Cgiceage1
CALIFORNIA'S ICE AGE
1. Pleistocene-Alpine (not continental) Glaciation developed
a. Characteristics:
U shaped valleys-horn shaped ridges, aretes polished surfaces, glacial till--moraines-terminal and lateral
b. Four major advances of Alpine glaciation
(1) In Southern Sierra Nevada--evidence exists (succession of 11 recognizable glacial
tills
(2) West of highway 395 at Independence Peak road west of Big Pine, in Owens Valley in
the access to Palisade Glacier California's largest living Glacier
(3) McGee till about 2.5 million years
(4)Sherwin till-younger than McGee but older than 700,000 yrs overlying Bishop Tuff
Uplift--several thousand feet between McGee to Sherwin time
Above these
(a) Like Lake Tahoe
(b) Lake Tenaya
(c) Tioga Pass
-60,000-90,000 yr. Volcanics
(4) Ice extended as low as 3,000 ft above sea level and was 6,000 ft thick in Yosemite
(5) Farthest South were above 8,700 on San Gorgonia Mt. in San Bernardino mountains