The temporal record of magmatism at Cerro Uturuncu, Bolivian Altiplano
D. D. Muir
D. N. Barfod
J. D. Blundy
A. C. Rust
R. S. J. Sparks
K. M. Clarke
10.6084/m9.figshare.3453914.v1
https://geolsoc.figshare.com/articles/dataset/The_temporal_record_of_magmatism_at_Cerro_Uturuncu_Bolivian_Altiplano/3453914
<p>Twenty-six new <sup>40</sup>Ar/<sup>39</sup>Ar plateau ages for 23 lavas and domes from the Uturuncu volcano in the Altiplano of SW Bolivia reveal a protracted eruptive
history from 1050±5 to 250±5 ka. Eruptions have been exclusively effusive, producing some 50 km<sup>3</sup> of high-K dacites and silicic andesites. Bimodal mineral compositions, complex mineral textures, the presence of andesitic
magmatic enclaves within dacites and linear chemical trends on binary element plots all indicate that magma mixing is an important
petrogenetic process at Uturuncu. Post-458 ka, distinct high and low MgO–Cr magmas are resolved. These magmas erupt during
similar times, suggesting that eruptions are tapping different parts of the magma system, albeit from the same vent system.
Volcanic and petrological features are consistent with the existence of a vertically extensive magma mush column beneath Uturuncu,
and calculated buoyancy forces are sufficient to drive effusive eruptions. Eruptive activity is episodic, with six eruptive
periods separated by hiatuses of >50 kyr. Cumulative volume curves demonstrate that the majority of the edifice formed between
595 and 505 ka. The episodicity of eruptions is most likely to be related to fluctuations in the magma supply to the underlying
Altiplano–Puno Magma Body.
</p>
2016-06-21 11:45:54
Eruptive activity
eruptive history
andesitic magmatic enclaves
eruptive periods
buoyancy forces
element plots
SW Bolivia
Cerro Uturuncu
Uturuncu volcano
vent system
mineral textures
petrogenetic process
Bolivian Altiplano
Bimodal mineral compositions
magma system
magma supply
Cumulative volume curves
magma mush column
50 km 3
chemical trends
23 lavas
eruption
silicic andesites
petrological features
505 ka
Geology