限中心,表明汶川地震震后恢复调整变化对芦山地震具有促进作用;(3)基于流动重力异常变化在芦山7.0级地震前做过一定程度的中期预测,尤其是地点预测。     

贵州高原百花水库浮游植物功能群的动态变化及驱动因子

为了解贵州高原百花水库浮游植物功能群的动态变化与环境因子的关系,于2020年1—12月(除2月份)对浮游植物与水环境指标进行逐月采样,利用RDA和相关性分析,结合群落更替指数(BC)对百花水库浮游植物功能群进行分析.结果表明:1)2020年百花水库共鉴定出浮游植物7门64种,其中绿藻门物种数最多为27种,其次为硅藻门和蓝藻门,浮游植物总生物量的范围为124.8~2235.4 μg/L;2)百花水库浮游植物共归类为26个功能群,其中S1、L_M、J、B、P、D、MP、Y和W1为优势功能群,多数适宜生存在中营养的水体.功能群B、D和L_M是长期处于优势地位的功能群,以梅尼小环藻(Meneghiniana cyclotella)、尖针杆藻(Synedra acus)和飞燕角甲藻(Ceratium hirundinella)为主;3)综合营养状态指数(TLI(Σ))为36.90~50.20,生态状态指数(Q)值为0.73~3.46,说明百花水库处于中营养状态.4)分析结果表明,水温和pH共同影响浮游植物优势功能群的动态变化.