Significance and origin of surface textures on broken sand grains in deep-sea sediments



The surface textures of fine sand particles from the Deep Sea Drilling Project Leg 39 have been studied via scanning electron microscopy. A large portion of the coarsest fraction of these grains from deep sea cores were formerly fragments of larger sand-sized grains that had been mechanically broken. Surface textures characteristic of previous aeolian and subaqueous environments were preserved in fragments broken from the original larger grain surfaces, thus making palaeo-environmental reconstruction possible.

Previously, characteristic mechanical markings had not been observed on deep sea sands; the momentum of grain to grain collisions with respect to fine sands is generally insufficient to initiate mechanical breakage.