The present study is concerning the systematic descriptions of the Middle Jurassic (Callovian) ammonite fauna from the Damghan Area (eastern Alborz) and contains a rather rich ammonite fauna. The described ammonites come from the Middle part of the Dalichai Formation, consisting of an alternation of green marl, grey limestone and marly limestone. In this research, the biostratigraphy of these rocks is discussed with special emphasis on the abundant ammonite fauna (Reineckeiidae family). Altogether, 74 specimens of ammonites belonging to 14 species, 3 genera, 3 sub genera from Reineckeiidae family are described. Palaeobiogeographically the ammonite fauna is closely related to that of the sub-Mediterranean Province of the northwestern Tethys. The ammonites represent four zones,
i.e.
Rehmannia (
Loczyceras) cf.
segestena (Anceps Zone),
Rehmannia (
Loczyceras)
reissi (Anceps Zone),
Rehmannia (
Loczyceras)
rehmanni (Anceps Zone),
Rehmannia (
Loczyceras)
sequanica
densicostata (Coronatum Zone),
Reineckeia (
Tyrannites)
convex
a (Gracilis Zone),
Reineckeia (
Tyrannites)
pictava (Gracilis Zone),
Reineckeia (
Reineckeia)
anceps anceps (Anceps Zone),
Reineckeia (
Reineckeia)
anceps elmii (Anceps Zone),
Reineckeia (
Reineckeia) cf. fehlmani (Anceps Zone),
Reineckeia (
Reineckeia)
nodosa (Athleta Zone),
Collotia cf.
multicostat (Anceps Zone),
Collotia cf.
gaillardi (Coronatum Zone),
Collotia cf.
oxyptychoides (Athleta Zone),
Collotia cf.
collotiformis (Athleta Zone).
The type section of this formation consists of 107 m of light-grey to bluish-grey limestone with thin intercalations of marl. According to Steiger [1] , the thickness of the formation is about 50 to 120 m (average: 100 m, reaching more than 300 m in the eastern Alborz). The lower boundary of the Dalichai Formation is an unconformity due to the Mid-Cimmerian tectonic event (the marine transgression of the Dalichai Formation over the Shemshak Formation is diachronous). In many areas, the upper boundary of the Dalichai Formation is, however, gradational. In a few areas, it is continuous but sharp and followed by the Lar Formation. The sedimentary environments, in which this formation was deposited, are the lower shelf to continental slope. The Dalichai Formation is rich in ammonites, which were studied by different palaeontologists (e.g. Seyed-Emami et al. [2] [3] [4] [5] [6] , Schairer et al. [7] , Majidifard [8] [9] , Vaziri et al. [10] [11] , Shams et al. [12] , Behfar et al. [13] , Sarbandi Farahani et al. [14] , Dietze et al. [15] ), one of important ammonite families (with high frequency) of the Dalichai Formation in Alborz, is Reineckeiide (e.g. Seyed-Emami et al. [16] ). This family is assumed as one of the index Callovian ammonite fauna. In this research from studied sections, 74 Reineckeiide with frequency (17.2%) (Chart 1), were collected that belong to the Callovian.
2. Material and Methods2.1. Locality of Sections
Absharaf section: 60 km northwesth of Damghan (co-ordinates: 35˚56'25.7''N, 53˚47'21.4''E) (Figure 1(a)). The Dalichai Formation at the Absharf was measured northwesth of Damghan with a total thickness of 618 m. It ranges from the Upper Bajocian to Kimmeridgian and can be subdivided, from bottom to top, into six members (Figure 2).
Chart 1. Relative abundances of ammonite families at the studied sections from the Damghan Area.
Position of the Absharaf (a), Talu (b) and Ahvanu (c), sections of the Dalichai Formation in the Alborz of north Iran.
Stratigraphic column of Dalichai Formation in Absharaf section.
Talu section: 10 km northeast of Damghan (co-ordinates: 36˚19'3.3''N, 54˚26'7.7''E) (Figure 1(b)). The Dalichai Formation at the Talu was measured northeast of Damghan with a total thickness of 207.5 m. It ranges from the Upper Bajocian to the Oxfordian and can be subdivided, from bottom to top, into five members (Figure 3).
