David Hilton, Ph.D.

scripps institution of oceanography

My interests in hydrogeology date back to my master's degree in London. In 1995, I had the opportunity of working in the Kalahari Desert in a collaborative project between the Vrije Universiteit (Amsterdam), the Dutch Government and the Geological Survey of Botswana. The Groundwater Resouce Evaluation Study (GRES - phase II) was concerned with estimating both long- and short-term trends in aquifer replenishment as a means of overall groundwater resource evaluation in the Kalahari. I worked closely with Edson Selaolo of the Geological Survey who analysed the helium isotope characteristics of Kalahari groundwaters as part of his Ph.D. thesis. The emphasis is on using helium as a geochronometer and testing its utility as a paleo-recharge monitor. New work is taking place with the Australian Geological Survey Organisation - utilising groundwater from Central Australia - and the USGS (West Mojave River Basin) to consider further the relationship(s) between the accumulation of radiogenic helium and other geochronometers such as C-14 and Cl-36.