MATERIAL

Zaladu Section (Ozbak-Kuh Mountains)

The Zaladu section is located on the slope of the mountain near the Gushkamar village (Figure 1). The Zaladu section continues below the interval described by Leven and Taheri (2003). The following successive beds are exposed from the base upwards (Figure 2):

Ghaleh Formation

1. White quartzite sandstone with interbeds of green platy shale in the middle. The sandstone occurs at the base of the Ghaleh Formation and rests along a sharp contact of shale with thin interbeds of sandstone and limestone of the Shishtu Formation. Approximately 75 m below the base of Ghaleh Formation, the limestone in the Shishtu Formation (sample Z69) contains Eostaffella acuta, Archaediscus krestovnikovi, A. aff. A. globosus, Biseriella minima, and Endotaxis brazhnikovi of supposed Serpukhovian age (Table 1).

25 m

2. Thinly to coarsely layered grainstone, locally sandy, dolomitized, and silicified with brachiopods, corals, bryozoans, crinoids, and foraminifers. The following foraminiferal species were identified: Parastaffella aff. P. utkaensis Eostaffella ovoidea, E. pseudostruvei elongatissima, E. parastruvei forma recta, E. libera, E. aff. E. postmosquensis, E. acutiformis, E. designata, E. ovoidea, E. parastruvei, E. pseudostruvei elongatissima, E. pseudostruvei cf. E. chomatifera Plectostaffella (Plectostaffella) seslavica, Pl. (Pl.) aff. P. orbiculata, Millerella aff. excavata, Parastaffella aff. P. utkaensis, Biseriella minima, B. parva, Globivalvulina kamensis, Monotaxinoides sp., Deckerella sp., Archaediscus krestovnikovi, A. vischeriensis, Asteroarchaediscus sp. (samples Z86-Z102).
 
45 m
 
3. Gray, greenish shale with interbeds of thinly layered marls and medium layered fine to medium grainstone with corals, bryozoans, crinoids, and foraminifers Eostaffella cf. E. mirifica, Plectostaffella (Plectostaffella) bogdanovkensis, Monotaxinoides convexus, Tetrataxis planocula, Neoarchaediscus aff. N. gregori acutiformis (samples Z108-Z129).
25 m
 
4. Dark gray, thinly to coarsely layered fine to coarse grainstone with cherty nodules. Bioturbation is prominent. Abundant corals and foraminifers occur. The following species are identified: Eostaffella designata, E. aff. E. nalivkini, E. pseudostruvei angusta, E. cf. proikensis, E. designata, Plectostaffella (Plectostaffella) bogdanovkensis, Pl. (Pl.) jakhensis, Pl. (Pl.) varvariensis, Millerella mixta, M. aff. M. paraumbilicata, M. variabilis, M. ex gr. M. conica, Mediocris mediocris, Endothyra bowmani, Plectoendothyra spirilliniformis, Biseriella parva, Tetrataxis aff. T. acutiformis, Deckerella sp., Neoarchaediscus gregori gregori, N. parvus, N. postrugosus, N. latispiralis, N. incertus, N. probatus, Asteroarchaediscus cf. A. bashkiricus, A. cf. A. ovoides (samples Z130-Z171). Up section, there occur Eostaffella ex gr. E. ikensis, Millerella cf. M. variabilis, M. cf. M. uralica, M. ex gr. M. marblensis, Mediocris mediocris, Pseudonovella irregularis, Plectostaffella (Plectostaffella) uzbekistanica, Semistaffella cf. S. variabilis, Pseudostaffella ex gr. P. antiqua, Planoendothyra aljutovica (samples Z177-Z179). At the top of this unit Eostaffella pseudostruvei chomatifera, Millerella ex gr. M. marblensis, Pseudonovella irregularis, Semistaffella sp., Pseudostaffella antiqua, P. paracompressa, P. composita, Biseriella sp., Neoarchaediscus postrugosus were found (sample Z183).

67 m

The total thickness of the Ghaleh Formation in this section is 162 m.

