Stratigraphic landscape analysis, thermochronology and the episodic development of elevated, passive continental margins
Extensive low relief plateau surfaces at high elevation, termed ‘peneplains’ in this bulletin, have been a challenge to geologists seeking to explain the long-term evolution of rift margin landscapes. Attempts to understand these plateaux have long focussed on topography leading to controversial theories of landscape evolution, many of which have now been dismissed within current ideas of plate tectonic development of passive margins during continental fragmentation. This book provides a ‘state-of-the-art’ review of these landscapes with specific focus on new research, particularly with respect to the on-shore/off-shore sedimentary records which has led to a re-evaluation of such landscapes within a new scientific approach termed ‘stratigraphic landscape analysis (SLA)’ (Chapter 3).
This extremely well illustrated book provides a concise thoughtful review in 150 pages of the topic based on the detailed research of Scandinavian and Greenland landscapes previously carried out by the authors, before expanding discussion to other continental passive margins in the southern hemisphere. The early part of the book presents a comprehensive introduction of key points regarding passive margins with useful definition and discussion of terminology, long a source of geological debate, and the formation of different types of surface allowing reconstructions of a relative chronology of landscape evolution. The following chapter (4) introduces low-temperature thermochronology, particularly apatite fission-track methods, to provide a thermal history, thereby allowing better appreciation of the timing of uplift events and the calculation of the amount of bedrock erosion by denudation.
This is exemplified in Chapter 5 by a detailed investigation of West Greenland demonstrating the utility of combining stratigraphic landscape analysis with thermochronology to establish multiple uplift and subsidence events following rifting of the continental margin. This is expanded in the subsequent chapter by assessment of the geological evidence from other passive margins, again emphasising that present day topography may reflect a series of a sequence of episodic post-rifting tectonic and denudational events. This allows the final chapters (7&8) of the book to critically evaluate a number of presently accepted hypotheses for the formation of such passive margin landscapes leading to revised interpretations that reflect the complicated sequence of post break-up uplift and subsidence events revealed by detailed stratigraphic landscape analysis.
Reviewed by Wishart Mitchell
STRATIGRAPHIC LANDSCAPE ANALYSIS, THERMOCHRONOLOGY AND THE EPISODIC DEVELOPMENT OF ELEVATED, PASSIVE CONTINENTAL MARGINS by PAUL F GREEN, KARNA LIDMAR-BERGSTROM, PETER JAPSEN, JOHAN M BONOW & JAMES A CHALMERS
Published by: Geological Survey of Denmark and Greenland. Publication date: 2013
ISBN: 978-87-7871-372-8 List Price: DKK 250 + VAT 150pp W:
www.geus.dk/publications/bull/nr30/index-uk.htm