Deutsch
 
Datenschutzhinweis Impressum
  DetailsucheBrowse

Datensatz

 
 
DownloadE-Mail
  Sr‐Enriched Glassy Picrites From the Karoo Large Igneous Province are Evolved, not Primitive Magmatic Rocks

Ashwal, L. D., Ziegler, A., Glynn, S., Truebody, T., Bolhar, R. (2021): Sr‐Enriched Glassy Picrites From the Karoo Large Igneous Province are Evolved, not Primitive Magmatic Rocks. - Geochemistry Geophysics Geosystems (G3), 22, 4, e2020GC009561.
https://doi.org/10.1029/2020GC009561

Item is

Dateien

einblenden: Dateien
ausblenden: Dateien
:
5006399.pdf (Verlagsversion), 8MB
Name:
5006399.pdf
Beschreibung:
-
Sichtbarkeit:
Öffentlich
MIME-Typ / Prüfsumme:
application/pdf / [MD5]
Technische Metadaten:
Copyright Datum:
-
Copyright Info:
-
Lizenz:
-

Externe Referenzen

einblenden:

Urheber

einblenden:
ausblenden:
 Urheber:
Ashwal, Lewis D.1, 2, Autor
Ziegler, Alexander1, 2, Autor
Glynn, S.2, 3, Autor              
Truebody, Tristan1, 2, Autor
Bolhar, Robert1, 2, Autor
Affiliations:
1External Organizations, ou_persistent22              
2GFZ SIMS Publications, Deutsches GeoForschungsZentrum, Potsdam, ou_1692888              
33.1 Inorganic and Isotope Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum, ou_146040              

Inhalt

einblenden:
ausblenden:
Schlagwörter: fractional crystallization, glass, Karoo, mantle source, picrite
 Zusammenfassung: Magmatic products of the Karoo Large Igneous Province can be divided into a volumetrically dominant, compositionally uniform low‐Ti tholeiitic suite, and a subordinate, geographically restricted, compositionally diverse, incompatible‐rich high‐Ti suite. High‐Ti picrites contain up to 2,400 ppm Sr, 1,900 ppm Ba, and 550 ppm Zr, which seems unusual for olivine‐enriched rocks. We studied six Karoo picrites to determine the phase(s) in which Sr resides. Samples consist of 10–30% olivine phenocrysts in a groundmass of brown glass, augite, feldspar, ilmenite, and apatite. Glass compositions vary, but are generally evolved, ranging from basaltic trachyandesite to dacite. X‐ray intensity maps demonstrate that most of the Sr resides in the glasses, and to a lesser extent, in feldspars, if present. Some samples contain two texturally and compositionally distinct glasses, best modeled in terms of magma hybridization: variably accumulated olivine phenocrysts surrounded by evolved Sr‐rich (to 9,470 ppm) Type 2 melts formed by extensive olivine fractionation were infiltrated by chemically distinct Type 1 melts. Upon eruption, Type 2 melt quenched to minor glass around olivine phenocrysts, and the dominant Type 1 glass acquired its evolved composition by quench crystallization of groundmass mineral phases. Both glasses are rich in H2O (up to 3.8 wt. %) but are nearly devoid of CO2. Calculated parental melts have much higher K2O and incompatible trace elements (e.g., Sr or Ba >1,200 ppm) relative to low‐Ti tholeiites. The unusual parental melt compositions imply derivation by small degrees of partial melting from SCLM mantle sources enriched in Sr and other incompatibles.

Details

einblenden:
ausblenden:
Sprache(n): eng - Englisch
 Datum: 2021-02-262021-04-052021
 Publikationsstatus: Final veröffentlicht
 Seiten: -
 Ort, Verlag, Ausgabe: -
 Inhaltsverzeichnis: -
 Art der Begutachtung: -
 Identifikatoren: DOI: 10.1029/2020GC009561
GFZPOF: p4 MESI
GFZPOF: p4 T3 Restless Earth
 Art des Abschluß: -

Veranstaltung

einblenden:

Entscheidung

einblenden:

Projektinformation

einblenden:

Quelle 1

einblenden:
ausblenden:
Titel: Geochemistry Geophysics Geosystems (G3)
Genre der Quelle: Zeitschrift, SCI, Scopus, oa , OA seit 15. September 2021
 Urheber:
Affiliations:
Ort, Verlag, Ausgabe: -
Seiten: - Band / Heft: 22 (4) Artikelnummer: e2020GC009561 Start- / Endseite: - Identifikator: CoNE: https://gfzpublic.gfz-potsdam.de/cone/journals/resource/journals159
Publisher: American Geophysical Union (AGU)