How Time-Resolved Synchrotron-Based X-Ray Tomography Can Help Geologists to Keep Things Moving
Abstract: Our expanding economies demand an ever-growing supply of mineral ores, hydrocarbons, and energy. Ore formation, hydrocarbon extraction, geothermal energy harvesting, and safe storage of CO2, chemical, and nuclear wastes are essential applications that revolve around the interaction of fluids with the rocks that host them. Geologists have worked to advance our understanding of fluid-rock interaction for decades, with obvious success. However, most of our knowledge builds on experiments that preclude the direct observation of the processes at action and that derived data from indirect measurements or post-mortem analyses. This is a severe shortcoming, as most of the processes that control fluid-rock interaction happen on the grain scale, are subject to hydraulic-chemical-mechanical coupling, and are therefore often highly nonlinear in space and time.
Time-resolved X-ray microtomography enables us to look into experimental vessels and document fluid-rock interaction in four-dimensional datasets. Using X-ray transparent environments that allow reproducing crustal conditions, we can image mineral reactions, rock deformation, and fluid migration and quantify their rates and scales directly from image data. For the first time, we can now identify and quantify the microscale feedback between these processes that likely govern the macroscale behavior of rocks.
Ultimately, these novel insights will enable us to better evaluate and even control fluid-rock interaction in the above applications.
However, our ability to bring about a step change in experimental geosciences relies critically on support from imaging beam lines. After an introduction that gives a brief overview of currently available X-ray transparent experimental environments, I will talk about the needs of geoscientists in terms of access to beam lines, long-term experiments, image resolution and sample size, fast and ultrafast data acquisition, intelligent data management, and computing support.