# Anti-phase variation of long eccentricity and precipitation in inland Asia during the middle Miocene Climatic Optimum (MMCO)

Zhongbao Zhang, Junsheng Nie, Alexis Licht, Nathan Cogné, Anta-Clarisse Sarr, Tiantian Shen, Xingwan Liu, Weihang Wang, Peng Gao, Lin Li, et al.

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Zhongbao Zhang, Junsheng Nie, Alexis Licht, Nathan Cogné, Anta-Clarisse Sarr, et al. Anti-phase variation of long eccentricity and precipitation in inland Asia during the middle Miocene Climatic Optimum (MMCO). Geological Society of America Bulletin, 2024, 137 (1-2), pp.51-66. 10.1130/B37333.1. insu-04628645

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1 Anti-phase variation of long eccentricity and precipitation in
2 inland Asia during the middle Miocene Climatic Optimum

3 Zhongbao Zhang<sup>1,2</sup>, Junsheng Nie<sup>1,3,*</sup>, Alexis Licht<sup>2</sup>, Nathan Cogne<sup>4</sup>, Anta-Clarisse

4 Sarr<sup>5</sup>, Tiantian Shen<sup>1</sup>, Xingwan Liu<sup>1</sup>, Weihang Wang<sup>1</sup>, Peng Gao<sup>1</sup>, Lin Li<sup>6</sup>, Marc

5 Poujol<sup>4</sup>, Abel Guihou<sup>2</sup>, Pierre Deschamps<sup>2</sup>, Lewei Hao<sup>7</sup>

6 <sup>1</sup>Ministry of Education Key Laboratory of Western China's Environmental Systems,
College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000,
China

9 <sup>2</sup>Aix Marseille Univ, CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France

10 <sup>3</sup>School of Earth Sciences, Lanzhou University, Lanzhou 73000, China

11 <sup>4</sup>Univ Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, France

12 <sup>5</sup>Univ. Grenoble Alpes, Univ. Savoie Mont-Blanc, CNRS, IRD, ISTerre, 38000 Grenoble,
France

14 <sup>6</sup>Department of Geosciences, University of Arizona, Tucson, Arizona, USA

15 <sup>7</sup>Key Laboratory of Petroleum Resources, Northwest Institute of Eco-Environment and
Resources, Chinese Academy of Sciences, Lanzhou 730000, China

17 *Corresponding author
18 ABSTRACT

19 The mechanisms and pace of orbital forcing on precipitation in inland Asia during
20 the Cenozoic remain poorly understood. Many previous studies using magnetic proxies for
21 precipitation have shown a consistent signal of long eccentricity (405 kyr) on hydrological
22 records of central China that are younger than ~11 Ma. Most studies suggest that variations
23 of rainfall amount were controlled by Northern Hemisphere summer insolation, with peak
24 of precipitation associated with eccentricity maxima. We report here multiple magnetic
25 records dating back to the middle Miocene Climatic Optimum (MMCO, ~14-17 Ma ago)
26 including a detailed record from a new section in the Qaidam Basin, dated by a combination
27 of magnetostratigraphy, U-Pb geochronology and apatite low-temperature
28 thermochronology. Our records show the exact opposite: they display dominant 405 kyr
29 wet-dry cycles, but the wetter intervals correspond to eccentricity minima and ice-volume
30 maxima during the MMCO. Taken at face value, these results question the origin
31 (monsoonal or westerly-derived?) of the precipitation reaching central China during the
32 middle Miocene and the mechanisms enhancing monsoonal penetration inland Asia. We
33 yet suggest that this antiphase relationship could also reflect biases in magnetic proxies for
34 precipitation during the wettest climatic phases, which can result in the dissolution of
35 magnetic minerals and a significant underestimation of past rainfall amount.
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# INTRODUCTION

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As the hydroclimate of mid-latitude Eurasia (30°-60°N, 30°-120°E) impacts over 50% of the global population (Wang et al., 2022a), numerous studies have focused on understanding the mechanisms driving precipitation in this region. Many of them highlight recurring long-eccentricity cycles (405 ka) in regional sedimentary archives (Abels et al., 2010; Aziz et al., 2003; Frisch et al., 2019; Gao et al., 2021; Hui et al., 2023; Liu et al., 2021; Mandic et al., 2011; Nie, 2018; Wang et al., 2019). Neogene lacustrine sediment records from southern Europe reveal clear 405-kyr cycles with lake highstands coinciding with eccentricity maxima, interpreted as the coupling of high-amplitude eccentricity-modulated precession and wetter westerly atmospheric circulation (Abels et al., 2010; Aziz et al., 2003; Mandic et al., 2011; Valero et al., 2014). Similarly, Miocene sediment records from East Asia provide evidence supporting wetter intervals at eccentricity maxima during the late Cenozoic, which are believed to be the result of high amplitudes of eccentricity-modulated precession that enhanced the East Asian summer monsoon (EASM) (Hui et al., 2023; Liu et al., 2021).

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However, the mechanisms and driving forces of precipitation changes at long eccentricity timescale in Central Eurasia (Fig. 1), particularly during the Miocene, remain unclear. The few Miocene records of central Asia have been variously interpreted regarding their phase relationship between wet-dry variation and eccentricity and their dominant atmospheric circulation. For example, a co-variation between precipitation and long eccentricity was reported in the Tianshui Basin of northeastern Tibetan Plateau during the late Miocene (Wang et al., 2019), but it is uncertain whether the moisture originated from the westerlies or the EASM. By contrast, Nie et al. (2022) observed desert greening with
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eccentricity minima in the late Miocene of northwestern Tarim Basin, attributed to
enhanced westward moisture transport caused by weakened EASM. These Miocene humid
events during eccentricity minima have also been reported in other Central Asian basins
(Frisch et al., 2019; Voigt et al., 2017), but with a moisture source considered as westerly-
derived. They proposed that the strong evapotranspiration and precipitation seasonality
forced by high amplitudes of eccentricity-modulated precession should be responsible for
increased aridity and drying during eccentricity maxima.

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Here, we present a new, well-dated, precipitation index record from the Qaidam Basin in the northeastern Tibetan Plateau (NTP). Combining it with multiple wet-dry variation records from the NTP and the China Loess Plateau (CLP), we clearly demonstrate anti-phased changes between precipitation and long eccentricity during the middle Miocene Climatic Optimum (MMCO). Climate simulations provided here support a greater contribution of westerly moisture in this period. We propose to explain these humid events during low eccentricity phases by latitudinal shifts of the westerly belt over the Paratethys. These findings emphasize the spatial differences in the hydrological response to orbital forcing in Eurasia, and provide a new perspective for interpreting past Eurasian hydroclimate archives.

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GEOLOGICAL SETTING

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The Qaidam basin is a triangular intermontane basin, laying on the northeastern
Tibetan Plateau, with an area of ~120,000 km² and an average elevation of ~3000 m (Yin
et al., 2008). The northeast, northwest, and south sides of the basin are bounded by the
Qilian Shan, Altun Tagh Range, and Qimen Tagh-Eastern Kunlun Shan, respectively (Fig.

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2). Thousands of meters of clastic deposits are exposed in northern margin of the basin due to tectonic deformation and erosion. In ascending order, the Cenozoic strata that filled the basin are subdivided into the Lulehe, Xiaganchaigou, Shangganchaigou, Xiayoushashan, Shangyoushashan, Shizigou, and Qigequan formations (Fang et al., 2007; Yin et al., 2008). These formations were previously assigned to Eocene to Holocene ages based on ostracod assemblages and sparse pollen. However, recently reported mammalian fossil assemblages and apatite fission track results in the northeastern Qaidam basin suggested younger ages than previously assumed. The new age model dated the basal Cenozoic unit in the basin (Lulehe Formation) to Oligocene or early Miocene (Nie et al., 2020; Wang et al., 2022b; Wang et al., 2017).

Our sampled section is located in the northern Qaidam Basin, so we refer to it as the QN section. The QN section is exposed in the western flank of Eboliang I Anticline (Fig. 2). Due to limited formation exposure, the QN section is divided into the QN-1 section to the east and the QN-2 section to the west. The QN-1 section spans ~480 m from 38°43'06"N, 92°48'51"E to 38°42'38"N, 92°48'20"E, and the QN-2 section spans ~690 m from 38°43'34"N, 92°47'42"E to 38°43'14"N, 92°46'51"E. The two sections are ~2000 m apart and the strata are continuous with each other (Fig. 2).

The lower 425 m of the QN section primarily consists of light brown to gray-green mudstone and some green sandy mudstone and siltstone interlayers, with a series of gypsum layers in siltstone. The 711-887 m strata of the section are mainly composed of brown to brick red thick mudstone interbedded with tine gray-green mudstone. The 0-425 m and 711-887 m can be distinguished from other strata by finer composition, representing a lower-energy lacustrine depositional environment. The 425-711 m and 887-1167 m
contain red to green sandstones, siltstones, and mudstones, characterized by abundant brick red and gray-green sandstone interlayers, with trough-cross bedding and erosive bases observed in the coarser deposits (Fig. 3). These formations, characterized by coarse grain sizes and abundant gypsum layers, display a distinct upward coarsening and thickening trend, indicating a deltaic depositional environment. Detailed lithologic features of the QN section are presented in Figure 3 and Supplementary File 1.

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## 112 MATERIALS AND METHODS

### 113 Detrital Apatite Low-Temperature Thermochronology

To constrain the depositional age of the QN section, we dated the stratigraphic successions by using detrital apatite fission track (AFT) and (U-Th)/He analyses (AHe). Three detrital apatite samples were collected from the bottom (5 m, ZZ1), middle (753 m, ZZ6) and top (1154 m, ZZ9) of the QN section (Fig. 3). A total of 356 apatite grains were used from three medium- to coarse-grained sandstone samples of the QN section for fission track dating. We used the laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) protocol of Cogné et al. (2020) at the GeOHeLiS platform (University of Rennes - France). All samples were mounted in a 1.5 mm thick epoxy disc. The apatite grains were etched using a 5.5 M HNO₃ at 21°C for 20s. The grain mounting and etching are similar to the protocol described by Donelick et al. (2005). Spontaneous fission track counting was carried out using a Zeiss AxioImage M1 equipped with an automated stage system using TrackWorks software at a magnification of 1000 × available at the GeOHeLiS platform. The U/Ca ratios analysis was conducted using a quadrupole Agilent 7700 × ICP-MS coupled to an ESI NWR193UC Excimer laser, employing a 40 µm laser spot with a
repetition rate of 5 Hz and energy of 4 J/cm² for a duration of 30 seconds. Data reduction was performed using Iolite v 4.6 5 (Paton et al., 2011) with a modified version of the Trace Elements data reduction scheme (Cogné et al., 2020; Woodhead et al., 2007) and an in-house Python script for ages calculation.