Absheni Formation

5. Interbedded shale and siltstones with thin to medium layered sandy grainstone and oolitic, locally dolomitized limestone with cherty nodules, and with fine-grained quartz sandstone. The limestone dominates in the lower and upper parts of Unit 5 and contains numerous solitary corals, brachiopods, bryozoans, crinoids, and foraminifers. The lower part of the unit contains an abundant foraminiferal assemblage including Eostaffella sp., Millerella sp., Seminovella nana, S. carbonica, S. aperta, Pseudostaffella subquadrata, Neostaffella ex gr. N. larionovae, Neostaffella sp., Ozawainella mosquensis, O. vozhgalica, Ozawainella sp., Eoshubertella obscura obscura, E. obscura mosquensis, Fusiella pulchella, F. praecursor paraventricosa, F. aff. longa, Profusulinella parva, P. staffellaeformis, P. omiensis, P. beppensis, P. pseudoparva n. sp., P. prisca prisca, P. convoluta, Taitzehoella cf. T. pseudolibrovichi, Aljutovella sp. 1, Al. stocklini n. sp., Al. iranica n. sp., Al. cafirniganica, Al. gorgiji n. sp., Al. artificialis, Al. conspecta, Al. priscoidea , Al. aff. Al. cybaea, Al. aff. Al. devexa, Al. complicata, Al. subaljutovica, Tetrataxis acutiformis, Howchinia gibba, Neoarchaediscus sp., Asteroarchaediscus sp. (Table 1; samples Z189-Z231). The middle part of Unit 5, composed mainly of shale, yielded Fusiella aff. F. paradoxa, Parastaffella sp., Ozawainella eoangulata, Pseudostaffella ex gr. P. subquadrata, Profusulinella omiensis, Putrella aff. P. donetziana, Putrella sp. (samples Z235-Z250). The upper part of the formation contains Fusiella aff. F. praetypica, F. aff. F. paradoxa, F. praecursor paraventricosa, Ozawainella aff. O. vozhgalica, Pseudostaffella sp., O. ex gr. O. mosquensis, Profusulinella omiensis, Aljutovella ex gr. Al. stocklini n. sp., Al. ex gr. Al. cafirniganica, Tetrataxis minima, T. aff. T. pusilla, Deckerella sp. (samples Z262-Z290).

110 m

Greenish gray shale with thin interbeds of dolomitized sandy and bioclastic limestone and sandstone. The limestone includes fragments of brachiopod shells and bryozoan and pelmetazoan skeletons. At the top, the shale is red-colored and shows signs of intensive bioturbation.

75 m

The total thickness of the Absheni Formation is 185 m. Correspondingly, the thickness of the Sardar Group in this section is 347 m.

Anarak Section

The section is located 25 km to the southeast of the town of Anarak (Figure 1) near the Kuh-e-Bande Abdulhussien Mountain (height 1625 m). We reconstructed the succession of displaced Shishtu and Sardar beds by means of foraminiferal data. The position of samples in this section is shown in Figure 2 and Figure 3.

Ghaleh Formation

1. The Ghaleh Formation begins at the bottom with red and yellowish-brown gypsiferous shale. The upper part includes interbeds of thinly layered marly and sandy limestone. The deposits lie along a sharp contact with the eroded surface of the Shishtu limestone. This feature, and the presence of gypsum in the shale, implies a hiatus at the formation boundary. We observe no angular unconformity.

51 m

2. Coarsely layered dark gray massive grainstone with interbeds of dolomite and thinly layered marly wackstone with abundant corals, crinoids, fragments of brachiopod valves, and foraminifers.

