Pre-Eruptive Conditions of the Hideaway Park Topaz Rhyolite: Insights into Metal Source and Evolution of Magma Parental to the Henderson Porphyry Molybdenum Deposit, Colorado

Mercer, Celestine N.; Hofstra, Albert H.; Todorov, Todor I.; Roberge, Julie; Burgisser, Alain; Adams, David; Cosca, Michael A.

doi:10.1093/petrology/egv010

Cited by 62 publications

(32 citation statements)

References 115 publications

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“…Our data support similar rapidity at Questa and suggest rapid devolatilization could have occurred numerous times through the lifespan of the magma system. Finally, we view these data as further evidence that ore deposition requires an alignment of numerous factors, including the magma source (Stein, 1985;Rosera et al, 2013;Mercer et al, 2015a), the degree and style of magma differentiation at depth (Audétat and Pettke, 2003;Audétat 2010;2015), the role of mafic magmas (Keith et al, 1986;Mercer et al, 2015a), and the system's ability to degas along conduits (Shinohara et al, 1995).…”

Section: Intrusive Volumes At the Questa Mo Deposit And Implications mentioning

confidence: 83%

“…Climax-type deposits are commonly assembled following the volcanic peak within long-lived magmatic centers (e.g., Carten et al, 1993;Mercer et al, 2015a). They are typically interpreted to have been assembled as multiple discrete, relatively small-volume, cylinder-shaped intrusions (e.g., Wallace et al, 1968Wallace et al, , 1968White et al, 1981;Keith et al, 1986;Carten et al, 1988;Seedorff and Einaudi, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…The Mo abundances observed in Climax-type deposits are commonly interpreted to be result of streaming volatiles and metals concentrated from a structurally deeper, low-(Mo), fractionating magmatic reservoir (e.g., Keith and Shanks, 1985;Lowenstern, 1994;Klemm et al, 2008;Seo, 2014;Audétat, 2015;Mercer et al, 2015a). In these models, a magmatic cupola serves as a conduit for lower-density fluids that combine with fluids exsolving from the crystallizing and convecting magma to form the hydrothermal system (Shinohara et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

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Intrusive history of the Oligocene Questa porphyry molybdenum deposit, New Mexico

2019

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Subsurface mapping and core analyses of upper crustal intrusions and mineralization at the Questa porphyry molybdenum deposit, New Mexico, reveal that Mo-mineralization occurred through episodic emplacement of at least six intrusive units. The structure of intrusions associated with the Questa deposit is documented in a series of detailed cross sections and visualized with a 3D animation. Mineralizing intrusions are underlain by two post-mineralization intrusions and cut by late-stage barren dikes. The plutonic complex was structurally focused along a system of preexisting flat-lying faults and their associated fractures. Mineralization is spatially associated with specific intrusive units in the subsurface, and the highest Mo ore grades within established ore blocks are structurally associated with the smallest intrusions. Existing U/Pb thermal ionization mass spectrometry (TIMS) zircon geochronology in conjunction with new relative chronology presented herein indicate that mineralization began before 24.91 Ma. We present three new chemical abrasion U/Pb TIMS zircon ages-one from an amphibole-bearing intrusion associated with high-grade mineralization (dark-matrix porphyry, 24.74 ± 0.37 Ma), a rhyolite dike that cuts ore-grade rocks (24.50 ± 0.02 Ma), and an equigranular granite discovered during deep drilling (23.67 ± 0.02 Ma). The dark-matrix porphyry contains clasts of an earlier amphibole-free intrusion that is spatially associated with low-grade mineralization. Thus, mineralizing intrusions were, in part, intruded into slightly older porphyries, confirming that episodic mineralization continued after 24.91 Ma. The age of the barren dike (24.50 ± 0.02 Ma) is indistinguishable from that of a previously dated granite porphyry that is associated with low-grade mineralization (<0.05 wt% MoS 2 ; Questa granite porphyry). These data suggest that mineralization waned by 24.5 Ma and that ore deposition occurred over ~500 ka. The new 23.67 Ma age of the deep equigranular granite, which underlies the Questa granite porphyry, further suggests that intrusions underlying the deposit were not related to mineralization. Detailed subsurface mapping and exploratory drilling indicate that intrusions associated with mineralization were small in volume and cooled rapidly, as evidenced by multiple internal contacts within sheets and rebrecciation textures. On the basis of observed cross-section reconstructions, petrology, alteration, and mineralization, the porphyritic rhyolite intrusions associated with mineralization in one of the largest orebodies in the deposit (the deep northeast) are less than 20-m-thick sheets that are separated by andesite wall rock. Thus, there is no evidence that this orebody formed above a cylindrical magma conduit that facilitated rapid convection, as is often modeled in these systems. We hypothesize that a set of similarly small-volume intrusions were responsible for the bulk of the ore in the southwest ore zone. Our interpretation that the mineralizing intrusions are small, thin, and subhorizontal ...