For the AHe analyses, 25 euhedral and transparent apatite grains with length and width greater than 70 µm were selected from a sandstone sample (ZZ6) at 753m of the section under an electron microscope. Each grain was wrapped in a platinum capsule, 1 mm × 1 mm, and thermally outgassed for 5 minutes under vacuum at ~900°C using a diode laser. Then, the grains were spiked with ³He, and the gas volumes were measured using a PrismaPLus QME 220 quadrupole mass analyzer. After degassing, the outgassed grains were dissolved and spiked with ²³⁵U and ²³⁰Th. U and Th abundance are then deduced from ²³⁵U/²³⁸U and ²³⁰Th/²³²Th ratios measured by ICP-MS. The age calculation of each grain was processed by the alpha-ejection correction factor, which can be calculated from the grain dimension (Farley et al., 1996). Five Durango apatite fragments were run as reference standards along with our samples to verify the accuracy of the analysis. All above AHe analyses for the QN section were performed at the National Institute of Natural Hazards, Ministry of Emergency Management of China (NINH-MEMC).

## 145 Carbonate U-Pb dating

To further constrain the depositional age of the QN section, one secondary sparite sample, C9, was collected at 1167 m from the top of the section for carbonate U-Pb dating at the Envitop platform (CEREGE, Aix-Marseille University). The sample was cut to expose fresh surfaces and prepared in a 100 µm-thick thin section. 100 circular spots of 150 µm diameter were picked to perform U-Pb dating after screening to maximize U-Pb variability. Calcite ablation was performed using an ESI (Electro Scientific Industries) laser (193 nm ArF Excimer laser)
connected to an Element XR (Thermo Fish Scientific) Inductively coupled mass spectrometer.
WC1 carbonate (Roberts et al., 2017) and NIST 614 glass reference materials were used to correct
the inter-elemental fractionation. Raw data were processed with Iolite® software and U-Pb ratios
corrected for fractionation were calculated using an in-house Excel macro. U-Pb ages are calculated
by using Tera-Wasserburg diagrams with IsoplotR (Vermeesch, 2018). Details on the
methodology and the analytic parameters are given in Godeau et al. (2018) and their online
supporting data section. Detailed data are available in Table S3.

## Detrital Zircon U-Pb Dating

Given the potential impact of sediment provenance on the efficacy of magnetic proxies in delineating precipitation variations (Wang et al., 2022c), we employed detrital zircon-age spectra to evaluate the provenance of the sediments. Zircon grains in the QN section were collected from the same locations as the AFT samples (ZZ1, ZZ6 and ZZ9. Fig. 3). Besides, another detrital zircon sample was collected from a river in the Altun Piedmont to represent the zircon composition of the Altyn Tagh Range. These samples were separated by standard heavy liquid techniques, selected randomly and dated by LA-ICP-MS at CEREGE, with an Element XR ICP-MS connected to an ESI laser (ArF 193 nm) ablation system. Zircons were ablated with a 25 microns spot diameter, 15 Hz pulse repetition rate, an energy fluence of 1.5 J cm⁻² and a carrier gas flow of 0.975 L/min, and using zircon 91500 as primary reference material (Wiedenbeck et al., 1995). Data reduction, dates and date uncertainties calculation were conducted with an in-house MATLAB script; details about our zircon U-Pb dating workflow and data reduction steps can be found in Licht et al. (2024) and are given in Supplementary File 2. Briefly, our data reduction protocol combines steps from previously published procedures, such as the calculation of excess variance (Paton et al., 2010), the consideration of signals coming from different
176 detectors (Pullen et al., 2018), and the impact of <sup>207</sup>Pb beam intensity on date uncertainties
177 (Matthews and Guest, 2017). The discordance filter used to screen for concordant grains is
178 the Concordia distance of Vermeesch (2021), using a threshold of 10% discordance and 5%
179 of reverse discordance. Ages used for plotting are the Concordia age of Vermeesch (2021).
180 The three zircon validation reference materials used during these sessions yielded offset
181 around TIMS ages < 1% in most cases, < 2% otherwise. Detailed data are available in
182 Table S4.

183 Magnetostratigraphy

184 A total of 462 samples were collected at intervals of 2–10 m throughout the section
185 using a gasoline-powered drill for magnetostratigraphic analysis. All drilled samples were
186 oriented in situ by the solar compass and were corrected by ~0.7° for local declination
187 anomaly. Subsequently, the core samples were cut into the standard of ~2-cm-long cylinder
188 specimens and then subjected to progressive thermal demagnetization in the laboratory.
189 Thermal demagnetization was performed at 19 different temperatures: 50, 100, 150, 200,
190 250, 300, 350, 400, 450, 500, 550, 580, 610, 630, 650, 660, 670, 680 and 690 °C. The
191 sample remanence at each temperature was measured using a 2G cryogenic magnetometer
192 in a magnetically shielded space. Samples collected in 2018 and 2019 were demagnetized
193 and magnetic remanence was measured at Lanzhou University, China, and China
194 University of Geosciences (Beijing, China), respectively. A least-square fitting technique
195 was used to evaluate the characteristic magnetization (CHRM) using Paleo-Mag software
196 of Jones (2002), and then determined the CHRM directions with the Fisher statistics (Fisher,
197 1953). Any data with contradictory declinations and inclinations, as well as maximum
198 angular deviation (MAD) angles greater than 15°, were excluded from the analysis.
This study employed the magnetic proxy χ<sub>fd</sub>/HIRM (frequency-dependent magnetic susceptibility/hard isothermal remanent magnetization) to identify precipitation changes in the QN section. A total of 754 loose samples were collected in roughly 2 m intervals from the QN section and cut into standard cylindrical specimens with dimensions of 26 × 22 mm (diameter × height). In the laboratory, we measured the low frequency and high frequency magnetic susceptibility (χ<sub>lf</sub> and χ<sub>hf</sub>) at a frequency of 976 and 15616 Hz, respectively, in a field of 200 A/m by a three-frequency Kappabridge instrument. Isothermal remanent magnetization (IRM) intensities, IRM-0.3T and IRM1.2T [saturation isothermal remanent magnetization (SIRM)], were imparted at -0.3T and 1.2T magnetic fields, and field addition and measurement were performed using a Model 670 IRM pulse magnetizer and a JR-6 Spinner Magnetometer. The frequency-dependent magnetic susceptibility (χ<sub>fd</sub>) was calculated as χ<sub>lf</sub> - χ<sub>hf</sub>, and Hard IRM (HIRM) can be calculated as (IRM<sub>1.2T</sub> + IRM<sub>-0.3T</sub>)/2.

Following these measurements, χ<sub>fd</sub>/HIRM were calculated. All the above magnetic parameter measurements were performed at the Paleomagnetism and Environmental Magnetism Laboratory of the China University of Geosciences, Beijing, China.

We performed a spectral analysis of the χ<sub>fd</sub>/HIRM time series of the QN section using Acycle v2.2 software (Li et al., 2019) to identify the dominant periodicity. Time series were first linearly interpolated to 2-kyr intervals, and then de-trended by applying the LOWESS model. Finally, spectral analysis was conducted using the 2π Multitaper method (Ghil et al., 2002) with a red-noise model (Mann and Lees, 1996) to determine significant spectral peaks. Evolutionary spectra are obtained by applying the continuous wavelet transforms (Ginsted et al., 2004) in time series analysis.
222 Climate Simulations

223 We generated 3 early Miocene simulations with the Earth System Model IPSL-
224 CM5A2 (Sepulchre et al., 2020) in order to test the sensitivity of Central Asia precipitation
225 to eccentricity. IPSL-CM5A2 includes the atmosphere model LMDz5A (Hourdin et al.,
226 2013) at a nominal resolution of 3.75° in longitude by 1.85° in latitude with 31 irregularly
227 distributed vertical levels, the land surface and vegetation model ORCHIDEE (Krinner et
228 al., 2005) and the ocean model NEMOv3.6 (Madec, 2016) at a resolution of 2° by 2°
229 refined at 0.5° in the equatorial region. Ocean and atmosphere are coupled with the OASIS
230 coupler (Valcke, 2013). The simulations are based on the early/mid- Miocene paleographic
231 reconstruction from (Poblete et al., 2021) (Fig. S12) and have been run with 560 ppm pCO2
232 (other greenhouse gases set at pre-industrial value). Sepulchre et al. (2020) provide a full
233 description of the model. Details on the early Miocene setup and assessment of simulated
234 climate dynamics over the Asia can be found in Sarr et al. (2022) and Tardif et al. (2023).
235 We initiated the simulations from a 3,000 model years long early Miocene simulation with
236 modern orbital parameters, for which deep-ocean temperature have reached a quasi-
237 equilibrium (see Sarr et al., 2022). Each orbital configuration has then been run for
238 additional 1,000 model years starting from the last day of initial simulation. Eccentricity
239 has been setup to zero, nullifying the impact of precession in the NoE configuration. HBS
240 (perihelion on the 21st of June) and HAS (perihelion on the 21st of December)
241 configurations have a high eccentricity (0.06) and different longitudes of the perihelion
242 from the moving equinox (270° for HBS and 90° for HAS). HBS and HAS therefore
243 exhibits a hot Boreal and Austral summer respectively. Obliquity fixed at 24.5°. Simulation
244 results are displayed using climatological averages over the last 100 yr of the simulation.
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## 246 RESULTS

### 247 Thermochronology

The three detrital AFT samples (ZZ1, ZZ6 and ZZ9, in ascending order of strata height) exhibit single grain age distribution in the range of 13.5 ± 10 and 219 ± 92 Ma (Table S1, all uncertainties are quoted at 2σ in the text, figures and table). Central ages ranged from 78 ± 5 Ma to 87 ± 6 Ma, and show no significant variation with stratigraphic height. All the P(χ²) values of 3 samples are very low (<< 0.01), which is likely reflecting a mixture of various age components. IsoplotR (Vermeesch, 2018) was used to do the radial plots, mixture modelling and kernel density estimate (KDE) (Fig. 4). For finite mixture modelling the number of peaks is decided by the software using BIC criteria. The three samples yielded two peaks, the young one being ca. 55-60 Ma, and the old one ca. 95-100 Ma (Fig. 4). A minimum age model was also performed for each sample as it is the best approach to determine the minimum age component (Vermeesch, 2019). ZZ1 yielded a minimum age for the distribution of 19.1 ± 8.5 Ma. ZZ9 also yielded a young age ca. 26.5 Ma but the result seems quite unstable given the uncertainty and proportion of this model, and is based only on one uncertain single grain age. ZZ6 yielded a minimum age 47.8 ± 8.7 Ma.

The detrital AHe results show a large single-grain age span, from 21.4 to 182.5 Ma (Table S2). We used IsoplotR to perform the mixture modelling and KDE (Fig. 4). Finite mixture modelling exhibits multiple peaks, two of them similar to the ones of the fission track data (Fig. 4), and the youngest one ca. 27 Ma. KDE show a similar distribution than fission track as well. Finally, the minimum age model yielded an age of 21.4 ± 4.0 Ma. The
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latter is governed by the youngest grain of the distribution but at least two other grains
yielded ages below 30 Ma.

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U-Pb dating for a secondary sparite, C9, provides an additional radiometric age.

