Hydrothermal alteration of accessory minerals (allanite and titanite) in the late Archean Closepet granitoid (Dharwar Craton, India): A TEM study

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F24%3A00598968" target="_blank" >RIV/67985831:_____/24:00598968 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0009281924000540?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0009281924000540?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemer.2024.126130" target="_blank" >10.1016/j.chemer.2024.126130</a>

Result language

angličtina

Original language name

Hydrothermal alteration of accessory minerals (allanite and titanite) in the late Archean Closepet granitoid (Dharwar Craton, India): A TEM study

Original language description

Allanite, a member of the epidote supergroup, is a widespread rare earth element (REE)-rich accessory mineral in the late Archean Closepet batholith (Dharwar craton, India). It is commonly associated with titanite. Previously recognized shear zones served as preferential paths for magma and later fluids. As a response to hydrothermal activity, allanite exhibits complex alteration textures, geochemical features, and breakdown products that vary across the batholith. In the central zone, allanite displays the largest variations. It has decomposed into secondary allanite, bastnäsite, chlorite, thorite, calcite, pyrite, and galena. In the southern zone, magmatic allanite core is preserved. The alteration products in the marginal regions are limited to secondary allanite, bastnäsite, chlorite, thorite, and synchysite. The breakdown products and textural features of allanite in the northern intrusions differ strongly from those in the other zones of the Closepet batholith and are limited to secondary allanite and chamosite. However, nanoscale element remobilization at the interface between allanite and titanite is evident. The observed texture in allanite indicates a complete dissolution–reprecipitation process. The chemical variations and differences in alteration products after allanite indicate that the fluid composition changed along the Closepet granitoid. The fluids that altered the allanite were most likely F-, Cl-, and CO2-rich and alkaline but eventually became acidic. When the chlorine-bearing fluids reached the northern zone, the concentrations or active contributions of CO2, F and H2S were very low. The alteration products (bastnäsite, chlorite, and thorite) indicate a rather low-temperature fluid.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10504 - Mineralogy

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Chemie der Erde-Geochemistry

ISSN

0009-2819

e-ISSN

1611-5864

Volume of the periodical

84

Issue of the periodical within the volume

3

Country of publishing house

DE - GERMANY

Number of pages

19

Pages from-to

126130

UT code for WoS article

001317922100001

EID of the result in the Scopus database

2-s2.0-85194162615