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Section: Intrusive Volumes At the Questa Mo Deposit And Implications mentioning

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Intrusive history of the Oligocene Questa porphyry molybdenum deposit, New Mexico

2019

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“…Thin, rifted continental crust is represented by a sample of a 0.014 Ma strongly peralkaline rhyolite lava from Pantelleria, a small volcanic island in the Strait of Sicily 27 . At the other end of the spectrum, we analyzed two samples from centers formed on thick, cratonic crust: the 2.14 Ma, alkali rhyolite Huckleberry Ridge Tuff from the Yellowstone volcanic field, Wyoming, and the 27.49 Ma peraluminous rhyolite Hideaway Park Tuff of the Red Mountain intrusive complex in Colorado 28 .…”

Section: Resultsmentioning

confidence: 99%

Lithium enrichment in intracontinental rhyolite magmas leads to Li deposits in caldera basins

et al. 2017

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The omnipresence of lithium-ion batteries in mobile electronics, and hybrid and electric vehicles necessitates discovery of new lithium resources to meet rising demand and to diversify the global lithium supply chain. Here we demonstrate that lake sediments preserved within intracontinental rhyolitic calderas formed on eruption and weathering of lithium-enriched magmas have the potential to host large lithium clay deposits. We compare lithium concentrations of magmas formed in a variety of tectonic settings using in situ trace-element measurements of quartz-hosted melt inclusions to demonstrate that moderate to extreme lithium enrichment occurs in magmas that incorporate felsic continental crust. Cenozoic calderas in western North America and in other intracontinental settings that generated such magmas are promising new targets for lithium exploration because lithium leached from the eruptive products by meteoric and hydrothermal fluids becomes concentrated in clays within caldera lake sediments to potentially economically extractable levels.

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“…A diagenetic origin of the elements would involve the same processes as a possible origin of Li: dissolution of volcanic glass to release them, transport by oxidizing groundwater, and precipitation by several possible mechanisms. Baseline concentrations of K (4-5% K 2 O), Rb (hundreds ppm), U (5-15 ppm), Mo (few ppm), and F (thousands ppm) are high in silicic rocks and glass, both at McDermitt and worldwide (Table S1) [85]. That U, Mo, As, Se, V, and other elements are soluble in oxidized groundwater and insoluble-precipitate-in reduced water has long been recognized [86][87][88].…”

Section: Geochemistrymentioning

confidence: 99%

Lithium-Rich Claystone in the McDermitt Caldera, Nevada, USA: Geologic, Mineralogical, and Geochemical Characteristics and Possible Origin

Castor

Henry

2020

Minerals

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Lithium deposits in tuffaceous sediments of the McDermitt caldera constitute possibly the world’s largest Li clay resource, yet their characteristics and origin are not established. The 40 × 25 km McDermitt caldera collapsed during the eruption of ~1000 km3 of a 16.4 Ma, zoned peralkaline to metaluminous tuff; minor caldera magmatism ceased by 16.1 Ma. About 200 m of sediments mostly composed of glass from regional pyroclastic eruptions accumulated in the caldera until about 15.7 Ma. Closed hydrologic system diagenesis (CHSD) altered the tuffaceous sediments to a consistent vertical mineral zonation of clay, analcime, K-feldspar, and albite. Entire sedimentary sections in the southern and western parts of the caldera basin have ≥1500 ppm Li. Lithium-rich intervals are dominantly claystone. The most thoroughly studied deposit is a laterally continuous, ~3000 ppm Li zone in the lower sedimentary section that also has high K, Rb, Mo, As, and Sb (and partly Mg and F). Lithium occurs as an illitic clay (tainiolite?). The overlying, upper sedimentary section averages <2000 ppm Li which resides in smectite (hectorite). A transitional zone has variably mixed smectite–illite clay and averages ~2000 ppm Li. An 40Ar/39Ar age of ~14.9 Ma on authigenic K-feldspar in the illite zone is ~1.2 Ma younger than the 16.1 Ma end of magmatism in the caldera, which mitigates against a simple hydrothermal origin. Closed hydrologic system diagenesis was essential to Li mineralization, but Li budget calculations suggest a source of Li in addition to the tuffaceous sediments is required. This additional source could be Li originally in highly enriched magma that entered the diagenetic system through either (1) Li in magma exsolved into a hydrous volatile phase during eruption. The Li-rich volatile phase coated glass shards or was trapped in pumice and was quickly leached by surface or groundwater upon deposition in the caldera. (2) Residual magma immediately following ash-flow eruption and caldera collapse generated Li-rich hydrothermal fluids that mixed with meteoric water in the closed caldera basin, generating a hybrid diagenetic fluid. The hydrothermal fluid and hybrid diagenetic fluids would have existed only during initial basin sedimentation between about 16.4 and 16.1 Ma.

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Pre-Eruptive Conditions of the Hideaway Park Topaz Rhyolite: Insights into Metal Source and Evolution of Magma Parental to the Henderson Porphyry Molybdenum Deposit, Colorado

Cited by 62 publications

References 115 publications

Intrusive history of the Oligocene Questa porphyry molybdenum deposit, New Mexico

Intrusive history of the Oligocene Questa porphyry molybdenum deposit, New Mexico

Lithium enrichment in intracontinental rhyolite magmas leads to Li deposits in caldera basins

Lithium-Rich Claystone in the McDermitt Caldera, Nevada, USA: Geologic, Mineralogical, and Geochemical Characteristics and Possible Origin

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