Research Article Amount and location of tectonic uplift in the region of northwest from the Permian to the Neogene

Akram Alizadeh1

Received: 23 September 2020 / Accepted: 6 February 2021 © The Author(s) 2021 OPEN

Abstract The Urmia Lake Basin is located between the West and East provinces in the northwest of Iran. is the twentieth largest lake and second largest hypersaline lake in the world. Stratigraphic columns have been constructed, using published information, to compare the sedimentary units deposited from the Permian to the Neogene on the east and west sides of the lake, and to use these to quantity subsidence and uplift. East of the lake, the sedimentary section is more complete and has been the subject of detailed stratigraphic studies, including the compilation of measured sections for some units. West of the lake, the section is incomplete and less work has been done; three columns illustrate varia- tions in the preserved stratigraphy for the time interval. In all cases, the columns are capped by the Oligocene–Miocene Formation, which was deposited during a post-orogenic marine transgression and unconformably overlies units ranging from Precambrian to Cretaceous. Permian to Cretaceous stratigraphy is used to measure subsidence in the Lake Urmia basin up to the end of the Cretaceous, and then, the subsequent orogenic uplift, which was followed by further subsidence recorded by the deposition of the Qom Formation in the Oligocene–Miocene.

Keywords Tectonostratigraphy · Stratigraphic column · Quantitative subsidence · Qom formation · Urmia Lake · West azerbaijan

1 Introduction extraterrestrial events infuence sedimentary basins [17]. Quantitative subsidence analysis has been widely used Lake Urmia is a shallow lake located in northwest Iran in sedimentary basins developed on passive margins as (Fig. 1) and one of the largest permanent lakes in the Mid- well as in foreland, fore-arc and back-arc, and intracratonic dle East. Iran’s biggest internal lake is located between the basins [27]. provinces of Western and Eastern Azerbaijan. The water This study outlines the stratigraphic and structural evo- of Lake Urmia is hypersaline with a salinity of more than lution of the Lake Urmia region based on geological maps 180 g/L, which has risen to 300 g/L during recent years published by the Geological Survey of Iran. The Lake Urmia [11]. area in NW Iran is not only situated in an active tectonic Paleotectonics and plate-tectonic models are the best region in junction with Anatolia, escaping to the west, recorder for understanding the tectonics of sedimentary and the Iranian microcontinent, escaping to southeast basins and tectonostratigraphy deals with distinguishing along the major strike-slip faults, but it is also located at sedimentary sequences and tectonic setting [7]. Hori- the extension termination of the Main Recent Fault [22]. zontal motions of plates, thermal changes through time, Active tectonics of NW Iran and SE involve a coun- stretching and shortening of the crust, isostatic adjust- terclockwise rotating array of NWSE trending, right-lateral ments, mantle dynamics, surfcial processes, and even strike-slip faults [8].

* Akram Alizadeh, [email protected] | 1Department of , Faculty of Science, , 57153‑165 Urmia, Iran.

SN Applied Sciences (2021) 3:345 | https://doi.org/10.1007/s42452-021-04346-5

Vol.:(0123456789) Research Article SN Applied Sciences (2021) 3:345 | https://doi.org/10.1007/s42452-021-04346-5

Fig. 1 Geographic location of the Lake Urmia, northwestern Iran

Two main periods of uplift can be recognized in the Per- Paleocene and Eocene. The orogenic processes continue mian to Miocene stratigraphy of the Lake Urmia region. today in some of the Alpide mountain ranges [23]. The earliest coincides with the Cimmerian Orogeny in the Late Triassic [28]. The orogeny is attributed to the closure of the Paleo-Tethys Ocean in northern Iran [30]. The second 2 Tectonostratigraphy is the Alpine Orogeny attributed to the closing of the Neo- Tethys Ocean along the Zagros Suture Zone at the end of Following the Pan-African orogeny (about 550 million the Cretaceous. years ago), shallow marine sediments were deposited during the Late Ediacaran, and deposition extended 1.1 Cimmerian and alpine orogeny across large areas of Iran during the Paleozoic (e.g., Alborz, Eastern Iran, Zagros; [14]). After a general regres- The early Cimmerian orogeny (200–150 million years sion and a distinct hiatus Permian marine transgression ago) is one of the most important tectonic events in the resulted in deposition Silurian rocks in most parts of Iran; geological history of the Earth. The event was associated the Permian sediments are represented by the Dorud with compressional tectonics in northern Iran and ten- sandstones, and Ruteh and Nesen limestone in the sional tectonics in the south. The late Cimmerian orog- Alborz region [14]. eny occurred as a signifcant tectonic event in Iran in Late The Lower Triassic sedimentary rocks in Iran are Jurassic-Early Cretaceous times [24]. The Alpine orogeny mainly of a shallow marine or continental shelf origion is an orogenic phase continuing from the Late Mesozoic for example the Elika dolomites in Alborz, and the Sorkh into the Cenozoic and has formed the mountain ranges shale and Shotori dolomites in Central Iran [14]. Both of the Alpide belt. The Alpine orogeny was caused by continuous and discontinuous transitions have been Africa, India and the small Cimmerian plate colliding with described between Paleocene and Eocene strata as is Eurasia in the north. Convergent movements between the also the case with Eocene and Oligocene strata (e.g., tectonic plates had already begun in the early Cretaceous, Central Iran). The Oligocene and Miocene epochs were but the major phases of mountain building began in the characterized by rapid subsidence, deposition, and facies changes in both marine and continental sedimentary

Vol:.(1234567890) SN Applied Sciences (2021) 3:345 | https://doi.org/10.1007/s42452-021-04346-5 Research Article

Fig. 2 Field photos of the Upper Red and Qom Formations at the study area, looking east

basins [14]. Oligocene sediments in most parts of Iran are included in the Triassic Elika Formation [2, 20] and this are of shallow marine character, turning into deeper policy is followed on Fig. 4. marine facies in the Upper Oligocene through the Lower The column east of the lake (Fig. 4) is principally based Miocene (e.g., Qom; Fig. 2). The middle-upper miocene on four sources of information: The frst of these is a sec- sedimentary rocks are mostly continental. Quaternary tion measured through the Permian Dorud and Ruteh sediment is a prominent feature of the plains of Iran [14]. formations, west of Ajabshir, by Shahrabi [25]. The other The geology of the study area (Fig. 3) includes rocks sources for compiling the column east of the lake are the ranging in age from Precambrian to Quaternary, includ- descriptive notes on the 1:100,000 geological map of the ing recent lake sediments [3, 4]. Kelts and Shahrabi [19] Maragheh area [2]; a section measured through the Juras- showed that Paleozoic metamorphic rocks occur on the sic by Shahrabi [25] and, the fysch is shown on Fig. 4 with western side of the lake, whereas the rocky clifs on the an estimated thickness of 3000 m. eastern shores are composed of Mesozoic flysch. The These describe the Triassic as being represented by northwestern shores, and many of the islands, are formed the Elika formation consisting of limestone and dolomite. of Lower Miocene, represented by coral limestone of the They estimate the thickness of the formation at 250 m. In Qom Formation. th