Ahvanu section: 10 km north of Damghan (co-ordinates: 36˚13'29.9'N, 54˚11'13.0''E) (Figure 1(c)). The Dalichai Formation at the Ahvanu was measured north of Damghan with a total thickness of 153.5 m. It ranges from the Upper Bajocian to the Callovian and can be subdivided, from bottom to top, into four members (Figure 4).
2.2. Ammonites
Since the main part of the thesis deals with ammonites, numerous ammonites
Stratigraphic column of Dalichai Formation in Talu section
Stratigraphic column of Dalichai Formation in Ahvanu section
were collected from the sections. After identification they were described and used to define the international Standard Zones. The ammonite zonation is based on Cariou & Hantzpergue [17] .
3. Lithostratigraphy of Sections
Shemshak Formation: The Dalichai Formation is underlain by the Shemshak Formation, which consists of alternations of dark-green shales and medium-bedded, dark, fine-grained sandstones containing plant remains (Figure 5 and Figure 6).
Dalichai Formation: The base of the Dalichai Formation consists of medium- bedded, brown weathering sandy limestone (grainstone), green-grey silty marls, alternations of greyish-green marls, well-bedded greyish to yellow marly limestones and limestones and alternations of medium-bedded, grey limestones (mudstone to packstone) with cherts, green-grey marls (Figure 6 and Figure 7).
Lar Formation: The Lar Formation is represented by thick-bedded, cliff- forming, grey dolomitic limestones to limestones that, when weathered, are cream-coloured to yellowish (Figure 6 and Figure 8).
4. Systematic Palaeontology
As far as permitted by the preservation of the specimens, measurements of the following parameters are given: diameter (D) in mm, umbilical width (U), whorl height (H), whorl width (W), the latter all in % of diameter; whorl round height
Silt coal of the Shemshak Formation at the Talu section
Position of Dalichai Formation between Shemshak (below) and Lar (above) formations in the Talu section
Alternations of greyish-green marls and well-bedded greyish to yellow marly limestones of the Dalichai Formation at the Absharaf section
to whorl round width (Q), numbers of primary ribs per whorl (PR) and secondary ribs (SR). The specimens have been numbered according to sections (SH: Absharf section; T: Talu section; A: Ahvanu section).
Contacts of the Dalichai and Lar formations at the Absharaf section
1872 Perisphinectes segestana sp. nov.-GEMMELLARO: p. 246, Pl. 13, Figures 1-3.
1984 Rehmannia (Loczyceras) segestana (GEMMELLARO).-CARIOU: p. 72, Pl. 7, Figure 3 and Figure 4, Pl. 8, Figure 1.
2003 Rehmannia (Loczyceras) segestana (GEMMELLARO).-MAJIDIFARD: Pl. 9, Figure 1.
Material: 1 specimen from Absharaf section (SH-B18) and 3 specimens and 1 fragment from Talu section (T-T45, 95, 118, 119) and 1 fragmentary specimen from Ahvanu section (A-D3), (Table 1).
Description: Umbilical wall low and steep, whorl cross-section nearly elliposidal. The ribbing is relatively coarse and distant. The bullate and radiate primary ribs end at prominent and pyramidal lateral tubercles at one-third of flank height, from where they bifurcate or trifurcate with some intercalatory ribs. The rectiradiate secondary ribs terminate at ventral furrow. The secondary ribs are fainter and denser than the primaries. Some of the primary ribs do not divide.
Remarks: The present specimens are very similar to the specimen described and figured by CARIOU (1984: Pl. 7, Figure 3 and Figure 4).
1984 Rehmannia (Loczyceras) reissi (STEINM).-CARIOU: Pl. 10, Figures 1-4, Pl. 11, Figures 1-5.
Material: 7 specimens from Talu section (T-T46-50-57-62-120-121-122), (Table 2).
Description: Umbilical wall steep, whorl cross-section ovate. Ribbing relatively coarse, the slightly bullate and radiate primary ribs end at prominent and pyramidal lateral tubercles at one-third of flank height, from where they bifurcate or trifurcate with some intercalatory ribs. The secondary ribs terminate at a ventral furrow. There are prorsiradiate constrictions per whorl.
Remarks: The present specimens are similar to the specimen described and figured by CARIOU (1984: Pl. 10, Figure 3 and Figure 4).
1984 Rehmannia (Loczyceras) cf. rehmanni (OPP).-CARIOU: Pl. 3, Figure 2, Pl. 4, Figures 1-5, Figure 7, Pl. 5, Figures 1-3.
