Taija,
Whilst the precise situation of the Irish north Connemara Silurian basins with respect to the magmatic arc beneath Laurentia is not fully resolved (back-arc or intra-arc), their degree of preservation is remarkable. As, indeed , is that of the Ordovician fore-arc of South Mayo. I, and co-workers, have come to the conclusion that this is due to two key factors: firstly, the strength (or more accurately the thermal maturity at the time of deformation) of the lithosphere; and secondly the buoyancy (in isostatic terms) of the system. Preservation of original details over eons generally requires a basin to remain at upper crustal levels during its entire history.
I can send a (long) reference list to your personal email should you so require.
Paul
Paul D. Ryan
Emeritus Professor of Geology
EOS, NUI Galway, Ireland.
+353872956190
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From: Tectonics & structural geology discussion list [[log in to unmask]] on behalf of Taija Torvela [[log in to unmask]]
Sent: Tuesday, October 02, 2012 5:06 PM
To: [log in to unmask]
Subject: Closure of sedimentary basins?
Hi all,
I'm doing a study of a closed volcanosedimentary (back-arc) basin, and I'm searching for papers about the processes during basin closure. I would be especially keen to know about how the strain of the huge amounts of shortening at basin scale is accommodated during the inversion and finally the closure, and of how/why sometimes the primary structures are still very well preserved throughout the basin... The one I'm studying is 1900 Ma old and tightly to isoclinally folded at >500 m wavelength scale (and there seems to be some thrust faults as well), but almost everywhere you look you can still see the primary structures almost like they were formed yesterday! The rocks show clear schistosities for most parts of course, but that's about it (and sometimes not even that). I've found literally thousands of papers related to basin inversion tectonics and/or to fold&thrust belts, but trying to find the applicable ones among the mass... well you know how it is. So if anyone could hint of studies (modelling, field work, anything really) that could elucidate my specific dilemma, I would be very grateful.
Cheers
Taija
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Dr Taija Torvela
Lecturer
Applied Structural Geology
University of Leeds
School of Earth and Environment
Earth and Environment Building
Leeds
LS2 9JT
UK
+44 113 343 6620
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