Chapter 28 Geology of the Houtman Abrolhos islands

Abstract

This chapter provides information on the geology of the Houtman Abrolhos Islands. The Houtman Abrolhos islands are small rocky islands of Holocene and Pleistocene coral-reef limestone along the shelf margin 70 km from the coast of Western Australia. The exposed parts of this coral-reef complex consist of over 100 islands that exist in three groups (the Wallabi, Easter, and Pelsaert Groups). The islands of the Houtman Abrolhos are the outcropping portions of three shelfedge carbonate platforms. The islands of the Houtman Abrolhos are on three carbonate platforms that are separated by deep channels. The islands are the emergent parts of shallow reef platforms. Consequently they provide windows into platform geology, which includes coral-reef development in the late Quaternary. With more detailed research such a long-term record can also be coupled to an understanding of such short-term processes of environmental change as variations in seasurface temperature related to fluctuations of the Leeuwin Current.