Material: 1 fragmentary specimen from Talu section (T-T40) and 1 fragmentary specimen from Ahvanu section (A-B3), (Table 3).
Description: Umbilical wall low and steep, whorl cross-section oval. The bullate, distant and prorsiradiate primary ribs end mostly at conical, sharp tubercles at around one-third of flank height. The slightly prorsiradiate secondaries
Dimensions (in mm) of Rehmannia (Loczyceras) cf. segestana
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
SH-3-B18
7.8
14.1
33.3
23
1.4
14
-
T-3-T45
6.3
17.4
31.7
-
-
14
42
T-4-T95
5
1.8
34
-
-
14
-
T-4-T119
5.4
1.6
31.4
24
1.3
-
-
Dimensions (in mm) of Rehmannia (Loczyceras) reissi
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
T-3-T46
6
25
35
30
1.1
-
-
T-3-T50
4.5
-
33.3
33.3
1
13
45
T-4-T57
3.6
-
38.8
36.1
1
12
33
T-4-T62
5.1
1.7
37.2
29.4
1.2
-
-
T-3-T120
5.1
23.5
39.2
33.3
1.1
13
-
T-3-T121
5.6
1.6
37.5
-
-
-
-
T-3-T122
4.6
-
36.9
30.4
1.2
-
-
are bifurcating or trifurcating with some intercalatory ribs, ending at a smooth ventral band. Some of the primary ribs do not divide.
Remarks: The present specimens are very similar to the specimen described and figured by CARIOU (1984: Pl. 4, Figure 3 and Figure 6).
1968 Rehmannia (Loczyceras) sequanica sp. nov.-BOURQUIN: Pl. 24, Figure 3.
1984 Rehmannia (Loczyceras) sequanica densicostata nov. subsp.-CARIO: p. 172, Pl. 24, Figure 4 and Figure 5.
2003 Rehmannia (Loczyceras) sequanica (BOURQUIN).-MAJIDIFARD: Pl. 9, Figure 2.
Material: 1 specimen from Talu section (T-T32), (Table 4).
Description: Umbilical wall steep, whorl cross-section nearly rectangular. The bullate and radiate primary ribs end at faint lateral tubercles at around one-third of flank height, from where they bifurcate or quadrifurcate with some intercalatory ribs. The rectiradiate secondary ribs terminate at ventral furrow. The secondary ribs are fainter and denser than the primaries. Some of the primary ribs do not divide.
Remarks: Rehmannia (Loczyceras) sequanica densicostata is similar to Rehmannia (Loczyceras) segestana (GEMMELLARO), but in having fainter and thinner ribs and tubercles and in possessing quadrifurcating secondaries.
1984 Reineckeia (Tyrannites) pictava (BOURQIN) f. Savarensis.-CARIOU: Pl. 27, Figure 3 and Figure 4.
Material: 8 specimens and 1 fragment from Talu section (T-T37, 47, 51, 48, 61, 105, 107, 123, 124), (Table 5).
Description: Umbilical wall low and steep, whorl cross-section ovate. The bullate and radiate primary ribs end at faint lateral tubercles at around one-third of flank height, from where they bifurcate or trifurcate with some intercalatory
Dimensions (in mm) of Rehmannia (Loczyceras) rehmanni
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
T-3-T40
-
-
-
-
-
10
30
A-3-B3
7
24.2
30
22.8
1.3
20
32
Dimensions (in mm) of Rehmannia (Loczyceras) sequanica densicostata
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
T-4-T32
6.1
16.3
36
26.2
1.3
12
39
ribs. The rectiradiate secondary ribs terminate at ventral furrow. The secondary ribs are denser than the primaries. Some of the primary ribs do not divide.
1984 Reineckeia (Tyrannites) convexa sp. nov.-CARIOU: p. 197, Pl. 28, Figure 3 and Figure 4, Pl. 29, Figures 1-4.
2003 Reineckeia (Tyrannites) convexa CARIOU, 1984.-MAJIDIFARD: Pl. 8, Figure 2.
Material: 2 specimens from Talu section (T-T33, 36), (Table 6).
Description: Umbilical wall steep, whorl cross-section rectangular, venter rounded to broad. The bullate and distant primary ribs end mostly at conical sharp tubercles at around one-third of flank height. The rectiradiate secondaries are bifurcating or trifurcating with single intercalatory ribs, all ending at a ventral furrow. The secondary ribs are denser than the primaries, rarely, primary ribs do not divide.
