Great Basin paleoenvironmental studies project; Technical progress report, second quarter, September--November, 1993

Progress is described in the four tasks associated with this project. Task 1, Paleobotanical studies in the Great Basin, has as its objective the reconstruction of the response of vegetation to climate in order to identify periods of mesic climate at Yucca Mountain during the last 20,000 to 50,000 years. Past extremes in infiltration rates are expected to serve as estimates of climate that may be expected during the next 10,000 years at Yucca Mtn. Task 2, Paleofaunas, will construct a history of Great Basin vertebrates that will provide empirical evidence of past environmental and climatic conditions. The objective of Task 3, Geomorphology, is to document the responses of surficial processes and landforms to the climatic changes documented by studies of packrat middens, pollen, and faunal distributions. The goal of Task 4, Transportation, is to compare the results from three models that have been suggested as appropriate for evaluating flood flows on alluvial fans with the results obtained from the traditional one-dimensional, stochastic model used in previous research for Yucca Mountain. This research looked at three alluvial fans with rail transportation alignments crossing them