Kubergandin Fm
Type Locality and Naming
Includes in SE Murghab district (Mynkhadjr type), SE Murghab district (Istyk type (Dunkeldyk area), SE Murghab district (Gurdumdin type), SE Murghab district (Gurdumdin type Kastanatdjilga, Buryukurmes rivers), SE Murghab district (Gurdumdin type Shin and Igrymiyu rivers), SE Murghab district (Gurdumdin type Gurumd and Kattamardzhana rivers).
It was delineated by G. A. Dutkevich (1937). The Kubergandy type-section (37°52’N, 73°37’E; Base 3950 m a.s.l) of the Kubergandin Formation is of great importance as it serves as the stratotype for the regional Kubergandian Stage within the Tethyan stratigraphic scale.
Synonym: Kуберrандинская свита, Kubergandy Formation, Kubergandian Suite, Kubergandin suite, Kubergandinsky horizon; Kubergandinsky formation; Kubergandin horizon,
Lithology and Thickness
In the type section (Angiolini et al., 2015): “The Kubergandy Fm (Kubergand Fm) comprises bioclastic calcarenites, calcareous siltstones and sandstones and dark shales with a few volcaniclastic sandstones and intercalations of volcanic ashes. In the lower part, shales are dominant, and graded calcarenites and subordinate hybrid sandstones form planar to lenticular 20–50 cm-thick beds. In the upper part, calcarenites increase in frequency and thickness, forming m-thick channelized bodies with coarser grained texture. Microfacies analysis shows that the limestones mainly consist of bioclastic packstones with fusulinids, smaller foraminifers, algae, echinoderms, brachiopods, and bivalves. The limestones and the calcareous sandstones show neat sedimentary structures as cross-, convolute- and parallel laminations and gradation; beds with erosional base, channelized bodies and slumpings occur interbedded within the shales.”
[Version from Baratov, 1976, Russian-language]: It consists of interbedded clayey marl shales and fragmental detrital limestones (predominating in its upper part). The lower part (5-20 m) is composed of black thin-bedded limestones with shale interlayers (Karatau Fm (караташская свита)). Thickness is 5-140 m.
[A “Brown” lithology pattern for the marl is used – “continental” pattern in order to highlight difference from the enclosing limestone-dominated units.]
Relationships and Distribution
Lower contact
It overlies the Shindy Fm
Upper contact
It is overlain by the Gan Gr (Gana Gr) (Dhzamantal Fm)
Regional extent
It is widespread in the Southeast Pamir.
GeoJSON
Fossils
“The formation was reported [See Additional Information below.] to contain fusulinids and ammonoids and to comprise three biozones: the Misellina parvicostata zone, the Misellina ovalis-Armenina biozone and the Cancellina cutalensis biozone. … We have found fusulinids, foraminifers and conodonts. Fusulinids are mainly represented by Misellina termieri, Misellina sp., Neofusulinella ex gr. giraudi, Parafusulina cf. dzamantalensis, Yangchienia cf. compressa and primitive species of Cancellina). The majority of the smaller foraminifers (neoendothyrins, palaeotextulariids, globivalvulinids, miliolates and nodosariates) are well known, but the FO (first occurrence) of Dagmarita, Graecodiscus, and Retroseptellina? Is noticeable. There are also interesting dasycladaleans (Gyroporella? sp., Velebitelleae gen. sp.), algospongia (Efluegelia johnsonii, Stacheoides sp.), classical microproblematica (Archaeolithoporella hidensis and Tubiphytes obscurus), echinoderms, brachiopods, bivalves. Conodonts comprise Hindeodus wordensis, Mesogondolella idahoensis, M. lamberti, M. pingxiangensis, Pseudohindeodus ramovsi, Sweetognathus fengshanensi, and S. subsymmetricus. Deep-water ostracods are also present.” (Angiolini et al., 2015)
Age
Depositional setting
“Sedimentary structures (laminations and gradation; beds with erosional base, channelized bodies and slumpings) indicate that the formation was deposited below the storm wave base down a slope. Microfacies analysis of the calcarenitic beds confirms this interpretation, as they consist of coarse bioclastic packstones with transported foraminifers, undetermined bioclasts and algal lumps, which are all highly abraded and fragmented indicating they were transported and resedimented along the slope from a nearby carbonate platform. They are mixed with an autochthonous fauna of bivalves, brachiopods, echinoderms and nodosariate foraminifers, which are typical of slope settings.” (Angiolini et al., 2015; for at least the type section).
