Samana Suk Formation

Akhtar et al. (2019), Dhamtaur area (Eastern Hazara): the Permian and Triassic sequences are missing here, so the Middle Jurassic Samana Suk Formation rests, across a major unconformity, above the Precambrian Hazara Formation, and is overlain by the Cretaceous Chichali, Lumshiwal and Kawagarh formations — a condensed Precambrian-to-Eocene succession (~1.5 km) of the Hazara fold-and-thrust belt.

Akhtar, S., Rahim, Y., Hu, B., Tsang, H., Ibrar, K.M., Ullah, M.F. & Bute, S.I. (2019)

Hemphill & Kidwai (1973, USGS PP 716-B): in the Khisor-Bhittanni-Marwat ranges the Samana Suk Limestone ranges as young as Late Jurassic (late Callovian) on a cephalopod fauna (Spath 1939) and rhynchonellid/terebratulid brachiopods (Sahni 1939); brown/grey crystalline limestone (oolitic, pyrite-coated near the top) with abundant ammonites, ~1,030 ft east of Shaikh Budin and absent in the Khisor Range south of Budh Banda.

Hemphill, W.R. & Kidwai, A.H. (1973)

Nizami & Sheikh (2007) logged 43.27 m of the Samana Suk Formation at Chichali Nala (Surghar Range) and recognised oolitic, peloidal, intraclastic and grapestone grainstones, skeletal wackestones/packstones and carbonate mudstones, recording shallowing-upward shallow-shelf carbonate-platform cycles on the northern Indian-plate Tethyan margin.

Nizami, A.R. & Sheikh, R.A. (2007)

Jamil et al. (2024): measured outcrop thickness 88 m in the Paniala section (Khisor Range) and 98 m in the Chichali section (Surghar Range) — thinner than the regional 200–400 m; the existing figure is retained.

Jamil, M., Ullah, I., Rahim, H.U., Khan, I., Abbas, W., Rehman, M.U., Rashid, A., Umar, M., Ali, A. & Siddiqui, N.A. (2024)

At Chichali Nala the formation rests conformably on the Shinawari Formation and is disconformably overlain by the Chichali Formation across a lateritic/ferruginous hardground encrustation (Nizami & Sheikh 2007).

Nizami, A.R. & Sheikh, R.A. (2007)

Calkins et al. (1975): in Hazara the Samana Suk Limestone is a black to dark-grey, thick-bedded, commonly cross-bedded, pelletal-to-oolitic biogenic limestone at least ~1,100 ft (335 m) thick (Fatmi, 2 mi N of Kalapani), disconformable on the Datta Formation and sheared against the overlying Chichali shale. Dasycladacean algae close to Neogyroporella indicate a Late Jurassic to earliest (pre-Aptian) Cretaceous age; correlatives include the Sulaiman Limestone Group, the Takatu Limestone and the Chiltan Limestone.

Calkins, J.A., Offield, T.W., Abdullah, S.K.M. & Ali, S.T. (1975)

Butt (1989): in the Hazara Arc the Upper Jurassic Samana Suk Limestone is a shallow-shelf carbonate blanket with oolitic texture, secondary yellow dolomite patches and shelly layers of oysters, gastropods and bivalves; its Upper Jurassic age is fixed by the gastropod genera Nerinea and Cossmanea (Butt 1962).

Butt, A.A. (1989)

Jamil et al. (2024): a shallow-marine carbonate ramp — wackestone and packstone microfacies dominate, with occasional grainstone and mudstone; the Chichali (Surghar) section spans supratidal to outer-ramp settings, the Paniala (Khisor) section intertidal to middle ramp.