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The experimental analysis obtained data from 100 measurement points (Table S3). The lower intercept on the Tera-Wasserburg plot (Fig. 5) yields an age of 12.61 ± 0.73 Ma (2σ; MSWD: 0.94).

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The U-Pb ages of the 385 concordant zircon grains from the three samples of the QN section span between 3093.1 Ma and 44.9 Ma. IsoplotR-generated kernel density estimations reveal two dominant U-Pb age peaks for zircons in the samples, at around 200-300 Ma and 400-500 Ma, respectively (Fig. 6). Furthermore, a minor proportion of pre-Cambrian age distribution (spanning from ca. 2.8 Ga to 550 Ma) was also detected (Fig. 6; Table S4). The river sediment sample from the Altun Piedmont yielded 110 concordant zircon ages spanning from ca. 2667.8 Ma to 50.7 Ma. These ages show a distinct age peak at 400-500 Ma, with a minor proportion of pre-Cambrian ages (Fig. 6).

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## Magnetostratigraphy

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The intensity of the natural remanent magnetization (NRM) of the QN section samples is within the range of 1.10 × 10⁻⁶ to 5.32 × 10⁻⁴ A/m (Table S5). Progressive thermal demagnetization of most specimens distinguishes two distinct magnetic components: a low temperature component, usually removed at 200-300°C, which can be interpreted as viscous remanence magnetization; and a high temperature component, usually decaying toward the origin between 200-300°C and 580-690°C, representing a characteristic remanence magnetization (Fig. S1). The Zijderveld plots (Zijderveld, 1967) show that the remanent magnetization decays rapidly at 680°C, indicating that hematite is

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291 the main magnetic carrier of the sediment magnetization. Some specimens also decrease
292 rapidly at 580°C, revealing the presence of magnetite (Fig. S1). Based on the criteria listed
293 in the Methods, 382 of 462 (83%) samples from the QN section gave a reliable CHRM.
294 All accepted CHRM directions yield a value of -0.4019 for the Jackknife test (Tauxe and
295 Gallet, 1991) which falls in the range of 0 to -0.5 (Fig. S2), indicating that the ChRM
296 directions of the QN sections are primary. The magnetostratigraphic analysis of 382
297 samples revealed the presence of 9 normal polarity zones (N1-N9) and 10 reversed polarity
298 zones (R1-R10, see Fig. 7).

299 Cyclostratigraphy

300 The $\chi_{fd}$/HIRM of the specimens presents a time series of high-frequency value
301 fluctuations, ranging from 2.2-79.1 $\times$ 10$^{-6}$ m$^3$ kg$^{-1}$ (Fig. 8; Table S6). We noted that
302 $\chi_{fd}$/HIRM values increased clearly during 17-14 Ma, with a mean value of 26.1 $\times$ 10$^{-6}$ m$^3$
303 kg$^{-1}$ for 17-14 Ma and 20.6 $\times$ 10$^{-6}$ m$^3$ kg$^{-1}$ for the other periods. We utilized recurrence
304 analysis of “determinism” (DET) to quantify the predictability of this proxy dynamics
305 (Marwan et al., 2007; Westerhold et al., 2020). Our findings indicate that $\chi_{fd}$/HIRM values
306 during the MMCO (17-14 Ma) was more stochastic (less predictable) (Fig. S3).

307 The power spectra of $\chi_{fd}$/HIRM data from the QN profile exhibit clear orbital period
308 signals, including eccentricity (405-kyr and 100-kyr), obliquity (40-kyr), and precession
309 (20-kyr) (Fig. 8). However, the 40-kyr and 20-kyr cycles are not apparent in the wavelet
310 analysis (Fig. 9). The reason is that the average sampling resolution for the QN profile is
311 ~5.5 ka, which is close to the minimum resolution to resolve (5 ka) the precession cycle
312 so that the precession cycles can be displayed in the power spectrum for all intervals on
313 average. Instead, 32% of the actual sampling intervals are larger than 5 ka, as shown by
314 the sample resolution curve (Fig. S4B), resulting in insignificant precession cycles in
315 wavelet analysis. For the same reason, the obliquity cycles are also inapparent in the
316 wavelet analysis because there are many sampling intervals larger than 10 ka, especially
317 before 16.5 Ma (Fig. S4B). Nonetheless, the resolution of our data is sufficient to resolve
318 the eccentricity cycles. Both 405-kyr and 100-kyr cycles are demonstrated in the power
319 spectrum at the 99% confidence level (Fig. 8). In wavelet analysis, the 405-kyr signal
320 persists in the time series, while the 100-kyr signal appears intermittently (Fig. 9).
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323 DISCUSSION

323 Age Model

324 Previous studies have assigned the oldest stratigraphic sequence exposed on the
325 Eboliang I Anticline to Eocene age (53-36.5 Ma) based mainly on pollen analysis and
326 ostracod assemblages (HGSI, 2003; IGSQP, 2004; XBGMR, 1993). Based on this rough
327 constraint and the correlation between the observed polarities and Geomagnetic polarity
328 time scale (GPTS) (Ogg, 2020), we thus assigned the depositional age of bottom strata to
329 the Eocene and then yield an old age-model for QN section (Fig. S5).
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330 However, the old age-model is inconsistent with the apatite low-temperature
331 thermochronology results. The detrital AFT and AHe results from QN section reveal
332 multiple age peaks that may correspond to the cooling ages of different source rocks. Since
333 source rocks have to undergo erosion/cooling before being transported and deposited, the
334 youngest age peak (obtained through minimum age model) that represents the cooling time
335 of the youngest basin source rock can constrain the lower bound of the specimen
336 depositional age. It is, however, possible that apatite grains may be affected by post-
depositional burial and thus age rejuvenation. If annealing / diffusion has occurred, it cannot be a full resetting of the ages, as otherwise one would expect a single, less dispersed, age population per sample, especially for fission track data. We argue that partial resetting is also unlikely. Firstly, the age distribution is very similar over the 1 km section. If partial annealing had occurred, we would expect a decreasing of the age distribution towards the base of the section. Secondly, AHe ages should, theoretically, be younger than AFT as the thermal sensitivity of He diffusion is lower than the FT annealing. Although this is compositionally dependent, our AHe ages come from grains that are relatively small and have low eU for some of them (Table S2), making them prone to such low temperature diffusion. Therefore, if resetting had occurred, we would expect to see younger ages in the AHe distribution compared to the AFT distribution. However, our results do not show this pattern. Thus, we assume that both AHe and AFT ages are likely to reflect source exhumation ages, and that the minimum ages of AFT for sample ZZ1, and AHe for ZZ6 (ca. 20 Ma) are a good indicator that the QN section was deposited during Neogene. Combining the above age differences and the poor correlation between observed polarities and GPTS in the old-age model (Fig. S5), we believe that there is low confidence in this age scenario for the QN profile. These age results highlight the uncertainty of formation defined by pollen and ostracod analyses (Hanson et al., 2001; Horton et al., 2004; Sun et al., 1999). Therefore, based on the constraints of apatite dating and the correlation between magnetic polarity and the GPTS, we conclude that the depositional age of the QN section should be Neogene rather than Eocene (Fig. 7).

Our age model for the QN section is obtained using the dynamic time warping algorithm (Lallier et al., 2013). The dynamic time warping method is an automated
investigation by assessing the matching degree (correlation costs) between the observed magnetic polarities and the GPTS (Ogg, 2020). Each correlation yields a cost for ranking the potential solutions by considering minimizing the local variation in sediment accumulation rate. According to the above special rules, the software was run 10000 times and 6000 minimum costs were outputted, and the solution with the least cost is considered the “best-fit correlations”. Four potential solutions for the QN section with lower cost are shown in Figure S6. Among them, the least-cost scheme suggests that the observed magnetic column correlates with the magnetostratigraphic Chrons C5Dr.1n-C5ACn (~17.7-13.7 Ma). This age model predates the U-Pb age (ca. 12.6 Ma) for secondary sparite from the top of the QN section (Fig. 5) and proposes a < 1 Myr delay between the deposition of the dated carbonate and its later recrystallization. Such delay is common for early diagenetic calcite (Montano et al., 2021; Montano et al., 2022). Notably, the χfd/HIRM records under this age model display more pronounced Earth orbital cycles compared to the alternative age scenarios (Fig. S7). Therefore, we employ this age model for our study.

## Evolution of Depositional Environments and Provenance

Two distinct depositional environments were identified at the QN section: a lacustrine environment at depths of 0-425 m and 711-887 m, and a deltaic environment at depths of 425-711 m and 887-1167 m (Fig. 3). The depositional environment of the QN section is highly dependent on the hydrological budget of the Qaidam Basin, as it is situated on its northern edge and far from the Cenozoic depocenters (Yin et al., 2008). We notice that fluctuation amplitudes of the χfd/HIRM record for the lower lacustrine interval are smaller than the upper lacustrine interval, and the high amplitude fluctuations of the lower
delta interval persist through the upper lacustrine interval (Fig. S8). This suggests that the primary control of the $\chi_{fd}$/HIRM record in the study site is not the depositional environment.

Depositional environments did have an effect on the $\chi_{fd}$/HIRM record, though, as it is clear that increased $\chi_{fd}$/HIRM fluctuations did not initiate at 17 Ma (onset of the MMCO), but instead at the interval of lacustrine to delta environment transition (C5Cn.2n; ~16.42 Ma).

Despite this complexity, each depositional environment in the studied section includes multiple 405-kyr cycles, so environmental shifts are above the timescales of orbital cycles, which are the focus of this study.

The AFT and zircon U-Pb ages at the QN locality suggest no significant changes in sediment provenance during the middle Miocene. AFT results from different heights of the profile exhibit similar age distributions (Fig. 4). Zircon age distribution of all three samples show distinct age peaks at around 200 Ma and 400 Ma (Fig. 6). These results are consistent with previous studies of nearby stratigraphic units and suggest that the sediment sourced from either one or both of the Altyn Tagh Range and the Qilian Shan (Cheng et al., 2016). However, the limited 200 Ma zircon component from rivers draining the Altyn Tagh Range (Fig. 6, ZZA), and the low abundance of these ages in the Qilian Shan suggest the presence of other sources during the middle Miocene. Although significant 200 Ma zircon source rocks are available in the eastern Kunlun Range on the western margin of the Qaidam Basin (Jolivet et al., 2015; Roger et al., 2003), the Cenozoic depocenters were situated farther south of the QN locality (Yin et al., 2008), making it challenging for the source material from the eastern Kunlun Range to reach our study area. We suspect that this issue may be caused by our Altun Piedmont zircon ages being obtained from modern riverbeds so they could potentially fail to reflect the zircon age distribution of the middle Miocene,
or insufficient and unrepresentative sampling that do not accurately represent the provenance. Consequently, despite the presence of 200-300 Ma granites in the Altyn Tagh Range (Gehrels et al., 2003a, b), they do not appear in the detrital zircon ages of the river sample. Collectively, these results suggest a stable sediment source at QN site during the middle Miocene, but further investigation is necessary to identify the exact sources and their evolution history.