Additional Information
Age:
In accordance with the decisions of the Tashkent conference (Decisions..., 1959), the Kubergandin Fm is attributed to (and defines) the Kubergandian horizon (regional stage) of the Lower Permian, of which it is the stratotype. A. D. Miklukho-Maclay (1963) included this horizon in the Darvazian stage he distinguished. E. Y. Leven (1967) considered the lower part of the Kubergandian Suite to be Lower Permian, and the upper part to be Upper Permian; later (Leven, 1975), he referred it to the Chusyan and Kubergandian stages of the "middle" Permian he distinguished. B. M. Gushin (1973) considers the Kubergandian Suite to be Upper Permian.
BUT, it is now correlated by fusulinids and other fossils to span the upper 2/3rds of the international Kungurian Stage (upper Early Permian). The Kubergandin Fm extends into the uppermost part of the Bolorian regional stage (the entire Bolorian correlates to upper Artinskian through the lower part of Kungurian) and the Fm extends upward into the lowermost Murgabian regional stage (=Roadian) (e.g., Angiolini et al., 2015). “based on conodonts (Mei and Henderson, 2001, 2002; Henderson and Mei, 2003, 2007), most of the Kubergandy Fm (Kubergand Fm) was deposited in the Kungurian, reaching the early Roadian only in its upper part in the Kubergandy type section. The overlying Gan Gr (Gana Gr) in some sections begins in the latest Kungurian, but within the lower Roadian in others; therefore, the Kubergandin Fm is assigned to mid-early Kungurian to the top of Kungurian for graphics purposes here. [But, for regional summary strat; the Kurteke Fm bioherms are inserted in the uppermost interval (=> 85% up in Kungurian)
Age span:
Beginning stage: Kungurian
Fraction up in beginning stage: 0.3
Beginning date (Ma):
Ending stage: Kungurian
Fraction up in ending stage: 0.85
Ending date (Ma):
Depositional setting:
“Sedimentary structures (laminations and gradation; beds with erosional base, channelized bodies and slumpings) indicate that the formation was deposited below the storm wave base down a slope. Microfacies analysis of the calcarenitic beds confirms this interpretation, as they consist of coarse bioclastic packstones with transported foraminifers, undetermined bioclasts and algal lumps, which are all highly abraded and fragmented indicating they were transported and resedimented along the slope from a nearby carbonate platform. They are mixed with an autochthonous fauna of bivalves, brachiopods, echinoderms and nodosariate foraminifers, which are typical of slope settings.” (Angiolini et al., 2015; for at least the type section).
Depositional-pattern:
Additional Information
From Baratov, 1976, details on fossils: “In the lower part of the Kubergandin Fm, there are representatives of the Misellina zone: Pseudofusulina ex gr. fusiformis (Schellw. et Dyhr.), Parafusulina globosaeformis Lev., P. postkraifti Lev., P. vulgarisiformis Mor., Misellina dyhrenfurthi (Dutk.), M. claudiae (Depr.), M. aliciae (Depr.), and others. Together with them, the Bostyrian ammonoid complex (Tumanian, 1963; Pavlov, 1972) has been discovered, containing representatives of the genera Crimites, Neocrimites, Pamiritella, Agathiceras, Cardiella, Marathonites, Perrinites, Eothinites, Metalegoceras, Daraelites, Prothalassoceras, Thalassoceras, Propopanoceras, Medlicottia, Propinacoceras.
In the part of the Kubergandian Fm belonging to the Misellina zone, there is also a younger than the Bostyrian, Sulistyksky ammonoid complex (Pavlov, 1965), which includes Perrinites ex. gr. hilli (Smith) and representatives of the genera Pseudovidrioceras, Gaetanoceras, Prostacheoceras, Paraghaticeras, Epadrianites, Sicanites. Here, a possibly even younger Kubergandian complex (Tumanian, 1963) has also been found, characterized by representatives of Tauroceras, Paraceltites, Epiglyphioceras, Adrianites, Sundaites.*
The upper part of the Kubergandian Fm, E. Y. Leven and B. M. Guminniy attribute to the Cancellina zone. Here, Neofusulinella lantenoisi Depr., Yangchienia haydeni longa Lev., Chusenella tieni Chen, Pseudofusulina chihsiaensis Lee, Parafusulina grupperaensis (Thomps. et Mill.), P. shaksgamensis Reich., Misellina claudiae (Depr.), Cancellina primigena Hayden, C. nipponica Oz., Armenina cl. salgirica M.-Maclay, Pseudodoliolina ozawai Yabe et Hanzawa, Minojapanella sp., and others were found.”
Angiolini, L., et al. (11 authors) (2015) From rift to drift in South Pamir (Tajikistan): Permian evolution of a Cimmerian terrane. Jour. Asian Earth Sciences, 102: 146-169. http://dx.doi.org/10.1016/j.jseaes.2014.08.001