Remarks: The blunt, coarse and strong ribs distinguish this species from other species.
1984 Reineckeia (Reineckeia) fehlmanni JEANNET.-CARIOU: p. 278 Pl. 42, Figures 1-3.
1986 Reineckeia (Reineckeia) fehlmanni JEANNET.-SEQUEIROS et al.: Pl. 2, Figure 8.
Dimensions (in mm) of Reineckeia (Tyrannites) pictava
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
T-3-T37
6.8
23.5
35.2
29.4
1.1
19
-
T-3-T47
2.2
1.8
3.1
3.6
0.8
-
-
T-3-T51
2.1
1.9
3.8
3.3
1.1
17
-
T-3-T48
4.5
1.7
44.4
37.7
1.1
-
-
T-3-T61
4.1
-
41.4
39
1
-
-
T-3-T105
3
36.6
40
36.6
1
16
-
T-3-T107
2.9
-
37.9
44.8
0.8
-
-
T-4-T123
2.4
3.3
41.6
3.3
12
-
-
T-4-T124
3.3
-
39.3
30.3
1.2
-
-
Dimensions (in mm) of Reineckeia (Tyrannites) convexa
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
T-3-T33
7
35.7
38.5
28.5
1.3
14
42
T-3-T36
6.3
36.5
39.6
25.3
1.5
14
42
Material: 1 specimen from Absharaf section (SH-C45), (Table 7).
Description: Umbilical wall low and steep, whorl cross-section broad-ovate to rectangular, venter broad. Nearly all of the bullate and distant primary ribs end at pyramidal, sharp tubercles at around one-third of flank height. The bullate secondaries are bifurcate or trifurcate with single intercalatory ribs, ending at a smooth ventral band. The ribs are inner part in the last visible whorl are rectiradiate and on the outer part prorsiradiate.
1818 Nautilus anceps-REINECKE: p. 82, Pl. 7, Figure 61.
1951 Reineckeia anceps REINECKE.-JEANNET: p. 127, Pl. 48, Figure 2 and Figure 3.
1984 Reineckeia (Reineckeia) anceps anceps (REINECKE).-CARIOU: p. 220, Pl. 33, Figure 4 and Figure 5, Pl. 34, Figure 1, Figure 2 and Figure 5, Pl. 35, Figure 1, Figure 4 and Figure 5.
1988 Reineckeia (Reineckeia) anceps (REINECKE).-CARIOU & KRISHNA: p. 160, Pl. 2, Figure 2 and Figure 3, Pl. 3, Figure 1.
1995 Reineckeia (Reineckeia) sp. ex gr. R(R.) anceps (REINECKE).-SEYEDE- EMAMI et al.: p. 43, Pl. 2, Figure 1.
2002 Reineckeia (Reineckeia) anceps (REINECKE).-SEYEDE-EMAMI et al.: 185, Figures 2-4.
2003 Reineckeia (Reineckeia) anceps (REINECKE).-MAJIDIFARD: p. 114, Pl. 7, Figure 4, Figure 5 and Figure 7.
2003 Reineckeia (Reineckeia) anceps (REINECKE).-CARRASCO-Ramirz: Figure 9 and Figures 10(a)-(d).
Material: 2 fragments from Absharaf section (SH-B9,15), and 1 specimen from Talu section (T-T34), (Table 8).
Description: Moderately evolute, coronate Reineckeia with broad-oval to broad rectangular whorl cross-section. Umbilical wall low and vertical, umbilical shoulder distinct. Ribbing relatively coarse. The slightly bullate and somewhat prorsiradiate primary ribs end at prominent and pyramidal lateral tubercles at one-third of flank height, from where they bifurcate in a somewhat prorsiradiate manner seldom they quadrifurcate with some intercalatory ribs. The slightly incurved secondary ribs terminate at a smooth ventral band. There are four prorsiradiate constrictions per whorl.
Dimensions (in mm) of Reineckeia (Reineckeia) cf. fehlmanni
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
SH-3-C45
7.3
1.2
35.6
27.3
1.3
11
27
Dimensions (in mm) of Reineckeia (Reineckeia) anceps anceps
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
T-3-T34
7
21.4
44.2
30
1.4
13
29
Remarks: The present specimens are very similar to the specimen described and figured by MAJIDIFARD (2003: Pl. 7, Figure 7).
