Museum Expeditions & Field Trips - 2011
The geology of the Lake District never ceases to amaze as it is one of the most complex and varied areas of the United Kingdom. High fells and valleys shaped by wind, water and the glaciation of the Pleistocene, rock exposures ranging from igneous volcanics to sedimentary limestones, mineral mining and quarries for the extraction of rock for roofing, paving and aggregate make this undoubtedly one of the most interesting places in England to see geological landforms and collect rock specimens.Day 1 - Scout Scar.
Day 2 - Bowder, Honister and Seathwaite Fell.
The locally famous Bowder Stone is an 18m long boulder of fine grained andesite lava belonging to the Birker Fell Formation of the Borrowdale Volcanic Group and weighs some 2000 tonnes. It lies at the bottom of Bowder Crag from which it fell and now lies near to the River Derwent.
Honister Slate Mine lies high up in the Honister Pass that connects Borrowdale with Buttermere. Although Honister Slate is not not a true slate - but a hard compacted green ash fall tuff datng from the Ordovician - it has historically been used as a roofing medium, particularly in the town of Keswick. The approach to the mine can easily be seen due to the millions of tonnes of rock spoil covering both sides of the pass where miners of old dumped anything that they thought was unusable. Today, this resource is being recovered to be carved into household objects such as bowls, coasters and cheese boards. For further information on the mine click
Seathwaite Fell is located just to the north of Scafell Pike - the highest point in England. The area is composed almost entirely of andesite and basalt boulders along with eutaxitic ignimbrites (see below for a description). This area was once violently volcanic and many ash fall deposits can be seen. There is also a volcanic bomb - a clot of andesitic lava almost half a metre across - thought to have been ejected from a vent in the Buttermere Valley, some 6 kms distant. Volcanic Bombs are rare features in the UK.
Day 3 - Side Pike, Langdale. Lying across the Rossett Gill Fault, this area is strewn with bright pink welded eutaxitic ignimbrites. These rocks originated from the material produced during pyroclastic surge eruptions and are composed of pumice, ash and lava. As the material collects and is compressed, the components become flattened and give the rock a "streaky" texture. The darker flattened streaks are known as fiammes.
Day 4 - Arnside.
The cliffs here have been termed "the finest Visean fossil strata in NW Europe". These strata date from the Lower Carboniferous and were laid down when this part of Britain lay under a warm shallow tropical sea. Fossils are abundant in the cliff faces at Blackstone Point and include corals, brachiopods, crinoids and bivalves. Time and tide have eroded some of these and driftage along the shoreline means that water worn specimens can be found along the foreshore near the promenade at the southern end of the town.
Stone Museum of Geology extends its grateful thanks to our very knowledgeable guides, Peter & Kate Kelsall.