◄ Carnets Geol. 16 (25) ►
Department of Geology, Faculty of Science, University of
Birjand, Birjand (Iran); present address: Technology Incubators, Razi
University, PO Box 67149/67346, Kermanshah (Iran)
Department of Geology, Faculty of Science, University of Birjand, Birjand (Iran)
Department of Geology, Faculty of
Science, University of Birjand, Birjand (Iran)
Department of Geology, Faculty of
Science, University of Birjand, Birjand (Iran)
Published online in final form (pdf) on December 12, 2016
[Editor: Bruno Granier; language editor: Stephen Carey]
Upper Albian and Lower Cenomanian ammonites occur on the eastern margin of the Lut block in eastern Iran. The ammonite assemblages described herein are from the Nimbolook and Kerch sections located west of Qayen. The following taxa are described: Mantelliceras mantelli (J. Sowerby, 1814), Mantelliceras saxbii (Sharpe, 1857), Mantelliceras sp. 1, Mantelliceras sp. 2, Mantelliceras sp. 3, Sharpeiceras laticlavium (Sharpe, 1855), Sharpeiceras schlueteri (Hyatt, 1903), Puzosia (Puzosia) mayoriana (Orbigny, 1841), Hyphoplites costosus C.W. Wright & E.V. Wright, 1949, Mortoniceras (Mortoniceras) cf. fallax (Breistroffer, 1940), Mantelliceras cf. mantelli (J. Sowerby, 1814), Calycoceras (Gentoniceras) aff. gentoni (Brongniart, 1822), Idiohamites fremonti (Marcou, 1858), Mariella (Mariella) sp., Mariella (Mariella) dorsetensis (Spath, 1926), and Turrilites costatus Lamarck, 1801. The ammonite assemblages clearly indicate a late Albian-middle Cenomanian age for the Nimbolook section and late Albian-early Cenomanian age for the Kerch section.
• systematic paleontology;
• Lut block;
Sharifi J., Raisossadat S.N., Mortazavi Mehrizi M. & Motamedalshariati M. (2016).- Albian and Cenomanian ammonites of the Eastern margin of the Lut block (East Iran).- Carnets Geol., Madrid, vol. 16, no. 25, p. 591-613.
Ammonites albiennes et cénomaniennes de la bordure orientale du bloc de Lut (E Iran).- Des ammonites de l'Albien supérieur et du Cénomanien inférieur sont présentes sur la bordure orientale du bloc de Lut dans la partie orientale de l'Iran. Les associations ammonitiques décrites ici proviennent des coupes de Nimbolook et de Kerch, toutes deux situées à l'ouest de Qayen. Les taxons suivants sont décrits : Mantelliceras mantelli (J. Sowerby, 1814), Mantelliceras saxbii (Sharpe, 1857), Mantelliceras sp. 1, Mantelliceras sp. 2, Mantelliceras sp. 3, Sharpeiceras laticlavium (Sharpe, 1855), Sharpeiceras schlueteri (Hyatt, 1903), Puzosia (Puzosia) mayoriana (Orbigny, 1841), Hyphoplites costosus C.W. Wright & E.V. Wright, 1949, Mortoniceras (Mortoniceras) cf. fallax (Breistroffer, 1940), Mantelliceras cf. mantelli (J. Sowerby, 1814), Calycoceras (Gentoniceras) aff. gentoni (Brongniart, 1822), Idiohamites fremonti (Marcou, 1858), Mariella (Mariella) sp., Mariella (Mariella) dorsetensis (Spath, 1926), et Turrilites costatus Lamarck, 1801. Les associations ammonitiques indiquent clairement un âge Albien supérieur-Cénomanien moyen pour la coupe de Nimbolook et un âge Albien supérieur-Cénomanien inférieur pour celle de Kerch.
• Albien ;
• Cénomanien ;
• Crétacé ;
• ammonites ;
• paléontologie systématique ;
• biostratigraphie ;
• bloc de Lut ;
The central Iran area is bounded to the east by the Lut Block (Aghanabati, 2011). Cretaceous deposits are widely exposed on the eastern margin of the Lut block. Tirrul et al. (1983), Fauvelet and Eftekhar Nezhad (1990), Raisossadat and Skelton (2005), Khazaei et al. (2011), Babazadeh et al. (2010), Raisossadat et al. (2012), Moulodi et al. (2014) and Sharifi et al. (2015) have published on aspects of the area's regional geology, Cretaceous stratigraphy and micro- and macropaleontology. The focus of this study is on the discovery and description of upper Albian and middle Cenomanian ammonites. The ammonite fauna described here comes from two sections. The Nimbolook section is located at 59°01'20"E 33°52'15"N and the Kerch section is located at 58°52'45"E 33°37'15"N (Figs. 1 - 2 ).
This paper is one of the few paleontological studies of eastern Iran. For many of the species described, this is the first record from eastern Iran.
Figure 2: Location of the measured sections (stars).
2.1. Kerch section:
This section consists of a succession of 255 m of marl and marly limestone which contains ammonites. The carbonate succession overlies an Albian igneous unit (Fauvelet and Eftekhar Nezhad, 1990) and underlies a siliciclastic unit of red conglomerate and sandstone. The sequence straddles the Albian-Cenomanian boundary (Figs. 3 - 4 ). Ammonites are scarce with 17 specimens collected, all from the upper third of the section. Ammonites identified are Mantelliceras mantelli (J. Sowerby, 1814), Mantelliceras saxbii (Sharpe, 1857), Mantelliceras sp. 1, Mantelliceras sp. 2, Sharpeiceras laticlavium (Sharpe, 1855), Sharpeiceras schlueteri (Hyatt, 1903), Puzosia (Puzosia) mayoriana (Orbigny, 1841) and Hyphoplites costosus C.W. Wright & E.V. Wright, 1949 (Figs. 7 - 8 ). The ammonite assemblage suggests that the section is of late Albian - early Cenomanian age.
Figure 4: Stratigraphic columns of the Kerch section (A), view of the Kerch section (B), and marl and marly limestone beds (C).
