Matches in SemOpenAlex for { <https://semopenalex.org/work/W4220898766> ?p ?o ?g. }
Showing items 1 to 70 of
70
with 100 items per page.
- W4220898766 abstract "<p>Garnet chronology, with Sm-Nd and Lu-Hf isotope systems, can yield precise dates of metamorphic and tectonic events which can be directly linked to specific pressure-temperature conditions during its growth. Presence of inclusions within garnet porphyroblasts alters the inherent parent/daughter ratios resulting in erroneous ages and Sm-Nd ages can be severely affected by monazite and phosphate inclusions, whereas, Lu-Hf ages can be strongly influenced by inclusions of zircon with its high Hf content. The various leaching protocols to remove micro-inclusions from garnet include mixtures of HNO<sub>3</sub>+HCl to remove monazite inclusions in metabasic garnets, single step H<sub>2</sub>SO<sub>4 </sub>leaching to eliminate phosphate inclusions; the zircon inclusions were eliminated by partial dissolution technique with HF-HCl. Inspired from previous studies, we carried out sequential H<sub>2</sub>SO<sub>4 </sub>(discarded) followed by aqua regia leaching (collected) to increase the spread in the <sup>147</sup>Sm/<sup>144</sup>Nd ratios and thus improve the precision on the Sm-Nd ages.</p><p>Experiments were performed on garnet porphyroblasts separated from two samples of garnet-orthopyroxene-cordierite granulite enclaves from around Karimnagar, Eastern Dharwar craton, India. Three garnet fractions from each of the samples were separated and sequentially leached with concentrated H<sub>2</sub>SO<sub>4</sub> and concentrated aqua regia to remove the phosphate and oxide inclusions respectively. Regressing the leached residual garnet fractions along with their whole-rock yielded ages (at 2SD) of 2696&#177;10 Ma and 2683&#177;15 Ma. The residual garnet fractions yielded higher <sup>147</sup>Sm/<sup>144</sup>Nd ratios, indicating cleaner garnet fractions. An even greater improvement on the precision of the Sm-Nd ages was observed when the aqua regia leachates were analyzed and regressed along with the whole-rock and leached garnet fractions, with higher<sup> 147</sup>Sm/<sup>144</sup>Nd ratios than the analyzed garnets yielded ages with improved precisions of 2695&#177;8Ma and 2682&#177;9 Ma, thereby improving the precision of the fitted isochron. The <sup>147</sup>Sm/<sup>144</sup>Nd ratios in the aqua regia leachate fractions range ~ 1.955-2.934, which improves the precision on the age. The garnet aqua regia leachate fractions contain very high Sm concentrations (11.6-20.4 &#181;g/g) and lower Nd concentrations (3.18-4.18 &#181;g/g) compared to the garnet leached residue (Sm 4.35-5.02 &#181;g/g and Nd 1.61-4.13 &#181;g/g) and, therefore, likely represent co-genetic fluid phase released during aqua regia partial dissolution from the garnet lattice and appear to represent the metamorphic fluid compositions.</p><p>The Y+REE in metamorphic garnets would track the equilibration between garnet and the fluid environment in which it grew. As Y+REE are incorporated in garnet as trivalent ions replacing divalent ions in dodecahedral sites, likely explanations of our results are either introduction of menzerite-like components via the exchange vector [YM<sub>-1</sub>. (Mg, Fe) Al<sub>-1</sub>] or substitution of Y+REE by alkali components via the exchange vector [Y(Na, Li)M<sub>-2</sub>]. Since the aqua regia leachate fractions lie on the same isochron with the whole-rock and residual (leached) garnet fractions, we consider that the leachates do not involve elemental partitioning. It is likely that metasedimentary protoliths yield higher concentrations of leached LREE and may be applicable more for those compositions.</p><p>&#160;</p>" @default.
- W4220898766 created "2022-04-03" @default.
- W4220898766 creator A5010363987 @default.
- W4220898766 creator A5032867321 @default.
- W4220898766 creator A5049764999 @default.
