Eruptive history of Earth's largest Quaternary caldera (Toba, Indonesia) clarified

Journal Article · Fri Mar 01 00:00:00 EST 1991 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1991)019<0200:EHOESL>2.3.CO;2· OSTI ID:5732007

Chesner, C A ^[1]; Rose, W I ^[2]; Drake, R; Deino, A ^[3]; Westgate, J A ^[4]

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1. Eastern Illinois Univ., Charleston (USA)
2. Michigan Technological Univ., Houghton (USA)
3. Institute of Human Origins, Berkeley, California (USA)
4. Univ. of Toronto, Scarborough, Ontario (Canada)

Single-grain laser-fusion {sup 40}Ar/{sup 39}Ar analyses of individual sanidine phenocrysts from the two youngest Toba (Indonesia) tuffs yield mean ages of 73{plus minus}4 and 501{plus minus}5 ka. In addition, glass shards from Toba ash deposited in Malaysia were dated at 68{plus minus}7 ka by the isothermal plateau fission-track technique. These new determinations, in conjunction with previous ages for the two oldest tuffs at Toba, establish the chronology of four eruptive events from the Toba caldera complex over the past 1.2 m.y. Ash-flow tuffs were erupted from the complex every 0.34 to 0.43 m.y., culminating with the enormous (2500-3000 km{sup 3}) Youngest Toba tuff eruption, caldera formation, and subsequent resurgence of Samosir Island. Timing of this last eruption at Toba is coincident with the early Wisconsin glacial advance. The high-precision {sup 40}Ar/{sup 39}Ar age eruption of such magnitude may provide an important marker horizon useful as a baseline for research and modeling of the worldwide climatic impact of exceptionally large explosive eruptions.

• OSTI ID: 5732007
• Journal Information: Geology; (USA), Vol. 19:3; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CALDERAS
AGE ESTIMATION
TECTONICS
INDONESIA
ARGON 39
ARGON 40
CLIMATES
FISSION TRACKS
GEOLOGIC HISTORY
GEOLOGIC MODELS
GLACIERS
GLOBAL ASPECTS
ISLANDS
ISOTOPE DATING
ISOTOPE RATIO
QUATERNARY PERIOD
TUFF
VARIATIONS
VOLCANIC ROCKS
ARGON ISOTOPES
ASIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CENOZOIC ERA
DEVELOPING COUNTRIES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GEOLOGIC AGES
IGNEOUS ROCKS
ISOTOPES
LIGHT NUCLEI
NUCLEI
PARTICLE TRACKS
RADIOISOTOPES
ROCKS
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES
580000* - Geosciences