## 412 Dominant Eccentricity Forcing on Qaidam Hydroclimate?

The $\chi_{fd}/\text{HIRM}$ ratio is generally regarded as an effective proxy for precipitation in inland Asia. $\chi_{fd}$ and HIRM reflect the concentration of fine (nanometer-scale) ferrimagnetic and hematite grains produced during pedogenic weathering, respectively. The production of hematite requires less precipitation compared to ferrimagnetic grains (Balsam et al., 2011; Liu et al., 2013; Nie et al., 2017). Therefore, high values of $\chi_{fd}/\text{HIRM}$ represent heavy precipitation and intense diagenetic weathering. The $\chi_{fd}/\text{HIRM}$ ratio has been validated as a sensitive indicator of precipitation variations using surface soils on the CLP and the NTP (Gao et al., 2021; Liu et al., 2013; Nie et al., 2017). This environmental magnetic parameter has been widely applied in the NTP and the CLP to indicate precipitation variations (Gao et al., 2021; Liu et al., 2021; Liu et al., 2013; Liu et al., 2016; Luo et al., 2021; Nie et al., 2017; Ren et al., 2020; Su et al., 2019).

Long-term magnetic susceptibility ($\chi_{lf}$) records from the CLP and NTP during the MMCO were also collected for comparison. As demonstrated before, magnetic enhancements of these three sections were caused by increase of ultrafine ferromagnetic grains whose content is proportional to the degree of pedogenesis and regional precipitation (Guan et al., 2019; Nie et al., 2010; Qiang et al., 2010).
Time series analysis of environmental magnetic results reveals a significant 405 kyr wet-dry variation for the QN locality during the MMCO (Figs. 8 and 9). We also observe a similar contemporaneous wet-dry cycle in the western Qaidam Basin and the CLP based on the $\chi_{if}$ of fluvial-lacustrine sediments and loess, respectively (Figs. 10 and S9) (Guan et al., 2019; Hao et al., 2008; Qiang et al., 2010). Cyclostratigraphy analysis on the $\chi_{if}$ records of the Huatugou section in the northwest Qaidam Basin and the Qin'an and Zhuanglang sections on the CLP all show a dominant 405kyr wet-dry cycle, in-phase with the $\chi_{fd}/HIROM records from the QN section during the MMCO (Fig. 10). We note that the $\chi_{fd}$ record of QN also show similar pattern as the $\chi_{fd}/HIROM record, with similar phasing relationship with eccentricity (Fig. S10). These results suggest that precipitation over the CLP and Qaidam Basin evolved with a distinct long eccentricity cycle at that time. Strikingly, both the above records and our results show wetter intervals corresponding to eccentricity minima on the 405-kyr timescale (Figs. 10 and S11), which is in stark contrast to precipitation records of East Asia since the Late Miocene, which commonly show wetter intervals during eccentricity maxima (Hui et al., 2023; Liu et al., 2021; Nie, 2018).

To better understand why rainfall peaks during eccentricity minima, we simulated the impact of insolation forcing with middle Miocene boundary conditions using an Earth system model (Figs. S13 and S14). Unsurprisingly, we find that monsoonal intensity over East China and rainfall intensity over the Qaidam Basin were particularly sensitive to precession, which is modulated by eccentricity. At high eccentricity, precipitation can be much lower or much higher than during periods of no eccentricity depending on the position of the perihelion (Fig. 11). It is thus difficult to explain why periods of low eccentricity appear wetter in our record. We find no major change of atmospheric
circulation between eccentricity extrema in the climate simulations (Fig. 12). However, the climate simulations highlight that the mid-Miocene atmospheric circulation was significantly different from today: (a) Wind patterns over the Qaidam Basin indicate westerly-winds blowing year-round and a moisture source either from the Paratethys or from the central part of the Neotethys. By contrast, East China experiences summer monsoon winds. (b) The Qaidam basin experienced two rainy seasons, in Spring and Fall, in contrast with East China, which experienced only a summer rainfall season (Fig. 11). These fundamental differences between modern day and the mid-Miocene circulation imply to look for unusual mechanisms to explain the anti-phased eccentricity forcing on precipitation.

## 462 Hydrological Implications

Previous studies suggest that during the warm MMCO, favorable geographical and atmospheric conditions enabled the westerly belt to penetrate into the Asian interior (Frisch et al., 2019; Wang et al., 2019). The highlands that currently block westerly moisture from entering the interior, such as the Pamirs and Tianshan Mountains in the west and the Qilian Shan in the east, did not reach high elevations until late Miocene (Bougeois et al., 2018; Heermance et al., 2018; Miao et al., 2022; Wang et al., 2020). Furthermore, a warmer climate in the middle Miocene likely resulted in increased evapotranspiration from the mid-latitude Atlantic and Paratethys region for the westerlies, potentially increasing the amount of moisture delivered to inland Asia. Interestingly however, lakes in southern Europe, fed by westerly-derived moisture, display maximum levels during eccentricity maxima (Abels et al., 2010; Aziz et al., 2003; Mandic et al., 2011; Valero et al., 2014). We propose three scenario that could explain a peak of rainfall during eccentricity minima in central Asia.
First, Frisch et al. (2019) and Voigt et al. (2017) propose a potential mechanism to understand the MMCO anti-phase changes between eccentricity and precipitation in Central Asia. They suggest that the hydrological budget in this prominently arid region is most sensitively controlled by the balance of evaporation and precipitation. Despite the high eccentricity enhanced precipitation, the high amplitudes of eccentricity-modulated precession resulted in recurring periods of high potential evapotranspiration and extreme precipitation seasonality, ultimately led to a negative water budget. Evaporative salt deposits (gypsum) are more prevalent during low eccentricity periods in our record (Fig. 10A), which does not support this scenario.

Alternatively, we propose that change of westerly jet position between eccentricity extrema could partly explain why eccentricity minima appear wetter in our record. During low eccentricity periods of the Miocene, the positive shift in benthic $\delta^{18}$O (Fig. 10) indicates cold polar climate (Foster et al., 2012). This may have led to strengthened Mongolia and Siberian highs (Porter and An, 1995; Sun et al., 2012). Subsequently, intensified northern hemisphere high-pressure system can push the polar front southward, resulting in a southward migration of the westerly belt (Chang et al., 2017; Luo et al., 2009).
This southward shift could have more regularly centered the westerly belt over the Paratethys in western Asia, enhancing its moisture supply. Conversely, polar warming during eccentricity maxima may have led to a weakened high-pressure system in the Northern Hemisphere, causing the northward retreat of the westerlies, their shift above inland western Asia and reducing their moisture contribution to mid-latitude Asia, ultimately resulting in arid conditions. This scenario is in agreement with the overall atmospheric circulation patterns seen in our climate simulations, though they fail
reproducing a clear migration of the westerly belt with changing eccentricity. This
mechanism would have disappeared during the late Miocene, with the gradual retreat of
the Paratethys (Bosboom et al., 2014; Bosboom et al., 2011; Rogl, 1999) and the uplift of
the Central Asian mountains, blocking westerly moisture from penetrating further inland
(Caves, 2017; Liu et al., 2014; Sun et al., 2017).

Additionally, the contribution of an alternative moisture source during periods of eccentricity minima cannot be rejected, though it is not seen in the simulations. Nie et al. (2022) proposed that the weakening EASM enhanced westward monsoonal moisture transport along the northern periphery of the Tibetan Plateau, associated with the westward shift of the West Pacific subtropical high and intensified Mongolian anticyclone, resulted in desert wetting at eccentricity minimum in Tarim Basin during the late Miocene. Our simulation results reveal a southward shifted EASM belt compared to the late Miocene (Fig. 12). Therefore, we infer that the above processes may have been amplified during the MMCO with the retreat of the monsoon circulation, thereby affecting the Qaidam Basin and CLP. Late Miocene uplift of the Tibetan Plateau could have caused a reorganization of the Asian atmospheric circulation patterns and removed this effect (An et al., 2001; Miao et al., 2022; Miao et al., 2012). This mechanism remains yet to be tested and confirmed with other records and simulations.

Finally, we point out that the low rainfall amount estimates for high eccentricity
times could actually reflect a possible bias in the χ<sub>fd</sub>/HIRM proxy in the wettest climate
conditions. Indeed, modern calibrations suggest that above ~1000 MAP, magnetic
susceptibility decreases along with increasing precipitation due to ferrimagnetic mineral
dissolution or non-production (Balsam et al., 2011). Though our climate simulations
521 indicate an arid climate with low precipitation (<500 mm annually), Miocene leaf fossils
522 from the Qaidam Basin indicate a higher precipitation level during the MMCO. Song et al.
523 (2020) reported a fossil leaf assemblage from the Dahonggou section in the northeastern
524 Qaidam Basin (Fig. 2A), which correlates laterally with the QN section. Using the Climate-
525 Leaf Analysis Multivariate Program (CLAMP), a method that links modern vegetation leaf
526 characteristics with climate data to infer ancient climatic conditions during vegetation
527 growth periods (Khan et al., 2014; Spicer et al., 2016), they quantitatively reconstructed
528 mean annual precipitation in the region to exceed 1000 mm (Song et al., 2020). Though
529 the age of the site yielding fossil leaves is not astrochronologically constrained, this
530 assemblage indicates that periods of high rainfall (>1000 mm annually) during the MMCO
531 are likely and may cause occasional ferrimagnetic mineral dissolution, resulting in intervals
532 of low magnetic susceptibility. In this sense, low magnetic susceptibility values during
533 periods of high eccentricity might reflect wetter (and not drier) periods, favored by the
534 dissolution of magnetic minerals. This interpretation is in agreement with the less common
535 occurrence of gypsum beds during high eccentricity periods, suggesting wetter conditions
536 (Fig. 10A). However, this interpretation lacks confirmation from petrographic evidence for
537 dissolution. If confirmed by further petrographic studies, evidence for partial dissolution
538 during wet periods would open the way to the re-interpretation of many previous
539 hydrological records based on magnetic proxies.
540

540

541 CONCLUSIONS

542 Detailed apatite low-temperature thermochronology and magnetostratigraphy
543 results suggest that the fluvial-lacustrine sedimentary sequences of the QN profile at the
northern Qaidam Basin were deposited between ~17.7-13.7 Ma. The AFT and zircon age spectra indicate that there was no significant change in provenance during this period. Our climate record, as revealed by the $\chi_{fd}/\text{HIRM}$ and $\chi_{fd}$ indicators, shows a distinct anti-phase relationship between long eccentricity and precipitation in inland Asia during the MMCO. We favor two explanations for this antiphase. Latitudinal migration of the westerly belt over the middle Miocene Paratethys could force wet-dry variations in mid-latitude Asia on long eccentricity timescales and result in wetter conditions during low eccentricity times; by contrast, the anti-phase relationship could result from magnetic mineral dissolution during wetter, high-eccentricity intervals, regardless of the source of the humidity in the Qaidam Basin. Given that the MMCO is considered a possible climate analog for a future with no permanent ice sheets in the Northern Hemisphere, this study provides valuable insights into potential hydrological changes during such periods and the complexity of past hydrological records during warm periods.

