FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1991700257> ?p ?o ?g. }

• W1991700257 endingPage "518" @default.
• W1991700257 startingPage "503" @default.
• W1991700257 abstract "This study explores the possibility of establishing Nd isotopic variations in seawater over geologic time. Calcite, aragonite and apatite are examined as possible phases recording seawater values of ϵNd. Modern, biogenic and inorganically precipitated calcite and aragonite from marine environments were found to have Nd concentrations of from 0.2 to 70 ppb, showing that primary marine CaCO3 contains little REE and that Nd/Ca is not greatly enhanced relative to seawater during carbonate precipitation. Very young marine limestone and dolomite containing no continental detritus have ~200 ppb Nd. All the carbonates are LREE enriched (−0.16 ≤fSmNd≤−0.45). Modern and very young Atlantic and Pacific carbonates have ϵNd in the range of shallow Atlantic and Pacific seawater respectively, implying that they derive their REE from local seawater. The Nd in well preserved carbonate fossils is ≤4 × 104 ppb, much greater than in their modern counterparts but like the high values found for carbonates in other studies. We believe the high REE contents (at the 500 ppb level) in some detritusfree carbonates are due to REE-rich Fe-hydroxide in/on the carbonate. In favorable cases, such material may record seawater ϵNd values, however introduction of extraneous REE may obscure the original isotopic composition of pure CaCO3 because of its very low intrinsic primary REE abundance. Modern biogenic apatite is also shown to have very low REE content (<150 ppb Nd) but appears to quickly scavenge REE from seawater. Inorganically precipitated apatite from phosphorites has high concentrations of seawater-derived REE. Young phosphorite apatite from the Atlantic and Pacific oceans has ϵNd in the range of the seawater from these oceans. Older apatite samples of similar age from different localities bordering common oceans record similar values of ϵNd(T). Sedimentary apatite has ϵSr(T) values in good agreement with the curves for 87Sr86Sr of seawater as a function of time. Individual conodonts from a single formation yield the same ϵSr(T) and ϵNd(T). Other workers have shown that sedimentary apatite preserves seawater REE patterns. These characteristics suggest that sedimentary apatite can be used to determine ϵNd(T) in ancient seawater. The seawater values so inferred range between −1.7 and −8.9 over the last 700 my and lie in the range of modern seawater, showing no evidence for drastic changes. High values of seawater ϵNd(T) in the Triassic and latest Precambrian may correlate with the breakup of large continental landmasses. The initial ϵNd(T) =−15.0 of a 2 AE old phosphorite implies the presence of ~ 1.5 AE old continental crust at 2 AE ago. The approach outlined here can be used to constrain the age of the exposed crust as a function of time." @default.
• W1991700257 created "2016-06-24" @default.
• W1991700257 creator A5025128086 @default.
• W1991700257 creator A5087692200 @default.
• W1991700257 date "1985-02-01" @default.
• W1991700257 modified "2023-10-15" @default.
• W1991700257 title "Sm-Nd in marine carbonates and phosphates: Implications for Nd isotopes in seawater and crustal ages" @default.
• W1991700257 cites W1966022318 @default.
• W1991700257 cites W1966100409 @default.
• W1991700257 cites W1970859167 @default.
• W1991700257 cites W1971225875 @default.
• W1991700257 cites W1975495305 @default.
• W1991700257 cites W1976620802 @default.
• W1991700257 cites W1980295996 @default.
• W1991700257 cites W1980525651 @default.
• W1991700257 cites W1986431264 @default.
• W1991700257 cites W1987669424 @default.
• W1991700257 cites W1988754280 @default.
• W1991700257 cites W199634666 @default.
• W1991700257 cites W1996735177 @default.
• W1991700257 cites W1998105210 @default.
• W1991700257 cites W2001312000 @default.
• W1991700257 cites W2002057489 @default.
• W1991700257 cites W2002115922 @default.
• W1991700257 cites W2003297399 @default.
