A Glasgow legacy: the scientific determination of the age of the Earth.

Professor R. M. Ellam

Scottish Universities Environmental Research Centre,

The age of the Earth has been a central philosophical and spiritual question since 17^th century theologians like Archbishop Ussher and John Lightfoot constructed chronologies based on biblical interpretation.  Their results were stated very precisely but are now considered highly inaccurate.  James Hutton’s concept of “no vestige of a beginning, no prospect of an end” greatly challenged contemporary orthodoxy and is perhaps an underestimated contribution to the Scottish Enlightenment.  As geology gained confidence, eminent Victorians such as Lyell, Playfair and Darwin found their evidence for the vastness of geological time at odds with the thermodynamics of the Natural Philosophers; led from Glasgow by Lord Kelvin.  As we now know, Kelvin’s calculations failed to take account of, yet to be discovered, radioactive heat.  In 1913, Frederick Soddy, working in the Department of Chemistry in the University of Glasgow, introduced the concept of isotopes.  It is a delicious irony that the same radioactive isotopes that solved the thermodynamic conundrum of how an ancient Earth had stayed warm have also been exploited to date that very antiquity.  This talk will explore the development of thinking on the age of the Earth with particular focus on the contribution from Glasgow.

Making the most of coal – applications in palaeoenvironment and human health.

Dr David Large

University of Nottingham

The value of coal in the geological record is grossly underestimated. This presentation aims to illustrate novel ways in which coal and lignite can be used to understand the evolution of the Earth’s environment and the link between palaeoenvironment and human health.  Starting with ways of estimating time in coal seams this will be developed to illustrate how estimated rates of atmospheric deposition in coal can be used to explore the link between massive volcanism and climate change.  Finally a fascinating case study linking environmental change at the Permo-Triassic Boundary and human health will be discussed.

Canadian sand in Scotland: are the Morar and Torridon groups the foreland basin to the Grenville Mountain Belt?

Maarten Krabbendam

British Geological Survey, Edinburgh

The Torridon sandstone in NW Scotland represent a very thick pile of fluviatile sandstones of early Neoproterozoic age.  Discussions about potential correlations across the Moine Thrust with the vast tract of metasedimentary Moine rocks date back to the 19^th century geologist Peach, Horne and Clough.  I will present recently-discovered sedimentary structures on the lowest Moine rocks in Sutherland and Ross-shire: suggesting deposition as high-energy, braided fluvial deposits.  I will compare and contrast the Torridon and Morar groups and show that the two groups are similar in lithology, stratigraphy, sedimentology, geochemistry and detrital zircon ages. I will argue that the Torridon and Morar group can be directly correlated across the Moine Thrust and that both deposits formed part of a large foreland basin in front of the c.1000 Ma Grenville Mountain Belt, similar to the Ganges Basin in front of the Himalayas today.

11th March 2010

Earthquakes in Unusual Places: ‘Stable’ Craton Tectonics

Dr Clark Fenton

Department of Civil & Environmental Engineering, Imperial College London

The majority of earthquakes are relatively well-behaved and occur where we would expect, along plate margins where contemporary crustal deformation is concentrated.  However, a small but significant number of damaging earthquakes occur in regions far from plate boundaries, including Precambrian shields, which would normally be considered aseismic.  The sources of these earthquakes are often cryptic, having no prior surface expression, making the identification of potentially active structures very difficult, if not impossible.   These events have recurrence intervals in excess of 10⁵ years and in some cases occur on faults that show no evidence for brittle behaviour in the last billion years!  The occurrence of such earthquakes poses a major problem for seismic hazard assessment and consequently safe civil engineering design.  Exceptionally long recurrence intervals and a lack of surface expression means that such events are often not preserved in the geological record.  Thus, ‘traditional’ palaeoseismic techniques are often of little use.  However, by studying the surface effects of recent surface faulting earthquakes in stable continental interiors and also detailed analysis of intraplate seismicity allows an insight into the seismotectonics of ‘stable’ plate interiors.

The power of Geology

Professor Peter Westbroek (Joint Celebrity Lecturer)

Leiden University

Global heating, overpopulation, exhaustion of natural resources, globalization ... all these problems are connected and affect the earth at large. The world leaders pull their levers, but, whatever they do, things only get worse. An epidemic of global fear is spreading and already shows its ugly face in outbreaks of intolerance, fundamentalism, and xenophobia. This fear is the worst of all our predicaments. What we need is an inner light, an attitude of detachment, a balanced state of mind. This, I argue, is what geology can bring about. Through our science we can gaze into the abyss of time, fathom the depth of our roots, witness the immense creativity of emergence, and admire the majestic odyssey of our planet’s history. Geology is a neglected treasure trove bringing admiration for this planet and confidence in ourselves. Its method is universal and its results are open to everybody. Thanks to geology we are in a position to overcome our fears, properly address the problems ahead and experience our life as a unique adventure.