Hong Ao

• Doctor of Philosophy
• Institute of Geology and Geophysics, Chinese Academy of Sciences

The Nihewan fluvio-lacustrine sequence (North China) has recorded late Pliocene–Pleistocene climatic and environmental changes, and contains valuable information on early human evolution in high-latitude East Asia. We carried out a combined mineral-magnetic and geochemical investigation on a sequence from the Xiantai section, eastern Nihewan Basin....

Magnetostratigraphic studies have established a first-order chronological framework for the Paleolithic sites in the Nihewan Basin (North China), which enabled tracking early human evolution in East Asia. However, to fully understand how well early humans were adapted to climate change, a truly precise dating of the Paleolithic sites is required. H...

a b s t r a c t Here we present an improved astronomical timescale since 5 Ma as recorded in the ODP Site 1143 in the southern South China Sea, using a recently published Asian summer monsoon record (hematite to goethite content ratio, Hm/Gt) and a parallel benthic d 18 O record. Correlation of the benthic d 18 O record to the stack of 57 globally...

Here we construct a Pleistocene astronomical timescale for the Nihewan fluvio–lacustrine sediments (North China), via tuning a stacked summer monsoon index generated from grain size and low-field magnetic susceptibility records to orbital obliquity and precession. Combining the summer monsoon records retrieved from the Nihewan and the Chinese loes...

Intensification of northern hemisphere glaciation (iNHG), ~2.7 million years ago (Ma), led to establishment of the Pleistocene to present-day bipolar icehouse state. Here we document evolution of orbital- and millennial-scale Asian winter monsoon (AWM) variability across the iNHG using a palaeomagnetically dated centennial-resolution grain size rec...

The Tibetan Plateau is the world's largest high-elevation ecosystem. Here, we present evidence of stone artefacts from an in-situ stratigraphic sequence with the accelerator mass spectrometry 14 C and optically stimulated luminescence dates to show that the sophisticated microlithic technologies emerged on the central Tibetan Plateau (CTP) as early...

The relationship between initial Homo sapiens dispersal from Africa to East Asia and the orbitally paced evolution of the Asian summer monsoon (ASM)—currently the largest monsoon system—remains underexplored due to lack of coordinated synthesis of both Asian paleoanthropological and paleoclimatic data. Here, we investigate orbital-scale ASM dynamic...

Whether there are links between geomagnetic field and Earth's orbital parameters remains unclear. Synchronous reconstructions of parallel long-term quantitative geomagnetic field and climate change records are rare. Here, we present 10Be-derived changes of both geomagnetic field and Asian monsoon (AM) rainfall over the last 870 kyr from the Xifeng...

The mid-Pleistocene transition 1.25 to 0.6 million years ago marked a major shift in global climate periodicity from 41,000 to around 100,000 years without a concomitant orbital forcing shift. Here, we investigate Asian climate dynamics associated with two extreme glacial loess coarsening events at the onset and middle of the mid-Pleistocene transi...

The mid-Pleistocene transition (MPT) from ~ 1.25 to ~ 0.6 million years ago (Ma) marked a major shift in periodicity of Earth’s climate variability from dominantly ~ 40- to ~ 100-thousand years (kyr) without a concomitant shift in orbital forcing. Here we advance understanding of Asian climate dynamics associated with two glacial extreme loess coar...

Constraining monsoon variability and dynamics in the warm unipolar icehouse world of the Late Oligocene can provide important clues to future climate responses to global warming. Here, we present a ~4-thousand year (ka) resolution rubidium-to-strontium ratio and magnetic susceptibility records between 28.1 and 24.1 million years ago from a distal a...

Across the Miocene–Pliocene boundary (MPB; 5.3 million years ago, Ma), late Miocene cooling gave way to the early-to-middle Pliocene Warm Period. This transition, across which atmospheric CO 2 concentrations increased to levels similar to present, holds potential for deciphering regional climate responses in Asia—currently home to more than half of...

Asia contains more than half the world’s population, and their lives are significantly related to summer monsoon moisture supply. Here, we investigate features and dynamics of late Pleistocene–middle Holocene Asian summer monsoon variability in the Nihewan Basin, North China, which was a critical home for early humans in East Asia throughout the Qu...

The Yellow River is the 2nd longest river in China and the 6th longest river in the world. However, the timing and mechanism of its integration remains debated. During the establishment of its present geometry, the Yellow River captured and deeply incised into a series of local drainage basins along its Upper and Middle Reaches. The termination of...