Samples were taken from several levels. Sample A40 was taken from the base and yielded Eostaffella pseudostruvei pseudostruvei, Plectostaffella (Plectostaffella) seslavica Semistaffella variabilis, Pseudostaffella cf. P. antiqua, Monotaxinoides grandis, Globivalvulina bulloides, Tetrataxis sp. (Table 2). Higher in the sequence, sample A71 contains few Eostaffella sp., Semistaffella variabilis, Plectostaffella (Plectostaffella) bogdanovkensis, Pseudostaffella cf. P. antiqua, Globoendothyra sp., Bradyinidae gen. indet, Globivalvulina bulloides, Eolasiodiscus donbassicus, Monotaxinoides grandis, Tetrataxis conica, T. parviconica, T. aff. T. acuta, Deckerella composita, Neoarchaediscus cf. N. grandis, N. incertus, Tetrataxis sp., Biseriella parva. The upper part of Unit 2 (samples A72-A86) contains more abundant and diverse foraminifers, including Eostaffella ex gr. E. postmosquensis acutiformis, E. aff. E. ljudmilae, E. parastruvei chusovensis, E. ovoidea, E. raguschensis, E. aff. E. pseudostruvei chomatifera, Millerella pressa, M. variabilis, M. paraconica, Mediocris mediocris, M. brevisculus, Plectostaffella (Plectostaffella) bogdanovkensis, Pl. (Pl.) seslavica, Pl. (Pl.) jakhensis, Pl. (Varistaffella) varsanofievae, Pl. (V.) ziganica, Semistaffella variabilis, S. minuscilaria, Pseudostaffella antiqua, P. compressa, P. praegorskyi, P. paracompressa, P. nikolaevskiensis, P. composita, P. grandis, P. aff. P. gorskyi, Plectoendothyra(?) sp., Bradyinidae gen. indet., Eolasiodiscus donbassicus, Monotaxinoides grandis, M. convexus, Biseriella minima, Tetrataxis grandis, T. parviconica, T. quasiconica, T. planocula, T. minima, Cribrostomum posteximinium, Neoarchaediscus rugosimilis, N. postrugosus, N. latispiralis, Asteroarchaediscus subbashkiricus, A. bashkiricus (Table 2).

95 m

Total thickness of the Ghaleh Formation in Anarak section is 146 m.

Absheni Formation

3. Thinly layered fine to coarse grainstone with thin shale interbeds. A contact with the limestone of Unit 2 is complicated by a fault. Abundant foraminifers are represented by Eostaffella acuta, Eostaffella sp., Millerella pressa, M. ex gr. M. marblensis, Novella primitiva, Mediocris brevisculus, Pseudostaffella antiqua, P. aff. P. paracompressa, Pseudostaffella subquadrata, Neostaffella pseudoquadrata, N. rotundata, Ozawainella mosquensis, O. paracompressa, O. vozhgalica, O. ferganensis, O. aff. O. paratingi O. kurakhovensis, Profusulinella ex gr. P. parva, P. aff. P. pseudorhomboides, P. prisca, Aljutovella cf. Al. cybaea, Al. tumida, Al. cafirniganica, Al. artificialis, Al. subaljutovica, Al. iranica n. sp., Al. aff. Al. stocklini n. sp., Endothyra bashkirica, Planoendothyra spirilliniformis, Endothyranella gracilis, Bradyinidae gen. indet., Globivalvulina sp., Tetrataxis parviconica, T. grandis, Palaeotextularia bruta, Neoarchaediscus incertus, N. gregori, Eolasiodiscus sp. (samples A89-A118).

22 m

4. Shale, with thin wackstone-packstone interbeds (samples A120-A139). Limestone interbeds yield Eostaffella exilis, E. acuta, Millerella variabilis, Novella primitiva, N. irregularis, Seminovella carbonica, Pseudostaffella aff. P. nikolaevskiensis, Pseudostaffella subquadrata, Neostaffella sp., Ozawainella eoangulata, O. aff. O. grandis, O. aff. O. paratingi, O. mosquensis, Profusulinella omiensis, Pr. staffellaeformis, Pr. prisca, Pr. pseudoparva n. sp., Ps. aff. Ps. pseudorhomboides, Aljutovella tumida, Al. cafirniganica, Endothyra sp., Bradyinidae gen. indet., Tetrataxis sp., Climacammina sp. (sample A120-A127). At the top of the bed there are single Ozawainella ex gr. O. paratingi, ?Putrella sp. and Palaeostaffella moellerites Reitlingerina sp. (sample A139).

