Precision gravity networks at Lassen Peak and Mount Shasta, California

Lassen Peak—Our most active volcano

Bulletin of the Seismological Society of America ◽

10.1785/bssa0060010001 ◽

1916 ◽

Vol 6 (1) ◽

pp. 1-7

Author(s):

J. S. Diller

Keyword(s):

Active Volcano ◽

Lassen Peak

Download Full-text

The 1936, 1945-1947, and 1950 earthquake sequences near Lassen Peak, California

Journal of Geophysical Research Atmospheres ◽

10.1029/96jb02793 ◽

1997 ◽

Vol 102 (B1) ◽

pp. 449-457 ◽

Cited By ~ 5

Author(s):

R. D. Norris ◽

K. L. Meagher ◽

C. S. Weaver

Keyword(s):

Lassen Peak ◽

Earthquake Sequences

Download Full-text

Age of the Rockland tephra, western USA

Quaternary Research ◽

10.1016/j.yqres.2004.03.001 ◽

2004 ◽

Vol 62 (1) ◽

pp. 94-104 ◽

Cited By ~ 23

Author(s):

M.A. Lanphere ◽

D.E. Champion ◽

M.A. Clynne ◽

J.B. Lowenstern ◽

A.M Sarna-Wojcicki ◽

...

Keyword(s):

North America ◽

National Park ◽

Fall Deposit ◽

Ion Microprobe ◽

Western North America ◽

Weighted Mean ◽

Central California ◽

Ash Fall ◽

Lassen Peak ◽

Eruption Age

The age of the Rockland tephra, which includes an ash-flow tuff south and west of Lassen Peak in northern California and a widespread ash-fall deposit that produced a distinct stratigraphic marker in western North America, is constrained to 565,000 to 610,000 yr by 40Ar/39Ar and U–Pb dating. 40Ar/39Ar ages on plagioclase from pumice in the Rockland have a weighted mean age of 609,000 ± 7000 yr. Isotopic ages of spots on individual zircon crystals, analyzed by the SHRIMP-RG ion microprobe, range from ∼500,000 to ∼800,000 yr; a subpopulation representing crystal rims yielded a weighted-mean age of 573,000 ± 19,000 yr. Overall stratigraphic constraints on the age are provided by two volcanic units, including the underlying tephra of the Lava Creek Tuff erupted within Yellowstone National Park that has an age of 639,000 ± 2000 yr. The basaltic andesite of Hootman Ranch stratigraphically overlies the Rockland in the Lassen Peak area and has 40Ar/39Ar ages of 565,000 ± 29,000 and 565,000 ± 12,000 yr for plagioclase and groundmass, respectively. Identification of Rockland tephra in ODP core 1018 offshore of central California is an important stratigraphic age that also constrains the eruption age to between 580,000 and 600,000 yr.

Download Full-text

A Recent Volcanic Eruption near Lassen Peak, California. Howel Williams

The Journal of Geology ◽

10.1086/623609 ◽

1929 ◽

Vol 37 (2) ◽

pp. 186-187

Author(s):

Arthur Bevan

Keyword(s):

Volcanic Eruption ◽

Lassen Peak

Download Full-text

Correlation of the Rockland Ash Bed, a 400,000-Year-Old Stratigraphic Marker in Northern California and Western Nevada, and Implications for Middle Pleistocene Paleogeography of Central California

Quaternary Research ◽

10.1016/0033-5894(85)90031-6 ◽

1985 ◽

Vol 23 (2) ◽

pp. 236-257 ◽

Cited By ~ 61

Author(s):

Andrei M. Sarna-Wojcicki ◽

Charles E. Meyer ◽

Harry R. Bowman ◽

N. Timothy Hall ◽

Paul C. Russell ◽

...

Keyword(s):

San Francisco ◽

Hot Spring ◽

Temporal Correlation ◽

Middle Pleistocene ◽

Northern California ◽

Central California ◽

Mohawk Valley ◽

Glaciofluvial Deposits ◽

Lassen Peak ◽

Great Valley

Outcrops of an ash bed at several localities in northern California and western Nevada belong to a single air-fall ash layer, the informally named Rockland ash bed, dated at about 400,000 yr B.P. The informal Rockland pumice tuff breccia, a thick, coarse, compound tephra deposit southwest of Lassen Peak in northeastern California, is the near-source equivalent of the Rockland ash bed. Relations between initial thickness of the Rockland ash bed and distances to eruptive source suggest that the eruption was at least as great as that of the Mazama ash from Crater Lake, Oregon. Identification of the Rockland tephra allows temporal correlation of associated middle Pleistocene strata of diverse facies in separate depositional basins. Specifically, marine, littoral, estuarine, and fluvial strata of the Hookton and type Merced formations correlate with fluvial strata of the Santa Clara Formation and unnamed alluvium of Willits Valley and the Hollister area, in northwestern and west-central California, and with lacustrine beds of Mohawk Valley, fluvial deposits of the Red Bluff Formation of the eastern Sacramento Valley, and fluvial and glaciofluvial deposits of Fales Hot Spring, Carson City, and Washoe Valley areas in northeastern California and western Nevada. Stratigraphic relations of the Rockland ash bed and older tephra layers in the Great Valley and near San Francisco suggest that the southern Great Valley emerged above sea level about 2 my ago, that its southerly outlet to the ocean was closed sometime after about 2 my ago, and that drainage from the Great Valley to the ocean was established near the present, northerly outlet in the vicinity of San Francisco Bay about 0.6 my ago.

Download Full-text