2.2. Nimbolook section
In the Nimbolook section, a carbonate succession, 92 m thick, conformably overlies Aptian-Albian sedimentary rocks (Moulodi, 2013) and underlies red conglomerate and sandstone. The carbonates are divisible into two units (Figs. 5 - 6 ). The lower unit consists of 55 m of thickly bedded light grey non-ammonite-bearing limestone and the upper consists of 33 m of medium-bedded pink limestone with ammonites. Ammonites are very scarce with eight specimens recovered. The limestone includes biosparite and biomicrosparite (wackestones and packstones), which contain abundant molluscan debris (pelecypods, gastropods, and ammonites).
Ammonites identified include Mortoniceras (Mortoniceras) cf. fallax (Breistroffer, 1940), Mantelliceras sp. 3, Mantelliceras cf. mantelli (J. Sowerby, 1814), Calycoceras (Gentoniceras) aff. gentoni (Brongniart, 1822), Idiohamites fremonti (Marcou, 1858), Mariella (Mariella) sp., Mariella (Mariella) dorsetensis (Spath, 1926) and Turrilites costatus Lamarck, 1801 (Fig. 9 ). Based on the ammonite occurrences, this section is assigned a late Albian - middle Cenomanian age.
Figure 6: Stratigraphic columns of the Nimbolook section (A), upper half of the Nimbolook section (B) and basal contact of the Nimbolook section (C).
The collected ammonites are classified after the Treatise of Invertebrate Palaeontology, part L (Wright et al., 1996). Shell measurements are given in centimeters, in the following order; Diameter (D), whorl height (Wh), whorl breadth (Wb) and breadth of umbilicus (U).The abbreviations used to indicate the source of specimens are as follows: Ni, Nimbolook section; Ke, Kerch section.
Suborder Ammonitina Hyatt, 1889
Superfamily Desmoceratoidea Zittel, 1895
Family Desmoceratidae Zittel, 1895
Subfamily Puzosiinae Spath, 1922
Genus and Subgenus Puzosia Bayle, 1878
Puzosia (Puzosia) mayoriana (Orbigny, 1841)
2005 Puzosia (P.) mayoriana (Sowerby); Reboulet et al., p. 125, Fig. 3.A.
Material: Ke-1, Ke-2, and Ke-3, all crushed to varying degrees.
Description: Ke-1 is the largest (diameter 11.6 cm) and best preserved specimen of P. (P.) mayoriana from the Kerch section. All specimens have an oval whorl section, rounded flanks, broadly rounded ventrolateral shoulder and convex venter. Specimens have 1-2 well-developed constrictions on the last whorl. The constrictions are sharper in Ke-2. They arise from the umbilical wall, straight on the lower half of the flank, convex on the ventrolateral shoulder and flexing back and concave on the venter. Convex constrictions are most visible in Ke-1 and Ke-2. Specimens have 14-38, flexuous and dense ribs, arranged parallel to the constrictions. The constrictions are flanked by a collar rib, feeble on the flanks, but coarsening on the ventrolateral shoulder and venter.
Dimensions (in cm):
Occurrence: upper Albian to upper Cenomanian. Based on co-occurrence with specimens Ke-4, Ke-5, Ke-9 and Ke-10, both Ke-1 and Ke-2 are upper Albian and Ke-3 is lower Cenomanian.
Superfamily Hopliticeae H. Douvillé, 1890
Family Hoplitidae H. Douvillé, 1890
Subfamily Hoplitinae H. Douvillé, 1890
Genus Hyphoplites Spath, 1922
Hyphoplites costosus C.W. Wright & E.V. Wright, 1949
1949 Hyphoplites costosus; C.W. Wright & E.V. Wright, p. 484, Pl. XXIX, fig. 7.a-b.
Material: Ke-4 and Ke-5.
Description: Ke-4 is a half whorl of a discoidal shell. Ribs are sickle-shaped, fine and dense, and commence at the umbilicus. The ribs carry ventrolateral tubercles. The siphonal groove is engraved on the venter and passes through the ventrolateral tubercles. Ke-5 has similar ornamentation but is less well preserved.
Dimensions (in cm):
Occurrence: This species occurs in upper Albian strata of Hungary (Szives et al., 2007) and the lower and middle lower Cenomanian of southern England (C.W. Wright & E.V. Wright, 1949). Hyphoplites costosus has been found below M. mantelli (at the base of the Cenomanian) in the Kerch section.
Figure 7: Ke-1, Ke-2 and Ke-3: Puzosia (Puzosia) mayoriana (Orbigny, 1841), Ke-4 and Ke-5: Hyphoplites costosus C.W. Wright & E.V. Wright, 1949, Ke-6, Ke-7 and Ke-8: Mantelliceras mantelli (J. Sowerby, 1814) (all scales: 1 cm).
Superfamily Acanthoceratoidea Grossouvre, 1894
Family Brancoceratidae Spath, 1934
Subfamily Mortoniceratinae H. Douvillé, 1912
Genus and subgenus Mortoniceras Meek, 1876
Mortoniceras (Mortoniceras) cf. fallax (Breistroffer, 1940)
2002 Mortoniceras (Mortoniceras) pachys (Seeley, 1865); Amédro, p. 82, Pl. 9, fig. 1.
Material: Ni-1, specimen broken.
Description: Ni-1 is the only specimen attributable to this species. The whorl section is almost quadrangular. The ornamentation is distinct, and consists of eight ribs that extend in pairs from the umbilical tubercle and strengthen into bullae at mid-flank. There are eight large and prominent ventrolateral tubercles. The venter is flat and the ribs are slightly curved on it. The keel is crossed by the ventral ribs.
Dimensions (in cm):
Family Acanthoceratidae Grossouvre, 1894
Subfamily Mantelliceratinae Hyatt, 1903
Genus Mantelliceras Hyatt, 1903
Mantelliceras mantelli (J. Sowerby, 1814)
1984 Mantelliceras mantelli (J. Sowerby, 1814); Wright and Kennedy, p. 99, Figs. 20.A-D, 26.A, C, E; Pl. 16, fig. 5; Pl. 17, figs. 1, 3; Pl. 18, figs. 1-3; Pl. 19, figs. 1-6; Pl. 21, figs. 2, 4; Pl. 24, fig. 3; Pl. 36, fig. 1.
Material: Ke-6, Ke-7, and Ke-8.
