October 11, 2021
6:00 - 7:30 pm
Note: ETGS members will receive an email with info for logging into the meeting.
The Chalk and Jurassic Carbonates of England: Karst or Not? Presentation
Gareth Davies, TDEC & Stephen Worthington, Worthington Groundwater, Ontario
These rocks form the largest aquifers in South Central and Southern England and supply a major proportion of the water of the City of London and many other municipalities. There are also many springs, with some large ones. We went on two field trips (1996, 2004) and visited sinking streams, sinkholes, and springs. We visited abstraction wells that form the main method for obtaining groundwater in a beautiful landscape dotted with many Victorian-era pumping stations. In a conference (1996) we were educated on the fact that the British Geological Survey separate hydrogeology and geomorphology and none of this hydrogeology was considered to be karst (...esentially no caves...). In contrast, many academic institutions study karst and have done conventional types of "karst" work in it, studying the geomorphology and others studying springs and using injected tracing between sinks, boreholes and springs. Karst and large caves occur in the Carboniferous rocks of South Wales, Central and Northern England and remote parts Scotland and much of Ireland. However, these areas use surface water reservoirs for supply, so there are almost no wells, so few springs have been studied except by karst practitioners. However, through the decades many academics investigating karst have also studied the Jurassic and Chalk, and their results pose the question in the title. As usual, this raises issues of what type of aquifer it is and how it really behaves, which have repercussions on protecting water resources. However, recent work shows that things are changing for the better.
Gareth grew up in South Wales in a coal-mining community, next to a major karst area, and thus was interested in caves from the age of 15. He spent many years traveling in Asia, Europe, North America and Mexico exploring caves before marrying and moving to the US. He was awarded a BS degree from Millsaps College and an MS degree from the University of Southern Mississippi. His thesis dated speleothems from Tennessee cave using the uranium-thorium method. He moved to Oak Ridge and spent a couple of decades running his own company doing multiple tracer work from Puerto Rico to the US Rocky Mountains. After being a contractor, he later joined TDEC. He is a Fellow of the Geological Society of America.
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Page updated October 11, 2021