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Hydroclimate is an important factor controlling landscape evolution. But establishing the impact of hydroclimate is complicated by the influences of other processes and is especially hard to prove for those in deep time from geological record. During the late Permian, voluminous basaltic sediments were derived from the erosion of the Emeishan large igneous province in western South China. They provide a unique record critical in understanding the responses of tropical basaltic erosion to hydroclimate change without impacts of orogenic uplift, lithologic variation, vegetational difference and glacial‐interglacial change. Sampled successions define a negative carbon isotope excursion capable of making regional and global stratigraphic correlations in the middle Wuchiapingian interval corresponding to the final phase of the late Paleozoic ice age. This interval is associated with a petrofacies shift and a decreasing source weathering intensity, a downward shift of erosion loci, and a reduced coastal water paleosalinity. Applying present‐day temperature dependence pattern of basaltic weathering and using land surface temperatures approximated from nearby paleo‐seawaters, denudation rates were calculated for the Emeishan basaltic province and shows an increase from ∼71 to ∼107 m/Ma. This erosional acceleration is temporally correlated with a decrease in paleosalinity and likely linked to enhanced freshwater discharge in the middle Wuchiapingian. Scaling and landscape erosion modeling suggest ∼80%–130% increase in catchment precipitation could have driven this acceleration in denudation. Our work provides a positive test for the hydroclimate forcing on landscape erosion in deep time and underlines the mechanistic linkage of sediments with erosion and climate change. Plain Language Summary: Sedimentary records provide a unique way to track source weathering and erosion in the deep geological past. During the late Permian to early Triassic voluminous basaltic sediments were eroded from the Emeishan large igneous province, which was emplaced at ca. 260 Ma in southwestern China, into the adjacent basins. These late Permian sedimentary records are studied to understand the denudation of this tropical basalt province in the final period of the late Paleozoic ice age (LPIA). Our data reveal a negative organic carbon isotope excursion, decreasing weathering intensity and deepening erosional loci in the Emeishan basaltic province, and a reduced salinity due to greater rainfall in the middle Wuchiapingian interval. Denudation rate was estimated for the Emeishan province and a correlation of high denudation rates with lowered paleosalinity was documented in the Wuchiapingian. The accelerated denudation in the Emeishan basaltic province was ascribed to ∼80%–130% increase in catchment precipitation during the final phase of the late Paleozoic ice age. This work highlights the importance of sedimentary records to understand the deep time landscape evolution. Key Points: A negative carbon isotope excursion enables middle Wuchiapingian stratigraphic correlations from South China to GondwanaA decrease in weathering intensity and a deepening of erosional exhumation are indicated for the Emeishan basaltic provinceDenudation was accelerated due to ∼80%–130% increase in precipitation during the late Permian in SW China [ABSTRACT FROM AUTHOR]

Weathering of basalt in tropical environments is sensitive to climate change and considered to play a significant role in regulating climate evolution. Though extensively studied on the modern Earth and hypothesized for the geological past, basalt weathering is difficult to directly track in geological archives. We here focus on the basaltic sediments derived from the Emeishan large igneous province (LIP) in South China and determined their organic carbon content and isotope, mineral and geochemical compositions. Based on the newly obtained high-precision zircon U-Pb age of 251.79 ± 0.12/0.13/0.36 Ma, we establish temporal variations of weathering intensity for the Emeishan LIP basaltic landscapes in the tropical latitudes through the Permo-Triassic rapid climate warming periods. Analysis of weathering trends indicates a significant decrease in weathering intensity across the Permo-Triassic transition. This decrease in intensity is anomalous considering its coincidence with the climate warming at the Permo-Triassic transition, which tends to elevate chemical weathering rate of basalts and produce sediments with high chemical weathering intensity. Combining these weathering trends with present-day basalt weathering-temperature relationship and reported paleo-temperatures, total erosion rate is quantitatively estimated to increase from 282 ± 43 t/km2/yr in the latest Permian to > 1618 ± 187 t/km2/yr in the Early Triassic. This massive erosion in the Early Triassic is plausibly related to amplified extreme precipitation associated with intensification of the hydrological cycle in the Early Triassic hothouse climate. This study underlines the weathering responses of tropical landscapes to rapid climate warming. • One lowest Triassic claystone layer from South China is dated by CA-TIMS method. • Permo-Triassic weathering trends are reconstructed for the Emeishan basaltic province. • Permo-Triassic denudation rate is quantitatively estimated for the Emeishan basaltic province. • Early Triassic accelerated denudation is related to the intensified hydrological cycle. [ABSTRACT FROM AUTHOR]

