Aadhiseshan, KR and Jayananda, Mudlappa
(2025)
Archean crustal evolution and building of habitable continents: Insights from the Western Dharwar Craton.
Habitable Planet, 1 (1&2).
pp. 197-220.
ISSN 3079-5281
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| Abstract: |
This contribution presents a comprehensive review synthesis addressing Archean crustal
evolution, redox conditions of surface environments, oxygenation of ocean and microbial activity leading to building the habitable continent in the western Dharwar craton (WDC). The
WDC preserve ca. 3600–2600 Ma crustal record comprising TTG-type granitoids, volcanicsedimentary greenstone sequences and potassic granite plutons. Tectonic fabrics mapping
in the WDC reveal classical dome-keel patterns bordered by widely spaced regional shear
zones network with progressive increase of metamorphic grade from north to south. U–Pb
zircon ages and Sm–Nd whole rock isochrons suggest successive stages crust formation
which contribute to episodic continental growth during ca. 3450–3350 Ma, 3300–3200 Ma,
ca. 3230–3150 Ma, ca. 3000–2900 Ma, 2700–2600 Ma with spatially associated crustal
reworking events ca. 3150 Ma, ca. 3000–2950 Ma, 2600 Ma and ca. 2500 Ma leading to
stabilization of crust. Elemental and Nd isotope data of ca. 3400–3150 Ma greenstone volcanics reveal their derivation from primitive to deep mantle reservoirs in plume setting whilst
ca. 3000–2900 Ma volcanism originated in shallower heterogeneous mantle caused by asthenosphere upwelling. On the other hand, ca. 2700–2600 Ma volcanics generated by melting of depleted to enriched arc mantle. Distinct lithologic assemblages, combined with U–Pb
zircon ages, elemental and isotopes (whole rock Nd and zircon in-situ Hf) suggest that oldest
cratonic core formed by assembly of ca. 3600–3500 Ma ancient microcontinental remnants,
3400–3300 Ma oceanic plateau fragments, oceanic arcs and ocean ridge through horizontal motion close to 3200 Ma. Magmatic records and documented strain suggest vertical
motions are dominant tectonic mode prior to ca. 3400 Ma whilst horizontal motion initiated
ca. 3350 Ma onwards leading to building of oceanic arcs with subsequent collision of diverse
tectonic elements with eventual slab breakoff leading to mantle upwelling, lower crustal melting, caused gravitational collapse of high density supracrustal load forming keels with rise of
low density infracrustal granitoids resulting in domes. Tectonic fabric analysis of ca. 3000–
2850 Ma intracratonic basins developed on the stabilized continental crust through sagduction controlled by emplacement of dense volcanic traps on the basement. Finally, geological
framework and structural patterns of the ca. 2700–2600 Ma greenstone basins point to arc
settings. Collision of arcs with eventual slab breakoff leads to generation and emplacement of
Chitradurga–Arsikere–Banavara potassic plutons in the basement or in between the volcanic
arcs.
Redox sensitive elements and isotope biomarkers (Fe, N and Mass Independent
Fractionation-Sulphur isotopes) data on the sedimentary record reveal dominantly anoxic
environments during ca. 3400–3000 Ma whilst ca. 3000 Ma onwards a shift from anoxic to
minimum oxygen on ocean surface with periodic organic production linked to the microbial
activity and oxygenation building of habitable continent a few hundred million years prior to
the Great Oxidation Event (GOE) |
| Item Type: |
Journal Paper
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| Keywords: |
Archean, Dharwar craton, Habitable continent, Microbial activity, Redox conditions |
| Subjects: |
School of Natural and Engineering Sciences > Geology |
| Divisions: |
Schools > Natural Sciences and Engineering |
| Date Deposited: |
20 May 2026 09:19 |
| Last Modified: |
20 May 2026 09:19 |
| Official URL: |
https://www.sciltp.com/journals/hp/articles/250900... |
| Related URLs: |
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| Funders: |
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| Projects: |
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| DOI: |
https://doi.org/10.63335/j.hp.2025.0016 |
| URI: |
http://eprints.nias.res.in/id/eprint/3338 |
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