557

## 558 ACKNOWLEDGEMENTS

This work was financially supported by the Second Tibetan Plateau Scientific Expedition (2019QZKK0704) and the National Natural Science Foundation of China (4188810, 42030505). CEREGE Envitop analytical facility received support from the "Excellence Initiative" of Aix Marseille University A*MIDEX - project DATCARB, a french "Investissement d'avenir" program. A-C. Sarr is supported by a grant from Labex OSUG (Investissements d'avenir – ANR10 LABX56). A-C. Sarr was granted access to HPC resources of TGCC under allocation 2022-A0090102212 made by GENCI.

566
567 REFERENCE CITED

568 Abels, H. A., Aziz, H. A., Krijgsman, W., Smeets, S. J. B., and Hilgen, F. J., 2010, Long-
569 period eccentricity control on sedimentary sequences in the continental Madrid
570 Basin (middle Miocene, Spain): Earth and Planetary Science Letters, v. 289, no. 1-
571 2, p. 220-231, doi:10.1016/j.epsl.2009.11.011.

572 An, Z. S., Kutzbach, J. E., Prell, W. L., and Porter, S. C., 2001, Evolution of Asian
573 monsoons and phased uplift of the Himalayan Tibetan plateau since Late Miocene
574 times: Nature, v. 411, no. 6833, p. 62-66, doi:Doi 10.1038/35075035.

575 Aziz, H. A., Krijgsman, W., Hilgen, F. J., Wilson, D. S., and Calvo, J. P., 2003, An
576 astronomical polarity timescale for the late middle Miocene based on cyclic
577 continental sequences: Journal of Geophysical Research-Solid Earth, v. 108, no.
578 B3, doi:10.1029/2002jb001818.

579 Balsam, W. L., Ellwood, B. B., Ji, J., Williams, E. R., Long, X., and El Hassani, A., 2011,
580 Magnetic susceptibility as a proxy for rainfall: Worldwide data from tropical and
581 temperate climate: Quaternary Science Reviews, v. 30, no. 19-20, p. 2732-2744,
582 doi:10.1016/j.quascirev.2011.06.002.

583 Bosboom, R., Dupont-Nivet, G., Grothe, A., Brinkhuis, H., Villa, G., Mandic, O., Stoica,
584 M., Kouwenhoven, T., Huang, W. T., Yang, W., and Guo, Z. J., 2014, Timing,
585 cause and impact of the late Eocene stepwise sea retreat from the Tarim Basin (west
586 China): Palaeogeography Palaeoclimatology Palaeoecology, v. 403, p. 101-118,
587 doi:10.1016/j.palaeo.2014.03.035.
588 Bosboom, R. E., Dupont-Nivet, G., Houben, A. J. P., Brinkhuis, H., Villa, G., Mandic, O., 589 Stoica, M., Zachariasse, W. J., Guo, Z. J., Li, C. X., and Krijgsman, W., 2011, Late 590 Eocene sea retreat from the Tarim Basin (west China) and concomitant Asian 591 paleoenvironmental change: Palaeogeography Palaeoclimatology Palaeoecology, v. 592 299, no. 3-4, p. 385-398, doi:10.1016/j.palaeo.2010.11.019.

593 Bougeois, L., Dupont-Nivet, G., de Rafelis, M., Tindall, J. C., Proust, J. N., Reichart, G. J., 594 de Nooijer, L. J., Guo, Z. J., and Ormukov, C., 2018, Asian monsoons and 595 aridification response to Paleogene sea retreat and Neogene westerly shielding 596 indicated by seasonality in Paratethys oysters: Earth and Planetary Science Letters, 597 v. 485, p. 99-110, doi:10.1016/j.epsl.2017.12.036.

598 Caves, J. K., 2017, Late Miocene Uplift of the Tian Shan and Altai and Reorganization of 599 Central Asia Climate: GSA Today, doi:10.1130/gsatg305a.1.

600 Chang, H., An, Z. S., Wu, F., Song, Y. G., Qiang, X. K., and Li, L. Y., 2017, Late Miocene 601 - early Pleistocene climate change in the mid-latitude westerlies and their influence 602 on Asian monsoon as constrained by the K/Al ratio record from drill core Ls2 in 603 the Tarim Basin: Catena, v. 153, p. 75-82, doi:10.1016/j.catena.2017.02.002.

604 Chen, F. H., Chen, J. H., Holmes, J., Boomer, I., Austin, P., Gates, J. B., Wang, N. L., 605 Brooks, S. J., and Zhang, J. W., 2010, Moisture changes over the last millennium 606 in arid central Asia: a review, synthesis and comparison with monsoon region: 607 Quaternary Science Reviews, v. 29, no. 7-8, p. 1055-1068, 608 doi:10.1016/j.quascirev.2010.01.005.
609 Cheng, F., Jolivet, M., Fu, S. T., Zhang, C. H., Zhang, Q. Q., and Guo, Z. J., 2016, Large-scale displacement along the Altyn Tagh Fault (North Tibet) since its Eocene initiation: Insight from detrital zircon U-Pb geochronology and subsurface data: Tectonophysics, v. 677, p. 261-279

613 Cogné, N., Chew, D. M., Donelick, R. A., and Ansberque, C., 2020, LA-ICP-MS apatite fission track dating: A practical zeta-based approach: Chemical Geology, v. 531, p. 119302, doi:10.1016/j.chemgeo.2019.119302.

616 Donelick, R. A., O'Sullivan, P. B., and Ketcham, R. A., 2005, Apatite fission-track analysis: Low-Temperature Thermochronology: Techniques, Interpretations, and Applications, v. 58, no. 1, p. 49-94, doi:DOI 10.2138/rmg.2005.58.3.

619 Fang, X. M., Zhang, W. L., Meng, Q. Q., Gao, J. P., Wang, X. M., King, J., Song, C. H., Dai, S., and Miao, Y. F., 2007, High-resolution magneto stratigraphy of the Neogene Huaitoutala section in the eastern Qaidam Basin on the NE Tibetan Plateau, Qinghai Province, China and its implication on tectonic uplift of the NE Tibetan Plateau: Earth and Planetary Science Letters, v. 258, no. 1-2, p. 293-306, doi:10.1016/j.epsl.2007.03.042.

625 Farley, K. A., Wolf, R. A., and Silver, L. T., 1996, The effects of long alpha-stopping distances on (U-Th)/He ages: Geochimica Et Cosmochimica Acta, v. 60, no. 21, p. 4223-4229

628 Fisher, R. A., 1953, Dispersion on a sphere: Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, v. 217, no. 1130, p. 295-305
630 Foster, G. L., Lear, C. H., and Rae, J. W. B., 2012, The evolution of pCO2, ice volume and climate during the middle Miocene: Earth and Planetary Science Letters, v. 341-631, p. 344, doi:10.1016/j.epsl.2012.06.007.

633 Frisch, K., Voigt, S., Verestek, V., Appel, E., Albert, R., Gerdes, A., Arndt, I., Raddatz, J., Voigt, T., Weber, Y., and Batenburg, S. J., 2019, Long-Period Astronomical Forcing of Westerlies' Strength in Central Asia During Miocene Climate Cooling: Paleooceanography and Paleoclimatology, v. 34, no. 11, p. 1784-1806, doi:10.1029/2019PA003642.

638 Gao, P., Nie, J. S., Yan, Q., Zhang, X., Liu, Q. S., Cao, B., and Pan, B. T., 2021, Millennial Resolution Late Miocene Northern China Precipitation Record Spanning Astronomical Analogue Interval to the Future: Geophysical Research Letters, v. 48, no. 15

642 Gehrels, G. E., Yin, A., and Wang, X. F., 2003a, Detrital-zircon geochronology of the northeastern Tibetan plateau: Geological Society of America Bulletin, v. 115, no. 7, p. 881-896

645 Gehrels, G. E., Yin, A., and Wang, X. F., 2003b, Magmatic history of the northeastern Tibetan Plateau: Journal of Geophysical Research-Solid Earth, v. 108, no. B9

647 Ghil, M., Allen, M. R., Dettinger, M. D., Ide, K., Kondrashov, D., Mann, M. E., Robertson, A. W., Saunders, A., Tian, Y., Varadi, F., and Yiou, P., 2002, Advanced spectral methods for climatic time series: Reviews of Geophysics, v. 40, no. 1

650 Godeau, N., Deschamps, P., Guihou, A., Leonide, P., Tendil, A., Gerdes, A., Hamelin, B., and Girard, J. P., 2018, U-Pb dating of calcite cement and diagenetic history in
652

microporous carbonate reservoirs: Case of the Urgonian Limestone, France:

653

Geology, v. 46, no. 3, p. 247-250, doi:10.1130/G39905.1.

654

Grinsted, A., Moore, J. C., and Jevrejeva, S., 2004, Application of the cross wavelet

655

transform and wavelet coherence to geophysical time series: Nonlinear Processes

656

in Geophysics, v. 11, no. 5-6, p. 561-566, doi:DOI 10.5194/npg-11-561-2004.

657

Guan, C., Chang, H., Yan, M. D., Li, L. Y., Xia, M. M., Zan, J. B., and Liu, S. C., 2019,

658

Rock magnetic constraints for the Mid-Miocene Climatic Optimum from a high-

659

resolution sedimentary sequence of the northwestern Qaidam Basin, NE Tibetan

660

Plateau: Palaeogeography Palaeoclimatology Palaeoecology, v. 532, p. 109263,

661

doi:10.1016/J.Palaeo.2019.109263.

662

Hanson, A. D., Ritts, B. D., Zinniker, D., Moldowan, J. M., and Biffi, U., 2001, Upper

663

Oligocene lacustrine source rocks and petroleum systems of the northern Qaidam

664

basin, northwest China: Aapg Bulletin, v. 85, no. 4, p. 601-619

665

Hao, Q. Z., Oldfield, F., Bloemendal, J., and Guo, Z. T., 2008, The magnetic properties of

666

loess and paleosol samples from the Chinese Loess Plateau spanning the last 22

667

million years: Palaeogeography Palaeoclimatology Palaeoecology, v. 260, no. 3-4,

668

p. 389-404, doi:10.1016/j.palaeo.2007.11.010.

669

Heermance, R. V., Pearson, J., Moe, A., Liu, L. T., Xu, J. H., Chen, J., Richter, F., Garzione,

670

C. N., Nie, J. S., and Bogue, S., 2018, Erg deposition and development of the

671

ancestral Taklimakan Desert (western China) between 12.2 and 7.0 Ma: Geology,

672

v. 46, no. 10, p. 919-922
673

HGSI, 2003, HGSI (Hunan Geological Survey Institute) The Report of Regional

674

Geological Survey of Qiemo at Scale 1:250,000 China Industry Press, Beijing, pp.

