Ιδρυματικό Αποθετήριο [SANDBOX]
Πολυτεχνείο Κρήτης
EN  |  EL

Αναζήτηση

Πλοήγηση

Ο Χώρος μου

Rare earth element geochemistry of altered pyroclastic rocks in the Hashtjin area of north-west Iran

Nouri Tohid, Tehrani Parvin Najafzadeh, Masoumi Rahim, Christidis Georgios

Απλή Εγγραφή


URIhttp://purl.tuc.gr/dl/dias/505213E1-879D-45CB-9E8C-CC86F75EC2E2-
Αναγνωριστικόhttps://doi.org/10.1180/clm.2020.21-
Αναγνωριστικόhttps://pubs.geoscienceworld.org/claymin/article-abstract/55/2/150/591962/Rare-earth-element-geochemistry-of-altered-
Γλώσσαen-
Μέγεθος16 pagesen
ΤίτλοςRare earth element geochemistry of altered pyroclastic rocks in the Hashtjin area of north-west Iranen
ΔημιουργόςNouri Tohiden
ΔημιουργόςTehrani Parvin Najafzadehen
ΔημιουργόςMasoumi Rahimen
ΔημιουργόςChristidis Georgiosen
ΔημιουργόςΧρηστιδης Γεωργιοςel
ΕκδότηςCambridge University Pressen
ΠερίληψηThis study evaluates the rare earth element (REE) geochemistry in altered trachyandesitic ignimbrites, tuff and lava flows in the Hashtjin area by assessing chondrite-normalized REE patterns and Y/Ho geochemical ratios. Modifications in the REE patterns took place along altered fault zones that were affected by hypogene and supergene alterations. The precursor volcanic and pyroclastic rocks contain phenocrysts of plagioclase accompanied by augite, zircon, apatite and pyrite. Based on X-ray diffraction analysis, the main mineral assemblages of the altered units consist of kaolinite as the main clay mineral, SiO2 polymorphs (quartz and cristobalite) and anatase as a minor constituent. The chondrite-normalized REE patterns of argillic samples reveal fractionation of light REEs (LREEs) compared to heavy REEs (HREEs), together with a marked Eu anomaly and a weak W-type tetrad effect related to the weak non-charge radius control (CHARAC) behaviour of REEs and slightly higher Y/Ho and Zr/Hf ratios. The relationship between the Y/Ho and Zr/Hf ratios and recognizable T3 and T4 effects (tetrad effect) suggests that an increasing degree of water–rock interaction occurred during hypogene alteration processes by acidic hydrothermal fluids that were overprinted by supergene alteration. Water–rock interaction and adsorption by Mn-oxides and clay minerals are considered to have played important roles in determining the close to non-CHARAC behaviour of REEs during the argillic alteration of the pyroclastic rocks in the Hashtjin area.en
ΤύποςPeer-Reviewed Journal Publicationen
ΤύποςΔημοσίευση σε Περιοδικό με Κριτέςel
Άδεια Χρήσηςhttp://creativecommons.org/licenses/by/4.0/en
Ημερομηνία2021-07-21-
Ημερομηνία Δημοσίευσης2020-
Θεματική ΚατηγορίαArgillic alterationen
Θεματική ΚατηγορίαHashtjinen
Θεματική ΚατηγορίαIgnimbriteen
Θεματική ΚατηγορίαKaolinizationen
Θεματική ΚατηγορίαLanthanide tetrad effecten
Θεματική ΚατηγορίαPyroclastic rocksen
Θεματική ΚατηγορίαRare earth elements (REEs)en
Βιβλιογραφική ΑναφοράT. Nouri, P. N. Tehrani, R. Masoumi, and G. E. Christidis, “Rare earth element geochemistry of altered pyroclastic rocks in the Hashtjin area of north-west Iran,” Clay Min., vol. 55, no. 2, pp. 150–165, Jun. 2020. doi: 10.1180/clm.2020.21en

Υπηρεσίες

Στατιστικά