Jamil, M., Ullah, I., Rahim, H.U., Khan, I., Abbas, W., Rehman, M.U., Rashid, A., Umar, M., Ali, A. & Siddiqui, N.A. (2024)

Ali et al. (2013), Chichali Nala (Trans-Indus Ranges): the Callovian-Bathonian Samana Suk Formation (limestone with subordinate reddish-brown quartzose bioturbated sandstone and marl; nodular with thin conglomerate intervals) yields four carbonate microfacies (laminated lime mudstone; bioclastic lime mud-wackestone; bioclastic wacke-packstone; bioclastic grainstone, with peloidal and ooidal grainstone sub-microfacies) plus a calcareous-sandstone lithofacies, indicating inner-ramp deposition across near-shore/beach, lagoon, barrier-shoal and deeper sub-tidal settings. Corroborates and refines the curated shallow-marine environment.

Ali, F., Haneef, M., Anjum, M.N., Hanif, M. & Khan, S. (2013)

Hayat et al. (2016): microfacies and sequence-stratigraphic study of the Bathonian-Callovian Samana Suk Formation at Nammal (Namal) Gorge, Salt Range - mainly grey/yellowish/purple, fine-grained, thin-to-medium-bedded limestone with algal laminations and minor calcareous quartzose sandstone (yellowish-brown to brick-red) and marl; carbonate reservoir characterization. Corroborates the shallow-marine carbonate-platform setting with a Salt Range section.

Hayat, M., Rahman, M.U., Khan, N.A., Abdullah & Ali, F. (2016)

Ahmed et al. (1997), Surghar Range: the Samana Suk Formation is a shallow-marine shelf carbonate deposited to the middle Callovian, with shallowing-upward cycles and relative sea-level lowstands in the Bajocian, Bathonian and Callovian; a lower-Callovian hardground is overlain by transgressive middle-Callovian open-marine limestone and the platform closes with another hardground.

Ahmed, S., Mertmann, D. & Manutsoglu, E. (1997)

Jamil et al. (2024): extensive diagenetic calcite cementation, micritization and dolomitization (including baroque dolomite) pervasively reduced the pore network, making these Jurassic carbonates a tight reservoir; carbon and oxygen isotopes track the depositional and diagenetic variation.

Jamil, M., Ullah, I., Rahim, H.U., Khan, I., Abbas, W., Rehman, M.U., Rashid, A., Umar, M., Ali, A. & Siddiqui, N.A. (2024)

Asim et al. (2014): the (Middle Jurassic) Samana Suk Formation is among the proven Mesozoic RESERVOIR rocks in the Central Indus Basin (Drigri Anticline–Bahawalpur High).

Asim, S., Qureshi, S.N., Asif, S.K., Abbasi, S.A., Solangi, S. & Mirza, M.Q. (2014)

Craig et al. (2018): platform carbonates of the Middle Jurassic Samana Suk Formation are a producing reservoir in the Manzalai, Makori, Mela and Chanda fields (Kohat Basin), and the 2016 Halini-Deep-1 well made an oil-and-gas discovery in the Jurassic Samana Suk.

Craig, J., Hakhoo, N., Bhat, G.M., Hafiz, M., Khan, M.R., Misra, R., Pandita, S.K., Raina, B.K., Thurow, J., Thusu, B., Ahmed, W. & Khullar, S. (2018)

Ali et al. (2013): the ~50 m Samana Suk succession at Chichali Nala records two second-order and four third-order transgressive-regressive sequences (fluctuating sea level), with hardgrounds/condensed sections at seven vertical levels marking transgressive events - a sequence-stratigraphic framework for the formation.

Ali, F., Haneef, M., Anjum, M.N., Hanif, M. & Khan, S. (2013)

Diagenesis spans the marine-phreatic (dog-tooth and acicular rim cements), meteoric-phreatic (drusy equant spar, syntaxial overgrowths) and deep-burial realms (poikilotopic calcite, stylolite-associated ferroan dolomite), with fabric-selective to pervasive dolomitisation and later dedolomitisation (Nizami & Sheikh 2007).

Nizami, A.R. & Sheikh, R.A. (2007)