1984 Reineckeia (Reineckeia) anceps elmii (BOURQ).-CARIOU: Pl. 36, Figures 1-3, Pl. 37, Figures 1-2.
Material: 1 specimen from Absharaf section (SH-C50), and 1 specimen from Talu section (T-T31), (Table 9).
Description: Umbilical wall vertical, whorl cross-section broad-oval. The bullate primary ribs end atprominent, conical, and sharp lateral tubercles near the umbilical margin, from where they from trifurcate seldome quadrifurcate bundles. The rectiradiate secondary ribs terminate at a ventral furrow. There are depp and prorsiradiate constrictions on the last visible whorl.
1907 Reineckeia (Reineckeia) nodosa n. sp.-TILL: p. 124.
1939 Reineckeia (Reineckeia) nodosa TILL.-KUHN: p. 34, Pl. 2, Figure 14.
1984 Reineckeia (Reineckeia) nodosa TILL.-CARIOU: p. 246, Pl. 37, Figure 5, Figure 6 and Figure 7.
2003 Reineckeia (Reineckeia) nodosa TILL.-MAJIDIFARD: p. 124, Pl. 9, Figure 4.
2013 Reineckeia (Reineckeia) nodosa TILL.-SEYED-EMAMI et al.: p. 56, Figures 8k-1.
Material: 1 specimen from Absharaf section (SH-C54), and 4 specimens from Talu section (T-T29, 42, 38, 44), (Table 10).
Description: Whorl cross-section oval, venter rounded and broad. The bullate and distant primary ribs end at prominent and sharp tubercles at around mid-flank, from where they usually from quadrifurcate bundles. The secondary ribs terminate at a ventral furrow. There are three depp and prorsiradiate constrictions on the last visible whorl.
Remarks: The present specimens resemble the holotype (KUHN 1939: Pl. 2, Figure 14), and the material figured by CARIOU (1984: Pl. 37, Figure 5, Figure 6 and Figure 7).
Stratigraphic distribution: Upper Callovian, Athleta Zone.
Dimensions (in mm) of Reineckeia (Reineckeia) anceps elmii
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
SH-3-C50
4.9
32.6
34.6
24.4
1.42
12
-
T-3-T31
3.3
2.7
36.3
57.5
0.63
10
-
Genus Collotia (DE GROSSOUVRE, 1917) [29] .
Collotia cf. multicostata (PETITC, 1915) [30] .
Pl. 1, Figures 3a-b
1984 Collotia multicostata (PETITEC).-CARIOU: Pl. 48, Figures 1-7, Pl. 47, Figure 3 and Figure 4.
Material: 2 specimens from Absharaf section (SH-C42, 47), and 3 specimens and 1 fragment from Talu section (T-T52, 58, 69, 125), (Table 11).
Description: Umbilical wall steep, whorl cross-section elongated ellipse to rectangular. The ribbing is relatively coars, strong and distant. Primary ribs on the inner flank slightly bullate, terminating at around at one-third of flank height in small and weak tubercles. From where they bifurcate or trifurcate with some intercalatory ribs, the secondaries have intercalatory ribs and end at the ventral furrow. The secondaries are denser than the primaries.
Remarks: The present specimens are similar to the specimen described and figured by CARIOU (1984: Pl. 48, Figure 1 and Figure 4).
1984 Collotia gaillardi (ROMAN).-CARIOU: Pl. 54, Figures 2-5, Pl. 55, Figures 1-3, Pl. 56, Figures 1(a)-(c).
Material: 3 specimens from Talu section (T-T35, 76, 126), (Table 12).
Description: Shell evolut, umbilical wall low and steep, whorl cross-section elongated ellipse. There are completely conical and elongated tubercles at the umbilici margin and separated there from within the half (50%) distance of two secondary and forwarding ribs. The secondaries are denser than the primaries. Some of the primary ribs do not divide.
Remarks: The present specimens are similar to the specimen described and figured by CARIOU (1984: Pl. 54, Figure 2 and Figure 5).
