Abstract:

Microtextures analysis of quartz grains from the Y2 lake sediment of Antarctic Ardley Island was performed by Scanning Electron Microscopy(SEM)in order to investigate the forming mechanism of erosion bowled-pit on quartz grains in sediments influenced by penguin droppings.While this special characteristic didn't occure in the Y2 lake sediments without the influence of penguin droppings and other sedimentary environment.Because of penguin droppings' influences,there is a quite high fluorine ion content in the Y2 sediments.To understand the forming mechanism of the special characteristic,we used 1 mol·L-1 HF acid as dissolving solution to erode numerous quartz grains with fresh surfaces,and then compared it with natural features on quartz grains in the sediments.As a result,the micro-textures on the quartz grains by modeling in the laboratory are very similar to those found in the Y2 lake sediments influenced by penguin droppings,indicating that acidity and fluoride-bearing environment is likely the reason of forming the bowled-pit on quartz surface.Therefore,the close association between erosion bowl-pits and penguin droppings under the special natural conditions of Antarctica may provide valuable insight into the investigating on the Antarctic penguin ecology by the other new method of micro-textures analysis of quartz grains.