Plant macrofossils of Karaj Formation (middle Eocene) in Arangeh region, NW of Tehran, Central Alborz

The Karaj Formation, first introduced by Lorenz (1964) and named by Glaus 1965 It consists of sedimentary, pyroclastic and extrusive igneous rocks representing five official Members of lower shale, middle tuff, Asara shale, upper tuff and Kandovan shale in ascending order. The plant macrofossils studied in this paper were collected from sediments of middle Eocene Kandovan shale (based on Tehran 1:100000 sheet) in north side of Arangeh anticline (Arangeh province) and northeast of Karaj (northwest of Tehran). There has been no systematic and detailed study of the plant macrofossils of Karaj Formation to date. The plant macrofossils have been found in the Karaj Formation are mostly fossil wood and fossilized tree branches and stems, As the most accurate report of the plant macrofossils of the Karaj Formation includes only the plant fossils debris from monocotyledones without reference to a plant member (leaves, branches, etc.) In middle tuff, Asara shale and upper tuff Members have been different sections of the Karaj Formation (Assereto, 1966; Dedual, 1967). In aforementioned view, the main purpose of this article is to introduce at least generic groups of plant macrofossils from Karaj Formation and to provide a detailed study and to provide a starting point for future studies of Tertiary plant macrofossils, especially the Karaj Formation in Iran.

Arangeh region are located in NW of Tehran and NE of Karaj and between 51° 5'-10' E and 36° 54'-57' N. The localities studied is in northern highlands of rural district. The access path is Tehran, Karaj, road Chalus, Aderan  and Arangeh (before Karaj dam). Arangeh syncline (studied area) has been located along the NW-SE axis, northeast of Karaj city, north of thrust north of Tehran and south-southwest thrust of Imamzadeh Davood (Sheet 1:100000 Tehran) and studied area is in north edge of Arangeh syncline. The central core of the Arghana syncline is composed of sedimentary and partly pyroclastic layers of the Kandovan shale Member. The Kandovan shale Member in Arangeh syncline is divided into two parts. The lower part (Es6) of 100 m thick consists of shale, siltstone, sandstone and silty tuff which is entirely gray-brown in color and the upper part (Esc6) of the Kandovan shale in the syncline consists of layers of sandstone, shale and conglomerate with interlayers of tuff. The fossils studied in this paper are derived from sediments of the lower of Kandovan shale (Es6) in the region. The age of the Kandovan Shale Member in the Arangeh syncline (both lower and upper parts) is Middle Eocene.

The founded samples of region is consist of Horsetails (Equisetum), Lycophyta (Lycopodiales), comminute leaves from Monocotyledons from Cyperaceae (Poales), juvenile branches with pinnules and male Inflorescence from Dicotyledones from Casuarinaceae (Fagales order), organogenetic of Dicotyledones (probably fruit) and Rhizomes of Monocotyledons and most samples have been identified in the family, order or higher classes due to incompleteness and lack of proper preservation.
Sub Kingdom: Tracheophyta (Vascular Plants)
Division: Sphenophyta (Equisetophyta) (Horsetails)
Class: Sphenopsida (Equisetopsida)
Order: Equisetales
Family: Equisetaceae
Genus: Equisetum Linne, 1770
Division: Lycopodiophyta (Lycopodes)
Class: Lycopodiopsida
Order: Lycopodiales (Club mosses)
Division: Magnoliophyta (Angiospermae) (flowering plants)
Class: Liliopsida (Monocotyledons)
Order: Poales
Family: Cyperaceae (Sedges)
Class: Magnoliopsida (Dicotyledons)
Order: Fagales
Family: Casuarinaceae
Unknown Dicotyledons organogenetic
Unknown Rhizomes
Concolusion
In this study plant macrofossils from Karaj Formation, plant macrofossils of two Orders Poales and Fagales from Iran and plant macrofossils of two Division of Sphenophyta (Horsetails), Lycopodiophyta from Cenozoic sediments from Iran and Casuarinaceae Family from out of Gondwana are reported for the first time.
On the basis of material, it can be concluded that humid-temperate and environments of them are suggested lush and humid.
Keywords:.
References
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