Dimensions (in mm) of Reineckeia (Reineckeia) nodosa
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
SH-4-C54
4.5
1.5
28.8
44.4
0.6
6
-
T-3-T29
4
1.5
35
45
0.7
11
-
T-4-T42
2.8
39.2
39.2
53.5
0.7
8
-
T-4-T38
6.7
25.3
34.2
28.3
1.2
15
32
T-4-T44
5.1
-
37.2
35.2
1
8
14
Dimensions (in mm) of Collotia cf. multicostata
Specimen
D
U%
W%
H%
Q
PR2
SR/2
SH-3-C47
7
1.1
35.7
28.5
1.2
19
-
SH-3-C42
6.7
1
41.7
25.3
1.6
19
-
T-3-T52
5.7
-
24.5
22.8
1
-
-
T-4-T69
5.6
23.2
35.7
26.7
1.3
-
-
T-4-T125
3.6
2.2
41.6
31.6
1.1
16
-
Collotia cf. oxyptychoides (SPATH, 1927) [32] .
Pl. 1, Figures 4a-c
1984 Collotia cf. oxyptychoides (SPATH).-CARIOU: Pl. 61, Figures 1-3, Pl. 62, Figures 1-3, Pl. 63, Figures 1-4.
Material: 1 specimen from Talu section (T-T59), (Table 13).
Description: Umbilical wall low and steep, whorl cross-section broad-oval to broad rectangular. The primary ribs start at faint and regular nodes near the umbilical margin and divide mainly into two and three secondary ribs at about one-third of flank height. The secondary ribs are fainter and denser than the primaries. Some of the primary ribs do not divide.
Remarks: The present specimen is similar to the specimen described and figured by CARIOU (1984: Pl. 63, Figure 3).
Stratigraphic distribution: Upper Callovian, Athleta Zone.
Collotia cf. collotiformis (JEANNET, 1951) [26] .
Pl. 1, Figures 1a-b
1984 Collotia collotiformis (JEANNET).-CARIOU: Pl. 59, Figures 1-3, Pl. 60, Figure 1.
Material: 1 specimen from Absharaf section (SH-C46), (Table 14).
Description: Umbilical wall low and vertical, whorl cross-section ovate. The primary ribs start from umbilicus margin at one-third of round width with thick elongated tubercles. At this area, the primary ribs are divided into two and three secondary and forwarding ribs. The secondary ribs are fainter and denser than the primaries. Some of the primary ribs do not divide.
Remarks: The present specimen is similar to the specimen described and figured by CARIOU (1984: Pl. 60, Figure 1).
Stratigraphic distribution: Upper Callovian, Athleta Zone.
5. Conclusions
Follwing Reineckeiide family have been collected from the middle part of the Dalichai Formation at the sections:
Dimensions (in mm) of Collotia cf. gaillardi
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
T-4-T35
7.1
15.4
32.3
25.3
1.2
16
-
T-4-T76
6.4
1
32.8
32.8
1
19
-
T-4-T126
6.6
-
24.2
22.7
1
-
-
Dimensions (in mm) of Collotia cf. oxyptychoides
Specimen
D
U%
H%
W%
Q%
PR/2
SR/2
T-4-T59
3.9
30.7
41
-
-
-
-
Dimensions (in mm) of Collotia cf. collotiformis
Specimen
D
U%
H%
W%
Q
PR/2
SR/2
SH-4-C46
6
0.8
36.6
21.6
1.6
15
-
Chart 2. Percentage frequency species of Reineckiide family in Damghan area.
74 specimens of Reineckeiidae family from the Dalichai Formations belonging to 3 genera, 3 sub genera and 14 species are described.
The identified species of the Delichai Formation in the studied sections show following zones:
Gracilic from Early Callovian, Ancepcs, Coronatum from Middle Callovian, Athleta from Late Callovian.
Moreover, palaeogeographic reconstructions show the geographic position of the Iranian plate (North and Central Iran) during the Middle Jrassic time, at the southern margin of Eurasia at a latitude around 30˚N which rather corresponds to European areas (Enay & Cariou [33] , Wilmsen et al. [34] ).
