Abstract
Exposures of steeply dipping Jurassic limestones in the Surghar Range, West Pakistan, allow detailed observations of various biogenic and sedimentary features. Thin-bedded dolomites, desiccation cracks, scour-and-fill structures, and shallow-water benthonic Foraminifera, within a dominant lithology of pellet carbonate grainstones and mudstones, indicate very shallow carbonate shelf conditions at the time of deposition. Periods of subaerial exposure, and subsequent lithification are indicated by the presence of oriented bivalve borings, both on surfaces which have been desiccated and on one surface which has been corraded by tidal currents. The latter exposure surface contains pebbles of identical lithology within the reticular gullies. Encrusting oysters are common. Subma ine cementation of the surfaces is discounted because of the absence of inverted borings, superimposed bored surfaces, and extensively bioturbated sediment. End_of_Article - Last_Page 366------------
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