Description: Ke-6 is the largest and best preserved specimen of M. mantelli inform the Kerch section. The umbilicus is filled with sediments. Coiling is evolute to moderately involute, with a normal expansion rate and a subrounded to polygonal whorl section. Ornamentation is distinct. There are 13 primary, strong, radial and straight ribs that arise from umbilical shoulder, and secondary ribs are located between them. The primary ribs carry umbilical and lateral tubercles while ventrolateral tubercles occur on all ribs. Ribs crossing the venter bear strong ventrolateral clavi.
Ke-7 consists of a half whorl that is smaller and less well preserved than Ke-6. Ke-7 bears 17 strong ribs that are alternately and regularly long and short. Ribs are slightly curved on the sides in contrast to those of Ke-6. Two rows of bullae are visible on the primary ribs of the flanks while a single row is present on the secondary ribs. On the venter, all ribs are linked and tubercles are arranged parallel to each other. Ke-8 is similar than Ke-7, but its lateral ribs are more sinuous and its lateral tubercles are barely visible, due to erosion.
Occurrence: M. mantelli has a world-wide distribution. It is common in the lower two thirds of the lower Cenomanian and only rarely found above (Kennedy, 1994).
Dimensions (in cm):
Mantelliceras cf. mantelli (J. Sowerby, 1814)
1998 Mantelliceras mantelli (J. Sowerby, 1814); Kaplan et al., p. 115, Pl. 11, figs. 1-2; Pl. 17, figs. 12-13; Pl. 19, figs. 1-9; Pl. 22, figs. 3-4; Pl. 23, fig. 8; Pl. 24, figs. 4-6; Pl. 25, figs. 1-5.
Material: Ni-3, specimen broken, abraded ventrally.
Description: The specimen is a half whorl bearing 17 ribs. Seven primary ribs arise at the umbilical seam and extend across the flanks, with secondary ribs located between them. The flanks are nearly flat and the whorl section is oval to rectangular. Some of the primary ribs strengthen into rounded tubercles on the middle of the sides. Tiny ventrolateral nodes occur in places. All ribs are straight, strong and radial on the flanks but diminish toward the venter. Other Mantelliceras found in Kerch section have more prominent ornaments and more convex flanks than Ni-3.
Dimensions (in cm):
Mantelliceras saxbii (Sharpe, 1857)
1971 Mantelliceras saxbii; Kennedy and Hancock, p. 437, Pl. 79, figs. 1-5; Pl. 80, figs. 1-4; Pl. 81, figs. 1, 4, 6-8; Pl. 82, figs. 2, 4-5.
Description: Ke-9 is oval in cross section and widest in the middle of the flanks that are gently curved near the venter. The umbilicus is moderately deep, with a steep wall. The primary ribs arise from the umbilical shoulder. Secondary ribs arise at the middle of the flanks and are arranged irregularly between the primary ribs. In total there are 30 fine (contrast those of M. mantelli) and crowded narrow ribs. Tubercles are absent from the flanks, but occur in two rows bordering the venter. They are tiny, rounded and, in some cases, barely visible, due to abrasion.
Occurrence: Manteliceras saxbii Zone of western Europe (Gale, 1995; Gale et al., 1996; Amédro, 2008) and throughout the lower Cenomanian, but common only in the middle of the substage. It is recorded all over Europe, Russia, North Africa, Angola, Madagascar, Iran and Kazakhstan. Kennedy et al. (2008) noted that this species is distinct from M. mantelli in the lack of lateral tubercles, the dense ribbing and the compressed whorl section.
Dimensions (in cm):
Mantelliceras sp. 1
Material: Ke-10 and Ke-11, specimens broken.
Description: The ornamentation and the stratigraphic position suggest attribution to Mantelliceras but more definite identification is impossible. Ke-10 has about primary ribs (arising at the umbilical margin) and 11 irregular short secondary ribs (arising at mid-flank). The ribs are densely distributed, straight and linked on the venter, and bear ventrolateral tubercles. Ke-11 is a crushed specimen with two rows of ventrolateral tubercles and abraded, relatively widely spaced radial ribs on the sides.
Dimensions (in cm):
Mantelliceras sp. 2
Material: Ke-12 and Ke-13
Description: Ke-12 may represent M. saxbii, based upon the arrangement of the ribs and the lack of lateral tubercles. Ke-13 has a rounded and wide venter, a circular whorl section, 18 strong and densely distributed ribs that arise from umbilical bullae. Ke-13 is similar to Mantelliceras nitidum (Crick, 1907) as described by Kennedy et al. (2015) (Fig. 4. A-D, G-L ) but is too poorly preserved for confident specific determination.
Dimensions (in cm):
Mantelliceras sp. 3
Description: Ni-4 is a composite mould of the upper part of Nimbolook section. The umbilicus is covered by sediment and the ornamentation is visible only on the right side. Ni-4 has evolute coiling and a low expansion rate. The whorl section is oval and there are no tubercles, but 23-25 sharp ribs alternately long and short and dichotomously branching from the middle of the flanks.
Dimensions (in cm):
Figure 8: Ke-9: Mantelliceras saxbii (Sharpe, 1857), Ke-10 and Ke-11: Mantelliceras sp. 1, Ke-12 and Ke-13: Mantelliceras sp. 2, Ke-14: Sharpeiceras laticlavium (Sharpe, 1855), Ke-15, Ke-16: Sharpeiceras schlueteri (Hyatt, 1903) (all scales: 1 cm).
Genus Sharpeiceras Hyatt, 1903
Sharpeiceras laticlavium (Sharpe, 1855)
Description: The distinctive features of this species are the compressed, rectangular whorl section and very evolute coiling. The umbilicus features a steep wall. There are 24 coarse, straight ribs that originate from the umbilicus and extend across the sides of the whorl. All ribs bear umbilical, middle lateral and inner ventrolateral conical tubercles and much stronger outer ventrolateral clavi. The venter is flat and smooth. Ribs that reach the flanks disappear on the venter.
Dimensions (in cm):
Discussion: The flattened flank and coarser tuberculation separate this specimen from Sharpeiceras schlueteri. The difference between the two species is described in Delamette and Kennedy (1991).
