Skip to Main Content
Book Chapter

The Shemshak Group (Lower–Middle Jurassic) of the Binalud Mountains, NE Iran: Stratigraphy, depositional environments and geodynamic implications

By
Markus Wilmsen
Markus Wilmsen
1
GeoZentrum Nordbayern der Universität Erlangen-Nürnberg
,
Fachgruppe PaläoUmwelt, Loewenichstrasse 28, D-91054 Erlangen
,
Germany
2
Senckenberg Naturhistorische Sammlungen Dresden, Museum für Mineralogie und Geologie, Sektion Paläozoologie
,
Königsbrücker Landstrasse 159, D-01109 Dresden
,
Germany
Search for other works by this author on:
Franz Theodor Fürsich
Franz Theodor Fürsich
1
GeoZentrum Nordbayern der Universität Erlangen-Nürnberg
,
Fachgruppe PaläoUmwelt, Loewenichstrasse 28, D-91054 Erlangen
,
Germany
Search for other works by this author on:
Jafar Taheri
Jafar Taheri
3
Geological Survey of Iran
,
NE Branch, P.O. Box 91735-1166, Mashad
,
Iran
Search for other works by this author on:
Published:
January 01, 2009

Abstract

The Lower–lower Middle Jurassic non-marine sedimentary succession of the Binalud Mountains of NE Iran is correlated with the Jurassic part of the Shemshak Group of the Alborz Mountains and subdivided into three formations: the Arefi, the Bazehowz and the Aghounj formations. The succession rests, with angular unconformity, on a metamorphic basement deformed during the Late Triassic Eo-Cimmerian orogeny. The lowermost unit, the Arefi Formation, is subdivided into a lower Derekhtoot Member and an upper Kurtian Member. The Derekhtoot Member (up to 750 m thick) consists of very coarse-grained, chaotic boulder beds, breccias and conglomerates representing rock-fall deposits and proximal–middle alluvial fans, deposited along steep fault scarps. The succeeding Kurtian Member (>300 m) comprises finer-grained conglomerates with well-rounded clasts, reflecting deposition in a proximal braided river system. The overlying Bazehowz Formation is more than 1000 m thick and consists of vertically stacked, decametre-scale channel-fill cycles of the middle reaches of a braided fluvial system. The uppermost unit, the Aghounj Formation, consists of at least 400 m of granule- to pebble-size, thick-bedded and large-scale trough cross-bedded quartz conglomerates and sandy interbeds of a proximal braided fluvial system. The overall succession fines upwards due to erosion, down to metamorphic basement, of a high-relief source area in the NE, and rests on Cimmerian basement, suggesting that the strata are intramontane deposits of the Cimmerian mountain chain in NE Iran. This interpretation has important implications concerning the position of the NW–SE-trending Eo-Cimmerian suture in NE Iran, which should be placed further SW than formerly assumed.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

South Caspian to Central Iran Basins

M.-F. Brunet
M.-F. Brunet
CNRS-INSU and Université Pierre et Marie Curie, France
Search for other works by this author on:
M. Wilmsen
M. Wilmsen
Senckenberg Naturhistorische Sammlungen Dresden, Museum für Mineralogie und Geologie, Germany
Search for other works by this author on:
J. W. Granath
J. W. Granath
Granath & Associates Consulting Geology, USA
Search for other works by this author on:
Geological Society of London
Volume
312
ISBN electronic:
9781862395602
Publication date:
January 01, 2009

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal