DOI: 10.5281/zenodo.6426690
title: Petrophysical data for 29 samples from the Chicxulub impact crater.

description: Note: ɸ-porosity, ρ<sub>b</sub>-bulk density, ρ<sub>g</sub>-grain density, k-permeability, F-formation factor, m-cementation exponent, τ<sup>2</sup>-tortuosity, C<sub>s</sub>-surface conductivity, Vp-acoustic velocity of compressional waves. Uncertainty for porosity, density, permeability, velocity and conductivity is 5%. Uncertainty for formation factor, cementation exponent and tortuosity is 8%). Lith <sup>1 </sup>and Unit <sup>1</sup> after Morgan et al. (2017), Unit <sup>2</sup> after de Graaf et al. (2021, UIM-upper impact melt rock unit, LIMB-lower impact melt rock-bearing unit)) and Kaskes et al. (2021). Morgan, J. V., Gulick, S. P. S., Bralower, T. J., Chenot, E., Christeson, G. L., Claeys, P., et al. (2016). The formation of peak rings in large impact craters. Science, 354(6314), 878–882. https://doi.org/10.1126/science.aah6561 de Graaff, S. J., Kaskes, P., Déhais, T., Goderis, S., Vinciane, D., Ross, C. H., et al. (2021). New insights into the formation and emplacement of impact melt rocks within the Chicxulub impact structure, following the 2016 IODP-ICDP Expedition 364. Geological Society of America Bulletin. https://doi.org/doi: https://doi.org/10.1130/B35795.1 Kaskes, P., de Graaff, S. J., Feignon, J. G., Déhais, T., Goderis, S., Ferrière, L., et al. (2021). Formation of the crater suevite sequence from the Chicxulub peak ring: A petrographic, geochemical, and sedimentological characterization. Geological Society of America Bulletin. https://doi.org/https://doi.org/10.1130/B36020.1
description: This table synthetizes data relevant to the petrophysics of the lithologies recovered from Chicxulub impact crater peak ring. Cores were extracted in 2016 during IODP-ICDP Expedition 364 Chicxulub K-Pg Impact Crater (Hole M0077A), and the 29 samples presented in the table were analysed in 2017-2018 at the University of Montpellier. The samples are re-used shipboard discrete P-wave samples, they were selected to be representative of the diversity of lithologies encountered in Hole M0077A, dominated by shocked granites (19 samples) capped and cut by suevites (6 samples), impact melts (3 samples) and cataclasites (1 sample). Petrophysical measurements were made in order to bring new insight on the core and its heterogeneity, with implications for large scale processes such as hydrothermal systems. Porosity (ɸ in percent) and density (⍴b, ⍴g, bulk and grain density in g/cm3) were calculated using the triple weight method. The permeability k (in milliDarcies, where 1 mD = 10-15 m2) was measured on dry samples using steady state conditions at an effective pressure of 10 and 40 MPa. Formation factor (F, unitless) and surface conductivity (Cs in mS/m) were determined using Waxman and Smits (1968) equation after saturating the samples with fluids of known conductivities. The cementation exponent (m, unitless) and tortuosity (τ2, unitless) were calculated knowing the formation factor and the porosity (Archie, 1942; Walsh and Brace, 1984). Acoustic velocities (Vp, in km/s) were measured on dry and saturated samples at a 500 kHz ultrasonic frequency using coupled piezoelectric, a pulse generator and an oscilloscope. References: Archie, G. E. (1942). The Electrical Resistivity Log as an Aid in Determining Some Reservoir Characteristics. Transactions of the AIME, 146(01), 54–62. https://doi.org/10.2118/942054-G Walsh, J. B., & Brace, W. F. (1984). The effect of pressure on porosity and the transport properties of rock. Journal of Geophysical Research, 89(B11), 9425. https://doi.org/10.1029/JB089iB11p09425 Waxman, M. H., & Smits, L. J. M. (1968). Electrical Conductivities in Oil-Bearing Shaly Sands. Society of Petroleum Engineers Journal, 8(02), 107–122. https://doi.org/10.2118/1863-A