and situ and situ heterogeneity is common within each formation. Moreover, samples at various stages of maturation are rarely available. We apply the three-plug measuring technique for a vertical transversely isotropic (VTI) medium to investigate the ultrasonic wave velocity and permeability anisotropies of organic-rich chalks (ORC) within the tested sequence. We propose that in ORC diagenesis, the characteristics and distribution of the organic matter in the rock matrix change significantly throughout burial and thermal maturation, strongly affecting the velocities. Measuring the velocity hysteresis under varying confining pressures revealed that development of soft porosity with preferred orientation plays a crucial role in the early maturation stage (TMAX of 428 - 434°C), particularly under low effective stresses, while it is absent in the immature stage (TMAX of 403 - 415°C). The sensitivity of the wave velocities at low effective stresses results in variations in velocity anisotropy, which may potentially be utilized in seismic exploration to delineate the highly- pressured 'sweet spots' in unconventional organic -rich carbonates.

Gorman, B.L., Kraft, M.L., 2020. High-resolution secondary ion mass spectrometry analysis of cell membranes. Analytical Chemistry 92, 1645-1652.

https://doi.org/10.1021/acs.analchem.9b04492 This Feature describes the use a Cameca NanoSIMS instrument for directly imaging specific lipid and protein species in the plasma membranes of mammalian cells with approximately 100 nm-lateral resolution and discusses how these analyses have already begun to transform fundamental concepts in the field of membrane biology. Secondary ion generation is discussed with emphasis on the constraints that affect the detection and identification of membrane components, and then the sample preparation methodologies and data analysis strategies that address these constraints are described.

Grandy, J.J., Onat, B., Tunnicliffe, V., Butterfield, D.A., Pawliszyn, J., 2020. Unique solid phase microextraction sampler reveals distinctive biogeochemical profiles among various deep-sea hydrothermal vents. Scientific Reports 10, 1360.

https://doi.org/10.1038/s41598-020-58418-4 Current methods for biochemical and biogeochemical analysis of the deep-sea hydrothermal vent ecosystems in situ rely on water sample recovery, or analysis using underwater instruments with limited range of analyte detection and limited sensitivity. Even in cases where large quantities of sample are recovered, labile dissolved organic compounds may not be detected due to time delays between sampling and preservation. Here, we in situ present a novel approach for extraction of organic compounds from hydrothermal vent fluids through a unique solid phase microextraction (SPME) sampler. These samplers were deployed to sample effluent of vents on sulphide chimneys, located on Axial Seamount in the North-East Pacific, in the Urashima field on the southern Mariana back-arc, and at the Hafa Adai site in the central Mariana back-arc. Among the compounds that were extracted, a wide range of unique organic compounds, including labile dissolved organic sulfur compounds, were detected through high-resolution LC-MS/MS, among which were biomarkers of anammox bacteria, fungi, and lower animals. This report is the first to show that SPME can contribute to a broader understanding of deep sea ecology and biogeochemical cycles in hydrothermal vent ecosystems.

Grazhdankin, D.V., Marusin, V.V., Izokh, O.P., Karlova, G.A., Kochnev, B.B., Markov, G.E., Nagovitsin, K.E., Sarsembaev, Z., Peek, S., Cui, H., Kaufman, A.J., 2020. Quo vadis, Tommotian? Geological Magazine 157, 22- 34.

https://doi.org/10.1017/S0016756819001286 The concept of the Tommotian Regional Stage of the Siberian Platform has been closely linked to the idea of the 'Cambrian Explosion' of animals and protists when the entire Earth system shifted rapidly into Phanerozoic mode. We conducted a multidisciplinar y study of an informal 'synstratotype' of the lower Tommotian boundary