Occurrence: Sharpeiceras laticlavium is a cosmopolitan species indicative of the lower Cenomanian. The species occurs in N. carcitanense, S. schlueteri and M. saxbii Assemblage Zone faunas (Kennedy et al., 1979; Delamette and Kennedy, 1991; Kaplan et al., 1998).
Sharpeiceras schlueteri (Hyatt, 1903)
1982 Sharpeiceras mexicanum (Bose); Mancini, p. 254, Fig. 6.e.
Material: Ke-15 and Ke-16.
Description: Two specimens of S. schlueteri are found in the Kerch section. Ke-15 is the largest ammonite found there. Four coarse ribs that swell into umbilical, middle lateral, and inner and outer ventrolateral tubercles are preserved on the sides. Tubercles are strong and conical. In the adult, the inner ventrolateral tubercles tend to develop into a horn-like process (Kennedy, 1971). The inner ventrolateral tubercles are connected to a row of very prominent outer ventrolateral clavi by broad ribs. The sutures are clearly visible. The ornamentation of Ke-16 is similar to that of Ke-15 except that the ribs and tubercles are less prominent. Furthermore part of the umbilicus is visible although filled by sediment.
Dimensions (in cm):
Occurrence: It represents the Lower Cenomanian. Sharpeiceras schlueteri is a Subzone of the M. mantelli Zone and occurs in England, France, Germany, Angola, Mozambique, Texas and Peru (Kaplan et al., 1998; Kennedy et al., 2005) and Iran in this study.
Subfamily Acanthoceratinae Grossouvre, 1894
Genus Calycoceras Hyatt, 1900
Subgenus Gentoniceras Thomel, 1972
Calycoceras (Gentoniceras) aff. gentoni (Brongniart, 1822)
Material: Ni-5, broken specimen.
Description: Ni-5 is from the upper part of the Nimbolook section. The specimen has a massive whorl and deep umbilicus. It has 20-22 robust ribs on the venter but no lateral or ventral tubercles are observed.
Dimensions (in cm):
Occurrence: Calycoceras (Gentoniceras) gentoni occurs in the lower middle to lower upper Cenomanian (Kennedy and Juignet, 1994; Kaplan et al., 1998). The association of C. (G.) gentoni and Turrilites costatus in the same horizon at Nimbolook section, is of early middle Cenomanian age. The species is also known from France, England, Germany and central Iran.
Superfamily Turrilitoidea Gill, 1871
Family Anisoceratidae Hyatt, 1900
Genus Idiohamites Spath, 1925
Idiohamites fremonti (Marcou, 1858)
Description: Ni-2 is part of a U-shaped body chamber that is coiled in a plane open spiral. Ornaments consist of 16 oblique ribs, prominent on the flanks but becoming faint towards the venter where they are replaced by two rows of ventral tubercles. Lateral tubercles are absent. The ribs are densely distributed and narrow on the straight shaft but are broader with more widely spaced on the hooked whorl.
Occurrence: I. fremonti occurs in the Duck Creek limestone of northern Texas (upper Albian) (Adkins, 1932). Since I. fremonti is recorded at almost the same horizon as M. fallax in the Nimbolook section, its occurrence indicates the upper Albian. The present specimen is the first record from Iran.
Family Turrilitidae Gill, 1871
Genus and subgenus Mariella Nowak, 1916
Mariella (Mariella) dorsetensis (Spath, 1926)
1937 Mariella dorsetensis (Spath); Spath, p. 513.
Description: Ni-6 consists of two whorls of an internal mould with sinistral turrilitid coiling. The whorl section is rounded. Ribs are not visible between the tubercles present but they are located in the axis. The first three rows of tubercles are exposed on the whorl surface, with a fourth being concealed in the whorl suture. The first row of tubercles is pronounced and elongated across the upper half. The next three rows are arranged on the lower half of the flank equidistant from each other. They are conical, tiny and offset from the first row.
Occurrence: Lower Cenomanian of England, France, Poland, Zululand (South Africa) and central Iran. The present specimen represents the first record from east Iran.
Mariella (Mariella) sp.
Description: Ni-7 consists of three sinistral whorls with an oval whorl section. Ornamentation is visible on the first whorl and partially on the second. There are 13 transverse ribs on the first whorl and three rows of tubercles. The ribs appear at the upper whorl suture and are most prominent on the upper part of the flank. The first row of tubercles is a litle stretched in the upper half. Tubercles on the lower half are conical and pointed and have a rounded base. In the third row, some tubercles merge to form a spiral ridge.
Genus Turrilites Lamarck, 1801
Turrilites costatus Lamarck, 1801
Material: Ni-8 and Ni-9.
Description: Ni-8 is a specimen with a perfect whorl. Tubercles are distributed regularly and equidistant from their neighbours such that the first, second and third rows occur in the lower, middle and upper third, respectively. In the first row, tubercles are elongate and prominent. Ribs are not seen between the tubercles but they are located in the axis. Ni-9 is a broken specimen with the ornamentation visible on one side.
Our specimens (see Fig. 9 , Ni-8 and Ni-9) have the same rib density and uniform separation of ribs.Also significant is that they have the same apical angle.
Occurrence: Turrilites costatus has a middle Cenomanian acme at the base of the A. rhotomagense Zone and is rarer in the lower part of the upper Cenomanian. It has a cosmopolitan distribution including the former U.S.S.R. territory, Poland, Germany, France, Iran, United States of America and England.
Figure 9: Ni-1: Mortoniceras (Mortoniceras) cf. fallax (Breistroffer, 1940), Ni-2: Idiohamites fremonti (Marcou, 1858), Ni-3: Mantelliceras cf. mantelli (J. Sowerby, 1814), Ni-4: Mantelliceras sp. 3, Ni-5: Calycoceras (Gentoniceras) aff. gentoni (Brongniart, 1822), Ni-6: Mariella (Mariella) dorsetensis (Spath, 1926), Ni-7: Mariella (Mariella) sp., Ni-8 and Ni-9: Turrilites (Turrilites) costatus (Lamarck, 1801) (all scales: 1 cm).
