Magmatic lulls in the Sierra Nevada captured in zircon from rhyolite of the Mineral King pendant, California

Klemetti, Erik W.; Lackey, Jade Star; Starnes, Jesslyn K.

doi:10.1130/ges00920.1

Cited by 14 publications

(18 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rocks in the Borgarfjörður eystri region have undergone extensive metasomatic alteration by hydrothermal fluids (Vogler, 2014), limiting petrogenetic insight using whole-rock geochemical data. Therefore, we focus our analyses on zircon, a mineral that is generally resistant to hydrothermal alteration (Schmitt and Hulen, 2008;Watts et al, 2011;Bindeman et al, 2012;Milicich et al, 2013;Klemetti et al, 2014).…”

Section: Samplingmentioning

confidence: 99%

Detrital zircon resolve longevity and evolution of silicic magmatism in extinct volcanic centers: A case study from the East Fjords of Iceland

et al. 2017

View full text Add to dashboard Cite

Breiðuvík and Kaekjuskörð are two neighboring extinct eruptive centers in the East Fjords of Iceland. Together, they compose the second-largest volume of silicic rock in the country (after Torfajökull, an active volcanic system in southern Iceland). We use ages and compositions of detrital zircon collected from two rivers, the Stóraá and Krossá-Kaekjudalsá, to investigate the origins and longevity of silicic magmatism at Breiðuvík-Kaekjuskörð. Zircon populations from the two catchments have identical median U-Pb dates (12.9 Ma), O isotopes (δ 18 O Vienna standard mean ocean water = 3.1‰ versus 3.3‰), and Hf isotopes (ε Hf = 14.7). We interpret coherence of zircon elemental and isotopic compositions to indicate that a significant volume of relatively uniform silicic material was produced in close temporal and spatial proximity between 11.2 ± 0.7 Ma and 15.0 ± 0.9 Ma (all errors are 1σ), dominated by assimilation-fractional crystallization processes. To test the robustness of this longevity estimate, we applied Monte Carlo modeling to the Breiðuvík-Kaekjuskörð detrital zircon results and found the age span to be statistically resolvable at ≥2.8 m.y. While this lifespan is comparable to those of large mafic-silicic volcanic systems that have been described in other settings globally, it is the longest reported estimate for any Icelandic volcano, where typical longevity is thought to be ~0.5-1.5 m.y. The ≥2.8 m.y. lifespan we present for Breiðuvík-Kaekjuskörð is a conservative assessment, because the dates used in this study only represent the zircon-saturated period of magmatic activity. This study demonstrates that detrital zircon analysis of volcanigenic sediment provides an efficient and powerful tool that can illuminate histories of zircon-saturated magmatism at targeted volcanic centers and systems. This approach can be particularly valuable in dominantly mafic provinces where silicic material is subordinate (e.g., ocean islands, flood basalt provinces), where glaciation, erosion, or alteration has transformed the landscape, or in areas that are inaccessible (e.g., obscured by glacial ice). ., 2017, Detrital zircon resolve longevity and evolution of silicic magmatism in extinct volcanic centers: A case study from the

show abstract

Section: Samplingmentioning

confidence: 99%

Detrital zircon resolve longevity and evolution of silicic magmatism in extinct volcanic centers: A case study from the East Fjords of Iceland

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Early Cretaceous (ca. 136-134 Ma) rhyolites within the Mineral King pendant in the southern Sierra Nevada suggest that voluminous rhyolitic volcanism occurred during this purported magmatic lull (Klemetti et al, 2014), and coeval basaltic to dacitic volcanic rocks are sandwiched within the ca. 140-135 Ma Goldstein Peak Formation Martin and Clemens-Knott, 2015).…”

Section: Implications For Understanding Arc Magmatism and Tectonicsmentioning

confidence: 97%

“…The Triassic and Early Jurassic arc zircon also show the tightest clustering of zircon trace-element compositions across all five parameters, suggesting a compositionally uniform magmatic source. Klemetti et al (2014) concluded that similarly restricted zircon traceelement compositions, coupled with lower Th concentrations and δ 18 O values, measured in Early Jurassic rhyolite in the Mineral King pendant indicated little involvement of continental crust or magmatic precursors. The retroarc data overlap with the Great Valley Group data in all three geochemical plots, including Ce/Yb and U/Yb values, but extend to higher Th/U values (Fig.…”

Section: Integrating Arc and Detrital Zircon Data Setsmentioning

confidence: 98%

“…Indeed, well-documented Triassic magmatism in the eastern Sierran arc (Barth et al, 2012(Barth et al, , 2018 may have formed near the locus of continental magmatism within the arc, such that its preservation in the detrital record is largely limited to the retroarc region. Marginally higher Th/U values in retroarc detrital zircon hint at even greater involvement of continental crust, in contrast to lower Th/U values of Early Jurassic zircon in rhyolite within the Mineral King Pendant, which were interpreted to represent part of an extensive accreted island-arc volcanic system (Klemetti et al, 2014).…”

