Matches in SemOpenAlex for { <https://semopenalex.org/work/W3185839298> ?p ?o ?g. }
Showing items 1 to 90 of
90
with 100 items per page.
- W3185839298 endingPage "23" @default.
- W3185839298 startingPage "1" @default.
- W3185839298 abstract "Abstract Mountain Pass is the site of the most economically important rare earth element (REE) deposit in the United States. Mesoproterozoic alkaline intrusions are spatiotemporally associated with a composite carbonatite stock that hosts REE ore. Understanding the genesis of the alkaline and carbonatite magmas is an essential scientific goal for a society in which critical minerals are in high demand and will continue to be so for the foreseeable future. We present an ion microprobe study of zircon crystals in shonkinite and syenite intrusions to establish geochronological and geochemical constraints on the igneous underpinnings of the Mountain Pass REE deposit. Silicate whole-rock compositions occupy a broad spectrum (50–72 wt % SiO2), are ultrapotassic (6–9 wt % K2O; K2O/Na2O = 2–9), and have highly elevated concentrations of REEs (La 500–1,100× chondritic). Zircon concordia 206Pb/238U-207Pb/235U ages determined for shonkinite and syenite units are 1409 ± 8, 1409 ± 12, 1410 ± 8, and 1415 ± 6 Ma (2σ). Most shonkinite dikes are dominated by inherited Paleoproterozoic xenocrysts, but there are sparse primary zircons with 207Pb/206Pb ages of 1390–1380 ± 15 Ma for the youngest grains. Our new zircon U-Pb ages for shonkinite and syenite units overlap published monazite Th-Pb ages for the carbonatite orebody and a smaller carbonatite dike. Inherited zircons in shonkinite and syenite units are ubiquitous and have a multimodal distribution of 207Pb/206Pb ages that cluster in the range of 1785–1600 ± 10–30 Ma. Primary zircons have generally lower Hf (<11,000 ppm) and higher Eu/Eu* (>0.6), Th (>300 ppm), Th/U (>1), and Ti-in-zircon temperatures (>800°C) than inherited zircons. Oxygen isotope data reveals a large range in δ18O values for primary zircons, from mantle (5–5.5‰) to crustal and supracrustal (7–9‰). A couple of low-δ18O outliers (2‰) point to a component of shallow crust altered by meteoric water. The δ18O range of inherited zircons (5–10‰) overlaps that of the primary zircons. Our study supports a model in which alkaline and carbonatite magmatism occurred over tens of millions of years, repeatedly tapping a metasomatized mantle source, which endowed magmas with elevated REEs and other diagnostic components (e.g., F, Ba). Though this metasomatized mantle region existed for the duration of Mountain Pass magmatism, it probably did not predate magmatism by substantial geologic time (>100 m.y.), based on the similarity of 1500 Ma zircons with the dominantly 1800–1600 Ma inherited zircons, as opposed to the 1450–1350 Ma primary zircons. Mountain Pass magmas had diverse crustal inputs from assimilation of Paleoproterozoic and Mesoproterozoic igneous, metaigneous, and metasedimentary rocks. Crustal assimilation is only apparent from high spatial resolution zircon analyses and underscores the need for mineral-scale approaches in understanding the genesis of the Mountain Pass system." @default.
- W3185839298 created "2021-08-02" @default.
- W3185839298 creator A5076806244 @default.
- W3185839298 creator A5081057040 @default.
- W3185839298 creator A5087891557 @default.
- W3185839298 date "2022-01-01" @default.
- W3185839298 modified "2023-10-01" @default.
- W3185839298 title "Temporal and Petrogenetic Links Between Mesoproterozoic Alkaline and Carbonatite Magmas at Mountain Pass, California" @default.
- W3185839298 cites W1242895745 @default.
- W3185839298 cites W1965413280 @default.
- W3185839298 cites W1966105461 @default.
- W3185839298 cites W1969859799 @default.
- W3185839298 cites W1999652704 @default.
- W3185839298 cites W2001539791 @default.
- W3185839298 cites W2002197121 @default.
