Journal
GEOLOGICA CARPATHICA
Volume 73, Issue 1, Pages 25-42Publisher
SLOVAK ACAD SCIENCES GEOLOGICAL INST
DOI: 10.31577/GeolCarp.73.1.2
Keywords
provenance; tectonic setting; paleoweathering; Gadvan Formation; Abadan Plain; Zagros Basin
Categories
Funding
- Research Institute of Petroleum Industry (RIPI)
Ask authors/readers for more resources
The petrography and geochemistry of clastic rocks from the Gadvan Formation in the Abadan Plain (southwest Iran) were analysed to infer their weathering intensity, compositional maturity, provenance, and tectonic setting. The results indicate high intensity of chemical weathering in the source area, with felsic to intermediate parent rocks similar to the massive granitoids of the Arabian Shield. Low-grade metamorphism and a convergence process in a collisional setting are also observed.
The petrography and geochemistry of clastic rocks from the Gadvan Formation in the Abadan Plain (southwest Iran) were analysed to infer their weathering intensity, compositional maturity, provenance, and tectonic setting. The Index of Compositional Variability (0.47-0.71) indicates high compositional and mineralogical maturity. The Chemical Index of Alteration and the Plagioclase Index of Alteration suggest high intensity of chemical weathering in the source area. In addition, a remarkable high content of REE and LREE/HREE and Th/U ratios, as well as high C-value (1.7) suggest high chemical weathering in the source area. Rounded zircon grains, mineral homogeneity, and a lack of feldspar grains could be related to high weathering and the effect of recycling. Elemental ratios (La/Sc, La/Co, Th/Sc, Th/Co, GdN/YbN, Cr/Ni, Co/Th, La/Yb, and La/Th), bivariate diagrams (La/Sc vs. Co/Th, La/Sc vs. Th/Co, Cr/Th vs. Th/Sc, Th/Yb vs. Ta/Yb, and La/ Yb vs. La/Th), and an enrichment of Nb, Zr, Th, La, Cr, Ni contents imply felsic to intermediate parent rocks, which are similar to the massive granitoids of the Arabian Shield. This could be supported by the dominance of zircon grains, as well as inclusions of rutile and tourmaline in quartz grains in the Gadvan sandstones. Moreover, further petrographical evidences, such as undulatory quartz grains, rare biotite and a small orientation of grains is also related to low-grade metamorphism in a felsic source rock. Finally, the Mudrock Maturity Index and tectonic discrimination diagrams reveal a convergence process in a collisional setting, in which the Zagros Mountains originated.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available