Fluid flow in the Earth’s crust is driven by pressure gradients and temperature changes induced by internal heat and is associated with structural and geochemical processes in the basement and sedimentary basins. Groundwater, hydrothermal brines and gases circulating in the subsurface interact across different tectonic and geological settings. Under near-lithostatic conditions, fluids and rocks may be expelled at-surface, featuring a variety of geological phenomena ranging from hydrothermal systems to sedimentary and hybrid volcanism and cold seeps onshore and offshore. These vertical fluid flow expressions are characterised by complex geochemical reactions where life can adapt to thrive in extremely harsh environments, making them ideal windows to study the deep biosphere. Several works have demonstrated that CO2- and CH4-dominated vents played a key role in the evolution of our planet and the cycles of life during several geological eras. Similar structures on other planets are promising sites for exploration where habitable niches could have been present. Elevated pore pressures in deep reservoirs make piercements ideal natural laboratories to capture precursors of seismic events and dynamically triggered geological processes. Yet, the geochemical and geophysical processes associated with the evolution of these vertical fluid flow features and piercements remain poorly understood.
This session welcomes contributions from communities working on magmatic and sedimentary environments and interacting domains on Earth and in the Universe using geophysical, geochemical, biological, microbial, geological, remote sensing, numerical and laboratory studies to promote a better understanding of modern and paleo fluid-driven systems in the upper crust. We call for contributions from 1) investigations of tectonic discontinuities pre-existing geological structures; 2) the geochemical reactions occurring at depth and the surface, including micro- and biological studies; 3) geophysical imaging and monitoring of fluid flow systems; 4) experimental/numerical studies about fluid flow evolution; 5) studies of piercement dynamics related to climatic and environmental implications