INENCO   05446
INSTITUTO DE INVESTIGACIONES EN ENERGIA NO CONVENCIONAL
Unidad Ejecutora - UE
artículos
Título:
High-temperature emplacement of the Cerro Galán and Toconquis Group ignimbrites( Puna Plateau NW Argentina) determined by TRM analisys
Autor/es:
LESTI CHIARA; PORRECA, M.; GIORDANO, G.; MATTEI, M.; CAS RAYMOND; WRIGHT, H.; FOLKES, C.; JOSE G. VIRAMONTE
Revista:
BULLETIN OF VOLCANOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2011
ISSN:
0258-8900
Resumen:
temperatures in the Cerro Galán ignimbrite and Toconquis
Group ignimbrites were determined using thermal
remanent magnetization of lithic clasts embedded within
the deposits. These ignimbrites belong to the Cerro
Galán volcanic system, one of the largest calderas in the
world, in the Puna plateau, NW Argentina. Temperature
estimates for the 2.08-Ma Cerro Galán ignimbrite are
retrieved from 40 sites in 14 localities (176 measured
clasts), distributed at different distances from the caldera
and different stratigraphic heights. Additionally, temperature
estimates were obtained from 27 sample sites (125
measured clasts) from seven ignimbrite units forming
the older Toconquis Group (5.604.51 Ma), mainly
outcropping along a type section at Rio Las Pitas, Vega
Real Grande. The paleomagnetic data obtained by
progressive thermal demagnetization show that the clasts
of the Cerro Galán ignimbrite have one single magnetic
component, oriented close to the expected geomagnetic
field at the time of emplacement. Results show therefore
that most of the clasts acquired a new magnetization
oriented parallel to the magnetic field at the moment of
the ignimbrite deposition, suggesting that the clasts were
heated up to or above the highest blocking temperature
(Tb) of the magnetic minerals (Tb=580°C for magnetite;
outcropping along a type section at Rio Las Pitas, Vega
Real Grande. The paleomagnetic data obtained by
progressive thermal demagnetization show that the clasts
of the Cerro Galán ignimbrite have one single magnetic
component, oriented close to the expected geomagnetic
field at the time of emplacement. Results show therefore
that most of the clasts acquired a new magnetization
oriented parallel to the magnetic field at the moment of
the ignimbrite deposition, suggesting that the clasts were
heated up to or above the highest blocking temperature
(Tb) of the magnetic minerals (Tb=580°C for magnetite;
outcropping along a type section at Rio Las Pitas, Vega
Real Grande. The paleomagnetic data obtained by
progressive thermal demagnetization show that the clasts
of the Cerro Galán ignimbrite have one single magnetic
component, oriented close to the expected geomagnetic
field at the time of emplacement. Results show therefore
that most of the clasts acquired a new magnetization
oriented parallel to the magnetic field at the moment of
the ignimbrite deposition, suggesting that the clasts were
heated up to or above the highest blocking temperature
(Tb) of the magnetic minerals (Tb=580°C for magnetite;
4.51 Ma), mainly
outcropping along a type section at Rio Las Pitas, Vega
Real Grande. The paleomagnetic data obtained by
progressive thermal demagnetization show that the clasts
of the Cerro Galán ignimbrite have one single magnetic
component, oriented close to the expected geomagnetic
field at the time of emplacement. Results show therefore
that most of the clasts acquired a new magnetization
oriented parallel to the magnetic field at the moment of
the ignimbrite deposition, suggesting that the clasts were
heated up to or above the highest blocking temperature
(Tb) of the magnetic minerals (Tb=580°C for magnetite;Tb) of the magnetic minerals (Tb=580°C for magnetite;
Tb=600630°C for hematite). We obtained similar emplacement
temperature estimations for six out of the seven
volcanic units belonging to the Toconquis Group, with the
exception of one unit (Lower Merihuaca), where we found
two distinct magnetic components. The estimation of
emplacement temperatures in this latter case is constrained
at 580610°C, which are lower than the other ignimbrites.
These estimations are also in agreement with the lowest
pre-eruptive magma temperatures calculated for the
same unit (i.e., 790°C; hornblendeplagioclase thermometer;
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
These estimations are also in agreement with the lowest
pre-eruptive magma temperatures calculated for the
same unit (i.e., 790°C; hornblendeplagioclase thermometer;
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
These estimations are also in agreement with the lowest
pre-eruptive magma temperatures calculated for the
same unit (i.e., 790°C; hornblendeplagioclase thermometer;
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
temperature estimations for six out of the seven
volcanic units belonging to the Toconquis Group, with the
exception of one unit (Lower Merihuaca), where we found
two distinct magnetic components. The estimation of
emplacement temperatures in this latter case is constrained
at 580610°C, which are lower than the other ignimbrites.
These estimations are also in agreement with the lowest
pre-eruptive magma temperatures calculated for the
same unit (i.e., 790°C; hornblendeplagioclase thermometer;
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
These estimations are also in agreement with the lowest
pre-eruptive magma temperatures calculated for the
same unit (i.e., 790°C; hornblendeplagioclase thermometer;
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
These estimations are also in agreement with the lowest
pre-eruptive magma temperatures calculated for the
same unit (i.e., 790°C; hornblendeplagioclase thermometer;
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface
Folkes et al. 2011b). We conclude that the Cerro Galán
ignimbrite and Toconquis Group ignimbrites were emplaced
at temperatures equal to or higher than 620°C, except for
Lower Merihuaca unit emplaced at lower temperatures. The
homogeneity of high temperatures from proximal to distal
facies in the Cerro Galán ignimbrite provides constraints for
the emplacement model, marked by a relatively low eruption
column, low levels of turbulence, air entrainment, surface