Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

The Triassic of Aghdarband

Author
A. W. Ruttner
Geological Survey of France
Abstract
A particular sequence of Triassic rocks is exposed in the erosional window of Aghdarband in the easternmost part of the Kopet Dagh (Koppeh Dagh) mountains, 100 kilometers east-southeast of the town Mashhad. It bears obvious relations to special sections of the Nakhlak Group (Central Iran), and it shows also some similarities lo lowest parts of Triassic  sequences in North-Iran (Alborz Mountains). But on the whole, the Triassic rock sequence in question has an individuality of its own; it is the result of an intermittent sedimentation in a Triassic "Aghdarband Sea".
In this Triassic rock sequence four formations are distinguishable; these are, from base to top:
the Sefid Kuh Limestone Formation
the Nazarkadeh Limestone Formation
the Sina Volcanic Formation
the Miankuhi Shale Formation.
Originally, these (our formations were comprised lo a Triassic Aghdarband Group (A. RUTTNER, 1991, 1993). According to the suggestion of the National Iranian Stratigraphy Committee, however, the Miankuhi Formation should better not be included in that Group, because of the probable existence of a considerable gap of sedimentation between this Formation and the top of the underlying Sina Formation. But, since such a gap in sedimentation exists very probably also at the base of the Sina Formation, it seems advisable to abandon the term "Aghdarband Group" altogether and to deal with each of the four formations individually.
The Qara Gheitan Formation below the Sefid Kuh Limestone Formation is more complete exposed at sites outside the Aghdarband area proper. The Ghaleh Qabri Shales- exposed far lo the east of Aghdarband - await still a closer examination.
Keywords
Triassic
Aghdarband

Subjects

References: Sefid Kuh limestone Formation
 
A. BAUD, R. BRANDNER and D. DONOFRIO: The Sefid Kuh limestone - a Late Lower Triassic carbonate ramp (Aghdarband, NE-Iran.) Abh.Geol.B.-A., vol.38, p.125-137, Vienna 1991.
A. RUTTNER, Geology of the Aghdarband Area (Kopel Dagh.) NE-Iran. - Abh. Geol.B.A., B.-A., vol.38, p.26f, p.26f, Vienna 1991.
from the mountain Sefid Kuh, 6,6 kilometers WNW of the mining settlement Aghdarband.
 
 
References: Nazarkardeh Formation (="fossil horizon 1" at the geological map)
 
L.KRYSTYN and F. TATZREITER: Middle Triassic ammonoids from Aghdarband (NE-Iran) and their paleobiogeographical significance.-Abh.Geol.B.-A., vol. 38, p. 139-163, Vienna 1991.
A. BAUS, G. STAMPFLI and D. STEEN: The Triassic Aghdarband Group: volcanism and geological evolution.- Abh. Geol.B.-A., vol. 38 p. 125-137, Vienna 1991.
M. SIBLIK: Triassic Brachiopods from Aghdarband.­Abh. Geol.B.-A., vol. 38, p. 165-174, Vienna 1991.
Geology of the Aghdarband Area (Kopet Dagh, NE-Iran). - Abh. Geo!. B. A., vol 38, p. ~9-30., Vienna 1991.
M. DA VOUDZADEH & K. SEYED-EMAMI, Stratigraphy of the Triassic Nakhlak Group, Anarak Region, Central Iran.- Geological Survey of Iran, Report No. 28, p.5-28, Tehran 1972.
E.T, TOZER. Trassic Ammoinoids and Daonella from thg the Nakhlak Group, Anarak Region, Central Iran.- Geological Survey of Iran, Report No. 28, p.29-69, Tehran 1972.
 
 
References : Sina volcanic Formation
 
A. RUTTNER, Geology of the Aghdarband Area (Kopet Dagh), NE-Iran. - Abh. Geol, B.-A., vol. 38, p. 30-44), Vienna 1991.
A. BAUD. G. STAMPFLI & D. STEEN: The Triassic Aghdarband Group: volcanism and geological evolution- Abh. Gcol. B.-A., vol. 38, p. 125-137, Vinna 1991.
L.KRYSTYN & F. TATZREITER: Middle Triassic Ammonoids from Aghdarband (NE-Iran) and their paleobiogeographical significance- Abh. Geol. B.-A, vol. 38, p.139-163, Vienna, 1991.
M. SIBLIK: Triassic Brachiopods from Aghdarband (NE-Tran).
- Abh. Geol. B.-A., vol. 38, p.165-174.
E. KRISTAN- TOLLMANN: Echinoderms from the Middle Triassic Sina Formation (Aghdarband Group) in NE-Iran. - Abh-Geol B.-A., vol. 38, p.175-194, Vienna 1991.
 
E. KRTSTAN-TOLLMANN: Ostracods from the Middle Triassic Sina Formation (Aghdarband Group) in NE-Iran. -Abh. Geol. vol. 38, p. 195-200, Vienna 1991.
R. OBERHAUSER: Triassic Foraminifera from the Faqir Marl Bed of the Sina Formation (Aghdarband Group, NE-Iran). Abh. Geol. B.-A., vol. 38, p. 201-204, Vienna 1991.
D.A. DONOFRIO: Radiolaria and Porifera (Spica) from the Upper Triassic of Aghdarband (NE-Iran). -Abh. Geol. B. -A., vol. 38, p. 205-222, Vienna 1991.
M. DA VOUDZADEH & K. SEYED- EMAMI, Stratigraphy of the Triassic Nakhlak Group, Anarak Region, Central Iran. - Geological Survey of Iran, Report No. 28, 5- 28, Tehran 1972.
 
References: (Miankuhi Formation)
A. RUTINER, Geology of the Aghdarband Area (Kopet Dagh), NE-Iran. - Abh. Geol. B.-A., vol. 38, p. 44-47, Vienna 1991.
M. BOERSMMA & J. H.A.V AN KONIJNENBURG-VAN CITIERT: Late Triassic Plant Megafossils from Aghdarband (NE-Iran)- Abh. Geol.B.-A.,vol. 38, p. 223-225.
K. SEYED-EMAMI, G. SCHRAIER & a .A. BEHROOZI: Einige ammoniten aus der Kashafrud - Formastion (Mittlerer Jura) E Mashhad (NE- Iran) - Mitt. Bayer. Staatsslg.,Palaont. hist. Geol., vol. 34, p. 145-158, Munchen, 1994.
 
Scientific Quarterly Journal of Geosciences
Volume 7, 27-28
Spring & Summer 1999, vol. 7, No. 27-28
Summer 1999
Pages 78-95