Augustine Crooked Creek Tephra

Start: 8375 yBP ± 210 Years [1]

Stop: 7725 yBP ± 210 Years [1]

Event Type: Explosive

Event Characteristics:
  • Tephrafall [1]

Description: From Reger and others (1995): "One of several grayish brown-weathering Holocene tephras in Kenai Lowland that are the products of brief, small eruptions of Cook Inlet volcanoes-and not known to be widely distributed-is the Crooked Creek tephra, which is first recognized and informally named in this study. This tephra is identified in 11 stratigraphic sections (table 2 [in original text]) in a narrow belt from west of Tustumena Lake northeast to the vicinity of Sterling (fig. 4 [in original text]). Correlation within this set of samples is good to excellent (SC=0.93-0.99) (table 5 [in original text]). We know of no correlative tephras in the region, but we speculate (from the distribution and high silica content) that Crooked Creek tephra could have been erupted from Mt. Augustine. The Crooked Creek tephra was deposited between 7,725+/-210 14C yr ago and 8,375+/210 14C yr ago (fig. A25; table 2, C10 and C17 [in original text]). It could possibly be the distal equivalent of tephra layer G, which dates >1,830+/-80 14C yr B.P. and <39,890 14C yr B.P. on Augustine Island (Beget and Kienle, 1992)."

References Cited

[1] Catalog and initial analyses of geologic data related to middle and late Quaternary deposits, Cook Inlet region, Alaska, 1996

Reger, R. D., Pinney, D. S., Burke, R. M., and Wiltse, M. A., 1996, Catalog and initial analyses of geologic data related to middle and late Quaternary deposits, Cook Inlet region, Alaska: Alaska Division of Geological & Geophysical Surveys Report of Investigation 95-06, 188 p., 6 sheets, scale 1:250,000.

Complete Eruption References

Catalog and initial analyses of geologic data related to middle and late Quaternary deposits, Cook Inlet region, Alaska, 1996

Reger, R. D., Pinney, D. S., Burke, R. M., and Wiltse, M. A., 1996, Catalog and initial analyses of geologic data related to middle and late Quaternary deposits, Cook Inlet region, Alaska: Alaska Division of Geological & Geophysical Surveys Report of Investigation 95-06, 188 p., 6 sheets, scale 1:250,000.
website with links to PDF files
Hard Copy held by AVO at FBKS - CEC shelf