Kurteke Fm

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).

[LOCAL UNIT COEVAL WITH UPPERMOST Kubergandin Fm – Inserted as upper 20% of its time-span just to display on regional strat column and GeoJSON paleogeography] “The Kurteke Formation was introduced by Leven (1967) for a succession of bioclastic and massive microbialitic and coral limestones, which was lying at the core of horseshoe arranged paleogeographic domains, surrounded by the deeper water settings described above.

The type section is Kurteke 1 section at Kurteke (37°49’51.20”N–74°02’20.60”E; 4317 m a.s.l.) on the right hydrographic side of the valley which is the second left inflow of the Kurteke River.

Synonym:

“The lower part of the Kurteke Fm consists of partly covered red bioclastic limestones with crinoids and fusulinids, which crop out discontinuously; they pass to 15–25 cm-thick cherty bioclastic calcarenite beds with rare volcaniclastic ashes. These grade in turn to massive limestones locally microbialitic, becoming more bioclastic towards the top. At the top, the massive limestones are eroded by a laterally discontinuous conglomerate and pass to a mostly covered succession which according to the Russian authors contains a laterite and then black limestones of Triassic age. This succession, however, is laterally cut by a thrust surface stacking the Gan Gr on top of the measured section. Along the thrust surface a foliated cataclasite is present. At Mamasar Bulak, bioclastic calcarenites–calcirudites with crinoids, brachiopods, bryozoans and corals crop out below very recrystallized massive limestones. Microfacies analysis shows that the formation comprises at the base grainstones and packstones with fusulinids, smaller foraminifers, echinoderms, brachiopods, algal lumps and bryozoans. The microfacies associated to the microbialites comprise peloidal packstones with brachiopods, whereas in the upper part there are again bioclastic packstones with fusulinids, smaller foraminifers, algal lumps, and echinoderms. … The total thickness of the formation is 86 m.” (Angiolini et al.. 2015)

“The formation contains fusulinids, smaller foraminifers, algae, echinoderms, brachiopods (species of the genera Martinia, Overtonina, Retimarginifera, Costiferina, Magniplicatina, Boloria, Labaia, and Spiriferella), bryozoans, and Tubiphytes sp. The conodonts Mesogondolella lamberti, M. siciliensis, and Sweetognathus subsymmetricus, were found at the base of the formation in a microfacies comprising Climacammina sp., Donezella hirtipes, Eotuberitina sp., Globivalvulina sp., Lasiodiscus tenuis, Mizzia? sp., Neoendothyra cf. staffelloides, Parafusulina? sp., Permocalculus? sp., Polytaxis? sp., Postendothyra sp., Schubertella sp., and T. obscurus. Worthy of note is also the occurrence of Cancellina cutalensis and of Neoschwagerina simplex, Parafusulina? cf. shakgamensis, Praesumatrina neoschwagerinoides, and Yangchienia sp.” (Angiolini et al., 2015)

“The Kurteke Fm represents several carbonate platform environments from the inner shelf with microbialites and peloidal packstones to higher energy platform margin settings where bioclastic shoals accumulated. Except for a few ash bed at the base, no volcanic layers have been recorded in the massive limestones of the Kurteke Fm, probably due to the unfavorable depositional conditions (i.e. high hydrodynamic energy, erosion).” (Angiolini et al., 2015)