Ammonites provide one of the most precise biostratigraphical tools for correlating Cretaceous sedimentary rocks. Cretaceous stages, boundaries and index faunas in Europe have been discussed by Birkelund et al. (1984) and Hancock (1991). The Albian and Cenomanian stages are discussed respectively by Hart et al. (1996) and Tröger and Kennedy (1996). Albian and Cenomanian ammonites biozonation (Table 1 ) have been considered by Kennedy (1971), Wright and Kennedy (1984), Owen (1999, 2002), Hoedemaeker et al. (2003), Gale et al. (2005), Wilmsen (2007), Kennedy and Latil (2007), and Reboulet et al. (2014).
The ammonite fauna collected from the Kerch section consists of seven taxa and that from the Nimbolook section is of eight taxa. Based on these faunas we suggest zones and subzones that are correlatable with the standard biozonation (Table 1 ).
Table 1: Ammonite zonation compiled after Kennedy (1994), Wright and Kennedy (1984), Hancock (1991), Marcinowski et al. (1996), Gale et al. (2005), Wilmsen (2007), Kennedy and Latil (2007), Amédro (2008), Kennedy et al. (2013), and Reboulet et al. (2014). Items marked in bold are recorded in this study.
It is possible to use the Mantelliceras mantelli Zone for the base of the Cenomanian in both sections. The M. mantelli zone fauna is: Mantelliceras mantelli, M. saxbii, M. sp., Sharpeiceras laticlavium, S. schlueteri in the Kerch section (Fig. 10 ) and Mantelliceras cf. mantelli, Mariella (Mariella) dorsetensis in the Nimbolook section (Fig. 11 ). At the Kerch section, the Sharpeiceras schlueteri subzone and the Mantelliceras saxbii subzone indicate the middle and upper lower Cenomanian, respectively. The Mortoniceras fallax zone marks the upper Albian in Nimbolook section. The uppermost Nimbolook section belongs to the lower middle Cenomanian and is defined by the Turrilites costatus subzone.
The ammonite assemblages clearly indicate a late Albian-middle Cenomanian age for strata containing ammonites in the Nimbolook section and a late Albian-early Cenomanian age in the Kerch section.
Figure 10: Ammonite range chart in the Kerch section, eastern Iran.
Figure 11: Ammonite range chart in the Nimbolook section, eastern Iran.
Ammonites presented here come from two sections at the eastern margin of the Lut block. The Kerch section consists of marl and marly limestone and Nimbolook is of limestone. Both sections pass upward into a siliciclastic unit (red conglomerate and sandstone). During a bed-by-bed search, almost all the ammonites collected were recovered from the upper half of the sections which belong to the upper Albian and the lower Cenomanian. We determine the position of the Albian - Cenomanian boundary in both sections with M. mantelli zone. This paper is a preliminary contribution to our understanding of the ammonitic paleontology of the Lut block. The figured materials and the stratigraphic columns showing ammonite occurrence provide a foundation for further studies in the Lut block.
The authors thank J. Kennedy (Oxford University) and M. Wilmsen (Senckenbergische Naturforschende Gesellschaft), for helpful discussions of the specimens. We are indebted to C. Meister (Natural History Museum of Geneva) and B. Matrion, who acted as referees, for their useful suggestions. Logistical support for field work and laboratory facilities were partly financed by the University of Birjand. Thanks go to Iranian friends, especially Mr. H. Abdian, for their help in the field.
Adkins W.S. (1932).- The Mesozoic systems in Texas. In: Sellards E. H., Adkins W.S. & Plummer F.B. (eds.), The geology of Texas. Volume 1, Stratigraphy.- University Texas Bulletin, Austin, no. 3232, p. 239-518.
Aghanabati A. (2011).- Geology of Iran.- Ministry of Industry and Mines, Geological Survey of Iran, 586 p. [in Farsi]
Amidi S.M., Navaie A. & Bahremand M. (2005).- Geological map of Grimonj.- Geological Survey of Iran, scale 1/100,000, 1 sheet.
Amédro F. (2002).- Plaidoyer pour un étage Vraconnien entre l'Albien sensu stricto et le Cénomanien (système Crétacé).- Académie Royale de Belgique, Mémoire, Bruxelles, (Classe des Sciences), t. IV, 128 p. (9 Pls.).
Babazadeh S.A., Raisossadat S.N. & Ahrari F. (2010).- Biostratigraphy and evolutionary trend of the Cretaceous orbitolinids in the sedimentary succession of east Lut Block, south west of Qayen.- Sedimentary Facies, Mashhad, vol. 3, no. 1, p. 1-10.
Bayle É. (1878).- Explication de la Carte Géologique de France. Atlas. Fossiles principaux des terrains.- Ministre des Travaux publics, Imprimerie nationale, Paris, tome 1, 158 Pls.
Berthiaux A., Christmann P., Fauvelet E., Hatrival J.N., Maurizot P. & Vaslet D. (1981).- Geological map of Qayen.- Geological Survey of Iran, scale 1/100,000, 1 sheet.
Birkelund T., Hancock J.M., Hart M.B., Rawson P.F., Robaszynski F., Schmid F. & Surlyk F. (1984).- Cretaceous stage boundaries-proposals.- Bulletin of the Geological Society of Denmark, Copenhagen, vol. 33, p. 3-20.
Breistroffer R. (1940).- Révision des ammonites du Vraconnien de Salazac (Gard) et considérations générales sur ce sous-étage albien.- Travaux du Laboratoire de Géologie de l'Université de Grenoble, t. 22, p. 71-171.
Brongniart A. (1822).- Sur quelques terrains de craie hors du Bassin de Paris, p. 80-101. In: Cuvier G. & Brongniart A. (eds.), Description géologique des environs de Paris, 3e édition.- Dufour et d'Ocagne, Paris, 428 p.
Clark D.L. (1965).- Heteromorph ammonoids from the Albian and Cenomanian of Texas and adjacent areas.- Geological Society of America, Memoir, Boulder, vol. 95, 99 p. (24 Pls.).
Cobban W.A. (1987).- Ammonite faunas of the Sarten Sandstone (Cretaceous), Luna County, New Mexico.- United States Geological Survey, Bulletin, Washington D.C., 1641-B, B1-B17 (5 Pls.).
Crick G.C. (1907).- Cretaceous fossils of Natal. In: Anderson W. (ed.), Third and final report.- Report of the Geological Survey of Natal and Zululand, London, vol. 3, p. 161-250. URL: https://archive.org/details/reportgeologica00depagoog
Delamette M. & Kennedy W.J. (1991).- Cenomanian ammonites from the condensed deposits of the Helvetic Domain (Western Alps, France and Switzerland).- Journal of Paleontology, vol. 65, p. 435-465.
