INVESTIGADORES
VIRAMONTE Jose German
artículos
Título:
Large-scale silicic volcanism the result of thermal maturation of the crust. 13:56 WSPC/SPI-B368 Vol. 1 ch21: 215-230
Autor/es:
SHANAKA DE SILVA, GEORGE ZANDT, ROBERT TRUMBULL AND JOSÉ G. VIRAMONTE
Revista:
Advanced in Geosciences
Editorial:
Copernicus GmvbH (EGU)
Referencias:
Lugar: Alemania; Año: 2006 vol. 1 p. 215 - 230
Resumen:
Large Silicic Volcanic Fields (LSVF) are common features of the circum-paci.c
active continental margins in space and time. They are considered to be the
surface manifestations of batholith formation at depth and are commonly associated
with "ignimbrite .are-ups." The Late Miocene to Recent Altiplano-Puna
Volcanic Complex (APVC) of the Central Andes is one of the largest and best
preserved LSVF in the world. Here, available age and volume data on major ignimbrite
eruptions in the APVC shows that ignimbrite volcanism in the region
initiated at ¡«10Ma with several large but regionally restricted units such as
the Artola and Sifon ignimbrites and ignimbrites of the Vilama-Corutu center.
Activity continued for 10Ma to the recent but appears to have "pulsed"
with major episodes of activity at ¡«8, 6, and 4Ma. Activity since 4Ma has
been minor with the largest eruptions being those of the Purico and Laguna
Colorado centers at ¡«1Ma. Three characteristics of the available age and volume
data are: (1) Pulsing of the ignimbrite eruptions with an approximate two
million year period. (2) Trend to larger volume eruptions climaxing at about
4Ma. (3) Markedly diminished activity since 4Ma. Interestingly the pattern of
sudden onset of spatially di.use, volumetrically minor eruptions leading to a
focused catastrophic episode that is followed by quiescence seems to be a feature
of other large silicic volcanic .elds. This suggests a consistency of process
during ignimbrite .are-ups in space and time. We present a model of these
large silcic volcanic .elds as the result of progressive thermal (and mechanical)
maturation of the crustal column due to advection of heat by magmatism and
its e.ects on lithosphere strength. Elevation of the brittle-ductile transition to
within a few kilometers of the surface leads to eventual catastrophic failure of
the crust and explosive eruptions of thousands of cubic kilometers of magma
as regionally extensive ignimbrites.
as regionally extensive ignimbrites.¡«10Ma with several large but regionally restricted units such as
the Artola and Sifon ignimbrites and ignimbrites of the Vilama-Corutu center.
Activity continued for 10Ma to the recent but appears to have "pulsed"
with major episodes of activity at ¡«8, 6, and 4Ma. Activity since 4Ma has
been minor with the largest eruptions being those of the Purico and Laguna
Colorado centers at ¡«1Ma. Three characteristics of the available age and volume
data are: (1) Pulsing of the ignimbrite eruptions with an approximate two
million year period. (2) Trend to larger volume eruptions climaxing at about
4Ma. (3) Markedly diminished activity since 4Ma. Interestingly the pattern of
sudden onset of spatially di.use, volumetrically minor eruptions leading to a
focused catastrophic episode that is followed by quiescence seems to be a feature
of other large silicic volcanic .elds. This suggests a consistency of process
during ignimbrite .are-ups in space and time. We present a model of these
large silcic volcanic .elds as the result of progressive thermal (and mechanical)
maturation of the crustal column due to advection of heat by magmatism and
its e.ects on lithosphere strength. Elevation of the brittle-ductile transition to
within a few kilometers of the surface leads to eventual catastrophic failure of
the crust and explosive eruptions of thousands of cubic kilometers of magma
as regionally extensive ignimbrites.
as regionally extensive ignimbrites.¡«8, 6, and 4Ma. Activity since 4Ma has
been minor with the largest eruptions being those of the Purico and Laguna
Colorado centers at ¡«1Ma. Three characteristics of the available age and volume
data are: (1) Pulsing of the ignimbrite eruptions with an approximate two
million year period. (2) Trend to larger volume eruptions climaxing at about
4Ma. (3) Markedly diminished activity since 4Ma. Interestingly the pattern of
sudden onset of spatially di.use, volumetrically minor eruptions leading to a
focused catastrophic episode that is followed by quiescence seems to be a feature
of other large silicic volcanic .elds. This suggests a consistency of process
during ignimbrite .are-ups in space and time. We present a model of these
large silcic volcanic .elds as the result of progressive thermal (and mechanical)
maturation of the crustal column due to advection of heat by magmatism and
its e.ects on lithosphere strength. Elevation of the brittle-ductile transition to
within a few kilometers of the surface leads to eventual catastrophic failure of
the crust and explosive eruptions of thousands of cubic kilometers of magma
as regionally extensive ignimbrites.
as regionally extensive ignimbrites.¡«1Ma. Three characteristics of the available age and volume
data are: (1) Pulsing of the ignimbrite eruptions with an approximate two
million year period. (2) Trend to larger volume eruptions climaxing at about
4Ma. (3) Markedly diminished activity since 4Ma. Interestingly the pattern of
sudden onset of spatially di.use, volumetrically minor eruptions leading to a
focused catastrophic episode that is followed by quiescence seems to be a feature
of other large silicic volcanic .elds. This suggests a consistency of process
during ignimbrite .are-ups in space and time. We present a model of these
large silcic volcanic .elds as the result of progressive thermal (and mechanical)
maturation of the crustal column due to advection of heat by magmatism and
its e.ects on lithosphere strength. Elevation of the brittle-ductile transition to
within a few kilometers of the surface leads to eventual catastrophic failure of
the crust and explosive eruptions of thousands of cubic kilometers of magma
as regionally extensive ignimbrites.
as regionally extensive ignimbrites.
