Sedimentary rocks found high in the himalayan mountains have been found with fossils of clams and other marine life. what does this indicate about the origin of the himalayan mountains? a) there was once a large ocean at top of the mountains. b) animals that now live on the mountains once lived under water. c) the earth's crust that formed these mountains was once covered with an ocean. d) continental drift resulted two tectonic moving closer to each other over time.