675

1-281 (in Chinese with English abstract):

676

Horton, B. K., Dupont-Nivet, G., Zhou, J., Waanders, G. L., Butler, R. F., and Wang, J.,

677

2004, Mesozoic-Cenozoic evolution of the Xining-Minhe and Dangchang basins,

678

northeastern Tibetan Plateau: Magnetostratigraphic and biostratigraphic results:

679

Journal of Geophysical Research-Solid Earth, v. 109, no. B4

680

Hourdin, F., Foujols, M. A., Codron, F., Guemas, V., Dufresne, J. L., Bony, S., Denvil, S.,

681

Guez, L., Lott, F., Ghattas, J., Braconnot, P., Marti, O., Meurdesoif, Y., and Bopp,

682

L., 2013, Impact of the LMDZ atmospheric grid configuration on the climate and

683

sensitivity of the IPSL-CM5A coupled model: Climate Dynamics, v. 40, no. 9-10,

684

p. 2167-2192, doi:10.1007/s00382-012-1411-3.

685

Hui, Z. C., Liu, J., Chevalier, M., Wei, X., Chen, P., Zhang, J., Peng, T. J., and Zhou, X.

686

W., 2023, Multiple forcing on Late Miocene East Asian Summer Monsoon

687

Precipitation Variability in NE Tibetan Plateau: Catena, v. 221, p. 106752,

688

doi:10.1016/J.Catena.2022.106752.

689

IGSQP, 2004, IGSQP (Institute of Geological Survey of Qinhai Province) The Report of

690

Regional Geological Survey at Scale 1:250000 P.R.C. China Industry Press,

691

Beijing, pp. 1-386 (in Chinese):

692

Jolivet, M., Roger, F., Xu, Z. Q., Paquette, J. L., and Cao, H., 2015, Mesozoic–Cenozoic

693

evolution of the Danba dome (Songpan Garzê, East Tibet) as inferred from LA-
694

ICPMS U-Pb and fission-track data: Journal of Asian Earth Sciences, v. 102, p.

695

180-204, doi:10.1016/j.jseaes.2015.02.009.

696

Jones, C. H., 2002, User-driven integrated software lives: "Paleomag" paleomagnetics

697

analysis on the Macintosh: Computers & Geosciences, v. 28, no. 10, p. 1145-1151

698

Khan, M. A., Spicer, R. A., Bera, S., Ghosh, R., Yang, J., Spicer, T. E. V., Guo, S. X., Su,

699

T., Jacques, F., and Grote, P. J., 2014, Miocene to Pleistocene floras and climate of

700

the Eastern Himalayan Siwaliks, and new palaeoelevation estimates for the

701

Namling-Oiyug Basin, Tibet: Global and Planetary Change, v. 113, p. 1-10,

702

doi:10.1016/j.gloplacha.2013.12.003.

703

Krinner, G., Viovy, N., de Noblet-Ducoudre, N., Ogee, J., Polcher, J., Friedlingstein, P.,

704

Ciais, P., Sitch, S., and Prentice, I. C., 2005, A dynamic global vegetation model

705

for studies of the coupled atmosphere-biosphere system: Global Biogeochemical

706

Cycles, v. 19, no. 1, doi:10.1029/2003gb002199.

707

Lallier, F., Antoine, C., Charreau, J., Caumon, G., and Ruiu, J., 2013, Management of

708

ambiguities in magnetostratigraphic correlation: Earth and Planetary Science

709

Letters, v. 371, p. 26-36, doi:10.1016/j.epsl.2013.04.019.

710

Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., and Levrard, B., 2004,

711

A long-term numerical solution for the insolation quantities of the Earth:

712

Astronomy & Astrophysics, v. 428, no. 1, p. 261-285, doi:10.1051/0004-

713

6361:20041335.

714

Li, M. S., Hinnov, L., and Kump, L., 2019, Acycle: Time-series analysis software for

715

paleoclimate research and education: Computers & Geosciences, v. 127, p. 12-22
716 Licht, A., Folch, A., Sylvestre, F., Yacoub, A. N., Cogné, N., Abderamane, M., Guihou, A., Kisne, N. M., Fleury, J., Rochette, P., Nké, B. E. B., Zagalo, A.-h. H., Poujol, M., and Deschamps, P., 2024, Provenance of aeolian sands from the southeastern Sahara from a detrital zircon perspective: Quaternary Science Reviews, v. 328, p. 108539, doi:10.1016/j.quascirev.2024.108539.

721 Liu, C. Y., Nie, J. S., Li, Z. J., Qiao, Q. Q., Abell, J. T., Wang, F., and Xiao, W. J., 2021, Eccentricity forcing of East Asian monsoonal systems over the past 3 million years: Proceedings of the National Academy of Sciences of the United States of America, v. 118, no. 43

725 Liu, W. G., Liu, Z. H., An, Z. S., Sun, J. M., Chang, H., Wang, N., Dong, J. B., and Wang, H. Y., 2014, Late Miocene episodic lakes in the arid Tarim Basin, western China: Proceedings of the National Academy of Sciences of the United States of America, v. 111, no. 46, p. 16292-16296, doi:10.1073/pnas.1410890111.

729 Liu, Z., Liu, Q., Torrent, J., Barrón, V., and Hu, P., 2013, Testing the magnetic proxy χFD/HIRM for quantifying paleoprecipitation in modern soil profiles from Shaanxi Province, China: Global and Planetary Change, v. 110, p. 368-378, doi:10.1016/j.gloplacha.2013.04.013.

733 Liu, Z., Wei, G., Wang, X., Jin, C., and Liu, Q., 2016, Quantifying paleoprecipitation of the Luochuan and Sanmenxia Loess on the Chinese Loess Plateau: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 459, p. 121-130, doi:10.1016/j.palaeo.2016.06.034.
737

Ludwig, K. R., 2003, User's manual for Isoplot 3.6: A geochronological toolkit for
microsoft excel. Berkeley Geochronology Center:

738

739

Luo, C., Peng, Z. C., Yang, D., Liu, W. G., Zhang, Z. F., He, J. F., and Chou, C. L., 2009,
A lacustrine record from Lop Nur, Xinjiang, China: Implications for paleoclimate
change during Late Pleistocene: Journal of Asian Earth Sciences, v. 34, no. 1, p.
38-45, doi:10.1016/j.jseaes.2008.03.011.

740

741

742

743

Luo, Z., Nie, J., Moe, A. E., Heermance, R. V., Garzione, C., Herbert, T. D., Wang, Z., Li,
H., Zhang, R., Zhao, X., and Salzmann, U., 2021, Joint insolation and ice sheet/CO2
forcing on northern China precipitation during Pliocene warmth: Science Bulletin,
v. 66, no. 4, p. 319-322, doi:10.1016/j.scib.2020.10.025.

744

745

746

747

Madec, G., 2016, NEMO Ocean Engine Scientific Notes of Climate Modelling Center
IPSL, No. 27

748

749

Mandic, O., de Leeuw, A., Vukovic, B., Krijgsman, W., Harzhauser, M., and Kuiper, K.
F., 2011, Palaeoenvironmental evolution of Lake Gacko (Southern Bosnia and
Herzegovina): Impact of the Middle Miocene Climatic Optimum on the Dinaride
Lake System: Palaeogeography Palaeoclimatology Palaeoecology, v. 299, no. 3-4,
p. 475-492, doi:10.1016/j.palaeo.2010.11.024.

750

751

752

753

754

Mann, M. E., and Lees, J. M., 1996, Robust estimation of background noise and signal
detection in climatic time series: Climatic Change, v. 33, no. 3, p. 409-445, doi:Doi
10.1007/Bf00142586.

755

756
757 Marwan, N., Romano, M. C., Thiel, M., and Kurths, J., 2007, Recurrence plots for the
758 analysis of complex systems: Physics Reports-Review Section of Physics Letters,
759 v. 438, no. 5-6, p. 237-329, doi:10.1016/j.physrep.2006.11.001.

760 Matthews, W. A., and Guest, B., 2017, A Practical Approach for Collecting Large-n
761 Detrital Zircon U-Pb Data sets by Quadrupole LA-ICP-MS: Geostandards and
762 Geoanalytical Research, v. 41, no. 2, p. 161-180, doi:10.1111/ggr.12146.

763 Miao, Y. F., Fang, X. M., Sun, J. M., Xiao, W. J., Yang, Y. H., Wang, X. L., Farnsworth,
764 A., Huang, K. Y., Ren, Y. L., Wu, F. L., Qiao, Q. Q., Zhang, W. L., Meng, Q. Q.,
765 Yan, X. L., Zheng, Z., Song, C. H., and Utescher, T., 2022, A new biologic
766 paleoaltimetry indicating Late Miocene rapid uplift of northern Tibet Plateau:
767 Science, v. 378, no. 6624, p. 1074-1078, doi:10.1126/science.abo2475.

768 Miao, Y. F., Herrmann, M., Wu, F. L., Yan, X. L., and Yang, S. L., 2012, What controlled
769 Mid-Late Miocene long-term aridification in Central Asia? - Global cooling or
770 Tibetan Plateau uplift: A review: Earth-Science Reviews, v. 112, no. 3-4, p. 155-
771 172, doi:10.1016/j.earscirev.2012.02.003.

772 Montano, D., Gasparrini, M., Gerdes, A., Della Porta, G., and Albert, R., 2021, In-situ U-
773 Pb dating of Ries Crater lacustrine carbonates (Miocene, South-West Germany):
774 Implications for continental carbonate chronostratigraphy: Earth and Planetary
775 Science Letters, v. 568, doi:10.1016/J.Epsl.2021.117011.

776 Montano, D., Gasparrini, M., Rohais, S., Albert, R., and Gerdes, A., 2022, Depositional
777 age models in lacustrine systems from zircon and carbonate U-Pb geochronology:
778 Sedimentology, v. 69, no. 6, p. 2507-2534, doi:10.1111/sed.13000.
779 Nie, J., Garzione, C., Su, Q., Liu, Q., Zhang, R., Heslop, D., Necula, C., Zhang, S., Song, Y., and Luo, Z., 2017, Dominant 100,000-year precipitation cyclicity in a late Miocene lake from northeast Tibet: Sci Adv, v. 3, no. 3, p. e1600762, doi:10.1126/sciadv.1600762.

783 Nie, J. S., 2018, The Plio-Pleistocene 405-kyr climate cycles: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 510, p. 26-30, doi:10.1016/j.palaeo.2017.07.022.

786 Nie, J. S., Ren, X. P., Saylor, J. E., Su, Q. D., Horton, B. K., Bush, M. A., Chen, W. H., and Pfaff, K., 2020, Magnetic polarity stratigraphy, provenance, and paleoclimate analysis of Cenozoic strata in the Qaidam Basin, NE Tibetan Plateau: Geological Society of America Bulletin, v. 132, no. 1-2, p. 310-320, doi:10.1130/B35175.1.

790 Nie, J. S., Song, Y. G., King, J. W., and Egli, R., 2010, Consistent grain size distribution of pedogenic maghemite of surface soils and Miocene loessic soils on the Chinese Loess Plateau: Journal of Quaternary Science, v. 25, no. 3, p. 261-266, doi:10.1002/jqs.1304.

