Undergraduate student Eric Parker has been working with Dr. Aida Farough on a research project titled “Core-scale Anisotropic Analysis of Density and Porosity in a Submarine Volcano: Insights into Fluid Circulation in the Active Hydrothermal System at Brothers Volcano”.
Brothers Volcano is an arc volcano that was created by the subduction of the Pacific plate under the Australian plate. It is located 340 kilometers northeast of New Zealand and is the most hydrothermally active volcano on the Kermadec Arc. The cores used in this study were extracted during the 2 month long International Ocean Drilling Program Expedition 376 in 2018, in which Dr. Farough participated as a member of the petrophysics team. The purpose of Eric’s study is to measure the porosity of 65 mini cores drilled in both X and Z directions in order to calculate the distribution of pore spaces.
Porosity ranges from 12.5-44% and density ranges from 1.4-2.5 g/cm3 for the samples. The fresh dacite sample identified as a part of a young volcanic layer has a reference density of 1.6 g/cm3. The peaks of density are associated with hydrothermal alteration, defined by higher concentrations of dense minerals such as pyrophyllite, quartz and illite. Core density and porosity are a valuable addition to petrological analysis and downhole logging data and can be utilized in stratigraphic analysis. Density and porosity measurements combined with permeability, alongside alteration overprinting igneous stratigraphy, provides unique insight into mechanisms, pathways, and extent of fluid circulation and fluid-rock interactions at core-scale in the hydrothermal system at Brothers Volcano. Eric Presented his results in a poster at the AGU fall meeting in San Francisco, CA. Here’s the link to his abstract: https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/512307