Douvillé H. (1890).- Sur la classification des cératites de la craie.- Bulletin de la Société géologique de France, Paris, (3e série), vol. 18, p. 275-292.
Douvillé H. (1912).- Évolution et classification des Pulchelliidés.- Bulletin de la Société géologique de France, Paris, (4e série), vol. 11, p. 285-320.
Fauvelet E. & Eftekhar Nezhad J. (1990).- Explanation text of the Qayen quadrangle map 1:250,000.- Geological Quadrangle Map, Geological Survey of Iran, no. k7, 200 p.
Gale A.S. (1995).- Cyclostratigraphy and correlation of the Cenomanian Stage in western Europe.- Geological Society Special Publication, vol. 85, p. 177-197.
Gale A.S., Kennedy W.J., Burnett J.A., Caron M. & Kidd B.E. (1996).- The late Albian to early Cenomanian succession at Mont Risou near Rosans (Drôme, SE France): an integrated study (ammonites, inoceramids, planktonic foraminifera, nannofossils, oxygen and carbon isotopes).- Cretaceous Research, vol. 17, p. 515-606.
Gale A.S., Kennedy W.C., Voigt S. & Walaszczyk I. (2005).- Stratigraphy of the upper Cenomanian-lower Turonian Chalk succession at Eastbourne, Sussex, UK: Ammonites, inoceramid bivalves and stable carbon isotopes.- Cretaceous Research, vol. 26, p. 460-487.
Gill T. (1871).- Arrangement of the families of mollusks.- Smithsonian Miscellaneous Collections, vol. 227, 49 p. URL: http://www.biodiversitylibrary.org/item/16816#page/11/mode/1up
Grossouvre A. (1894).- Recherches sur la craie supérieure, 2, Paléontologie. Les ammonites de la craie supérieure.- Mémoires du Service de la Carte géologique détaillée de la France, Paris, 264 p.
Hancock J. M. (1991).- Ammonite scales for the Cretaceous System.- Cretaceous Research, vol. 12, p. 259-291.
Hart M.B., Amédro F. & Owen H.G. (1996).- The Albian stage and substage boundaries.- Bulletin de l'Institut royal des Sciences naturelles de Belgique, (Sciences de la Terre), vol. 66, Supplement, p. 45-56.
Hoedemaeker J., Reboulet S., Aguirre-Urreta M. B., Alsen P., Aoutem M., Atrops F., Barragan R., Company M., Gonzalez C., Klein J., Lukeneder A., Ploch I., Raisossadat N., Rawson F.P., Ropolo P., Vašíček Z., Vermeulen J. & Wippich M.G.E. (2003).- Report on the 1st International Workshop of the IUGS Lower Cretaceous Ammonite Working Group, the 'Kilian Group' (Lyon, 11 July 2002).- Cretaceous Research, vol. 24, p. 89-94.
Hyatt A. (1889).- Genesis of the Arietidae.- Memoir of the Museum of comparative Biology, Cambridge, MA, vol. XVI, no. 3, xi + 238 p. (14 Pls.). URL: http://www.biodiversitylibrary.org/item/91661#page/1/mode/1up
Hyatt A. (1900).- Cephalopoda, Textbook of Palaeontology, transl. C.R. Eastman.- Macmillan, London and New York, p. 502-604.
Hyatt A. (1903).- Pseudoceratites of the Cretaceous.- United States Geological Survey Monographs, vol. 44, 351 p.
Immel H. & Seyed-Emami K. (1985).- Die kreideammoniten des Glaukonitkalkes (O.Alb.-O.Cenman) des Kolah-Gazi-Gebirges sudostlich von Esfahan (Zentral Iran).- Zitteliana, vol. 12, p. 87-137.
Immel H., Seyed-Emami K. & Afshasr-Harb A. (1997).- Kreide-Ammoniten aus dem iranischen Teil des Koppeh-Dagh (NE-Iran).- Zitteliana, vol. 21, p. 159-190.
Kaplan U., Kennedy W.J., Lehmann J. & Marcinowski R. (1998).- Stratigraphie und Ammonitenfaunen des westfälischen Cenoman.- Geologie und Paläontologie in Westfalen, vol. 51, 236 p.
Kennedy W.J. (1971).- Cenomanian ammonite from southern England.- The Paleontological Association, London, 200 p.
Kennedy W.J. (1994).- Cenomanian ammonites from Cassis, Bouches-du-Rhône, France.- Paleopelagos, Roma, Special Publication, vol. 1, p. 209-254.
Kennedy W.J., Bilotte M. & Hansotte M. (1996).- Cenomanian ammonites from Pech de Foix (Ariège, France).- Geobios, vol. 29, p. 307-318.
Kennedy W.J., Chahida M.R. & Djafarian M.A. (1979).- Cenomanian cephalopods from the glauconitic limestone southeast of Esfahan, Iran.- Acta Palaeontologica Polonica, Warszawa, vol. 24, p. 3-50.
Kennedy W.J., Cobban W.A., Hancock J.M. & Gale A.S. (2005).- Upper Albian and lower Cenomanian ammonites from the Main Street Limestone, Grayson Marl and Del Rio Clay in northeast Texas.- Cretaceous Research, vol. 26, p. 349-428.
Kennedy W.J. & Hancock J.M. (1971).-Mantelliceras saxbii, and the horizon of the Martimpreyi Zone in the Cenomanian of England.- Palaeontology, vol. 14, p. 437-454.
Kennedy W.J. & Gale A.S. (2015).- Upper Albian and Cenomanian ammonites from Djebel Mrhila, Central Tunisia.- Revue de Paléobiologie, Genève, vol. 34, no. 2, p. 235-361.
Kennedy W.J., Jagt J.W.M., Amédro F. & Robaszynski F. (2008).- The late late Albian (Mortoniceras fallax Zone) cephalopod fauna from the Bracquegnies Formation at Strépy-Thieu (Hainaut, southern Belgium).- Geologica Belgica, Liège, vol. 11, p. 35-69.
