Dear Anupan (and others)
I can add some deeply historical references here.
Some of the cross-section geometries are outlined in:
Butler, R.W.H. 1987. Thrust sequences. J. Geol. Soc. London 144, 619-634
This includes a bunch of discussion on backthrusts and how they might work in these terms.
But these days I'm not sure that strictly defined sequences (and out-of-sequences") are that helpful. In emergent thrust systems where stratigraphy can be used to data thrust-fold activity, synchroncity is the rule. Check out Burbank's (and colleagues) work from the Himalayan foreland system in Pakistan from way back in the 1980s. A bunch of us came to similar conclusions using growth strata in Sicily:
Butler, R.W.H. & Lickorish, W.H. 1997. Using high resolution stratigraphy to date fold and thrust activity: examples from the Neogene of South-central Sicily. J. Geol. Soc. London 154, 633-643.
Seismic examples from DW thrust systems show coeval thrust activity. There are some images in the VSA -
Try:
http://see-atlas.leeds.ac.uk:8080/homePages/generic.jsp?resourceId=090000648000f208
Of course systems tend to migrate forward into undeformed strata with time (as predicted/explained by critical wedge theory) which gives an appearance of "in-sequence" development in many systems.... even if on an incremental basis thrust activity was random. And where growth strata are not preserved, strict sequences can be very hard top discriminate from synchronicity (at variable rates) - as investigated in the Moine Thrust Belt (sorry - another one of mine): Butler, R.W.H. 2004. The nature of ‘roof thrusts” in the Moine Thrust Belt, NW Scotland: implications for the structural evolution of thrust belts. J. Geol. Soc. London, 161, 849-859.
All these should be accessible via the Lyell Collection (but let me know if not and, as with the others, can send pdfs), The VSA is open access to all.
Happy hunting
Rob
________________________________________
From: Tectonics & structural geology discussion list [[log in to unmask]] On Behalf Of Rubén Somoza [[log in to unmask]]
Sent: 03 March 2012 12:29
To: [log in to unmask]
Subject: Re: OOST
Dear Anupan
See the paper of Jonas Kley “Transition from basement-involved to
thin-skined thrusting in the Cordillera Oriental of southern Bolivia”,
published in Tectonics, 15 (4), 763-775, 1996
Regards
Rubén
> Dear Colleagues,
>
> Can anyone please suggest me some published maps/papers that
> show (preferably with cross-sections) natural 'out-of-sequence' thrusts
> and their kinematic relationship with the adjacent 'in-sequence' thrusts
> (including backthrusts)?
> Secondly, if backthrusts form in the hinterlandside of a thrust front,
> should they be designated 'out-of-sequence'?
>
> Thanks in advance for any help.
>
> Dr. Anupam Chattopadhyay
> Reader, Dept. of Geology,
> Delhi University
> Delhi 110 007, India
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>
Rubén Somoza
Dpto. Ciencias Geológicas, FCEyN, UBA
Ciudad Universitaria, Pabellón 2
C1428EHA, Buenos Aires, Argentina
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