Matches in SemOpenAlex for { <https://semopenalex.org/work/W2034191508> ?p ?o ?g. }
- W2034191508 abstract "The Boise River Group of late Cenozoic age consists of basaltic lavas and intercalated fluvial and lacustrine sediments deposited in drainages of the Boise River and Boise River South Fork from 1.8 to 0.2 m.y. Basalts of the Boise River Group can be divided into two groups based on major and trace element chemistry. Boise River Group 1 basalts (BRG 1), which comprise the three oldest flows in the Smith Prairie area, are silica-saturated olivine tholeiites characterized by low alkalis, Mg/Fe, and Ni, high concentrations of high field strength elements (HFSE), and enrichment in the heavy isotopes of Sr, Nd, and Pb. They are chemically similar to basalts of the Snake River Plain, and both units probably derive from a similar, enriched mantle lithosphere source. Some BRG 1 flows (Long Gulch, Rock Creek) record the affects of crustal assimilation and fractional crystallization. Boise River Group 2 basalts (BRG 2) are all younger than BRG 1 (< 0.7 m.y.) and are transitional between olivine tholeiites and alkali olivine basalts. BRG 2 basalts are characterized by high alkalis, Mg/Fe, and Ni, lower HFSE concentrations, and isotopic compositions of Sr and Nd near bulk earth. These lavas have distinct geochemical characteristics and are not cogenetic with the older, BRG 1 flows or with coeval lavas of the Snake River Plain. Chemical variations within individual flows are consistent with low-pressure crystal fractionation of the observed phenocryst phases (olivine + plagioclase). Chemical variations between different flows within the same group cannot result from low-pressure fractionation but can be modeled by combined high-pressure pyroxene fractionation and low-pressure olivine + plagioclase fractionation. The high Mg numbers and Ni of the younger BRG 2 basalts are not consistent with enrichment of the light field strength elements by crustal assimilation; this enrichment must reflect a mantle source region characteristic. The trace element and isotopic systematics of this source region are similar (but not identical) to the asthenospheric source inferred for ocean island basalts. In contrast, chemical and isotopic systematics of the BRG 1 basalts imply derivation from ancient subcontinental lithosphere which has been isolated from the asthenosphere for at least 1.5 eons. The subcontinental lithosphere was affected by an early enrichment in Rb/Sr which supported growth of high 87Sr/86Sr. A second enrichment event, resulting in Fe-Ti metasomatism of the lithosphere, occurred later in response to intrusion of partial melts from a mantle plume rooted in the underlying asthenosphere. This is second enrichment event is required by the high Nb/Rb ratios of the BRG 1 lavas, and of similar lavas of the Snake River Plain. The transition from saturated olivine tholeiites of Boise River Group 1 to transitional-alkalic lavas of BRG 2 in the Smith Prairie region implies a time-dependent change in mantle source region, with early magmas derived from a shallow lithospheric source giving way to younger magmas derived from a deeper asthenospheric source. The eruption of these younger lavas along the flanks of the Snake River Plain coeval with eruption of saturated tholeiites of the Snake River Group to the south further implies an axial zonation to magmatism in the Snake River Province. The nature of this axial zonation suggests that the deeper asthenospheric melts were preferentially tapped along the margins of the Snake River Plain but were blocked from reaching the surface in the axial zone. These time-space relationships are consistent with a model in which thinned lithosphere near the rift axis undergoes extensive partial melting which overwhelms any asthenospheric melts that may attempt passage. The lithosphere is too cool to melt along the rift margins (where pressure release by extensional thinning is minor); subsequent small volumes of asthenospheric melt are able to traverse this region more easily and erupt with little or no lithospheric contamination." @default.
- W2034191508 created "2016-06-24" @default.
- W2034191508 creator A5047400113 @default.
- W2034191508 creator A5064788534 @default.
- W2034191508 date "1992-01-01" @default.
- W2034191508 modified "2023-09-23" @default.
- W2034191508 title "Continental basalts of the Boise River Group near Smith Prairie, Idaho" @default.
- W2034191508 cites W1508121865 @default.
- W2034191508 cites W1966917681 @default.
- W2034191508 cites W1968439712 @default.
- W2034191508 cites W1968587976 @default.
- W2034191508 cites W1970144175 @default.
- W2034191508 cites W1977749755 @default.
- W2034191508 cites W1997934570 @default.
- W2034191508 cites W2000517918 @default.
- W2034191508 cites W2001316768 @default.
- W2034191508 cites W2001791855 @default.
- W2034191508 cites W2003070232 @default.
- W2034191508 cites W2004872704 @default.
- W2034191508 cites W2013276232 @default.