794 Nie, J. S., Wang, W. H., Heermance, R., Gao, P., Xing, L., Zhang, X. J., Zhang, R., Garzione, C., and Xiao, W. J., 2022, Late Miocene Tarim desert wetting linked with eccentricity minimum and East Asian monsoon weakening: Nature Communications, v. 13, no. 1, doi:10.1038/S41467-022-31577-W.

798 Ogg, J., 2020, Geomagnetic polarity time scale, Geologic time scale 2020, Elsevier, p. 159-192.
800

Paton, C., Hellstrom, J., Paul, B., Woodhead, J., and Hergt, J., 2011, Iolite: Freeware for the visualisation and processing of mass spectrometric data: Journal of Analytical Atomic Spectrometry

801

802

803

Paton, C., Woodhead, J. D., Hellstrom, J. C., Hergt, J. M., Greig, A., and Maas, R., 2010, Improved laser ablation U-Pb zircon geochronology through robust downhole fractionation correction: Geochemistry Geophysics Geosystems, v. 11, doi:10.1029/2009gc002618.

804

805

806

807

Poblete, F., Dupont-Nivet, G., Licht, A., van Hinsbergen, D. J. J., Roperch, P., Mihalynuk, M. G., Johnston, S. T., Guillocheau, F., Baby, G., Fluteau, F., Robin, C., van der Linden, T. J. M., Ruiz, D., and Baatsen, M. L. J., 2021, Towards interactive global paleogeographic maps, new reconstructions at 60, 40 and 20 Ma: Earth-Science Reviews, v. 214, doi:10.1016/j.earscirev.2021.103508.

808

809

810

811

812

Porter, S. C., and An, Z. S., 1995, Correlation between Climate Events in the North-Atlantic and China during Last Glaciation: Nature, v. 375, no. 6529, p. 305-308, doi:10.1038/375305a0.

813

814

815

Pullen, A., Ibanez-Mejia, M., Gehrels, G. E., Giesler, D., and Pecha, M., 2018, Optimization of a Laser Ablation-Single Collector-Inductively Coupled Plasma-Mass Spectrometer (Thermo Element 2) for Accurate, Precise, and Efficient Zircon U-Th-Pb Geochronology: Geochemistry Geophysics Geosystems, v. 19, no. 10, p. 3689-3705, doi:10.1029/2018GC007889.

816

817

818

819

820

Qiang, X., An, Z., Song, Y., Chang, H., Sun, Y., Liu, W., Ao, H., Dong, J., Fu, C., Wu, F., Lu, F., Cai, Y., Zhou, W., Cao, J., Xu, X., and Ai, L., 2010, New eolian red clay

821
822

sequence on the western Chinese Loess Plateau linked to onset of Asian

823

desertification about 25 Ma ago: Science China Earth Sciences, v. 54, no. 1, p. 136-

824

144, doi:10.1007/s11430-010-4126-5.

825

Ren, X. P., Nie, J. S., Saylor, J. E., Wang, X. X., Liu, F. B., and Horton, B. K., 2020,

826

Temperature Control on Silicate Weathering Intensity and Evolution of the

827

Neogene East Asian Summer Monsoon: Geophysical Research Letters, v. 47, no.

828

15, doi:10.1029/2020GL088808.

829

Roberts, N. M. W., Rasbury, E. T., Parrish, R. R., Smith, C. J., Horstwood, M. S. A., and

830

Condon, D. J., 2017, A calcite reference material for LA-ICP-MS U-Pb

831

geochronology: Geochemistry, Geophysics, Geosystems, v. 18, no. 7, p. 2807-2814,

832

doi:10.1002/2016gc006784.

833

Roger, F., Arnaud, N., Gilder, S., Tapponnier, P., Jolivet, M., Brunel, M., Malavieille, J.,

834

Xu, Z., and Yang, J., 2003, Geochronological and geochemical constraints on

835

Mesozoic suturing in east central Tibet: Tectonics, v. 22, no. 4, p. n/a-n/a,

836

doi:10.1029/2002tc001466.

837

Rogl, F., 1999, Mediterranean and Paratethys. Facts and hypotheses of an Oligocene to

838

Miocene paleogeography (short overview): Geologica Carpathica, v. 50, no. 4, p.

839

339-349

840

Sarr, A. C., Donnadieu, Y., Bolton, C. T., Ladant, J. B., Licht, A., Fluteau, F., Laugie, M.,

841

Tardif, D., and Dupont-Nivet, G., 2022, Neogene South Asian monsoon rainfall

842

and wind histories diverged due to topographic effects: Nature Geoscience, v. 15,

843

no. 4, p. 314+, doi:10.1038/s41561-022-00919-0.
844

Sepulchre, P., Caubel, A., Ladant, J.-B., Bopp, L., Boucher, O., Braconnot, P., Brockmann,

845

P., Cozic, A., Donnadieu, Y., Dufresne, J.-L., Estella-Perez, V., Ethé, C., Fluteau,

846

F., Foujols, M.-A., Gastineau, G., Ghattas, J., Hauglustaine, D., Hourdin, F.,

847

Kageyama, M., Khodri, M., Marti, O., Meurdesoif, Y., Mignot, J., Sarr, A.-C.,

848

Servonnat, J., Swingedouw, D., Szopa, S., and Tardif, D., 2020, IPSL-CM5A2 – an

849

Earth system model designed for multi-millennial climate simulations:

850

Geoscientific Model Development, v. 13, no. 7, p. 3011-3053, doi:10.5194/gmd-

851

13-3011-2020.

852

Song, B. W., Spicer, R. A., Zhang, K. X., Ji, J. L., Farnsworth, A., Hughes, A. C., Yang,

853

Y. B., Han, F., Xu, Y. D., Spicer, T., Shen, T. Y., Lunt, D. J., and Shi, G. L., 2020,

854

Qaidam Basin leaf fossils show northeastern Tibet was high, wet and cool in the

855

early Oligocene: Earth and Planetary Science Letters, v. 537,

856

doi:10.1016/J.Epsl.2020.116175.

857

Spicer, R. A., Yang, J., Herman, A. B., Kodrul, T., Maslova, N., Spicer, T. E. V.,

858

Aleksandrova, G., and Jin, J. H., 2016, Asian Eocene monsoons as revealed by leaf

859

architectural signatures: Earth and Planetary Science Letters, v. 449, p. 61-68,

860

doi:10.1016/j.epsl.2016.05.036.

861

Su, Q. D., Nie, J. S., Meng, Q. Q., Heermance, R., Gong, L. S., Luo, Z., Wang, Z., Zhang,

862

R., and Garzione, C., 2019, Central Asian Drying at 3.3 Ma Linked to Tropical

863

Forcing?: Geophysical Research Letters, v. 46, no. 17-18, p. 10561-10567,

864

doi:10.1029/2019GL084648.

865

Sun, J. M., Liu, W. G., Liu, Z. H., Deng, T., Windley, B. F., and Fu, B. H., 2017, Extreme

866

aridification since the beginning of the Pliocene in the Tarim Basin, western China:
867 Palaeogeography Palaeoclimatology Palaeoecology, v. 485, p. 189-200,
868 doi:10.1016/j.palaeo.2017.06.012.

869 Sun, Y. B., Clemens, S. C., Morrill, C., Lin, X. P., Wang, X. L., and An, Z. S., 2012, Influence of Atlantic meridional overturning circulation on the East Asian winter monsoon: Nature Geoscience, v. 5, no. 1, p. 46-49, doi:10.1038/NGEO1326.

872 Sun, Z. C., Feng, X. J., Li, D. M., Yang, F., Qu, Y. H., and Wang, H. J., 1999, Cenozoic ostracoda and palaeoenvironments of the northeastern Tarim Basin, western China: Palaeogeography Palaeoclimatology Palaeoecology, v. 148, no. 1-3, p. 37-50

875 Tardif, D., Sarr, A. C., Fluteau, F., Licht, A., Kaya, M., Ladant, J. B., Meijer, N., Donnadieu, Y., Dupont-Nivet, G., Bolton, C. T., Le Hir, G., Pillot, Q., Poblete, F., Sepulchre, P., Toumoulin, A., and Banfield, W., 2023, The role of paleogeography in Asian monsoon evolution: a review and new insights from climate modelling: Earth-Science Reviews, v. 243, p. 104464, doi:10.1016/j.earscirev.2023.104464.

880 Tauxe, L., and Gallet, Y., 1991, A Jackknife for Magnetostratigraphy: Geophysical Research Letters, v. 18, no. 9, p. 1783-1786

882 Valcke, S., 2013, The OASIS3 coupler: a European climate modelling community software: Geoscientific Model Development, v. 6, no. 2, p. 373-388, doi:10.5194/gmd-6-373-2013.

885 Valero, L., Garces, M., Cabrera, L., Costa, E., and Saez, A., 2014, 20 Myr of eccentricity paced lacustrine cycles in the Cenozoic Ebro Basin: Earth and Planetary Science Letters, v. 408, p. 183-193, doi:10.1016/j.epsl.2014.10.007.
888 Vermeesch, P., 2018, IsoplotR: A free and open toolbox for geochronology: Geoscience
889 Frontiers, v. 9, no. 5, p. 1479-1493, doi:10.1016/j.gsf.2018.04.001.

890 Vermeesch, P., 2019, Statistics for fission-track thermochronology, in: Fission-track
891 thermochronology and its application to geology, M. Malusà and P. Fitzgerald Eds.,
892 Springer, Berlin. 393pp.:

893 Vermeesch, P., 2021, On the treatment of discordant detrital zircon U-Pb data:
894 Geochronology

895 Voigt, S., Weber, Y., Frisch, K., Bartenstein, A., Hellwig, A., Petschick, R., Bahr, A., Pross,
896 J., Koutsodendris, A., Voigt, T., Verestek, V., and Appel, E., 2017, Climatically
897 forced moisture supply, sediment flux and pedogenesis in Miocene mudflat
898 deposits of south-east Kazakhstan, Central Asia: Depositional Record, v. 3, no. 2,
899 p. 209-232, doi:10.1002/dep2.34.

900 Wang, S. W., Kim, W., Song, C. L., Park, E., Jo, H. W., Kim, J., and Lee, W. K., 2021a,
901 Relationships among water, food, energy, and ecosystems in the Mid-Latitude
902 Region in the context of sustainable development goals: Environmental Reviews,
903 doi:10.1139/er-2022-0041.

904 Wang, W., Zhang, P., Garzione, C. N., Liu, C., Zhang, Z., Pang, J., Wang, Y., Zheng, D.,
905 Zheng, W., and Zhang, H., 2021b, Pulsed rise and growth of the Tibetan Plateau to
906 its northern margin since ca. 30 Ma: Proceedings of the National Academy of
907 Sciences, v. 119, no. 8, p. e2120364119, doi:doi:10.1073/pnas.2120364119.
908 Wang, W., Zheng, W., Zhang, P., Li, Q., Kirby, E., Yuan, D., Zheng, D., Liu, C., Wang,
909 Z., Zhang, H., and Pang, J., 2017, Expansion of the Tibetan Plateau during the
910 Neogene: Nat Commun, v. 8, p. 15887, doi:10.1038/ncomms15887.

