Lisa Morgan, a research geologist for the U.S. Geological Survey, will present "The Track of the Yellowstone Hot Spot" at 4:30 p.m. today (Thursday, Dec. 3) in 209 Hubbard Hall. Admission is free. The talk is part of the Watkins Visiting Professorship Lecture Series. Morgan's focus is on the geology and geophysics of volcanic terrains. Because of weather-related flight delays, Morgan's scientific lecture, "Large hydrothermal systems above the Yellowstone magma chamber," has been rescheduled for 11:30 a.m. Friday, Dec. 4, in 101 Geology Building.