Event type:
Lecture, Evening meeting, Regional Group
Organised by:
Thames Valley Regional Group
Venue:
Wallingford Sports Park
Event status:
EVENT CLOSED
The Chalk can have surprisingly high densities of surface karst features (stream sinks and dolines), usually associated with the boundary between the Chalk and the overlying Palaeogene aged deposits. Some short natural karst caves have also been reported in the Chalk, including two near Reading in Berkshire.
Tracer tests from streams sinking into the Chalk have revealed rapid groundwater flow over distances of several kilometres. Tracer tests have also demonstrated rapid groundwater flow in areas away from surface karst features.
The results of Chalk tracer tests will be presented, and the implications for groundwater protection and contaminant transport will be discussed. The Chalk is also an important habitat for invertebrate fauna, and harbours 7 of the 8 stygobite species found in England.
Stygobites are only found in the subsurface and are uniquely adapted to live in an environment with no light and limited resources. These extraordinary shrimp-like animals are blind and lack pigmentation.
Recent genetic studies of three stygobite species found in the Chalk have revealed that they have been present in the UK for between 0.6 and 5.6 million years. These stygobite species provide an important contribution to UK biodiversity because other fauna only arrived around 10,000 years ago, following the end of the last glaciation.
Speaker
Dr Louise Maurice (BGS)
Venue
Wallingford Sports Club, OX10 9RB