Hostname: page-component-89b8bd64d-dvtzq Total loading time: 0 Render date: 2026-05-08T21:24:50.577Z Has data issue: false hasContentIssue false

Tracing multiple sources of sediments using trace element and Nd isotope geochemistry: provenance of the Mesozoic succession in the Kutch Basin, western India

Published online by Cambridge University Press:  10 June 2020

Angana Chaudhuri
Affiliation:
Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
Anirban Chatterjee
Affiliation:
Department of Geology, Presidency University, Kolkata 700073, India
Santanu Banerjee*
Affiliation:
Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
J.S. Ray
Affiliation:
Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad 380009, India
*
Author for correspondence: Santanu Banerjee, Email: santanu@iitb.ac.in
Rights & Permissions [Opens in a new window]

Abstract

An integrated approach involving Sr–Nd isotope, trace and rare earth element analyses tracks multiple sources of the Mesozoic sediments of the Kutch Basin at the western continental margin of India. High (87Sr/86Sr)t (ratio at time of deposition), negative εNd and high concentrations of large-ion lithophile elements (LILEs) indicate the upper continental source. Ratios of Nb/Ta and Zr/Hf suggest sedimentary and felsic igneous sources of sediments. The moderate to high concentration of La, Th and Sc, light rare earth elements (LREE-) enrichment, weak negative Eu anomalies and the relationship between εNd(0) and Th/Sc indicate the dominantly felsic composition of source rocks. However, low contents of Th, low values of (87Sr/86Sr)t and depleted mantle model age TDM < 1600 Ma indicate input from a younger mafic source. Increasing concentrations of Zr, Hf and Nd isotopes and a gradual increase in mean TDM from the older to the younger formations indicate erosional unroofing at the source terrain. The increasing (87Sr/86Sr)t through time relates to increased weathering of the source rock. The overwhelmingly southwesterly palaeocurrent direction of current-generated sedimentary structures, and the mean TDM ages trace suggest source areas of the Kutch Basin to Precambrian rocks in the north and NE of this basin. The TDM ages highlight the dominance of late Palaeoproterozoic source rocks. Nd isotope composition indicates that Proterozoic rocks of Marwar Supergroup and Erinpura Granite, in particular, served as main sediment contributors for the Mesozoic sediments in Kutch. We therefore conclude that the Mesozoic sediments in the Kutch Basin are predominantly of late Palaeoproterozoic age with lesser inputs from rocks of early Mesoproterozoic and early Palaeoproterozoic age.

Information

Type
Original Article
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
© The Author(s), 2020. Published by Cambridge University Press
Figure 0

Fig. 1. Geological map of Kutch mainland showing extents of Cenozoic and Mesozoic outcrops (after Biswas, 1977, 1981). Mesozoic succession of the Kutch Basin, western India (after Biswas, 1977, 1981).

Figure 1

Table 1. Trace-element concentrations of samples from Jhumara Formation. CN – chondrite-normalized

Figure 2

Table 2. Trace-element concentrations of samples from Lower Member, Jhuran Formation. CN – chondrite-normalized

Figure 3

Table 3. Trace-element concentrations of samples from Middle Member, Jhuran Formation. CN – chondrite-normalized

Figure 4

Table 4. Trace-element concentrations of samples from Upper Member, Jhuran Formation. CN – chondrite-normalized

Figure 5

Table 5. Trace-element concentrations of samples from Bhuj Formation. CN – chondrite-normalized

Figure 6

Fig. 2. Upper Continental Crust (UCC-) normalized trace-element patterns for samples from various formations, arranged in stratigraphic order, of the Mesozoic Kutch Basin. Normalizing values are from Rudnick & Gao (2003).

Figure 7

Fig. 3. Nb/Ta versus Zr/Hf plot for samples from the Mesozoic Kutch Basin.

Figure 8

Fig. 4. Composite log of the Jhumara, Jhuran and Bhuj formations (adapted from Biswas, 2005; Fursich et al. 2005; Mandal et al.2016). Chondrite-normalized REE patterns for Jhumara (lower), Jhuran (middle) and Bhuj (upper) are placed to the right of the log. Solid lines: LM – Lower Member; MM – Middle Member; UM – Upper Member. Dashed lines: MORB – mid-ocean-ridge basalt; NASC – North American Shale Composite; PAAS – Post Archean Australian Shale. Chondrite meteorite values from Boynton (1984). NASC, PAAS and MORB values from Taylor & McLennan (1985).

Figure 9

Fig. 5. Source-rock discrimination based on Th versus Sc plot (Cullers, 2002) for shale samples from Jhumara, Jhuran and Bhuj formations. Abbreviations as for Figure 4.

Figure 10

Fig. 6. Tectonic setting discrimination based on La/Th versus Hf (Floyd & Leveridge, 1987) for shale samples from Jhumara, Jhuran and Bhuj formations. Abbreviations as for Figure 4.

Figure 11

Fig. 7. (a) εNd(t) and (b) TDM versus (87Sr/86Sr)t plot for shale samples from Jhumara, Jhuran and Bhuj formations. Abbreviations as for Figure 4.

Figure 12

Fig. 8. Source-rock discrimination based on εNd versus Th/Sc plot (McLennan et al.1993) for shale samples from Jhumara, Jhuran and Bhuj Formation. Abbreviations as for Figure 4.

Figure 13

Fig. 9. Variations in εNd(0), TDM(Ga) and εNd(t) across Jhumara, Jhuran and Bhuj formations. Abbreviations as for Figure 4.

Figure 14

Table 6. Sm–Nd isotope data for samples from Jhumara, Jhuran and Bhuj formations

Figure 15

Fig. 10. Histogram of TDM distribution for the sediments in the Mesozoic Kutch Basin.

Figure 16

Fig. 11. Plot of fSm/Nd versus εNd(0) (modified after McLennan et al.1993) for shale samples from Jhumara, Jhuran and Bhuj formations. Abbreviations as for Figure 4.

Figure 17

Fig. 12. Average TDM versus average εNd(t) plot for Mesozoic sediments in the Kutch Basin compared with those of potential sources in Rajasthan. Error bars for the source points are 3σ. Data sources: George & Ray (2017) and Shukla et al. (2019).

Figure 18

Fig. 13. Schematic diagram of palaeodrainage pattern in the Early Cretaceous Kutch Basin and possible provenance areas.