Irthing Gorge Lower Carboniferous

Leader: Ben Johnson
Meet: 10.30 Gilsland Spa Car Park, NY636676

Rescheduled to 20th August

A look at the Upper Border Group, part of the Lower Carboniferous. A deep gorge is cut by the River Irthing exposing alternating sediments. We can also walk around to the remains of the Popping Stone NY 6350 6812. If time permits, we can drive up to Crammel Linn waterfall (Parking NY63616980) and better see the effects of the Gilsland Fault Belt. Steep paths, slippery when wet. Fossil hunting possibilities in river boulders.

Event Reminder: Sale Fell

Date: Wednesday 13 July 2022
Time: 18:30

Leader: Phil Davies
Meet: NY 191301 roadside parking at minor road from Wythop Mill to Routenbeck / Pheasant Inn, 200m NE of Wythop St Margaret’s Church.
Around & over Sale Fell, grassy paths, overlooking Bassenthwaite. Medium walk. Skiddaw Group strata: steeply inclined bedding; major quartz veining evident (depending on exact route); water expulsion structures (if we can find them!); minette / lamprophyre intrusion (see The Cumberland Geologist No.2); folding / minor thrust structure. Discuss local geological structure – BGS mapping has a major tight anticline here. Can we spot any way-up structures (apart from the water expulsion ones)? (I doubt it!).

Event Reminder: Glacial landforms in Upper Swindale

Date: Saturday 2 July 2022
Time: 10:30

Leader: Sylvia Woodhead
Meet:  NY 522143 park in a roadside layby, along the road to Swindale Foot, about 400m past the filter house at the end of Open Access land, where a bridleway goes off.

The route is a medium walk of about 5½m/8k, up to the valley head and Forces Falls, returning on the south eastern side of the valley. From the parking area we will follow the minor road past Swindale Foot, then take a permissive RSPB path in the valley bottom (may be wet), then up to Swindale Head Farm, joining the bridleway south, past The Knott, to the Local Geological Site (7_146) moraines, to Dodd Bottom, Hobgrundle Gill, then up to Forces Falls. We may continue on the steep bridleway up to the col into the upper Mosedale valley, source of an ice cap, returning on a rougher path on the SE side of the valley back to the cars.

For a detailed description of the geological site, please visit the following article: http://www.cumberland-geol-soc.org.uk/wp-content/uploads/2022/06/CGS-Swindale-Head-Excursion-Notes.pdf

Brief description of the Local Geological Site

Swindale Head exhibits a range of glacial features. Upper Swindale is a straight glacial trough, with a former ribbon lake floor, glacially over-steepened sides, and a truncated spur at Gouther Crag, formed in a previous glacial period. The trough end of Swindale Head preserves features from the Younger Dryas, or Loch Lomond Stadial, now dated as 12, 900 to 11,700 years ago, when it was believed that there was an extensive plateau ice cap over the Lake District peaks. A short-lived glacier abraded and shaped a rock outcrop, and left a complex suite of glacial morainic mounds.

Swindale Head preserves features from a time when the Lake District was plunged back into a mini-glacial period which lasted over 1000 years. An ice cap developed on the peaks, and an ice tongue, possibly the most easterly in the Lake District, moved north-eastwards down Swindale. The glacier did not flow very far down the valley, but it did abrade and shape the rock outcrop of The Knott. The melting ice deposited a number of ridges of moraine, whose crest lines indicate an ice flow direction. The ridges mark the extent of this mini Ice Age glacier.