- W2034191508 cites W2023540560 @default.
- W2034191508 cites W2024575502 @default.
- W2034191508 cites W2033093699 @default.
- W2034191508 cites W2036153230 @default.
- W2034191508 cites W2036177335 @default.
- W2034191508 cites W2040908727 @default.
- W2034191508 cites W2052665156 @default.
- W2034191508 cites W2059775769 @default.
- W2034191508 cites W2079595767 @default.
- W2034191508 cites W2090450022 @default.
- W2034191508 cites W2091845502 @default.
- W2034191508 cites W2093567690 @default.
- W2034191508 cites W2108056426 @default.
- W2034191508 cites W2108612177 @default.
- W2034191508 cites W2112664395 @default.
- W2034191508 cites W2359611212 @default.
- W2034191508 cites W2604583684 @default.
- W2034191508 cites W4245638129 @default.
- W2034191508 doi "https://doi.org/10.1029/92jb00209" @default.
- W2034191508 hasPublicationYear "1992" @default.
- W2034191508 type Work @default.
- W2034191508 sameAs 2034191508 @default.
- W2034191508 citedByCount "15" @default.
- W2034191508 countsByYear W20341915082012 @default.
- W2034191508 countsByYear W20341915082014 @default.
- W2034191508 countsByYear W20341915082018 @default.
- W2034191508 countsByYear W20341915082020 @default.
- W2034191508 crossrefType "journal-article" @default.
- W2034191508 hasAuthorship W2034191508A5047400113 @default.
- W2034191508 hasAuthorship W2034191508A5064788534 @default.
- W2034191508 hasConcept C120806208 @default.
- W2034191508 hasConcept C127313418 @default.
- W2034191508 hasConcept C151730666 @default.
- W2034191508 hasConcept C161509811 @default.
- W2034191508 hasConcept C17409809 @default.
- W2034191508 hasConcept C182402614 @default.
- W2034191508 hasConcept C192241223 @default.
- W2034191508 hasConcept C2776067542 @default.
- W2034191508 hasConcept C2780364934 @default.
- W2034191508 hasConcept C6363049 @default.
- W2034191508 hasConcept C67236022 @default.
- W2034191508 hasConcept C77928131 @default.
- W2034191508 hasConceptScore W2034191508C120806208 @default.
- W2034191508 hasConceptScore W2034191508C127313418 @default.
- W2034191508 hasConceptScore W2034191508C151730666 @default.
- W2034191508 hasConceptScore W2034191508C161509811 @default.
- W2034191508 hasConceptScore W2034191508C17409809 @default.
- W2034191508 hasConceptScore W2034191508C182402614 @default.
- W2034191508 hasConceptScore W2034191508C192241223 @default.
- W2034191508 hasConceptScore W2034191508C2776067542 @default.
- W2034191508 hasConceptScore W2034191508C2780364934 @default.
- W2034191508 hasConceptScore W2034191508C6363049 @default.
- W2034191508 hasConceptScore W2034191508C67236022 @default.
- W2034191508 hasConceptScore W2034191508C77928131 @default.
- W2034191508 hasLocation W20341915081 @default.
- W2034191508 hasOpenAccess W2034191508 @default.
- W2034191508 hasPrimaryLocation W20341915081 @default.
- W2034191508 hasRelatedWork W1662773732 @default.
- W2034191508 hasRelatedWork W1968439712 @default.
- W2034191508 hasRelatedWork W1969513735 @default.
- W2034191508 hasRelatedWork W2025311648 @default.
- W2034191508 hasRelatedWork W2030318022 @default.
- W2034191508 hasRelatedWork W2039616329 @default.
- W2034191508 hasRelatedWork W2042612634 @default.
- W2034191508 hasRelatedWork W2062717373 @default.
- W2034191508 hasRelatedWork W2092301511 @default.
- W2034191508 hasRelatedWork W2108612177 @default.
- W2034191508 hasRelatedWork W2116809173 @default.
- W2034191508 hasRelatedWork W2122622229 @default.
- W2034191508 hasRelatedWork W2132134032 @default.
- W2034191508 hasRelatedWork W2138522501 @default.
- W2034191508 hasRelatedWork W2145143116 @default.
- W2034191508 hasRelatedWork W2160478656 @default.
- W2034191508 hasRelatedWork W2267713172 @default.
- W2034191508 hasRelatedWork W2339134711 @default.
- W2034191508 hasRelatedWork W2478023870 @default.
- W2034191508 hasRelatedWork W2788901652 @default.
- W2034191508 isParatext "false" @default.
- W2034191508 isRetracted "false" @default.
- W2034191508 magId "2034191508" @default.