The Chinese loess is one of the most important terrestrial records of the Quaternary climate changes. However, the positional discrepancy of geomagnetic polarity boundaries, such as Matuyama-Brunhes boundary (MBB), between Chinese loess and marine sediments remains controversial, hampering to establish an accurate chronological framework for the Ch...

Intense Asian summer monsoon rainfall responds to high boreal summer insolation and environmental feedbacks in the early and middle Holocene. However, it is unclear what role of the Asian summer monsoon strength might have played for the heterogeneous wetness pattern in northern China. Here, we report two wet periods in the early and middle Holocen...

Global climate shifted to markedly warmer interglacial conditions across the “mid-Brunhes transition” (MBT, ~400 ka). However, a global MBT synthesis that spans marine and terrestrial evidence remains elusive, which limits our understanding of the role of the MBT in mid-Pleistocene human evolution. We synthesize Asian precipitation reconstructions...

The first major build-up of Antarctic glaciation occurred in two consecutive stages across the Eocene–Oligocene transition (EOT): the EOT-1 cooling event at ~34.1–33.9 Ma and the Oi-1 glaciation event at ~33.8–33.6 Ma. Detailed orbital-scale terrestrial environmental responses to these events remain poorly known. Here we present magnetic and geoche...

Magnetic susceptibility (χ) of loess-paleosol sequences on the Chinese Loess Plateau (CLP) has been widely used as a proxy for East Asian summer monsoon (EASM) precipitation variability. Such records typically show strong climate forcing in the ∼100 ka orbital eccentricity band, but exhibit weak precessional (∼23 ka) forcing relative to that seen i...

The global climate cyclicity transferred from an Early Pleistocene mode dominated by the obliquity periodicity to a new Middle Pleistocene state dominated by the eccentricity periodicity in the absence of any significant changes in orbital forcing, known as the Early–Middle Pleistocene transition (EMPT), is an unresolved issue of Milankovitch orbit...

The Quantougou (QTG) Fauna in central Lanzhou Basin is an important late Mid-Miocene fauna on the northeastern Tibetan Plateau margin, but its numerical age remains a matter of debate. Here, we present a new magnetostratigraphic record for a fluvio-lacustrine section to further constrain the age of the QTG Fauna. Results suggest that the studied se...

The fluvio-lacustrine sequence in the Lanzhou Basin, located at the northeastern margin of the Tibetan Plateau, is a rich source of Oligocene–Miocene mammalian fossils, critical to our understanding of the terrestrial Asian mammal and environmental evolution. While the Miocene mammalian faunas have been dated with magnetostratigraphy, the numerical...

The Chinese Loess Plateau (CLP) in North China is an important terrestrial archive that witnessed the environmental changes and mammal and early human evolution in Asia over the past 2.6 Ma. Establishing precise ages for the Pleistocene faunas on the CLP is critical for better understanding of these environmental, biological, and archaeological iss...

Pre-Quaternary terrestrial climate variability is less well understood than that during the Quaternary. The continuous eolian Red Clay sequence underlying the well-known Quaternary loess-paleosol sequence on the Chinese Loess Plateau (CLP) provides an opportunity to study pre-Quaternary terrestrial climate variability in East Asia. Here, we present...

The Xujiayao site in the Nihewan Basin (North China) is one of the most important Paleolithic sites in East Asia. Twenty Homo fossils, which were previously assigned to an archaic Homo sapiens group, have been excavated along with more than 30,000 lithic artifacts and ∼5000 mammalian fossil specimens. Dating of the Xujiayao hominin has been pursued...

A large number of terrestrial mammalian fossils were reported in the well-exposed Paleogene and Neogene fluvio-lacustrine strata in Western China. Their accurate ages are crucial to understand the mammalian and environmental evolution associated with the step-wise uplift of the Tibetan Plateau. At present their ages are surprisingly poorly constrai...

Lake Qinghai is the largest lake in China and situated in an important climate-sensitive zone on the northeastern margin of the Tibetan Plateau, making it an ideal place to study the environmental evolution of the northwest China as well as the interplay between the Asian monsoon and the westerlies in the late Quaternary. In this study, detailed ro...

This article provides a comprehensive review of the global monsoon that encompasses findings from studies of both modern monsoons and paleomonsoons. We introduce a definition for the global monsoon that incorporates its three-dimensional distribution and ultimate causes, emphasizing the direct drive of seasonal pressure system changes on monsoon ci...

