I am offering two 1-day field courses to be run in June, if there is sufficient interest and enrolments to make them viable.
These courses are independent of one-another - you can enrol on either or both, according to your interest and availability.
The courses are being offered on the same weekend: some people who live a substantial distance away may be interested in both courses and this would make attending them more workable.
Hope you find these proposals of interest, and to hear from you soon.
Nick Chidlaw
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Title: IMPROVED EXPOSURES AT KEY SITES WITHIN THE LATE PRECAMBRIAN MALVERNS COMPLEX
Saturday 22nd June 10.00 am - 5.00 pm
In the south west English Midlands the main ridge of the Malvern Hills forms a dramatic feature, particularly when viewed from the much lower country to the east. The main ridge is orientated north-south, narrow, and about 8 miles long; it reaches 425m above sea level; lower parts of the Hills lie to the west.
The types of rocks and their age here are (un)usual (my correction) for southern Britain. Most of the main ridge is composed of rocks formed late in Precambrian times, between c. 680 - 670 million years ago, during the Cryogenian period. These rocks are referred to collectively as the Malverns Complex, and they comprise an almost bewildering variety of metamorphic types, colourfully-patterned, and exposed in numerous old quarry workings and natural crags. They have drawn the interest of geologists for generations. The Malverns Complex is understood to have formed during a tectonic plate collision, and when the southern British crust was located in the southern hemisphere about 60 degrees from the equator; the climate was cold and the plate collision zone likely had numerous snow- and ice-covered active volcanoes. The Complex itself was formed far below in the depths of the crust, where a succession of magmas were forming, cooling and crystallising, and becoming altered by continuing episodes of plate compression. These rocks were subsequently uplifted and their overlying rocks eroded away, exposing them on the present land surface.
The Hereford & Worcester Earth Heritage Trust has for many years operated to record, conserve and promote the geology of the county. Recently, it has undertaken clearance of vegetation and pressure-cleaning of a number of key exposures in the Malverns Complex, in order for the rocks to be better studied and understood, at all levels of education.. This proposed course looks at some of these exposures, while the clearance work remains at its best.
No prior geological knowledge or of the study area would be assumed.
Tuition fee: £32.00
Deadline for course viability: Friday 10th May. If the course has become viable (minimum 10 enrolments) by this date, enrolments will be able to continue until 1 week (Saturday 15th June) before the course runs.
Image: part of Dingle Quarry in the Malvern Hills. The rock faces have recently been cleared of vegetation and exposures improved. The rocks include sheets of mafic and felsic igneous rocks within a diorite host, shearing is evident.
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Title: STUDY THE NEW RED DESERT
Sunday 23rd June 10.00 am - 5.00 pm. The course includes an exposure dependent on tides; the date and times have been chosen to include safe access.
This course looks at locations in the NW of Gloucestershire where can be found strata that are part of the 'New Red Sandstone Supergroup'; they were deposited in a variety of environments under a tropical arid climate during the Permian and Triassic periods between c. 300 - 200 million years ago, when Britain lay just N of the equator. We look at exposures of rocks interpreted as being laid down as desert dunes, in seasonal braided rivers and lakes, in estuaries and on coastlines. Reference is made to alluvial fan deposits (not included in the itinerary due to accessibility problems) also present in the area. Marine incursions into this desert environment were initially absent, but became increasingly common over time.
No prior geological knowledge or of the study area would be assumed.
Tuition fee: £32.00
Deadline for course viability: Friday 10th May. If the course has become viable (minimum 10 enrolments) by this date, enrolments will be able to continue until 1 week (Sunday 16th June) before the course runs.
Image: part of the cliff of the River Leadon near the village of Red Marley D'Abitot, exposing fluviatile deposits of the Helsby Sandstone Formation (Early / Middle Triassic). ------------------------------------------
