Holocene collapse of Socompa volcano and pre- and post-collapse growth rates constrained by multi-system geochronology
Por:
Grosse, Pablo, Danisik, Martin, Apaza, Facundo D., Guzman, Silvina R., Lahitte, Pierre, Quidelleur, Xavier, Self, Stephen, Siebe, Claus, van Wyk de Vries, Benjamin, Ureta, Gabriel, Guillong, Marcel, De Rosa, Rosanna, Le Roux, Petrus, Wotzlaw, Jorn-Frederik, Bachmann, Olivier
Publicada:
17 ago 2022
Categoría:
Geochemistry and petrology
Resumen:
Volcano sector collapses are catastrophic events that can mobilize huge
volumes of material and cause changes in the magmatic plumbing system,
leading to variations in growth rate and/or composition. Dating
pre-historic volcanic debris avalanche deposits is challenging.
Geological materials directly recording avalanche formation and amenable
to radiometric dating are rare, and, in the case of Holocene events, the
applicable radiometric dating techniques are scarce. Socompa volcano
suffered the largest collapse event in the Central Volcanic Zone of the
Andes, producing one of Earth's most spectacular and best-preserved
volcano avalanche deposits. We apply multiple dating techniques to
unravel the timing of Socompa's collapse and gain insights into its pre-
and postcollapse eruptive history. The age of the collapse event is
constrained by a C-14 age of 6,200-6,400 BP of a paleosol buried by the
avalanche, and by a post-collapse lava flow dated at 5.91 +/- 0.43 ka by
zircon double-dating. Bayesian age sequence modeling integrating these
ages determines that the collapse occurred at 6.18(-0.64)(+0.28) ka.
Four zircon eruption dates and one unspiked K-Ar age between 69.2 +/-
6.0 and 22.1 +/- 1.9 ka constrain the age of the youngest stage of
activity before the collapse. The ages, together with paleosurface
modeling and volume calculations, allow estimating growth rates for the
young pre-collapse and post-collapse stages of 0.2-0.3 km(3)/kyr and
0.5-2 km(3)/kyr, respectively, indicating a significant increase in
activity after the collapse event. The collapse may have triggered a new
growth phase or accelerated an ongoing one and was likely associated
with a Plinian eruption that produced widespread pumice fallout. The
pre- and post-collapse lavas have similar compositions and zircon
crystallization age distributions, suggesting that the same or a similar
magma reservoir was tapped before and after the collapse. Thus, huge
collapses such as Socompa's event can promote increased volcanic
activity as a consequence of the unloading effect, but the overall
plumbing system may not be affected enough to show significant
variations in erupted compositions, at least transiently. Our results
highlight the efficacy of the zircon double-dating method for dating
very young felsic lavas and for constraining the age of debris avalanche
deposits. This is particularly relevant in the Andean Central Volcanic
Zone and other regions with arid climates, where organic material is
rare and hence C-14 dating is often unfeasible. Furthermore, the
post-collapse zircon eruption age of 5.91 +/- 0.43 ka is the youngest
radiometric age yet obtained for a lava flow in the southern Central
Volcanic Zone, highlighting the youth of volcanic activity at Socompa,
and confirming its status as a Holocene active volcano.
Filiaciones:
Grosse, Pablo:
Consejo Nacl Invest Cient & Tecn CONICET, Buenos Aires, DF, Argentina
Fdn Miguel Lillo, Miguel Lillo 251, RA-4000 San Miguel De Tucuman, Tucuman, Argentina
Danisik, Martin:
Curtin Univ, John de Laeter Ctr, Perth, WA 6845, Australia
Apaza, Facundo D.:
UNSa CONICET, Inst Bio & Geociencias NOA IBIGEO, 9 Julio 14, RA-4405 Rosario De Lerma, Salta, Argentina
Guzman, Silvina R.:
UNSa CONICET, Inst Bio & Geociencias NOA IBIGEO, 9 Julio 14, RA-4405 Rosario De Lerma, Salta, Argentina
Lahitte, Pierre:
Univ Paris Saclay, GEOPS, CNRS, F-91405 Orsay, France
Quidelleur, Xavier:
Univ Paris Saclay, GEOPS, CNRS, F-91405 Orsay, France
Self, Stephen:
Univ Calif Berkeley, Earth & Planetary Sci Dept, Berkeley, CA 94720 USA
Siebe, Claus:
Univ Nacl Autonoma Mexico, Dept Vulcanol, Inst Geofis, Ciudad Univ, Ciudad De Mexico 04510, Mexico
van Wyk de Vries, Benjamin:
Univ Clermont Auvergne, Lab Magmas & Volcans, Observ Phys Globe Clermont Ferrand, IRD,UMR6524,CNRS, F-63178 Aubiere, France
Ureta, Gabriel:
Univ Catolica Norte, Millennium Inst Volcan Risk Res Ckelar Volcanoes, Ave Angamos 0610, Antofagasta, Chile
Univ Catolica Norte, Dept Ciencias Geol, Ave Angamos 0610, Antofagasta, Chile
Ctr Invest Gest Integrada Riesgo Desastres CIGIDE, Ave Vicuna Mackenna 4860, Santiago, Chile
Guillong, Marcel:
Swiss Fed Inst Technol, Dept Earth Sci, Clausiusstr 25, CH-8092 Zurich, Switzerland
De Rosa, Rosanna:
Univ Calabria, Dipartimento Biol Ecol & Sci Terra DiBEST, Via P Bucci 15-B, I-87036 Cosenza, Italy
Le Roux, Petrus:
Univ Cape Town, Dept Geol Sci, ZA-7700 Rondenbosch, South Africa
Wotzlaw, Jorn-Frederik:
Swiss Fed Inst Technol, Dept Earth Sci, Clausiusstr 25, CH-8092 Zurich, Switzerland
Bachmann, Olivier:
Swiss Fed Inst Technol, Dept Earth Sci, Clausiusstr 25, CH-8092 Zurich, Switzerland
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