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Hi Sanjeet, The outcrop appearance and deformation geometry surely could be the result of soft-sediment deformation, leading to some interesting stress state interpretations (thanks Dirk). However, Janos is absolutely right that some more info is needed (lithology, burial history(any?),...) prior to arriving at any conclusion from this very nice field photograph. It is usually impossible to speculate on the state of a rock during deformation only on the basis of a photograph. Regards Tim On Mon, Jan 20, 2014 at 7:34 AM, Dirk Nieuwland <[log in to unmask]> wrote: > Hallo Sanjeet, > > Thank you for sharing this very interesting field photo. > > Small scale thrusting in this fashion can be the result of uplift with > 'locked-in' horizontal stress. > If the horizontal stresses cannot be released during uplift, the only > stress orientation that is reduced is the vertical stress. > This is inevitable, because the vertical stress is simply the weight of > the overburden. For example, if the uplift is 1000 m, and the mean specific > gravity of the sediments is about 2,5 gr/cm3, the effective stress reduces > with 150 bar. > I tried the construction with a Mohr circle, but for a basin in rest and a > weak rock with a Poissons ration of 0.3 I could not create a thrust by > uplift only. > However, in a situation with a relatively weak rock and a compressional > state of stress to start off with (not thrusting but e.g. a strike-slip > regime) the small scale thrusting that you show could potentially be the > result. > The suggestion for this process comes from (I believe) John Ramsey, but I > do not have the reference at hand. > I think the example that John Ramsey used came from a Kimmeridge outcrop > at the English coast, I am sorry that I cannot be more precise. > > Regards, Dirk > > > Dirk Nieuwland > 4e Binnenvestgracht 13 > 2311NT Leiden > URL: www.newtec.nl > E: [log in to unmask] > M: +31 (0)621547949 > > On 19 Jan 2014, at 15:29, SANJEET SHARMA <[log in to unmask]> wrote: > > Dear All, > Please give your comments on the structure present in this > pic. > > With regards. > > ............................................................................................................................................ > Sanjeet Sharma > M.Sc. Applied Geology(2011) > Department of Earth and Planetary Sciences > University of Allahabad > Allahabd-211002, INDIA > Mob. No. : +91-945-283-0062 > <DSC04739a.jpg> > > > -- T.N. Debacker | +61 402 848 530 | Senior Structural Geologist | FrOGTECH | Canberra, ACT, Australia *http://www.linkedin.com/pub/timothy-debacker/6/b64/122 <http://www.linkedin.com/pub/timothy-debacker/6/b64/122> | http://www.frogtech.com.au <http://www.frogtech.com.au> | http://ugent.academia.edu/TimothyDebacker <http://ugent.academia.edu/TimothyDebacker>*