Section: Implications For Understanding Arc Magmatism and Tectonicsmentioning

confidence: 98%

See 1 more Smart Citation

A survey of Sierra Nevada magmatism using Great Valley detrital zircon trace-element geochemistry: View from the forearc

et al. 2019

View full text Add to dashboard Cite

The well-characterized Sierra Nevada magmatic arc offers an unparalleled opportunity to improve our understanding of continental arc magmatism, but present bedrock exposure provides an incomplete record that is dominated by Cretaceous plutons, making it challenging to decipher details of older magmatism and the dynamic interplay between plutonism and volcanism. Moreover, the forearc detrital record includes abundant zircon formed during apparent magmatic lulls, suggesting that understanding the long-term history of arc magmatism requires integrating plutonic, volcanic, and detrital records. We present trace-element geochemistry of detrital zircon grains from the Great Valley forearc basin to survey Sierra Nevadan arc magmatism through Mesozoic time. We analyzed 257 previously dated detrital zircon grains from seven sandstone samples of volcanogenic, arkosic, and mixed compositions deposited ca. 145–80 Ma along the length of the forearc basin. Detrital zircon trace-element geochemistry is largely consistent with continental arc derivation and shows similar geochemical ranges between samples, regardless of location along strike of the forearc basin, depositional age, or sandstone composition. Comparison of zircon trace-element data from the forearc, arc, and retroarc regions revealed geochemical asymmetry across the arc that was persistent through time and demonstrated that forearc and retroarc basins sampled different parts of the arc and therefore recorded different magmatic histories. In addition, we identified a minor group of Jurassic detrital zircon grains with oceanic geochemical signatures that may have provenance in the Coast Range ophiolite. Taken together, these results suggest that the forearc detrital zircon data set reveals information different from that gleaned from the arc itself and that zircon compositions can help to identify and differentiate geochemically distinct parts of continental arc systems. Our results highlight the importance of integrating multiple proxies to fully document arc magmatism, demonstrating that detrital zircon geochemical data can enhance understanding of a well-characterized arc, and these data may prove an effective means by which to survey an arc that is inaccessible and therefore poorly characterized.

show abstract

“…It has also long been understood that mountainous regions with significant relief experience surface recharge to appreciable depths (Forster & Smith, 1989). Figure 3b demonstrates how long it takes for fluid to transit from the surface (2011) and Klemetti et al (2014). Mineral abbreviations following Whitney and Evans (2010).…”

Section: Hydrothermal Fluid Flow At Empire Mountainmentioning

confidence: 99%

Reevaluating Fluid Sources During Skarn Formation: An Assessment of the Empire Mountain Skarn, Sierra Nevada, USA

Ramos

Hesse

Barnes

et al. 2018

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

Oxygen isotope analyses of skarn minerals have long been used to fingerprint the variable fluid sources involved in skarn formation. The Empire Mountain skarn of the Sierra Nevada (California, USA) batholith is identified as a low‐δ18O skarn and is thought to form due to surface fluid involvement that was enhanced by fractures that formed during host rock brecciation. Although geochemically well characterized, the Empire Mountain skarn is less understood in terms of its hydrodynamic history. In this study, we develop a two‐dimensional model of oxygen isotope transport during high‐temperature fluid‐rock interactions to assess the mechanisms by which low‐δ18O garnets could form exclusive of brecciation. Highlighting regions nearest to the intrusion that could form garnet, we make three primary observations: (1) the oxygen isotope composition of the fluids, and not temperature, dominantly controls δ18Ogarnet values; (2) >6‰ increases in δ18Ogarnet, from negative to positive values, are observed over the maximum time frame of garnet thermodynamic stability; and (3) incremental emplacement of the intrusion can produce oscillations in δ18Ogarnet values. Without invoking brecciation, we find that low‐δ18O garnets can form without the presence of surface fluids; they instead source 18O‐depleted pore fluids from adjacent units. Further, surface fluids that do not equilibrate with the surrounding rock at depth become low‐δ18O fluid sources during later stages of pluton emplacement. This study underscores that pore fluids at depth, regardless of their equilibrium state, can act as dormant low‐δ18O fluid sources and may be responsible for low‐δ18O‐valued garnets.

show abstract

Magmatic lulls in the Sierra Nevada captured in zircon from rhyolite of the Mineral King pendant, California

Cited by 14 publications

References 50 publications

Detrital zircon resolve longevity and evolution of silicic magmatism in extinct volcanic centers: A case study from the East Fjords of Iceland

Detrital zircon resolve longevity and evolution of silicic magmatism in extinct volcanic centers: A case study from the East Fjords of Iceland

A survey of Sierra Nevada magmatism using Great Valley detrital zircon trace-element geochemistry: View from the forearc

Reevaluating Fluid Sources During Skarn Formation: An Assessment of the Empire Mountain Skarn, Sierra Nevada, USA

Contact Info

Product

Resources

About