Formation and Organization of the Athalassic Salt Lakes of Australia :: Geology Research Papers

Formation and Organization of the Athalassic Salt Lakes of Australia Preface Upon my acceptance to the Biomes of Australia 2003 program – a biologically-oriented summer experience in the â€Å"Land Down Under† that, for the 6th consecutive year, has been organized by Dr. Warren Dolphin of Iowa State University – I was presented with the task of writing a research paper on an aspect of the Australian landscape. Anxious to apply my new knowledge of geomorphology and desiring to investigate an ecosystem from the holistic perspective of an environmental scientist, I settled upon investigating the formative elements of athalassic (inland) salt lakes and how they determine the ecological structure of salt lake playas. The research summarized in this report is an assimilation of fragmented literature on the subject and represents an attempt to integrate those pieces for better clarity. I believe that my travel companions, to whom I am obligated to present this information, shall derive a greater understanding of Australian salt lake systems f rom a broad examination of the subject than from an intensely focused analysis of but a single component. Although the information that I present is indeed broad in scope, the reader must realize that it falls short of comprehensiveness. The shear volume of literature prohibits designing anything other than a series of encyclopedias to encompass the full complexity of salt lake systems. It is my hope, rather, that this paper elicits the reader’s curiosity and prompts further reading on this fascinating area. The introduction draws a necessary overview of salt lakes in basic geographic and geologic terms. Part I examines the processes of basin and lake formation, first the physical mechanisms of creation and secondly the concentration of ions within the basin. Part II explores the effects of salinity and other chemical characteristics on lake fauna. Part III explains how climatic adjustments determine the composition of vegetation in and around salt lake basins. Together, these pieces should provide some insight to a central question of this paper: What physical and chemical characteristics of athalassic salt lakes, as determined by the regional climatic and hydrologic regime, determine local ecologies? Abstract The athalassic salt lakes of Australia arose during the continent’s shift to the present arid/semi-arid climate regime. Some, such as Lake Eyre are ephemeral and hold water only after infrequent and irregular rains; others flood intermittently or permanently contain water.