عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Shurab travertine spring is located 140 km the east of Tehran and at the beginning of the Gadook Gorge on the border of Tehran and Mazandaran provinces. The carbonate deposits are divided into two main categories: the first group of deposits that are forming at present time (active): and mostly of different colors such as red, yellow and orange, the second group of old (fossilized) deposits mainly adjacent to the railway line and is mostly cream colored. The age of these deposits is less than 100 years old. This spring originates from the fractures and drainage of the Barut Formation in the train tunnel. The morphology and sedimentary deposits in the cascade forms are layered. In this study, 25 samples of travertines and tufas were used for determination of texture and chemical composition. Types of travertines and tufas based on morphology and environment in the stack include 1- waterfall travertine 2- travertine with layered morphology and 3- calcareous tufa or framestone phytoherm. Also, according to the petrographic results of four types of lithofacies, according to the characteristic morphologies on the ground scale and hand specimens in the travertine deposits of the saltwater travertine were identified which include: 1- lithofacies raft boundstone; 2- lithofacies algae; 3- lithofacies crystalline crusts and 4- lithofacies Bandstone shrubs.