Salt lakes: carbonate/evaporite sedimentology and paleolimnology

在过去的十年里，人们对湖泊沉积物的兴趣和研究呈爆炸式增长。湖泊的底部沉积物可以提供湖泊本身和周围集水区发生的变化的非常详细的记录。由于湖泊占据地形封闭的盆地比其他沉积体系更敏感的气候引起的波动，这是毫不奇怪，这些封闭的盆地的沉积物是古环境研究的有吸引力的目标。然而，在我们能够“阅读”这一重要的过去环境变化档案之前，我们必须首先了解沉积物被带入盆地、沉积和变化的过程。简而言之，我们必须先了解现代湖泊，然后才能解释保存下来的古代记录。在过去的十年里，我的大部分研究都集中在理解现代封闭盆地盐湖中发生的复杂相互作用和沉积过程。虽然取得了重大进展，但仍有许多工作要做。笔者拟在加拿大西部的北方大平原、澳大利亚南部的西部火山平原区和艾尔半岛、东太平洋地区的加拉帕戈斯群岛等3个地区开展闭盆盐湖沉积学和古湖沼学研究。选择这三个地区是因为具体的环境问题以及每个地区湖泊系统的互补性。我这项研究的长期科学目标是（i）定量描述在选定盆地中运行的现代沉积过程，（ii）了解这些湖泊沉积物的起源和沉积后变化;（iii）在选定的盆地中解释碳酸盐矿物形成的环境条件，特别强调加拿大和澳大利亚湖泊中的神秘矿物白云石和单水方解石，最后（iv）解释过去10 k年中湖泊发生的环境变化，并将这些变化与任何自然演变趋势、区域气候波动和人为修改联系起来。

The past decade has witnessed explosive growth in interest and research on lake sediments. The bottom deposits of lakes can provide a very detailed record of changes that occurred both within the lake itself and in the surrounding catchment. Because lakes occupying topographically closed basins are more sensitive than other depositional systems to climate-induced fluctuations, it is no surprise that the sediments of these closed basins are attractive targets for paleoenvironmental research. However, before we can 'read' this important archive of past environmental change, we must first understand the processes by which the sediments are brought into the basin, deposited and changed. In short, we must understand the modern lakes before we can interpret the preserved ancient records. Much of my research over the past decade has concentrated on understanding the complex interactions and sedimentary processes occurring in modern closed basin salt lakes. Although significant advances have been made, there is still much to do. I propose to conduct research on the sedimentology and paleolimnology of closed basin salt lakes in 3 areas of the world: (i) Northern Great Plains of western Canada, (ii) western Volcanic Plains District and Eyre Peninsula of southern Australia, and (iii) Galapagos Islands in the eastern Pacific region. These three areas were chosen because of specific environmental concerns as well as the complementary nature of the lacustrine systems in each region. My long-term scientific objectives of this research are to (i) quantitatively describe the modern sedimentary processes operating in selected basins, (ii) understand the origin and post-depositional changes that have occurred in the deposits in these lakes; (iii) decipher the environmental conditions of carbonate mineral formation in selected basins, with particular emphasis on the enigmatic minerals dolomite and monohydrocalcite in the Canadian and Australian lakes, and finally (iv) interpret the environmental changes that have occurred in the lakes during the past 10k yrs, and relate these changes to any natural evolutionary trends, regional climatic fluctuations and anthropogenic modifications.