High-precision 40Ar/39Ar geochronology and volumetric investigation of volcanism and resurgence following eruption of the Tshirege Member, Bandelier Tuff, at the Valles caldera

Shear Velocity Evidence of Upper Crustal Magma Storage Beneath Valles Caldera

“…An ∼20% melt fraction within the cylinder would correspond to ∼40 km 3 of magma. Only a fraction of this volume (∼10%–25%, e.g., Annen et al., 2008) would need to be mobilized to fuel eruptions analogous to those that produced the ∼4 km 3 El Cajete pyroclastic deposits from ∼74 ka or the ∼6.8 km 3 Banco Bonito rhyolite flow from ∼69 ka (Nasholds & Zimmerer, 2022; Wolff et al., 2011; Zimmerer et al., 2016).…”

“…Post‐caldera volcanism primarily occurred between ∼1.23 and 0.5 Ma and the subsequent quiescence was interrupted by eruption of the ∼74 ka El Cajete pyroclastic deposits and ∼69 ka Banco Bonito rhyolite flow near the southwestern moat of the caldera (Nasholds & Zimmerer, 2022; Philips et al., 2007; Zimmerer et al., 2016). Petrologic evidence suggests that the Banco Bonito lavas were generated by renewed intrusion of more mafic melt (Wolff & Gardner, 1995).…”

“…Understanding the current state and evolution of caldera‐forming magmatic systems is an important challenge because these systems exhibit diverse life‐cycles with a wide variety of hazardous eruptive scenarios (Cashman & Giordano, 2014; Wilson et al., 2021). Valles Caldera was formed by two rhyolitic eruptions that each deposited >300 km 3 dense rock equivalent at ∼1.6 and ∼1.23 Ma, respectively (Cook et al., 2016; Goff et al., 2014; Nasholds & Zimmerer, 2022; Wu et al., 2021). It is often considered the type example of a resurgent caldera with a central dome, Redondo Peak, that was uplifted within ∼54 Kyr of the last caldera‐forming eruption and peripheral post‐caldera rhyolite flows following the contour of its ring fracture (Figure 1; Kennedy et al., 2012; Philips et al., 2007; Smith & Bailey, 1968).…”

Shear velocity evidence of upper crustal magma storage beneath Valles Caldera

“…Understanding the current state and evolution of caldera-forming magmatic systems is an important challenge because these systems exhibit diverse life-cycles with a wide variety of hazardous eruptive scenarios (Cashman and Giordano, 2014;Wilson et al, 2021). Valles Caldera was formed by two rhyolitic eruptions that each deposited >300 km 3 dense rock equivalent (DRE) at ~1.6 and ~1.23 Ma, respectively (Goff et al, 2014;Cook et al, 2016;Wu et al, 2021;Nasholds and Zimmerer, 2022). It is often considered the type example of a resurgent caldera with a central dome, Redondo Peak, that was uplifted within ~54 kyr of the last caldera-forming eruption and peripheral post-caldera rhyolite flows following the contour of its ring fracture (Figure 1; Smith and Bailey, 1968;Philips et al, 2007;Kennedy et al, 2012).…”