Dynamics of the plinian eruptive phase of Laacher See Volcano (Eifel, West Germany)

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6597000

Bogaard, P V.D.; Schmincke, H U

Phonolitic tuffs, erupted by Laacher See Volcano 11,000 a B.P., cover some 700,000 km/sup 2/ in Central and Northern Europe, form an important marker in Late Glacial sedimentary sections, and comprise some 5 km/sup 3/ phonolite magma (DRE). Some 80% of the magma was erupted during two major Plinian eruptive phases, which produced an airfall pumice bed and an overlying sequence of ash flow deposits and intercalated fallout pumice and are separated by a minor phreatomagmatic eruptive phase (MLST A). Ballistic blocks up to 1.5 m in diameter are abundant in near-vent deposits from most eruptive phases. With transport ranges up to 2.5 km, the ballistic blocks indicate initial velocities of the Plinian eruption columns of c. 300-350 m/s, which fits magmatic gas releases of 2-2.5 wt.-% (H/sub 2/O). Mass eruption rates are estimated as 3x10/sup 8/ to 4x10/sup 8/ kg/s, corresponding to vent radii of 200-250 m. The change in eruption style from a sustained Plinian column to repeatedly collapsing and recovering Plinian eruption columns is interpreted in terms of an interplay of vent erosion and volcanotectonic faulting during a 1 km lateral displacement of the eruptive vent.

• Research Organization: Univ. of Toronto, Scarborough, Ontario (Canada)
• OSTI ID: 6597000
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
FEDERAL REPUBLIC OF GERMANY
VOLCANOES
PUMICE
PETROGENESIS
TUFF
GEOLOGIC HISTORY
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
MAGMA
MAGMATISM
VOLCANISM
EUROPE
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
WESTERN EUROPE
580202* - Geophysics- Volcanology- (1980-1989)
580300 - Mineralogy
Petrology
& Rock Mechanics- (-1989)