Wednesday 11 August 2010

11 - 12th September - Tavistock Quarries

Tavistock Quarries
Leaders: Eddie Bailey and Sam Rhodes
Saturday 11th - Sunday 12th September 2010
We will spend the first day in and around Greystone Quarry near Tavistock. We will look at the geology (dolerite sill intruded into the Greystone Formation which is an abyssal siltstone - a stretch of hornfelsed siltstone is clearly visible in the quarry). We may also be able to find one or two outcrops nearby that help expand the local geology being introduced. We will also introduce the quarry workings.
The following day we will visit Meldon Quarry famous for its volcanics, hornfels and slates and complex structure, which has recently had to find a new purpose! The traditional rail ballast contract has been withdrawn due to the recession but investigations found that the quarry had materials that could be worked competitively into the bulk fill market. This will help keep Meldon going until the ballast market resumes. Boreholes were also recently drilled to help elucidate the geology to the south of the current excavations - the first boreholes for years.
Although the cores may not be available for inspection in September (they will have been crushed and tested) they give an opportunity to unravel the enigmatic thrusting and folding that characterises Meldon. We will also introduce the Geodiversity plans we have for Meldon and have lunch at our new rock park!
Booking is required - contact the G.A.

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