Lanzhou Basin lies on the northeastern margin of the Tibetan Plateau in western China and is a rich source of Oligocene-Miocene mammalian fossils. Obtaining precise age determinations for these fossils is important to address key questions concerning mammalian and environmental evolution in Asia associated with stepwise Tibetan Plateau uplift. Here...

Paleoenvironmental reconstructions provide the context for human evolution and behavior. However, it is difficult to resolve relative proportions of specific habitats at a given place and time, how these may have changed over time, and the explicit nature of particular habitats for human adaptation. This paper examines the paleoenvironmental contex...

This paper describes new fossils of Equus huanghoensis from an Early Pleistocene bed in Nihewan, Hebei Province, which confirms the classification of E. huanghoensis by Chinese researchers. The new fossils include a relatively complete male skull and mandible with all upper and lower dentition, a broken female skull with fragment of mandible and a...

This article provides a comprehensive review of the global monsoon that encompasses findings from studies of both modern monsoons and paleomonsoons. We introduce a definition for the global monsoon that incorporates its three-dimensional distribution and ultimate causes, emphasizing the direct drive of seasonal pressure system changes on monsoon ci...

This paper provides a comprehensive review of the Global Monsoon (GM) that encompasses findings from both modern and paleo monsoon studies. A definition for the GM is introduced that incorporates its three dimensional distribution and ultimate causes, emphasizing on the direct drive of seasonal pressure system changes on monsoon circulation, and de...

In Chinese loess, the Brunhes-Matuyama (B-M) geomagnetic reversal occurs similar to 25 k.y. prior to the age found in marine sediments. This offset has been attributed by some to post-depositional magnetic overprinting of loess, while others have argued it is due to errors in the loess time scale. Here we solve this long-standing debate by exploiti...

The environmental significances of climate change as reflected in the evolution of mammalian fauna, including humans ,in China during the Cenozoic are reviewed in this chapter. The mammal distributions and evolution of mammalian zoogeographic provinces in China during the Cenozoic are suggested to be significantly affected by the Asian monsoon deve...

The fluvio-lacustrine sequences in the Nihewan Basin of North China (known as the Nihewan Formation) are rich sources of Early Pleistocene Paleolithic sites and mammalian fossils (known as the Nihewan Fauna sensu lato), which offer an excellent opportunity to investigate the evolution of early humans and land mammals in East Asia. Also abundant mam...

The Nihewan Basin in North China has a rich source of Early Pleistocene Paleolithic sites. Here, we report a high-resolution magnetostratigraphic dating of the Shangshazui Paleolithic site that was found in the northeastern Nihewan Basin in 1972. The artifact layer is suggested to be located in the Matuyama reversed polarity chron just above the up...

Supplementary Information

The Nihewan Basin is an important area for studying the evolution of early hominids in China. Among 15 recently discovered and reported Lower Pleistocene sites in the Basin, eight (Majuangou, Xiaochangliang, Dachangliang, Banshan, Donggutuo, Feiliang, Huojiadi, Xujiapo) have been specifically analyzed by the authors. This paper is a synthesis of re...

It has been proposed that within the Tarim Basin tectonic activity has been limited since Triassic time. However, on the basis of magnetostratigraphy from the eastern Tarim Basin, which defines the chronology of sedimentation and structural evolution of the basin, we show that the basin interior has been uplifted and partitioned during Quaternary....

The Nihewan Basin (40°N) in North China is a rich source of Early Pleistocene Paleolithic sites and thus a key area for studying early human evolution in high-latitude (from an early human perspective) East Asia. Here a high-resolution magnetostratigraphic investigation is carried out on a fluvio-lacustrine section in the northeastern Nihewan Basin...

The Tarim Basin, one of the largest inland basins in the world, is situated in the northwestern China and to the north of the Tibetan Plateau. Continuous Cenozoic deposits have accumulated in this basin, which are crucial for investigating the growth of the Tibetan Plateau and the paleoclimatic evolution in Asian interior. Here we report the magnet...

The left-lateral strike-slip Altyn Tagh Fault (ATF) forming the northern boundary of the Tibetan Plateau accommodates parts of the overall convergence between the colliding Indian and Eurasian plates. Precise dating of the ATF activity is essential for understanding possible mechanisms of Tibetan Plateau deformation and uplift. Here we report a mag...