80 m
 
The thickness of the Absheni Formation in this section is 102 m, however, it is incomplete. Although slightly displaced, the section seems to record a continuous stratigraphic succession as confirmed by the analysis of the foraminiferal assemblages. The shale of Unit 4 is separated by a fault from the coarsely layered massive grainstone within Unit 4 (Unit 2a in Figure 2 and Figure 3). Unit 2a contains a foraminiferal assemblage similar to that of the upper part of Unit 2 of the Ghaleh Formation. The assemblage includes Eostaffella postmosquensis, E. lepida, Plectostaffella (Plectostaffella) acuta, Pl. (Pl.) jakensis, Pl. (Pl.) quadrata, Pl. (Varistaffella) ziganica, Pseudostaffella antiqua, Ps. grandis, Ps. compressa, Ps. nikolaevskiensis, Ps. latispiralis, Biseriella sp., Tetrataxis angusta, T. planocula, Palaeotextularia sp., Neoarchaediscus ex gr. incertus, Asteroarchaediscus bashkiricus, A. ex. gr. A. subbashkiricus, Eosigmolina sp. (samples A150-A160). The foraminiferal assemblage from higher levels (samples A144-A148) consists of Ozawainella sp., Profusulinella parva, Pr. aff. ellipsoidalis, Pr. aff. Pr. bona sphaerica, Aljutovella pseudoaljutovica, Eoschubertella sp., Monotaxinoides sp. According to these data, the limestone of Unit 2a is analogous of that of the upper part of Unit 2 and partially overlaps it. The estimated thickness of Unit 2a is 40 m.

5. Gray, locally plastered shale with thin interbeds of pink shale, sandstone, and thinly layered sandy grainstone with crinoids, corals, brachiopods, and foraminifers. Unit 5 is in tectonic contact with the underlying massive limestone of Unit 2a. Unit 5 is lithologically similar to Unit 4 but is distinguished by a younger foraminiferal assemblage. The lower and thicker part of the unit contains Seminovella operta, Millerella cf. M. mixta, Pseudostaffella aff. P. subquadrata, Neostaffella rotundata, N. eoangulata, N. aff. N. syzranica, Ozawainella mosquensis, O. kurachovensis, O. aff. O. paratingi, O. cf. O. stellae, Reitlingerina bradyi, Eoschubertella obscura obscura, Profusulinella (?) sp., and Putrella sp. near the top of this part (samples A168-A178). The upper part of Unit 5 includes Eostaffella ex gr. mutabilis, E. cf. acutissima, Novella irregularis, Neostaffella rotundata, N. syzranica, Ozawainella eoelongata, Eoschubertella obscura obscura, E. obscura compressa, Schubertella cf. S. penchiensis Sheng, Fusiella typica ventricosa, F. aff. F. praetypica, F. praecursor praecursor, F. praecursor paraventricosa, Fusulinella (Moellerites) bockiformis, F. (M.) praebocki , F. (M.) aff. F. globulus, Fusulinella (Fusulinella) aff. subpulchra contracta, Fusulinella sp. 1, Putrella persica n. sp., Putrella sp. 1 and 2, Beedeina bona anarakensis n. subsp. Beedeina sp., Reitlingerina bradyi, R. timanica, Glomospira sp., Endothyra sp., Bradyinidae gen. indet., Endothyranella gracilis, Globivalvulina sp., Tetrataxis acutiformis, T. aff. paraconica, Deckerella sp., Climacammina sp. (samples A183 - A193).

45 m

We acquired samples A208 and A211 from slightly adjacent to the line of the section studied, immediately below the base of the Zaladu Formation. Samples are related to the uppermost part of Unit 5. The following foraminifers were recovered: Seminovella nana, Pseudostaffella aff. P. lomovatica, Eoschubertella obscura procera, Fusiella praecursor paraventricosa, F. typica, F. aff. F. longa, Fusulina? sp. (Table 2). It is likely that Units 4 and 5 belong to a single, predominantly siliciclastic sequence that composes the upper half of the Sardar Group and is equivalent to the Absheni Formation of the Ozbak-Kuh section.

The shale of Unit 5 is overlain by a limestone sequence with Gzhelian (Orenburgian) Ultradaixina, ?Rauserites, Schellwienia, Rugosofusulina, Occidentoschwagerina (in the lower part), and Asselian Pseudoschwagerina (in the upper part) (Leven and Gorgij 2006). The sequence corresponds to the Zaladu Formation of the Ozbak-Kuh Mountain section. The contact between Unit 5 and the Zaladu Formation is indistinct. As in the Zaladu section, the Zaladu Formation in the Anarak section is preceded by dolomites of unknown (probably Sakmarian) age. (Leven and Taheri 2003). During fieldwork, the third author thought that these dolomites belonged to the Jamal Formation, however, the Jamal Formation is recognizable by Late Permian foraminifers previously reported in a different location (Sharkovski et al. 1965) and is characterized by a different lithology (grainstone, wackstone, and oolitic limestone). These dolomontes recently established as a new Tigh-Maadanou Foramation (Leven and Gorgil 2005).