- W3185839298 cites W2006396228 @default.
- W3185839298 cites W2007105153 @default.
- W3185839298 cites W2007584101 @default.
- W3185839298 cites W2013243503 @default.
- W3185839298 cites W2023742995 @default.
- W3185839298 cites W2024650254 @default.
- W3185839298 cites W2028413653 @default.
- W3185839298 cites W2030219984 @default.
- W3185839298 cites W2052159407 @default.
- W3185839298 cites W2054653182 @default.
- W3185839298 cites W2059010589 @default.
- W3185839298 cites W2062426713 @default.
- W3185839298 cites W2072391191 @default.
- W3185839298 cites W2073671350 @default.
- W3185839298 cites W2074487541 @default.
- W3185839298 cites W2083066926 @default.
- W3185839298 cites W2088111195 @default.
- W3185839298 cites W2090020014 @default.
- W3185839298 cites W2117517893 @default.
- W3185839298 cites W2141472067 @default.
- W3185839298 cites W2163800319 @default.
- W3185839298 cites W2164073782 @default.
- W3185839298 cites W2164636100 @default.
- W3185839298 cites W2535338388 @default.
- W3185839298 cites W2996308575 @default.
- W3185839298 cites W3000525986 @default.
- W3185839298 doi "https://doi.org/10.5382/econgeo.4848" @default.
- W3185839298 hasPublicationYear "2022" @default.
- W3185839298 type Work @default.
- W3185839298 sameAs 3185839298 @default.
- W3185839298 citedByCount "9" @default.
- W3185839298 countsByYear W31858392982022 @default.
- W3185839298 countsByYear W31858392982023 @default.
- W3185839298 crossrefType "journal-article" @default.
- W3185839298 hasAuthorship W3185839298A5076806244 @default.
- W3185839298 hasAuthorship W3185839298A5081057040 @default.
- W3185839298 hasAuthorship W3185839298A5087891557 @default.
- W3185839298 hasBestOaLocation W31858392981 @default.
- W3185839298 hasConcept C127313418 @default.
- W3185839298 hasConcept C140441402 @default.
- W3185839298 hasConcept C17409809 @default.
- W3185839298 hasConcept C2776212575 @default.
- W3185839298 hasConcept C2778849375 @default.
- W3185839298 hasConcept C42787717 @default.
- W3185839298 hasConcept C67236022 @default.
- W3185839298 hasConcept C83893233 @default.
- W3185839298 hasConceptScore W3185839298C127313418 @default.
- W3185839298 hasConceptScore W3185839298C140441402 @default.
- W3185839298 hasConceptScore W3185839298C17409809 @default.
- W3185839298 hasConceptScore W3185839298C2776212575 @default.
- W3185839298 hasConceptScore W3185839298C2778849375 @default.
- W3185839298 hasConceptScore W3185839298C42787717 @default.
- W3185839298 hasConceptScore W3185839298C67236022 @default.
- W3185839298 hasConceptScore W3185839298C83893233 @default.
- W3185839298 hasIssue "1" @default.
- W3185839298 hasLocation W31858392981 @default.
- W3185839298 hasOpenAccess W3185839298 @default.
- W3185839298 hasPrimaryLocation W31858392981 @default.
- W3185839298 hasRelatedWork W1968240910 @default.
- W3185839298 hasRelatedWork W2012247338 @default.
- W3185839298 hasRelatedWork W2040585759 @default.
- W3185839298 hasRelatedWork W2091184061 @default.
- W3185839298 hasRelatedWork W2095306682 @default.
- W3185839298 hasRelatedWork W2253144633 @default.
- W3185839298 hasRelatedWork W2378432995 @default.
- W3185839298 hasRelatedWork W3011950267 @default.
- W3185839298 hasRelatedWork W3185839298 @default.
- W3185839298 hasRelatedWork W3195522554 @default.
- W3185839298 hasVolume "117" @default.
- W3185839298 isParatext "false" @default.
- W3185839298 isRetracted "false" @default.
- W3185839298 magId "3185839298" @default.
- W3185839298 workType "article" @default.