Cite this paper
Zadesmaeil, M., Majidifard, M.R., Vaziri, S.H. and Jahani, D. (2017) Reineckeiidae (Ammonoidae) Fa- mily of the Dalichai Formation in Damghan Area (East Alborz), Iran. Open Journal of Geology, 7, 888-914. https://doi.org/10.4236/ojg.2017.76061
ReferencesSteiger, R. (1966) Die Geologie der west—Firuzkuh Area (zentral Elburz, Iran). Mitteilungen aus dem geologischen Institut der E.T.H. und Universitat Zurich, Neue Serie; 1-145.Seyed-Emami, K., Schairer, G. and Bolourchi, M.H. (1985) Ammoniten aus der unteren Dalichy-Formation (oberes Bajocium bis unteres Bathonium) der Umgebung von Abe-garm (Avaj, NW-Zentraliran). Zitteliana, 12, 57-85.Seyed-Emami, K., Schairer, G. and Alavi-Naini, M. (1989) Ammoniten aus der untern Dalichai-Formation (Unterbathon) ostlich von Semnan (SE-Alborz, Iran). Munchner Geowissenschaftliche Abhandlungen Reihe A: Geologie und Palaontologie, 15, 79-91.Seyed-Emami, K., Schairer, G., Aghanabati, S.A. and Fazl, M. (1991) Ammoniten aus dem Bathon der Gegend von Tabas-Nayband (Zentraliran). Munchner Geowissenschaftliche Abhandlungen Reihe A: Geologie und Palaontologie, 19, 65-100.Seyed-Emami, K., Fürsich, F.T. and Schairer, G. (2001) Lithostratigraphy, Ammonite Faunas and Palaeoenvironments of Middle Jurassic Strata in North and Central Iran. Newsletters on Stratigraphy, 38, 163-184. https://doi.org/10.1127/nos/38/2001/163Seyed-Emami, K. and Schairer, G. (2010) Late Jurassic (Oxfordian, Bimammatum Zones) Ammonites from the Eastern Alborz Mountains, Iran, Second Part. Neues Jahrbuch für Geologie und Palaontologie, 257, 267-281. https://doi.org/10.1127/0077-7749/2010/0071Schairer, G., Seyed-Emami, K. and Zeiss, A. (1992) Ammoniten aus der oberen Dalichai-Formation (Callov) ostlich von Semnan (SE-Alborz, Iran). Mitteilungen der Bayerischen Staatssammlung für Palaontologie und historische Geologie, 31, 47-67.Majidifard, M.R. (2003) Biostratigraphy, Lithostratigraphy, Ammonite Taxonomy and Microfacies Analysis of the Middle and Upper Jurassic of Northeastern Iran. Unpublished Ph.D. Thesis, Julius-Maximilians-Universitat, Wurzburg, 201 p.Majidifard, M.R. (2015) Late Bajocian-Bathonian Ammonites from Northeast Iran, Acta Palaeontologica Romaniae, 11, 25-41.Vaziri, S.H., Majidifard, M.R., Jahani, D. and Jamshidi, E. (2009) Litho- and Biostratigraphy of the Dalichai Formation in Northwestern Emamzadeh Hashem (Fil-e-Zamin Section), Central Alborz. Geosciences, 3, 83-96. [In Persian]Vaziri, S.H., Majidifard, M.R., Jahani, D. and Tahmasebi, M. (20011) Lithostratigraphy, Biostratigraphy and Sedimentary Environment of the Dalichai Formation in Ayeneh-Varzan Area, Central Alborz. [In Persian]Shams, M. and Seyed-Emami, K. (2010) Lithostratigraphy and Biostratigraphy of the Dalichai Formation (Middle Jurassic) in Parvar Area, North of Semnan, Central Alborz. Geosciences, 19, 1-10. [In Persian]Behfar, N., Seyed-Emami, K., Majidifard, M.R. and Behfar, A. (2012) Lithostratigraphy and Biostratigraphy of the Dalichai Fomation at Talu (Northeast Damghan, Alborz), Based on Ammonites. Geosciences, 21, 249-262. [In Persian]Sarbandi Farahni, T., Majidifard, M.R., Kebriaee-Zadeh, M.R. and Mohammadi, M. (2015) Study of the Lithostratigraphy and Biostrati of Ammonite Fauna of the Dalichai Formation at the Mahdishahr Section, N Semnan. Geosciences, 24, 27-38. [In Persian]Dietze, V., Seyed-Emami, K. and Raoufian, A. (2014) Morphoceras Douvillé, 1880 and Ebrayiceras Buckman, 1920 from the Dalichai Formation (Lower Bathonian) North and Northeast of Damghan (Northeast Alborz), Iran. Zitteliana A, 54, 