 The Grenadines are geologically older than St. Vincent and are situated on an extensive shallow bank of volcanic origin – known as the southern Lesser Antilles arc platform (SLAAP).The SLAAP is a product of Miocene uplift (23–16 Ma) and characterized by Eocene to Pliocene extrusive to intrusive igneous rocks along with sedimentary rocks such as limestone, marl, and chert, and epiclastic arc-derived volcaniclastic units composed of mudstone, sandstone, and conglomerate.The islands are composed of a variety of volcanic and sedimentary rocks.