Introduction to Lecture Programme
Once again we have been very fortunate that six outside speakers (plus our Hon President) have kindly given their time to come and speak to us in what I hope members will find an interesting and varied programme.
For the first time since 2009, the T N George Medal has been awarded, to Professor Jenny Clack of Cambridge University. Some of you may have seen the excellent TV programme on Prof Clack and her work, in the ‘Brilliant Minds’ series. I’m sure we can anticipate an equally impressive presentation in March.
A new feature for this session is a set of themed lectures on the subject of ‘North Atlantic Opening’ – I shall say a little about this near the end of this introduction. We have two talks this year – from Steve Jones of Birmingham in October on the Iceland Ridge and from Dave McInroy of BGS, Edinburgh (a Glasgow graduate) in February on the Rockall-Hatton microcontinent and pre-Palaeogene stretching.
I am conscious that we don’t have many Quaternary talks. That deficiency will be corrected this year when Tom Bradwell, also from BGS, Edinburgh will talk about the melting of the Scottish Ice Sheet. You may have seen some of his publications in SJG. He tells me that BGS have completed new sections of seabed mapping, including the Firth of Lorne.
Offshore areas of the Scottish ice Sheet (photo Tom Bradwell)
To round off 2012, our Hon President, Maggie Donnelly will round off an excellent term, for which we thank her warmly, by telling us about some ‘Geological Journeys’ that she has made.
It’s a long time since we had anyone speak to us on the deeper Earth, but Jon Mound from Leeds University is going to tell us about the outer core in January. Quite different from the inner core it plays a role in Earth’s magnetism; outer core-mantle relationships are also an active area of study.
If you can remember Thursday December 8, 2011, you will recall that a hurricane forced Glasgow University to close, our meeting had to be cancelled and Dave Chew from Imperial College, Dublin was not able to give his talk, even though he had bravely struggled to Glasgow. Let’s hope the April 18, 2013 is blessed with more clement weather for Dave’s return visit when he will tell us about calibrating some new isotopic dating techniques.
North Atlantic Opening
It seemed like a good idea to organize several lectures on a major geological theme and present them over 2-3 sessions. North Atlantic opening appeared to be a suitable topic, as most people probably know enough about the basics to be able to build their knowledge into something more substantial.
Image: Elliot Lim, CIRES
For most of the past billion years and more, Scotland and NW Ireland have been plastered against the edge of Laurentia. When Pangea began to break up, the movement of Africa away from South America marked the start of Atlantic opening. About 150 million years later the mid-Atlantic Ridge had reached the position of the Azores Triple Point.
From there, the ridge continued to grow to what is now the Charlie-Gibbs Fracture Zone (well seen on Google Earth) and continued between Labrador and West Greenland. At this point, something dramatic happened and the ridge switched to the east of Greenland and continued, splitting Britain and Ireland from North America during Palaeogene times. This gave rise to the familiar British and Irish Palaeogene Province and eventually to Iceland. The Iceland Ridge spans the Atlantic between Greenland and Scotland and Steve Jones will tell us about it and some of its important features in October.
Palaeogene opening occurred between Greenland and, not Ireland but the Rockall-Hatton Bank (or microcontinent) – shown in grey o the west of Ireland on the diagram. This is partly underlain by Rhinnian basement and has moved away from Ireland by pre-Palaeogene extension, as Dave McInroy will explain in February.
I am hoping to speakers to cover topics such as the following in later session(s):
Charlie-Gibbs Fracture Zone and change of the spreading direction;
Jan Mayen Fracture Zone and spreading further north;
Faroe Islands and their geology.
Any other suggestions would be most welcome.
Finally, I would like to remind members that next session (2013-14), it is our turn to host the Joint Celebrity lecture with the Edinburgh Society. Council will be glad to receive suggestions. (Remember that Edinburgh invited Iain Stewart a couple of years ago!)
Methinks we are all going to learn a lot of new stuff this session.
Best wishes,
Jim Morrison, Meetings Secretary.