- W4220898766 creator A5079894017 @default.
- W4220898766 date "2022-03-28" @default.
- W4220898766 modified "2023-09-25" @default.
- W4220898766 title "Improving the precision of garnet Sm-Nd ages using aqua regia leachate analyses" @default.
- W4220898766 doi "https://doi.org/10.5194/egusphere-egu22-9073" @default.
- W4220898766 hasPublicationYear "2022" @default.
- W4220898766 type Work @default.
- W4220898766 citedByCount "0" @default.
- W4220898766 crossrefType "posted-content" @default.
- W4220898766 hasAuthorship W4220898766A5010363987 @default.
- W4220898766 hasAuthorship W4220898766A5032867321 @default.
- W4220898766 hasAuthorship W4220898766A5049764999 @default.
- W4220898766 hasAuthorship W4220898766A5079894017 @default.
- W4220898766 hasConcept C107872376 @default.
- W4220898766 hasConcept C113196181 @default.
- W4220898766 hasConcept C127313418 @default.
- W4220898766 hasConcept C13965031 @default.
- W4220898766 hasConcept C140793950 @default.
- W4220898766 hasConcept C159390177 @default.
- W4220898766 hasConcept C159750122 @default.
- W4220898766 hasConcept C17409809 @default.
- W4220898766 hasConcept C177322064 @default.
- W4220898766 hasConcept C178790620 @default.
- W4220898766 hasConcept C185592680 @default.
- W4220898766 hasConcept C199289684 @default.
- W4220898766 hasConcept C2776212575 @default.
- W4220898766 hasConcept C2777612664 @default.
- W4220898766 hasConcept C2778849375 @default.
- W4220898766 hasConcept C544153396 @default.
- W4220898766 hasConcept C86803240 @default.
- W4220898766 hasConcept C90982505 @default.
- W4220898766 hasConceptScore W4220898766C107872376 @default.
- W4220898766 hasConceptScore W4220898766C113196181 @default.
- W4220898766 hasConceptScore W4220898766C127313418 @default.
- W4220898766 hasConceptScore W4220898766C13965031 @default.
- W4220898766 hasConceptScore W4220898766C140793950 @default.
- W4220898766 hasConceptScore W4220898766C159390177 @default.
- W4220898766 hasConceptScore W4220898766C159750122 @default.
- W4220898766 hasConceptScore W4220898766C17409809 @default.
- W4220898766 hasConceptScore W4220898766C177322064 @default.
- W4220898766 hasConceptScore W4220898766C178790620 @default.
- W4220898766 hasConceptScore W4220898766C185592680 @default.
- W4220898766 hasConceptScore W4220898766C199289684 @default.
- W4220898766 hasConceptScore W4220898766C2776212575 @default.
- W4220898766 hasConceptScore W4220898766C2777612664 @default.
- W4220898766 hasConceptScore W4220898766C2778849375 @default.
- W4220898766 hasConceptScore W4220898766C544153396 @default.
- W4220898766 hasConceptScore W4220898766C86803240 @default.
- W4220898766 hasConceptScore W4220898766C90982505 @default.
- W4220898766 hasLocation W42208987661 @default.
- W4220898766 hasOpenAccess W4220898766 @default.
- W4220898766 hasPrimaryLocation W42208987661 @default.
- W4220898766 hasRelatedWork W12219779 @default.
- W4220898766 hasRelatedWork W12678279 @default.
- W4220898766 hasRelatedWork W21865319 @default.
- W4220898766 hasRelatedWork W27352858 @default.
- W4220898766 hasRelatedWork W29253066 @default.
- W4220898766 hasRelatedWork W29578366 @default.
- W4220898766 hasRelatedWork W35317771 @default.
- W4220898766 hasRelatedWork W5349702 @default.
- W4220898766 hasRelatedWork W6627568 @default.
- W4220898766 hasRelatedWork W835421 @default.
- W4220898766 isParatext "false" @default.
- W4220898766 isRetracted "false" @default.
- W4220898766 workType "article" @default.