The Nihewan Basin of North China is a key archaeological area, in which most of the Early Pleistocene Paleolithic sites in China were found. Recent magnetostratigraphic dating of several Paleolithic sites in this basin have notably increased our understanding of early human colonization of high northern latitudes in East Asia. The Shangshazui (SSZ)...

The expansion of inland Asia deserts has considerably influenced the environmental, social and economic activities in Asia. Aridification of inland Asia, especially timing of the initiation of Asian desertification, is a contentious topic in paleoclimatology. Late Cenozoic eolian loess-red clay sequences on the Chinese Loess Plateau, which possess...

Lake Qinghai, the largest lake in China, is situated in an important climate-sensitive zone on the northeastern margin of Tibetan Plateau. In this study, the magnetic mineralogy of a late Pleistocene sediment core (1F, 18.6 m long) from the southern sub-basin deposition center of Lake Qinghai was studied using multiple rock-magnetic and non-magneti...

Here we present an improved astronomical timescale since 5 Ma as recorded in the ODP Site 1143 in the southern South China Sea, using a recently published Asian summer monsoon record (hematite to goethite content ratio, Hm/Gt) and a parallel benthic d18O record. Correlation of the benthic d18O record to the stack of 57 globally distributed benthic...

The magnetic susceptibility (χ) carried by pedogenic fine-grained ferrimagnets has been widely used as paleoclimatic proxy to elucidate long-term paleoclimatic variations for wind-blown terrestrial loess/paleosol sequences. However, the magnetic properties of the lithogenic parent material can mask the pedogenic signals. In this study, we systemati...

The Nihewan Basin (around 40°N, North China) is a major focus of investigations into hominid occupation in the eastern Asia during the early Pleistocene, thus the paleoenvironmental evolution in this area is crucial for understanding of early human habitation at high northern latitudes of East Asia. To retrieve reliable long-term paleoenvironmental...

The fluvio-lacustrine sequence in the Nihewan Basin is an important archive of Pleistocene climate and environmental changes in northern China, which provides excellent sources of early human settlements in high-latitude East Asia. Here a long-term environmental record from the Pleistocene fluvio-lacustrine sequence in this basin is revealed, based...

The fluvio-lacustrine sequence in the Nihewan Basin is an important archive of Pleistocene climate and environmental changes in northern China, which provides excellent sources of early human settlements in high-latitude East Asia. Here a long-term environmental record from the Pleistocene fluvio-lacustrine sequence in this basin is revealed, based...

The Nihewan Formation is exposed fluvio-lacustrine sediment in the Nihewan Basin about 150 km northwest of Beijing, China. The formation is of interest because it contains vertebrate mammal fossils that have been studied by geologists, palaeontologists, geochronologists, and palaeoanthropologists since the 1920s (Barbour, 1925; Teilhard de Chardin...

Here, we report an increased cooling coupled with an intensified aridification for the Xiantai fluvio-lacustrine sequence of Pleistocene age (1.9-0.1 Ma) in the Nihewan Basin (North China), known for the occurrence of several hominin sites. The cooling is related to an up-section decrease in propensity to chemical weathering as inferred from an inc...

The fluvio-lacustrine sequence of the Nihewan Basin in northern China consists mainly of alternating grayish-green silts and grayish-yellow silts/fine-grained-sands. A multi-parameter investigation was conducted on the two types of representative sedimentary facies from the Dachangliang section in the eastern Nihewan Basin, using environmental magn...

Magnetostratigraphic dating of the fluvio-lacustrine sequence in the Nihewan Basin, North China, has permitted the precise timing of the basin infilling and associated Nihewan mammalian faunas. The combined evidence of new paleomagnetic findings from the Hongya and Huabaogou sections of the eastern Nihewan Basin and previously published magnetochro...

We present a new magnetostratigraphic dating of the Feiliang Paleolithic site in the Nihewan Basin, northern China. Partially-oxidized magnetite and hematite were identified as the main carriers for the characteristic remanent magnetizations of the fluvio-lacustrine sediments. Paleomagnetic results suggest that the sequence recorded the very early...

Timing of the early habitation and stone technologies in the Nihewan Basin, North China has provided insights into our understanding of early human adaptability to high northern latitudes in East Asia. Here we contribute to this topic with detailed magnetostratigraphic investigation, coupled with mineral magnetic measurements and palynological anal...