Sediment chemistry and detrital zircon record in the Bosque and Paseo del Mar coastal areas from the southwestern Gulf of Mexico

The uplift of the Tibetan Plateau (TP) during the late Cenozoic is thought to be one of crucial factors controlling Asian climate. However, the complex interaction between tectonics and climate change is still unclear. Here we present the first record of clay mineralogy and elemental geochemistry covering ~12.7–4.8 Ma in a fluvial‐lacustrine sequence in the Xining Basin. Geochemical provenance proxies (Th/Sc, Zr/Sc, and Cr/Zr) in the <2‐μm fraction show a significant provenance change at ~8.8 Ma. Silicate‐based weathering indexes (CIA, CIW, and PIA) displayed coeval changes with provenance but discrepant changes with regional climate. Since the clay mineralogy exhibits significant change at ~7.8 Ma uncorrelated with modifications in provenance, it can be employed to reveal regional climate change. The rise in illite and associated decrease in the sum of smectite and illite/smectite mixed layers reflect gradual and slow aridification since ~12.7 Ma with intensified drying since ~7.8 Ma until approaching the modern climate status. Our results, together with other regional climatic and tectonic records, clearly illustrate that accelerated uplift of the northeastern TP since ~8–9 Ma has mainly modulated the regional erosion, weathering, transportation, and sedimentation and amplified the global cooling and drying trend toward the regional climate of modern conditions. Our study suggests that in the tectonically active northeastern TP, a comprehensive mineralogical and geochemical investigation of the fine‐grained fraction of the basin sediments could retrieve the interactions between tectonics and climate behind the complex change in exhumed lithology and sedimentary routing systems.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018GC007917

Late Miocene Intensified Tectonic Uplift and Climatic Aridification on the Northeastern Tibetan Plateau: Evidence From Clay Mineralogical and Geochemical Records in the Xining Basin

Geochemical characteristics and organic matter enrichment mechanism of black shale in the Upper Triassic Xujiahe Formation in the Sichuan basin: Implications for paleoweathering, provenance and tectonic setting

Sustainable ex-situ remediation of contaminated sediment: A review.

Pleistocene drainage basin integration led to progressive excavation of Tertiary-Quaternary sedimentary basins along the Yellow River in the northeastern Tibetan Plateau. Cosmogenic burial dating of ancestral river deposits and basin fi ll from two key watershed divides confi rms a fl uvial connection between basins at 0.5-1.2 Ma, prior to excavation by the Yellow River. Pres- ervation of the relict depositional surface that represents the maximum height of basin fi ll allows reconstruction of the volume of eroded material across a broad region. We quantify the iso- static response to this erosional unloading using a two-dimensional fl exural model. Calculated maximum vertical displacements for different effective elastic thicknesses vary from ~160 m to ~260 m near the Pleistocene spillway from the Qinghai paleo-lake. We suggest that the isostatic response to fl excavation along the Yellow River defeated local tributaries, isolated Lake Qinghai, and led to the development of an internally drained basin in the past 0.5-1.2 m.y.

Pleistocene drainage reorganization driven by the isostatic response to deep incision into the northeastern Tibetan Plateau

Mineralogy and geochemistry of modern Yellow River sediments: Implications for weathering and provenance

Terrace formation and river valley development along the lower Taohe River in central China

The pore evolution characteristics of organic-rich shale under semiclosed and open-system conditions were investigated through a pyrolysis simulation experiment conducted on marine low-maturity shale. The results show that the experimental samples of the two systems mainly developed organic pores, clay mineral intergranular pores, and brittle mineral dissolution pores during the evolution process. The shale porosity showed a non-linear growth trend with the thermal maturity increase. However, the porosity increase rate of the semiclosed system was higher than that of the open system. The pore structure characterization parameters of the experimental samples under the two systems were quite different. The samples of the semiclosed system developed wedge- or V-shaped pores with a diameter of several tens of nanometers, while those of the open system developed more small throats with a diameter of several nanometers to ink bottle-type and closed pores of tens of nanometers. For the marine organic-rich shale, the organic matter (OM) evolution was mainly affected by the formation pressure. In summary, a semiclosed system with a higher formation pressure is more conducive to the development of organic pores and the pore structure than an open system with a lower formation pressure. The best stage of pore evolution and development is the overmature stage.

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Xin Zhao

Papers

Mineralogy and geochemistry of modern Yellow River sediments: Implications for weathering and provenance

Terrace formation and river valley development along the lower Taohe River in central China

Pore Evolution Characteristics of Marine Organic-Rich Shale Based on a Pyrolysis Simulation Experiment