• W1991700257 cites W2006481975 @default.
• W1991700257 cites W2008550047 @default.
• W1991700257 cites W2011207873 @default.
• W1991700257 cites W2019768323 @default.
• W1991700257 cites W2019984710 @default.
• W1991700257 cites W2024887749 @default.
• W1991700257 cites W2030462897 @default.
• W1991700257 cites W2031628778 @default.
• W1991700257 cites W2032466071 @default.
• W1991700257 cites W2032645826 @default.
• W1991700257 cites W2034457640 @default.
• W1991700257 cites W2042822604 @default.
• W1991700257 cites W2046697179 @default.
• W1991700257 cites W2057091716 @default.
• W1991700257 cites W2057915298 @default.
• W1991700257 cites W2062152213 @default.
• W1991700257 cites W2062854879 @default.
• W1991700257 cites W2063784503 @default.
• W1991700257 cites W2068526736 @default.
• W1991700257 cites W2071759770 @default.
• W1991700257 cites W2073426602 @default.
• W1991700257 cites W2074080379 @default.
• W1991700257 cites W2076566162 @default.
• W1991700257 cites W2084027071 @default.
• W1991700257 cites W2084963785 @default.
• W1991700257 cites W2086042654 @default.
• W1991700257 cites W2091950619 @default.
• W1991700257 cites W2094898038 @default.
• W1991700257 cites W2098465684 @default.
• W1991700257 cites W2109723903 @default.
• W1991700257 cites W2139337289 @default.
• W1991700257 cites W2413894455 @default.
• W1991700257 cites W4232857131 @default.
• W1991700257 cites W4236104903 @default.
• W1991700257 doi "https://doi.org/10.1016/0016-7037(85)90042-0" @default.
• W1991700257 hasPublicationYear "1985" @default.
• W1991700257 type Work @default.
• W1991700257 sameAs 1991700257 @default.
• W1991700257 citedByCount "289" @default.
• W1991700257 countsByYear W19917002572012 @default.
• W1991700257 countsByYear W19917002572013 @default.
• W1991700257 countsByYear W19917002572014 @default.
• W1991700257 countsByYear W19917002572015 @default.
• W1991700257 countsByYear W19917002572016 @default.
• W1991700257 countsByYear W19917002572017 @default.
• W1991700257 countsByYear W19917002572018 @default.
• W1991700257 countsByYear W19917002572019 @default.
• W1991700257 countsByYear W19917002572020 @default.
• W1991700257 countsByYear W19917002572021 @default.
• W1991700257 countsByYear W19917002572022 @default.
• W1991700257 countsByYear W19917002572023 @default.
• W1991700257 crossrefType "journal-article" @default.
• W1991700257 hasAuthorship W1991700257A5025128086 @default.
• W1991700257 hasAuthorship W1991700257A5087692200 @default.
• W1991700257 hasConcept C107872376 @default.
• W1991700257 hasConcept C111368507 @default.
• W1991700257 hasConcept C127313418 @default.
• W1991700257 hasConcept C17409809 @default.
• W1991700257 hasConcept C178790620 @default.
• W1991700257 hasConcept C185592680 @default.
• W1991700257 hasConcept C197248824 @default.
• W1991700257 hasConcept C199289684 @default.
• W1991700257 hasConcept C2777746296 @default.
• W1991700257 hasConcept C2779002002 @default.
• W1991700257 hasConcept C2779866092 @default.
• W1991700257 hasConcept C2780181037 @default.
• W1991700257 hasConcept C2780191791 @default.
• W1991700257 hasConcept C2780659211 @default.
• W1991700257 hasConcept C528890316 @default.
• W1991700257 hasConcept C67443715 @default.
• W1991700257 hasConceptScore W1991700257C107872376 @default.
• W1991700257 hasConceptScore W1991700257C111368507 @default.
• W1991700257 hasConceptScore W1991700257C127313418 @default.

• next