15-22.Seyed-Emami, K., Schairer, G., Raoufian, A. and Shafeizad, M. (2013) Middel and Late Jurassic Ammonites from the Dalichai Formation West of Shahrud (East Alborz, North Iran). Neues Jahrbuch fur Geologie und Palaontologie, Abhandlungen, 267, 43-66. https://doi.org/10.1127/0077-7749/2012/0296Cariou, E. and Hantzpergue, P. (1997) Groupe Francais d’études du Jurassique, biostratigraphie du Jurassique, ouest-européen et Méditerranéen—Zonations parallèles et distribution des invertébrés et microfossiles. Bulletin des Centres de Recherches—Exploration Production d’Elf—Aquitaine, 17, 1-400.Hyatt, A. (1900) Cephalopoda. In: Zittel, K.A. and Eastmann, C.R., Eds., Textb. Paleontology, Vol. 1, MacMillian, New York, 502-592.Sachirardin J. ,et al. (1956)Le Callovien du sondage HNI de Blodelsheim (HautRhin) Bulletin du Service de la Carte geologique de Alsacee et du Lorraine 9, 39-84.Bourquin J. ,et al. (1968)Les Reineckeides Annales des Sciences de l Universite Besancon 4, 1-169.Gemmellaro G.G. ,et al. (1872)Sopra i cefalopodi Della zona con Stephanoceras macrocephalum (Schlot), Della Rocca chi Parra presso Calatafimi, Provinicia di Trapani, Sicillia Atti del Accademia gioenia di Scenze Naturali 3, 5-30.Steinmann, G. (1890) Cephalopoda, In: Steinmann, G. and Doderlein, L., Eds., Elemente der Palaontologie, 344-475.Oppel A. ,et al. (1856)Di Tithonis Etage Zeitschrift der deutchen geologischen Gesellschaft 17, 535-558.Bayle E. ,et al. (1878-1979)Fossiles principaux des terrains Memory Explorer Carte 4, 23-99.Cariou, E. (1984) Les Reineckeiidae (Ammonoidae, Callovien) de la Tethys occidentales Dimorphisme et evolution. Etude a partir des gisements du center-oust de la France. Documents des Laboratoires de Geologie Lyon, H.S. 8, 461-599, 69 pls.Jeannet, A. (1951) Stratigraphie und Palaeontologie des oolithischen von Eisenerzlagers Herznach un seiner Umgebung. Beitrage zur Geologie der Schweiz, geotechnische Serie, 13, 1-240.Reinecke, I.C.M. (1818) Maris protogaei Nautilos et Argonautas vulgo Cornua Ammonis., 90 p.Till A. ,et al. (1907)Die Cephalopodengebisse Jahrbuch der kaiserlich-koniglichen geologischen Reichsanstalt Wien 57, 535-682.De Grossouvre, A. (1917) Etude sur le groupe des Peltoceras toucasi et transversarium In: Petitclerc, P., Ed., Note sur des fossils nouveaux, rares ou peu connus de Lest de la France, Vesoul, S. 53-55.Petitc, P. (1915) Essai sur la faune du Callovien dans le Departement des Deux-Sevres et plus spécialement de celle des environs de Niort. Contribution à l’étude des terrains jurassiques dans l’ouest de la France, Vesoul (Louis Bon), 144 S., 14 T.Roman, F. (1930) Cephalopodes du Lias et du Jurassique moyen des re gions d Oudjda et du Grand Atlas (Maroc Oriental). Protectorat de la Re publique Franc, asia au Maroc. Direction ge ne rale des travaux publics. Service des Mine et de la Carte Geologique. Notes et memoires, 22 p.Spath, L.F. (1927-1933) Revision of the Jurassic Cephalopod Fauna of Kachh (Cutch): Memoirs of Geological Survey of India, Palaeontologia Indica. New Series 9, Memoir 2, 1-945.Enay, R. and Cariou, E. (1997) Ammonite Faunas and Palaeobiogeography of the Himalayan Belt during the Jurassic: Initiation of a late Jurassic Austral Ammonite Fauna. Palaeogeography, Palaeoclimatology, Palaeoecology, 134, 1-38. https://doi.org/10.1016/S0031-0182(96)00157-5Wilmsen, M., Fürsich, F.T., Seyed-Emami, K., Majidifard, M.R. and Zamani-Pedram, M. (2010) Facies Analysis of a Large-Scale Jurassic Shelf-Lagoon: The Kamar-e-Mehdi Formation of East-Central Iran. Facies, 56, 59-87. https://doi.org/10.1007/s10347-009-0190-8