SOUTH MOUNTAIN ANTICLINE

This locality in eastern US became synonymous with strain determination based on deformed oolites that E Cloos carried out in forties, and eventually published in 1947. The deformed oolites of South Mountain Anticline were used by Cloos to determine the finite strain and this work is the first towards the quantitative aspect of finite strain determination. On the basis of his study, Cloos showed that the strains were small on the normal but large on the overturned limb of the anticlinal fold and the long axes of oolites corresponded with the cleavage trajectories of the fold. However, Cloos was a little perplexed as the margins of deformed oolites were "frayed" which made actual micrometric analysis a difficult task. This was because of extensive pressure solution that gave rise to tectonic stylolites or spaced PS stripes. He found it hard to excatly measure the long and short axes of deformed oolites. The actual plastic deformation component of oolites is rather small. Shankar Mitra in 1978 did work on this antcline and was able to separate the components of pressure solution from plastic deformation from deformed rutile crystals in quartz grains.