Source provenance
Johnson, N.M., Opdyke, N.D., Johnson, G.D., Lindsay, E.H. & Tahirkheli, R.A.K. (1982). Magnetic polarity stratigraphy and ages of Siwalik Group rocks of the Potwar Plateau, Pakistan. Palaeogeography, Palaeoclimatology, Palaeoecology, 37, 17-42.
Cited by 4 units (4 published) · 0 field-level citations · 4 revision notes.
Reviewer-supplied. Foundational magnetostratigraphy of the Siwalik Group across six Potwar Plateau sections including the Kamlial, Chinji, Nagri and Dhok Pathan stratotypes. Nominal stratotype age ranges: Chinji 13.1-10.1 Ma, Nagri 10.1-7.9 Ma, Dhok Pathan 7.9-5.1 Ma; Kamlial-Chinji boundary within Chron 14 at ~13.1 Ma; a Nagri normal-polarity zone radiometrically (fission-track) dated at 9.50+/-0.63 Ma (Chron 9).
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Units citing this source
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- Age: Johnson et al. (1982): based exclusively on stratotype data, the Chinji Formation has a nominal magnetostratigraphic age range of 13.1–10.1 Ma (Kamlial–Chinji boundary within Chron 14 at ~13.1 Ma; Chinji–Nagri boundary near the top of Chron 10 at ~10.1 Ma). Formational boundaries may vary in age by ~10^5 yr within ~20 km of the stratotype.
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- Age: Johnson et al. (1982): nominal stratotype age range 7.9–5.1 Ma (lower boundary at the Nagri–Dhok Pathan contact ~7.9 Ma near the base of Chron 8; upper boundary at the Tatrot ‘stratotype’, Tatrot–Andar section, ~5.1 Ma). Both bounds are lithofacies boundaries and locally time-transgressive.
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- Age: Johnson et al. (1982), magnetic-polarity stratigraphy of the Potwar Plateau stratotypes: the Kamlial–Chinji boundary (top of the Kamlial Formation) lies within Chron 14 at about 13.1 Ma in the Khaur (Kamlial stratotype) area. The stratotype samples only the upper Kamlial; its lowermost part is not resolved by that section, consistent with the curated older bound (~18 Ma) derived elsewhere.
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- Age: Johnson et al. (1982): nominal stratotype age range 10.1–7.9 Ma. The conspicuous long normal-polarity zone within the Nagri Formation (magnetic Chron 9) is radiometrically (fission-track) dated at 9.50 ± 0.63 Ma, anchoring the Middle Siwalik chronology.