ROCK WEATHERING AND HILLSLOPE TRANSPORT IN MCMURDO DRY VALLEYS, ANTARCTICA

Antarctica has some of the slowest rock weathering and regolith erosion rates on Earth. The erosion rates have been consistently slow for at least past few million years. Therefore it is an ideal natural laboratory to observe the slow disintegration of rocks in situ. One major advantage of studying the rock weathering in Antarctica is that the resulting rocks and patterns reflect long period of time and yet the resulting chips are still clearly observable.

As the surficial boulders weather and break the chips fall next to the boulder. On a slope the chips are slowly transported downhill along with other eolian driven regolith. In this environment the breakdown of the rocks and the subsequent transportation are so slow that many of the chips can still be observed next to the boulder and in case of a locally rare lithology they form a distinct trail downslope of the source boulder. In McMurdo Dry Valleys we observed tens of in situ weathering boulders that had distinct chips on the downhill side forming a trail.

We found that Sandstone fragments travel (are found) about ten times farther than Granitic and Metamorphic fragments on a given slope angle. We will also present the results on the lateral dispersal of the chips and the travel distance fragment size relation.