Petrophysical properties of hydrothermally-altered pyroclastic deposits from Deception Island (Bransfield Strait, Antarctica)

作者：Michael J. Heap, Adelina Geyer, Jasmine Dibben, James Hickey, Guillem Gisbert, Oriol Vilanova‐Pagès, Jordi Ibáñez, Antonio Polo Sánchez, Santiago Giralt, Maëlys Moulin, Antonio M. Álvarez‐Valero · 发表于：Journal of Volcanology and Geothermal Research · 年份：2025 · DOI：10.1016/j.jvolgeores.2025.108399 · 被引用次数：8 · 研究领域：Methane Hydrates and Related Phenomena、Hydrocarbon exploration and reservoir analysis、Geological formations and processes

Deception Island is a composite volcano located in the Bransfield Strait, between the South Shetland Islands and the Antarctic Peninsula. The volcano is defined by a caldera-forming event, and the rocks forming the island—which range in composition from basalts to trachydacites-rhyolites—are typically classified as either pre-, syn -, or post-caldera. Here, we provide petrophysical properties (bulk density, porosity, P-wave velocity, permeability, thermal properties, Young's modulus, and uniaxial compressive strength) for representative lapilli tuffs (pyroclastic density current and fall deposits) from the pre-, syn -, and post-caldera volcanic activity. We find that dry bulk density varies from ~982 to ~1813 kg·m −3 , connected porosity varies from 0.30 to 0.62, P-wave velocity varies from ~0.3 to ~1 km·s −1 , permeability varies from ~10 −15 to ~10 −11 m 2 , thermal conductivity varies from ~0.3 to ~0.65 W·m −1 ·K −1 , thermal diffusivity varies from ~0.35 to ~0.25 mm 2 ·s −1 , specific heat capacity varies from ~0.8 to ~1.3 J·kg −1 ·K −1 , Young's modulus varies from ~1 to ~9 GPa, and that uniaxial compressive strength varies from ~1 to ~25 MPa. Our data show that P-wave velocity, Young's modulus, uniaxial compressive strength, thermal conductivity, and thermal diffusivity decrease, permeability increases, and specific heat capacity does not change systematically as a function of increasing porosity. We also find that the fall tuffs are more porous than the pyroclastic den...