Paleohydrology & The Role of Groundwater in Geologic Processes

On geologic time scales (105 to 106 years), groundwater flow systems have responded dramatically to changes in the Earth’s climatic regimes. During periods of Pleistocene glaciations, sea level was up to 120 m lower than today. Most of the past 2.5 million years have been dominated by these “ice house” conditions. During sea level low standsvast quantities of freshwater were sequestered in permeable sand layers in continental shelf environments. NM Tech hydrologists were among the first to quantify the volume of fresh groundwater (~ 105 km3) sequestered on continental shelf environments around the world (Cohen et al. 2009; Post et al. 2013). To put this number in perspective, the total amount of water pumped from the Ogallala aquifer in the western USA is less than 300 km3. In 2017, New Mexico Tech hydrologists (Denis Cohen and Mark Person) began collaborating with Dr. Aaron Metcalf, a marine geologists from the University of Malta, on a European Union funded project to understand the distribution of freshwater and erosional processes on the Mediterranean continental shelf and offshore New Zealand (

On longer time scales (107 to 108 years), groundwater flow systems have had a profound effect on the formation of energy and mineral deposits (Person and Garven, 1992; Person et al. 2012). In 2017, Professor Mark Person, in collaboration with hydrologists, economic geologists, structural geologists, geochemists from the University of Arizona received a $1M grant from the Keck Foundation to study the role of paleofluid flow in the formation of Copper and Uranium deposits within the Paradox Basin, Utah. Our team plans to test the hypothesis that Geofluids (reduced groundwater, petroleum & supercritical CO2) migrated up along faults adjacent to Paradox formation salt domes before flowing laterally through younger sandstone units, bleaching the redbeds white and depositing world class Uranium and copper deposits.

Mark Person points out paleo fluid flow pathways of reduced groundwater and petroleum that bleached coarse redbed sandstone units white millions of years ago.