An enthusiastic group of CAN members including 2 experienced Geologists helped get the 2nd annual Geology Field trip underway. Despite the weather trying to destroy the theme of “Edale Equatorial Environments”, this introduction to Field Geology took in:
The Mam Tor Shales. Richard and Kathryn explained the formation of the shales in a river delta environment and how the shales overlaid the Limestone beds. The scene was set as Kathryn used a series of flash cards to show just how the environment in the British Isles had changed over the past 600 million years or so through continental drift.
A spring. There are a number of fresh water springs in the area and how these form where the water percolates out from above an impermeable layer. We spent a little while looking in the spring water and were quite surprised to find caddis larvae and what appeared to be tiny crustaceans within a metre of the spring source.
The Odin mine. This is a transverse fault that has caused a “gash” in the landscape. As a result of the faulting, minerals (mainly galena and fluorites) can be found in the rock faces. Evidence of the transverse fault can be seen in the slickensides – gouges in the rock faces where the two faces abraded each other.
Fossil hunting. From Odin mine we walked down to Castleton for Lunch. We were tasked with finding and identifying (species level) the fossils in the dry stone walls. Possibly the highlight was this fossil of Spirifer Bisulcatus.
Following a very welcome break in Castleton for Lunch, the group moved up towards Winnats pass stopping to examine one (possibly two) volcanic vents in the fields adjacent to the road. Richard explained that the volcanic larva appeared in the later stages of the Carboniferous period and the type could be identified as this was aerated.
A long climb up Winnats pass with a discussion on the ‘dip’ of the strata and an explanation on how this happened. During the climb, more fossils were found and identified.
Finally, the group stopped at Windy Knoll (in the conditions, a highly appropriate name), where the rocks were examined and traces of oil could be clearly seen in the upper edges of the facies.
A short walk back to the cars and removal of waterproofs and we were all back safely. The consensus was this was a great day out and many thanks to Richard and Kathryn for the time and effort organising and leading us.