Hi Taylan,
You are looking at an interesting plate convergence region (East Anatolian plateau of 2 km average elevation) where presumably the mantle lithosphere is very thin -called upon by seismic studies- and the crust is not as thick as it was previously suggested (e.g Sengor and Kidd, 1979).
So, I agree with previous recommendations for calculating isostatic support first and then extract the residual topography (i.e., it is defined as the non-isostatic component of topography.
Because it is on the relevant topic, I can recommend you to look at our paper Göğüş and Pysklywec, 2008, (Geology), The mantle lithosphere delamination driving plateau uplift and synconvergent extension in Eastern Anatolia. We did not particularly separate these two types of topographic support (Isostatic vs Dynamic) however, you may want to track the surface evolution from a dynamic/delamination model with varying plate convergence rates.
Regards,
Oğuz
On 31 Aug 2012, at 13:05, Olivier Vanderhaeghe wrote:
Dear Taylan,
As Kurt is opening the "can", I would like to mention an interesting
paper regarding isostatic support of mountain belts considering the
crust/lithosphere thickness ratio :
Sandiford, M. and Powell, R., 1990. Some
isostatic and thermal consequences of
the vertical strain geometry in convergent
orogens. Earth Planet. Sci. Lett., 98,
154–165.
and a more recent attempt to develop this idea combining the different
modes of subduction (retreat/advance) and of crust-mantle
coupling/decoupling:
Vanderhaeghe O., and Duchene S., 2010. Crustal-scale mass transfer,
geotherm and topography at convergent plate boundaries. Terra Nova, 22,
315–323.
In order to evaluate surface uplift in Anatolia, I suggest to first
consider isostatic support considering the crust/lithosphere thickness
ratio (it is not too complicated to do), and then, if needed, open the
way to dynamic support of topography but this requires a much heavier
computation!
Good luck!
Olivier.
Le 31/08/2012 11:56, Stuewe, Kurt ([log in to unmask]<mailto:[log in to unmask]>) a écrit :
Dear Taylan,
As this is a subject I myself have entertained, let me chip in here:
Obviously, you first need to be clear about which of the vertical motions you want to think about (i.e. "uplift", "uplift of rocks" or "exhumation").... and Olivier put you to the classic paper on the subject (I also cannot resist the self-inflating temptation to point you to our own TECTONICS paper on the subject (Stuewe and Barr, 1998, "On uplift and exhumation during convergence", TECTONICS 17, p.80 ..... and the follow up paper in TECTONICS, 2000, 19, p.1056)
Then I would try to decide if your problem is an ISOSTATIC support problem one or one of DYNAMIC support.
If its the latter (i.e. DYNAMIC support), then all kinds of things can happen around subductions zones as we know they can both: (a) be related to mountain building and (b) to subsidence, depending on the ratio of slab roll back and convergence etc.. So in this case your problem includes a whole can-of-worms and is probably more a regional geology problem than a conceptual one. I would proceed trying to understand the history of regional dynamics......
If you do indeed think that your problem can be solved by thinking about it in terms of an ISOSTATIC support (although I think its unlikely ?), then you could proceed by using simple considerations of isostatically supported surface elevation (and its changes) in a 2-layer lithosphere as it is published in a number of Geodynamics text books....
If you also think this is the way to go, I may be able to point you further (outside this discussion forum?)
Best
Kurt
------------------------------------------
Ao Prof. Dr. Kurt Stuewe
Institut fuer Erdwissenschaften
Universitaetsplatz 2
A-8010 Graz
AUSTRIA
http://wegener.uni-graz.at
http://www.alpengeologie.org
--------------------------------------------
-----Ursprüngliche Nachricht-----
Von: Tectonics & structural geology discussion list [mailto:[log in to unmask]] Im Auftrag von Olivier Vanderhaeghe
Gesendet: Freitag, 31. August 2012 10:58
An: [log in to unmask]<mailto:[log in to unmask]>
Betreff: Re: Relation between uplift rate and subduction zone
Dear Taylan,
The first thing to clarify is whether you are dealing with 'uplift' or
'exhumation' (England and Molnar, 1990. Surface uplift, uplift or rocks,
and exhumation of rocks). Uplift is defined as the motion of a material
point relative to an external fixed reference frame (example: sea level)
whereas exhumation is defined as the motion of material points in
direction of the topographic surface above it. Uplift might be
deciphered from sedimentologic and paleoenvironmental data as well as
stable isotopic signatures whereas exhumation is mainly constrained by
thermobarometric and thermochronologic data of metamorphic rocks.
I hope that this helps.
Olivier Vanderhaeghe.
Le 30/08/2012 20:22, Scott T. Marshall a écrit :
Hi Taylan,
The classic backslip paper by Jim Savage shows analytical solutions for
the relationships you are seeking for a simple 2D dipping edge
dislocation during the interseismic period.
Savave, J. C., A Dislocation Model of Strain Accumulation and Release at
a Subduction Zone. JGR. Vol 88. No B6. Pages 4984-4996, 1983.
For the long-term deformation patterns due to 2D edge dislocations, you
can look for:
Freund, L. B., and D. M. Barnett (1976), A two-dimensional analysis of
surface deformation due to dip-slip faulting, Bull. Seismol. Soc. Am.,
66(3), 667-675.
Of course a 2D dislocation model is a large simplification of a real
subduction zone, but the models are useful for understanding the basic
controls on uplift and contraction rates in a subduction zone. Also be
aware, that the ability of these models to fit geodetic data has been
only somewhat successful. If you are looking for something more complex,
Kaj Johnson has published several papers on subduction zones using
numerical viscoelastic models.
Cheers,
-Scott
On 8/30/2012 1:50 PM, T.SANCAR wrote:
Dear Scientist
I am a PhD student in the field of active tectonics. I am studying
about Quaternary Evolution of Karlıova Triple Junction (KTJ). One of
the my major work is to calculate uplift rate of East Anatolia just
east of the KTJ. I have a result but I (think) have to test the result
somehow. For this, I am trying to understand relationship between
uplift rate and plate movement (e.g. angle of subducting plate,
velocitiy of it so on).
If you please recommend any paper about this issue?
Of course I am open any idea to test my result.
Many thanks for your help.
Yours Sincerely
Taylan
--
Taylan SANÇAR
Araştırma Görevlisi
Tunceli Üniversitesi, Mühendislik Fakültesi
Jeoloji Mühendisliği Bölümü
Tel: 0541 725 62 62
--
Olivier VANDERHAEGHE
Professeur
Dpt Geosciences
Geologie et Gestion des Ressources Minerales et Energetiques
Faculte des Sciences et Technologies
Universite de Lorraine
BP 239, 54506 Vandoeuvre les Nancy
France
+33 (0) 3 83 68 47 34
http://www.geologie.uhp-nancy.fr/Php/index.php
http://www.g2r.uhp-nancy.fr/annuaire/vanderhaeghe.html
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