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The carbonate‐dominated successions of the Tirgan Formation (Latest Barremian‐Early Aptian) in the Kopet‐Dagh Basin (Iran) were studied to decipher the tectonic and eustatic sea‐level effects, as well as the autogenic influence on lateral and vertical facies changes, depositional environment, and sequence stratigraphy of the tide‐wave‐dominated sediments at the northern margin of the Neo‐Tethys Ocean. Fourteen facies were identified in the studied sequences, here grouped into five facies associations according to the depositional setting: tidal flat (A), lagoon (B), shoal (C), shallow open‐marine (D), and deep‐open marine (E). A third‐order depositional sequence, including a transgressive system tract (TST) and a highstand system tract (HST) was also identified, along with several medium‐ and small‐scale, thickening‐ and shallowing‐upward cycles (parasequences). The development of the depositional sequence and parasequences of the studied successions of the Tirgan Formation were controlled by interactions between allogenic (tectonic and eustasy) and autogenic factors (wave and tidal hydrodynamic regimes). The allogenic factors mainly affected the stacking pattern and parasequence development of the TST deposits in the lower part of the Tirgan Formation, characterized mainly by the deep‐open marine association. Autogenic factors display a main influence on the stacking pattern and formation of the HST deposits and related parasequences, characterized by shallow open‐marine‐lagoon–shoal associations developed in the upper part of the Tirgan Formation. The tectono‐sedimentary model for the evolution of the tide‐wave‐dominated carbonate platform represented by the Tirgan Formation may be useful for further studies on sedimentary basin evolution or palaeogeographic reconstructions of the Neo‐Tethys margin. [ABSTRACT FROM AUTHOR]

Cyclic successions are one of the most important types of deposits in the carbonate platform of the Mississippian (Tournaisian-Viséan) in Gondwanan and Laurussian margins. The importance of climatically induced events impact on the amplitudes and frequencies of sea-level fluctuations in Mississippian of Iran is significant because the beginning, extent, duration, and significance of periods of climatically induced events in northern margin of Gondwana are not well recognized. A high-resolution sequence architecture in integration with paleoenvironmental reconstruction and foraminiferal biozonation from the Tournaisian-early Visean carbonate successions of the Mobarak Formation in Alborz basin along depositional strike (E-W- a distance of c. 340 km) suggests a mosaic-like pattern of deposition and compartmentalization of the depositional settings (homocline ramp to distally steepened ramp). According to the recognized facies, the stacking pattern of high-frequency cycles across the platform, and major accommodation events recognized on the correlated Fischer plots, six 3rd-order sequences (DS1–DS6) were identified. Detailed analysis on high-frequency cycles representing a highly variable number of shallowing-upward cycles, types, thicknesses, and facies heterogeneity along depositional strike. A combination of the episodic tectonic events along faults interacting with autocyclic processes, and inherited topographic irregularities are suggested as the driving mechanism for the cycle development. Six stages of Mobarak carbonate platform evolution based on understand the interplay of autocyclic and allocyclic controls are recognized in a hierarchical 3rd-order sequence stratigraphic framework and a chronological order: (1) early Hastarian corresponds to post-glacial transgressive episode with progressive backstepping of facies belts of early TST of DS1 throughout the region; (2) middle to late Hastarian corresponds to a major transgressional phase of DS1 following global temperature rise superimposed on different subsidence/uplift rates with the deformation of the platform along depositional strike; (3) Hastarian–Ivorian boundary corresponds to TST of DS2 with facies heterogeneity along depositional strike related to continuation of different subsidence/uplift rates. The absence of any systematic changes in the amplitude and period of cyclicity or lowstand deposits and subaerial surfaces during this phase shows the lack of influence of mid-Tournaisian glaciation and concurrent eustatic regression in northern margin of Gondwana. (4) early to middle Ivorian coincides with the RST of DS2 and TST of DS3 showing by remarkable topographic irregularities in the basin physiography and change in the position of the depocenter axis from a E–W trend to the center; (5) late Ivorian-early Moliniacian coincides with the RST of DS3 and DS4 showing by the Late Tournaisian thermal period and eustatic rise superimposed on uplift and subaerial exposure of the western part and subsidence in the central and eastern parts of the basin; (6) Moliniacian coincides with DS5-DS6 sequences showing by change from fault-related topography to major tilted fault-block topography accompanied by eustatic sea-level fall caused indirectly by the Viséan and Serpukhovian glaciations phases. • Analyze along-strike variations in stratigraphic architectural style of the Tournaisian-Viséan successions. • Synthesis of autocyclic and allocyclic controls on changes in accommodation space along depositional strike. • Access a framework for tectonic and climatically induced event histories in the northeastern margin of Gondwana. • The importance of climatically induced events impact on the amplitudes and frequencies of sea-level fluctuations. • Results are useful for correlation to Tournaisian-Viséan strata in other parts of Gondwana. [ABSTRACT FROM AUTHOR]