• Three tuffaceous layers from North China are dated by CA-TIMS method. • Permo-Carboniferous weathering trends are reconstructed for the southern North China. • A rapid climate warming is documented at the Permo-Carboniferous transition. • The climate fluctuation is causally linked to the Skagerrak-Centered large igneous province. Tracking climate change and its relationships with chemical weathering and massive volcanic activity in deep-time greatly improves our understanding of the Earth's climate system. The Permo-Carboniferous period is a critical time interval with million year-scale glacial-deglacial cycles and massive basaltic volcanism, such as the Skagerrak-Centered (also named Skagerrak or Jutland) large igneous province. To explore the volcanism-climate interactions in this period, we obtained high precision CA-TIMS U-Pb zircon ages for three tuffaceous layers from a cored upper Pennsylvanian-lower Permian marginal marine succession in southern North China. These ages calibrate the Permo-Carboniferous biostratigraphy between ∼301–296 Ma in North China. From this dated core succession, mudrock samples and their calculated weathering index values were screened to constrain the weathering trends for the source landscapes and demonstrate a rapid increase with a subsequent decrease in source chemical weathering intensity during the period of ∼299 to 296.5 Ma. These trends coincide with the southern Gondwana glacial records, low latitude temperature changes, relative sea-level variations, and shifts in atmospheric p CO 2 that together document an earliest Permian climate warming-cooling perturbation with a temperature maximum at ∼298 Ma. This climate warming in the Permo-Carboniferous icehouse correlates with the emplacement of the Skagerrak-Centered large igneous province, which likely released voluminous CO 2 that led to climate warming during the Permo-Carboniferous transition. The immediately following cooling could possibly result from the rapid post-eruptional weathering of the massive basaltic rocks of this province in tropical latitudes, which would have sequestered atmospheric CO 2 and promoted return to cooler icehouse conditions. This study supports the assertation that massive basaltic volcanism could first cause rapid climate warming and then may have an overall net cooling effect as previously suggested for the Deccan Traps and the Central Atlantic Magmatic Province. [ABSTRACT FROM AUTHOR]

• Document evolving chemical weathering indices in Cryogenian and Ediacaran successions of the Nanhua Basin, South China. • Covariant change of chemical weathering trends in South China and Oman reflects several contemporaneous climate cooling events. • Mean Annual Temperature (MAT) differences reach ~20 ℃ between the Marinoan cryochron and nonglacial interlude at around 30° latitude, and ~12 ℃ between Gaskiers cryochron and nonglacial interlude close to the equator. Three major late Neoproterozoic global cryochrons mark the coldest climate state in Earth history, with glaciers covering most, if not all, continents. However, the terrestrial paleosurface temperature differential between cryochron and nonglacial interlude is unknown. Time-equivalent Cryogenian and Ediacaran sedimentary successions from South China and Oman show multiple negative excursions of the corrected values of their chemical index of alteration (CIA corr). These excursions reflect climate cooling and correlate with the Sturtian, Marinoan and Gaskiers cryochrons. Based on the τ Na -MAT transfer function (sodium chemical depletion index-mean annual temperature), we estimate the temperature differential between Cryogenian cryochron and nonglacial interlude reached 20 ± 5.4 ℃ at around 30° paleolatitude, and 12 ± 5.4 ℃ temperature difference between the Ediacaran cryochron and nonglacial interlude near the equator. The fluctuation of CIA corr and MAT trends within individual cryochrons likely indicate cold-warm climate cycling during the Cryogenian cryochron. [ABSTRACT FROM AUTHOR]

Abstract The late Paleozoic Era was an interval of major tectonic and climatic changes, including formation of the supercontinent Pangea and the ~60-Myr-long Late Paleozoic Ice Age (LPIA). Although bauxite formation declined globally from the Carboniferous to the Permian in conjunction with global cooling, it was an interval of widespread bauxite formation in China. In South China, (1) the Jiujialu Formation bauxite deposits in central and northern Guizhou (Zunyi area) are of early-middle Visean age; (2) the Dazhuyaun Formation bauxite deposits in northern Guizhou (Wuchuan–Zheng'an–Daozheng area) to southern Chongqing (Nanchuan area) and southeastern Guizhou (Fuquan–Kaili area) are of Late Pennsylvanian–Early Permian age; and (3) the Heshan Formation bauxite deposits in western Guangxi to Yunnan are of Middle–Late Permian age. In North China, the Benxi Formation bauxite deposits are of Late Mississippian–Middle Pennsylvanian age. The contrasting trends in bauxite metallogenesis between China and the rest of the world imply different climatic patterns in the eastern Tethys (high annual humidity with seasonal dryness) and Pangea (aridification). This hypothesis is further supported by differences in the chemical index of alteration, or CIA (>80 in the eastern Tethys vs. ~50 in western Pangea), and in paleotemperatures (mean annual temperature, or MAT = ~20 °C in the eastern Tethys vs. ~4 °C in western Pangea) determined from Permo-Carboniferous siliciclastic deposits. Permo-Carboniferous bauxite deposits in South China formed in coastal plain and coastal karstic depression environments, in which the position of the groundwater table was related to sea-level changes. During the late Paleozoic, high-frequency eustatic fluctuations caused by waxing and waning of Gondwana icesheets controlled sedimentation in these coastal depositional systems, leading to cyclic accumulation of coal and bauxite deposits and cycles of vadose- and phreatic-type bauxite formation. The results of the present study show that, during interglacial stages, lateritization resulted from high p CO 2 , high sea-level and groundwater-table elevations, low precipitation, and limited vegetation cover, whereas during glacial stages, bauxitization of these ferralitic weathering products was promoted by low p CO 2 , low sea-level and groundwater-table elevations, high precipitation, and more extensive vegetation cover. Thus, a unique combination of geographic, climatic, and eustatic factors accounted for widespread formation of bauxite in South China during the LPIA. [ABSTRACT FROM AUTHOR]