http://www.sciencedirect.com/science/article/pii/S0264817219306555 Subaqueous volcanic-hydrothermal field is a complex hybrid geological system, where sediments originated from volcanic, hydrothermal, lacustrine, terrestrial, and biotic sources are mixed. Recent petrological studies on such sediments have indicated a potential relationship between volcanic-hydrothermal activities and oil generation and accumulation. Here, we explore the mechanisms of sedimentation and oil accumulation in well- laminated organic-rich fine-grained sedimentary rocks in Permian Lucaogou Formation deposited in the lacustrine Santanghu rift basin, NWChina. We conducted petrographic, carbon and oxygen isotopic, and organic geochemical analyses of fifty-four core samples from three wells (forty-eight samples from Well W1, two from W2, four from W3) designed for tight oil exploration. Four main observations and interpretations are: 1) The fine-grained sediments are a mixture of volcanic-hydrothermal detrital feldspar grains, authigenic quartz crystals, and primary lacustrine dolomite, forming interbedded tuffaceous shale and dolostone; 2) authigenic quartz crystals were precipitated from acidic hydrothermal fluids, whereas fine-grained angular alkaline feldspars were derived from subaqueous volcanic eruption; 3) the TOC content and oil generation potential increase with increased mixing of feldspars and carbonate minerals. Hence, the dolomite-bearing tuffaceous shale and tuffaceous dolostone are the best source rocks; and 4) the fine-grained sedimentary rocks are interpreted as a subaqueous volcanic-hydrothermal deposit that controls the source potential. The sedimentary processes of an ancient sediment-hosted geothermal system and its implications on hydrocarbon source rocks and accumulation were first identified. Algal bloom induced by subaqueous eruptions is the main cause for episodic deposition of organic matter and extreme heterogeneity in both lithofacies and source-rock distribution. The results suggest that cone-shaped buildups on seismic sections, which were formed by volcanic- hydrothermal deposits and contain highly-mixed feldspar and carbonate sediments, are the best hydrocarbon reservoirs, and demonstrate a strong relationship between volcanic-hydrothermal activities and hydrocarbon accumulation in an extensional tectonic setting.

Jin, Y., Kida, M., Yoneda, J., Konno, Y., Oshima, M., Tenma, N., Nagao, J., 2020. Natural gas hydrates recovered from the Umitaka Spur in the Joetsu Basin, Japan: Coexistence of two structure-I hydrates with distinctly different textures and gas compositions within a massive structure. ACS Earth and Space Chemistry 4, 77-85.

https://doi.org/10.1021/acsearthspacechem.9b00249 This study evaluated natural gas hydrates recovered from three different wells (J13R, J07RB, and J23R) at the Umitaka Spur in the Joetsu Basin, via Raman spectroscopy. The hydrates in two of the samples (J13R-13P and J07RB-5P) were of the particle displacement type, whereas sample J23R-3P displayed hydrates of the massive type. The hydrate crystals in all three samples contained a structure-I (sI) hydrate that primarily captures methane (CH ) molecules with ethane (C H ), carbon dioxide (CO ), and/or hydrogen sulfide (H S), which were 4 2 6 2 2 observable using powder X-ray diffraction and Raman spectroscopy techniques. In the massive type J23R-3P sample, two hydrate crystals with different textures were found to coexist, with one displaying an icy appearance and the other a columnar shape. Interestingly, the icy J23R-3P crystals were sI hydrates containing mostly CH with C H , CO , and H S, whereas the columnar J23R-3P crystals were sI CH hydrates containing 4 2 6 2 2 4 few other guest molecules. The coexistence of two different hydrates was not observed in the nodule type sediment (J13R-13P and J07RB-5P). Isotopic results suggested that the CH molecules in the icy and columnar 4 J23R-3P crystals originated from different CH sources. Different sI crystals coexisting in the same sample 4 would be because of high CH flux, a known feature in the Umitaka Spur. 4

Jin, Z., Wang, L., Zuidema, E., Mondal, K., Zhang, M., Zhang, J., Wang, C., Meng, X., Yang, H., Mesters, C., Xiao, F.-S., 2020. Hydrophobic zeolite modification for in situ peroxide formation in methane oxidation to methanol. Science 367, 193-197.

http://science.sciencemag.org/content/367/6474/193.abstract Abstract: Selective partial oxidation of methane to methanol suffers from low efficiency. Here, we report a heterogeneous catalyst system for enhanced methanol productivity in methane oxidation by in situ generated hydrogen peroxide at mild temperature (70°C). The catalyst was synthesized by fixation of AuPd alloy nanoparticles within aluminosilicate zeolite crystals, followed by modification of the external surface of the