Courses by Nick Chidlaw

March 2017 – Two one-day courses – Scotland and Wales

Nick Chidlaw is offering two 1-day courses in March, using a format that has pleasingly attracted many attendees on previous occasions. These courses are indoor-based, and describe field areas to which Nick has run field courses in the past. One of them describes the striking geology and landforms of the north-west of the Scottish mainland between Durness and Skye, the other focuses on the deposition and subsequent deformation of the Late Carboniferous coal-bearing strata in the main south Wales coalfield. Coal seams and adjacent strata are rarely exposed, but are described here from extensive opencasts . The courses may be attractive particularly to people who are not in a position to visit field locations, e.g. insufficient time available because of family / work commitments, health problems, or may be interested in the opportunity to study lithologies from exposures that are no longer accessible / extant. Each course would comprise powerpoint-based lectures, together with examination of hand specimens of relevant mineral and rock types, and published geological maps of the field areas. The hand specimens have been collected by the tutor in the field areas described.

The venue is the Buckingham Room (single storey building by the car park) at The Chantry, 52 Castle Street,Thornbury, South Glos. BS351HB. Tel: (01454) 414268. See venue website for further details, including location map.

On each course attendees would bring their own packed lunch and other refreshments, or go into the town for lunch.

These two 1-day courses have a fee of £25.00 each.

If you / anyone else you know would like to attend either or both of these offered courses please contact Nick Chidlaw   

Please note: these courses are to run on the same weekend, but are independent of each other: you can enrol on both if you wish to, or either one of them, according to your interests / availability.

The deadline for the minimum number (10) of enrolments is Saturday 4th February (4 weeks before the courses are due to run). Maximum number of attendees on each course 30. If the minimum number for each course is reached by this deadline, the arrangements will be able to continue; if not, the course(s) not reaching viability will be cancelled, and fees received will be returned to those who have sent them in, soon after. Enrolments above the minimum number for each course will be able to continue up to 1 week before it is due to run.

Field Geology in North West Scotland

Saturday 4th March 10.00 am – 5.00 pm

This course focuses on the bedrock geology of the mainland of north-west Scotland; the area includes the oldest rocks in the British Isles and some of the oldest exposed on the surface of the earth. The youngest are of Early Ordovician age, but these crop out over a relatively small area, and the majority of the rocks seen are of Precambrian age. Huge (and frankly unimaginable) lengths of time are represented. It is undoubtedly the most complex geology in the British Isles, but also the most striking and fascinating. The landforms associated with this geology are impressive: particularly notable is the almost treeless ice-scoured plateau of the coastal fringe, studded with small lochs and intervening rounded hillocks, and the isolated fin-like mountains rising up from this a few miles inland. It is a very different place from anywhere else in the British Isles.

A key feature of north west Scottish geology is that a major part of it developed when the earth was a radically different planet to that seen today. This includes the stability of the crust (more fluid), allowing magmatic activity and deformation to be more extensive; also the composition of the atmosphere (carbon dioxide rich with little oxygen) allowing different sedimentary rocks to form e.g.. Banded Iron Formations (BIF’s). Another key feature of the geology is its provenance, which belongs to that of Canada, Greenland and northern Scandinavia (all of which were at one time joined together) rather than much of the rest of the British Isles. Along the entire eastern margin of the study area is an enormous and impressive complex of stacked thrust sheets containing associated rocks such as mylonites, which developed during the Caledonian mountain-building in Silurian times, and known as the Moine Thrust Zone.        

A handout outlining the day’s programme, and a list of optional suggested reading, will be provided on the course. No prior knowledge of geology or the study are is assumed.

Late Carboniferous Coal-bearing strata in south Wales: natural exposures, quarries and opencast mines 

Sunday 5th March 10.00 am – 5.00 pm

During the Carboniferous period (359 – 299 million years ago) conditions became established for the first time for coal deposition to occur on a global scale. Coal-bearing strata were laid down in a variety of latitudes and under a variety of climates: in the northern hemisphere mostly during Carboniferous times, and in the southern hemisphere mostly in the following Permian period ( 299 - 252 million years ago). This has left a legacy of major coal deposits distributed widely across our present continents. Although land plants had evolved to form the first forests during the preceding Devonian period, it was during the Carboniferous period when they became widely distributed on earth; this, coupled with the persistent development of mires across extensive areas, allowed peat deposits to form time and again, during burial these converted to coal.

Our understanding of the deposition of coal-bearing strata has been hugely increased by the mining of coal as an energy resource, particularly from the beginnings of the Industrial Revolution in Britain and Europe in the 18th century. Britain has an abundance of coal-bearing strata, and this was extensively mined until alternative resources of energy and economic globalisation increased from the early 20th century; today, large-scale deep mining is no longer operational in Britain, but extensive opencast mines continue to work, mostly in Scotland with some in Wales and England.

On this course, you will be introduced to the deposition of the coal-bearing strata of Late Carboniferous age in Britain, and their deformation during the mountain-building events (Variscan Orogeny) at the end of the period. The tutor has run field courses in south Wales where opportunities to study the main coal-bearing strata and their deformation have existed in huge opencast coal operations, and where those rocks exposed are no longer accessible or extant. Such locations, which include bituminous and anthracitic coal seams up to around 2 metres thick, will be illustrated from photographs taken at the time of the visits. Other locations including natural exposures, working and disused quarries and track cuttings, will also be described to provide a stratigraphic coverage up through the coal – bearing strata.  

A handout outlining the day’s programme, and a list of optional suggested reading, will be provided on the course. No prior knowledge of geology or the study are is assumed.