Kennedy W.J. & Jolkicev N. (2004).- Middle Cenomanian ammonites from the type section of the Sanandinovo Formation of northern Bulgaria.- Acta Geologica Polonica, Warszawa, vol. 54, p. 369-380.
Kennedy W.J. & Juignet P. (1983).- A revision of the ammonite faunas of the type Cenomanian. I. Introduction, Ancyloceratina.- Cretaceous Research, vol. 4, p. 3-83.
Kennedy W.J. & Juignet P. (1984).- A revision of the ammonite faunas of the Cenomanian. 2 The families Binneyitidae, Desmoceratidae, Engonoceratidae, Placenticeratidae, Hoplitidae, Schloenbachiidae, Lyelliceratidae and Forbesiceratidae.- Cretaceous Research, vol. 5, p. 93-161.
Kennedy W.J. & Juignet P. (1994).- A revision of the ammonite faunas of the type Cenomanian, Acanthoceratinae Calycoceras (Calycoceras), C. gentoniceras and C. newboldiceras.- Cretaceous Research, vol. 15, p. 17-57.
Kennedy W.J., Klinger H.C. & Lehmann J. (2015).- Cretaceous faunas from Zululand and Natal, South Africa. The ammonite Subfamily Mantelliceratinae Hyatt, 1903.- African Natural History, Cape Town, vol. 11, p. 1-42.
Kennedy W.J. & Latil J.-L. (2007).- The Upper Albian ammonite succession in the Montlaux section, Hautes-Alpes, France.- Acta Geologica Polonica, Warszawa, vol. 57, p. 453-478.
Kennedy W.J., Walaszczy I., Gale A., Dembicz K. & Praszkier T. (2013).- Lower and middle Cenomanian ammonites from the Morondava Basin, Madagascar.- Acta Geologica Polonica, Warszawa, vol. 63, p. 625-655.
Khazaei A.R., Raisossadat S.N. & Asadi S. (2011).- Rudist bivalves (Requieniidae Family) in early Cretaceous sediments from SW Qayen, eastern Iran, paleobiogeographic aspects.- Sedimentary Facies, Mashhad, vol. 3, p. 52-67 [English abstract].
Klinger H.C. & Kennedy W.J. (1978).- Turrilitidae (Cretaceous Ammonoidea) from South Africa, with a discussion of the evolution and limits of the family.- Journal of Molluscan Studies, Oxford, vol. 4, p. 1-48.
Lamarck J.B.P.A. de (1801).- Système des animaux sans vertèbres.- Paris. 432 p.
Latil J.L. (1995).- Les Lyelliceratinae Spath, 1921 (Ammonitina, Ammonoidea) de l'Albien inférieur et moyen dans le bassin de Paris et sur les bordures du bassin vocontien: Stratigraphie, paléobiogéographie et taxonomie. In: Bulot L. G., Argot M. & Arnaud H. (eds.): Lower Cretaceous cephalopod biostratigraphy of the western Tethys.- Géologie Alpine, mémoire Hors Série, vol. 20, p. 327-381.
Lehmann J. (2000).- Upper Albian ammonites from ODP leg 171B off northern Florida.- Palaeontology, vol. 43, p. 41-61.
Mancini E.A. (1982).- Early Cenomanian cephalopods from the Grayson Formation of north-central Texas.- Cretaceous Research, vol. 3, p. 241-259.
Marcinowski R. (1970).- The Cretaceous transgressive deposits east of Czestochowa (Polish Jura Chain).- Acta Geologica Polonica, vol. 20, no. 3, p. 413-449.
Marcinowski R., Walaszczyk I. & Olszewska-Nejbert D. (1996).- Stratigraphy and regional development of the mid-Cretaceous (upper Albian through Coniacian) of the Mangyshlak Mountains, western Kazakhstan.- Acta Geologica Polonica, vol. 46, p. 1-60.
Marcou J. (1858).- Geology of North America, with two reports on the prairies of Arkansas and Texas, the Rocky Mountains of New Mexico, and the Sierra Nevada of California.- Zürcher Furrer, 144 p.
Meek F.B. (1876).- A report on the invertebrate Cretaceous and Tertiary fossils of the upper Missouri country. In: Hayden F.V. (ed.).- Report of the United States Geological Survey of the Territories, Washington D.C., vol. 9, lxiv + 629 p.
Meister C. & Piuz A. (2015).- Cretaceous ammonites from the Sultanate of Oman (Adam Foothills).- GeoArabia, Manama, vol. 20, no. 2, p. 17-74.
Mosavinia A. & Wilmsen M. (2011).- Cenomanian Acanthoceratoidea (Cretaceous Ammonoidea) from the Koppeh Dagh, NE Iran, taxonomy and stratigraphic implications.- Acta Geologica Polonica, vol. 61, p. 175-192.
Moulodi D., Motamedalshariati M., Raisossadat S.N. & Mortazavi M. (2014).- Paleoecology of Cretaceous deposits (Albian-Cenomanian?) in northwest of Qayen based on foraminifera.- Proceedings of the 8th Symposium of Iranian Paleontological Society ( 21-22 May 2014), Zanjan, 4 p. [in Farsi]
Nowak J. (1916).- Zur Bedeutung von Scaphites für die Gliederung der Oberkreide.- Verhandlungen der Geologischen Reichsanstalt 1916, p. 55-67.
Orbigny A. d' (1840-1842).- Paléontologie française: Terrains crétacés. 1. Céphalopodes.- Masson, Paris, p. 1-120 (1840); p. 121-430 (1841); p. 431- 662 (1842).
Owen H.G. (1999).- Correlation of Albian European and Tethyan ammonite zonations and the boundaries of the Albian stage and substages: Some comments.- Scripta Geologica, Leiden, Special Issue, 3, p. 129-149.
Owen H.G. (2002).- The base of the Albian Stage; comments on recent proposals.- Cretaceous Research, vol. 23, p. 1-13.
Raisossadat S.N. & Skelton P. (2005).- First record of rudist fauna from the Qayen area, eastern Iran.- 7th International Symposium on the Cretaceous (5-9 September 2005), Neuchâtel, Scientific Program and Abstracts, p. 177-178.