911 Wang, X., Carrapa, B., Sun, Y. C., Dettman, D. L., Chapman, J. B., Rugenstein, J. K. C.,
912 Clementz, M. T., Decelles, P. G., Wang, M., Chen, J., Quade, J., Wang, F., Li, Z.
913 J., Oimuhammadzoda, I., Gadoev, M., Lohmann, G., Zhang, X., and Chen, F. H.,
914 2020, The role of the westerlies and orography in Asian hydroclimate since the late
915 Oligocene: Geology, v. 48, no. 7, p. 728-732, doi:10.1130/G47400.1.

916 Wang, X., Nie, J., Stevens, T., Zhang, H., and Xiao, W., 2022c, Resolving conflicting
917 models of late Miocene East Asian summer monsoon intensity recorded in Red
918 Clay deposits on the Chinese Loess Plateau: Earth-Science Reviews, v. 234, p.
919 104200, doi:10.1016/j.earscirev.2022.104200.

920 Wang, Z. X., Huang, C. J., Licht, A., Zhang, R., and Kemp, D. B., 2019, Middle to Late
921 Miocene Eccentricity Forcing on Lake Expansion in NE Tibet: Geophysical
922 Research Letters, v. 46, no. 12, p. 6926-6935, doi:10.1029/2019GL082283.

923 Westerhold, T., Marwan, N., Drury, A. J., Liebrand, D., Agnini, C., Anagnostou, E., Barnet,
924 J. S. K., Bohaty, S. M., De Vleeschouwer, D., Florindo, F., Frederichs, T., Hodell,
925 D. A., Holbourn, A. E., Kroon, D., Lauretano, V., Littler, K., Lourens, L. J., Lyle,
926 M., Palike, H., Rohl, U., Tian, J., Wilkens, R. H., Wilson, P. A., and Zachos, J. C.,
927 2020, An astronomically dated record of Earth's climate and its predictability over
928 the last 66 million years: Science, v. 369, no. 6509, p. 1383+
929 Wiedenbeck, M., Alle, P., Corfu, F., Griffin, W. L., Meier, M., Oberli, F., Vonquadt, A.,
930 Roddick, J. C., and Speigel, W., 1995, 3 Natural Zircon Standards for U-Th-Pb,
931 Lu-Hf, Trace-Element and Ree Analyses: Geostandards Newsletter, v. 19, no. 1, p.
932 1-23, doi:DOI 10.1111/j.1751-908X.1995.tb00147.x.

933 Woodhead, J. D., Hellstrom, J., Hergt, J. M., Greig, A., and Maas, R., 2007, Isotopic and
934 elemental imaging of geological materials by laser ablation inductively coupled
935 plasma-mass spectrometry: Geostandards and Geoanalytical Research, v. 31, no. 4,
936 p. 331-343

937 XBGMR, 1993, XBGMR (Xinjiang Bureau of Geology and Mineral Resources) Regional
938 Geology of Xinjiang Uygur Autonomous Region Geological Publishing House,
939 Beijing (1993), pp. 1-841 (in Chinese with English abstract):

940 Yin, A., Dang, Y. Q., Zhang, M., Chen, X. H., and McRivette, M. W., 2008, Cenozoic
941 tectonic evolution of the Qaidam basin and its surrounding regions (Part 3):
942 Structural geology, sedimentation, and regional tectonic reconstruction: Geological
943 Society of America Bulletin, v. 120, no. 7-8, p. 847-876, doi:10.1130/B26232.1.

944 Zijderveld, J., 1967, A. C. demagnetization of rocks: Analysis of results: Method in
945 Palaeomagnetism

946
947 FIGURE CAPTIONS

948 Figure 1. Overview map of the study sites and the dominant atmospheric circulation
949 systems. Black dashed line depicts the modern Asian summer monsoon limit (Chen et al.,
950 2010). Q, Qaidam Basin; CLP, Chinese Loess Plateau; HTG, Huatugou; QA, Qin'an; ZL,
951 Zhuanglang. Revised from Nie et al. (2017).

952 Figure 2. Generalized tectonic and topographic maps of the study region. (A) Map of the
953 Qaidam Basin and location of the study site. (B) Geological map of the Eboliang I Anticline
954 showing the location of the QN magnetostratigraphic section. (C) Google Earth image of
955 the QN section region, the blue dash line indicates the sampling path.

956 Figure 3. Lithofacies description and stratigraphic columns for the QN section.
957 Photographs on the left show the QN section strata.

958 Figure 4. Radial plots and kernel density estimates of apatite low-temperature
959 thermochronology results from the QN section. Plot calculated using IsoplotR (Ludwig,
960 2003). The results for the minimum age model are marked in red. The ZZ1 sample at the
961 bottom (5 m) of the section exhibits a minimum apatite fission track (AFT) age component
962 at ~19.1 Ma. The ZZ6 sample shows the minimum apatite (U-Th)/He (AHe) age
963 component at ~21.4 Ma.

964 Figure 5. Photograph of secondary sparite (A), laser ablation area for U-Pb dating (B), and
965 its Tera-Wasserburg plot (C). The results show a lower intercept date at ~12.6 Ma.

966 Figure 6. Visual comparison of detrital zircon U-Pb ages from the bottom (ZZ1-5 m),
967 middle (ZZ6-753 m), and top (ZZ9-1154 m) of the QN section, and Altun Piedmont (ZZA).
968 Detrital zircon U-Pb age spectra are depicted as kernel density estimations and age
969 histograms.

970 Figure 7. Correlation of the QN magnetostratigraphy with the geomagnetic polarity
971 timescale. Sites of the apatite low-temperature thermochronology analysis are plotted on
972 the right side of the stratigraphic column for general age constraint. Observed polarity in
973 terms of normal (N) and reverse (R) magnetozones. ATF, apatite fission track; AHe, apatite
974 (U-Th)/He dating; GPTS, Geomagnetic polarity time scale; Dec, declination; Inc,
975 inclination; VGP, virtual geomagnetic polarity. RM and GM, red and green mudstone; RS
976 and GS, red and green sandstone; RCS and GCS, red and green medium-coarse sandstone;
977 RS/GS, Red and green sandstone interbeds; GCS/RCS, Red and green medium-coarse
978 sandstone interbeds.

979 Figure 8. Timeseries of insolation, Benthic δ¹⁸O stack, and QN section χfd/HIRM and their
980 power spectral plots. (A) 21 June insolation at 35° N (Laskar et al., 2004). (B) Benthic δ¹⁸O
981 stack (Westerhold et al., 2020). (C) χfd/HIRM records from the QN section. (D, E, F) Power
982 spectral plot of A, B, and C, respectively. The orange shading highlights the middle
983 Miocene Climatic Optimum. The numbers in boxes D, E, and F indicate peaks larger than
984 the 95% confidence level (units in kyr), with red numbers representing main Earth orbital
985 cycles.

986 Figure 9. Continuous wavelet transform of the χfd/HIRM record from the QN section. The
987 color scale indicates power, and which warm color indicates larger power. The shaded
988 areas illustrate the cone of influence, where edge effects become important. The 405-, 128-,
989 100-, 40-, 23-, and 19-ky periodicities are labeled and indicated by the black dashed lines.
Figure 10. Paleoenvironmental variations of QN section during the middle Miocene and comparison with other records. (A) Gypsum layer marker, the stratigraphic units are divided into 50 ka intervals and any unit containing a gypsum layer is colored black. (B) $\chi_{fd}$/HIRM records from the QN section. (C) $\chi_{lf}$ records from the Huatugou section. (D) $\chi_{lf}$ records from the Zhuanglang section. (E) $\chi_{lf}$ records from the Qin'an section. (B, C) are located in the Qaidam Basin and (D, E) are located in the Chinese Loess Plateau. (F) Benthic $\delta^{18}$O stack (Westerhold et al., 2020). (G) 21 June insolation at 35°N (Laskar et al., 2004). The dashed lines in B, C, D, E, F and G are their 405 kyr components.

Figure 11. Seasonal cycle of precipitation under the mid-Miocene geographical configuration. Precipitation are averaged over [80°E-100°E, 35-42°N] and [100°E-118°E, 25-42°N], corresponding to the two red rectangles on the geographical map, were used to reflect the precipitation dynamics of the northeastern Tibetan Plateau and the Chinese Loess Plateau, respectively. The Earth orbital parameters used for the simulation are shown in Table S7.

Figure 12. Seasonal vertically integrated moisture transport response to change in Earth's orbit eccentricity. The red rectangles represent the rough locations of the Northeastern Tibetan Plateau and East Asia. The Earth orbital parameters used for the simulation are shown in Table S7.
<figure><img src="image_3.png" /><figcaption>Figure 1</figcaption></figure>
<figure><img src="image_4.png" /><figcaption>Figure 2</figcaption></figure>
<table><caption>Figure 3</caption><thead><tr><td>Lithofacies code</td><td>Color</td><td>Description</td><td>Interpretation</td></tr></thead><tbody><tr><td>GM</td><td>greyish-green</td><td>Massive mudstone. very hard</td><td>semideep-deep lacustrine</td></tr><tr><td>RM</td><td>Red</td><td>Massive mudstone. very hard</td><td>Shallow lacustrine</td></tr><tr><td>RS</td><td>Red</td><td>Fine, well-sorted sandstone, massive</td><td>Deltaic front sheet sand deposits</td></tr><tr><td>GS</td><td>greyish-green</td><td>Fine, well-sorted sandstone, massive</td><td>Deltaic front sheet sand deposits</td></tr><tr><td>RCS</td><td>Red</td><td>Medium-coarse sandstone. Cross-beds. erosional basal contact</td><td>Fluviodeltaic channel deposits</td></tr><tr><td>GCS</td><td>greyish-green</td><td>Medium-coarse sandstone. Cross-beds. erosional basal contact</td><td>Fluviodeltaic channel deposits</td></tr><tr><td>Y</td><td>Light gray and white</td><td>Fibrous gypsum, layer parallel and 1-2cm beds</td><td>In situ gypsum forming in shallow</td></tr></tbody></table>

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<figure><img src="image_11.png" /><figcaption>Figure 4</figcaption></figure>

<figure><img src="image_12.png" /></figure>

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<figure><img src="image_17.png" /><figcaption>Figure 5</figcaption></figure>
<figure><img src="image_18.png" /><figcaption>Figure 6</figcaption></figure>
<figure><img src="image_19.png" /><figcaption>Figure 7</figcaption></figure>

◆ The minimum age component of apatite low-temperature thermochronology

◇ The lower intercept date of Carbonate U-Pb dating
<figure><img src="image_20.png" /><figcaption>Figure 8</figcaption></figure>
<figure><img src="image_21.png" /><figcaption>Figure 9</figcaption></figure>
<figure><img src="image_22.png" /><figcaption>Figure 10</figcaption></figure>
<figure><img src="image_23.png" /><figcaption>Figure 11</figcaption></figure>
<figure><img src="image_24.png" /><figcaption>Figure 12</figcaption></figure>