Dr Siddiquie has contributed to the marine geology of the Bay of Bengal and the Arabian Sea and prepared a sediment distribution map of the seas around India. His studies have shed new light on the origin of the Laccadive Ridge and its relationship with the Western continental margin of India. His success in locating nad proving large resources of calcareous sediments in offshore areas of Laccadive islands and in the delineation of the submarine oil pipeline route is of considerable importance in the context of proper utilization of the offshore resources.