Raisossadat S.N., Mosavinia A., Kazaie A.R. & Asadi S. (2012).- Stratigraphy of Cretaceous deposits in Southwest of Qayen area (East of Iran).- Proceedings of the 5th Symposium of Iranian Paleontological Society, International Center for Science, High Technology and Environmental Sciences, Mahan, Kerman, p. 216-222.
Reboulet S., Giraud F. & Proux O. (2005).- Ammonoid abundance variations related to changes in trophic conditions across the Oceanic Anoxic Event 1d (latest Albian, SE France).- Palaios, Lawrence, vol. 20, p. 121-141.
Reboulet S., Giraud F., Colombié C. & Carpentier A. (2013).- Integrated stratigraphy of the lower and middle Cenomanian in a Tethyan section (Blieux, southeast France) and correlations with Boreal basins.- Cretaceous Research, vol. 40, p. 170-189.
Reboulet S., Szives O., Aguirre-Urreta M.B., Barragán R., Company M., Idakieva V., Ivanov M., Kakabadze M.V., Moreno-Bedmar J.A., Sandoval J., Baraboshkin E.J., Caglar M.K., Fozi I., González-Arreola C., Kenjo S., Lukeneder A., Raisossadat S.N., Rawson P.F. & Tavera J.M. (2014).- Report on the 5th International Meeting of the IUGS Lower Cretaceous Ammonite Working Group, the Kilian Group (Ankara, Turkey, 31st August 2013).- Cretaceous Research, vol. 50, p. 126-137.
Seyed-Emami K. & Aryai A.A. (1981).- Ammoniten aus dem unteren Cenoman von Nordostiran (Koppeh-Dag).- Mitteilungen aus der Bayerischen Staatssammlung für Paläontologie und Historische Geologie, München, vol. 21, p. 23-39.
Seyed-Emami K. (1982).- Turrilitidae (Ammonoidea) from the glauconitic limestone near Esfahan (Central Iran).- Neues Jahrbuch für Geologie und Paläontologie Abhandlungen, Stuttgart, vol. 163, p. 417-434.
Sharifi J., Mortazavi Mehrizi M., Raisossadat S.N. & Motamedoshariati M. (2015).- Lithofacies and depositional environment of siliciclastic deposits of the Lower Cretaceous at Kerch section, SW Qayen.- 33rd National Geosciences Symposium, Tehran (February 22-23, 2015), p. 1-10.
Sharpe D. (1853-1857).- Description of the fossil remains of Mollusca found in the Chalk of England. I, Cephalopoda.- Monograph of the Palaeontographical Society London, 68 p. (27 Pls.), 1853, p. 1-26 (Pls. 1-10); 1855, p. 27-36 (Pls. 11-16); 1857, p. 37-68 (Pls. 17-27).
Sowerby J. (1814).- The mineral conchology of Great Britain, 1.- Meredith, London, Part 10, p. 109-124 (Pls. 51-56).
Spath L.F. (1922).- On the Senonian ammonite fauna Pondoland.- Transactions of the Royal Society of South Africa, Cape Town, vol. 10, p. 113-148.
Spath L.F. (1923-1943).- A monograph of the Ammonoidea of the Gault.- Monograph of the Palaeontographical Society London, 787: 1-72 (1923); 73-110 (1925a); 111- 146 (1925b); 147-186 (1926); 187-206 (1927); 207-266 (1928); 267-311 (1930); 313-378 (1931); 379-410 (1932); 411-442 (1933); 443-496 (1934); 497-540 (1937); 541- 608 (1939); 609-668 (1941); 669-720 (1942); 721-827, i-ix (1943).
Swensen A.J. (1962).- Anisoceratidae and Hamitidae (Ammonoidae) from the Cretaceous of Texas and Utah.- Brigham Young University Geology Studies, Provo, vol. 9, p. 53-82.
Szives O., Csontos L., Bujtor L. & Fozy I. (2007).- Aptian-Campanian ammonites of Hungary.- Geologica Hungarica, Budapest, (Series Palaeontologica), Fasc. 57, 182 p.
Thomel G. (1972).- Les Acanthoceratidae cénomaniens des chaines subalpines méridionales.- Mémoires de la Société géologique de France, Paris, (NS), vol. 116, 204 p.
Tirrul R., Bell I., Griffis R. & Camps V. (1983).- The Sistan suture zone of eastern Iran.- Geological Society of America, Bulletin, vol. 94, p. 134-150.
Tröger K.-A. & Kennedy W.J. (1996).- The Cenomanian stage.- Bulletin de l'Institut royal des Sciences naturelles de Belgique, (Sciences de la Terre), vol. 66, Supplement, p. 57-68.
Wilmsen M. (2007).- Integrated stratigraphy of the upper lower - lower middle Cenomanian of northern Germany and southern England.- Acta Geologica Polonica, vol. 57, no. 3, p. 263-279.
Wilmsen M., Niebuhr B., Wood C.J. & Zawischa. D. (2007).- The fauna and palaeoecology of the middle Cenomanian Praeactinocamax primus Event from the type-locality Wunstorf quarry, northern Germany.- Cretaceous Research, vol. 28, p. 428-460.
Wright C.W., Callomon J.H. & Howarth M.K. (eds., 1996).- Cretaceous Ammonoidea. In: Kaesler R.L. (ed.), Mollusca 4 (revised).- Treatise on Invertebrate Paleontology, Geological Society of America, New York; University of Kansas, Lawrence, Part L, 362 p.
Wright C.W. & Kennedy W.J. (1984).- The Ammonoidea of the Lower Chalk, Part 1.- Monograph of the Palaeontographical Society, London, 126 p.
Wright C.W. & Kennedy W.J. (1990).- The Ammonoidea of the Lower Chalk. Part 3.- Monograph of the Palaeontographical Society, London, p. 219-194.
Wright C.W. & Wright E.V. (1949).- The Cretaceous ammonite genera Discohoplites Spath and Hyphoplites Spath.- Quarterly Journal of the Geological Society, vol. 104, p. 477-497.
Zaborski P.M.P. (1985).- Upper Cretaceous ammonites from the Calabar region, south-east Nigeria.- Bulletin of the British Museum (Natural History), (Geology), vol. 39, p. 1-72.
Zittel K.A. (1895).- Grundzüge der Paläontologie (Paläozoologie), Oldenbourg.- Munich and Leipzig, 972 p.