Facies Analysis and Sequence Stratigraphy of the Qal'eh Dokhtar Formation (Middle–Upper Jurassic) in the West of Boshrouyeh, East Central Iran

Abstract

The study area is located in the east Tabas Block in Central Iran. Facies analysis of the Qal'eh Dokhtar Formation (middle Callovian to late Oxfordian) was carried out on two stratigraphic sections and applied to depositional environment and sequence stratigraphy interpretation. This formation conformably overlies and underlies the marly‐silty Baghamshah and the calcareous Esfandiar formations, respectively. Lateral and vertical facies changes documents low‐ to high energy environments, including tidal‐flat, beach to intertidal, lagoon, barrier, and open‐marine. According to these facies associations and absence of resedimentation deposits a depositional model of a mixed carbonate–siliciclastic ramp was proposed for the Qal'eh Dokhtar Formation. Seven third‐order depositional sequences were identified in each two measured stratigraphic sections. Transgressive systems tracts (TSTs) show deepening upward trends, i.e. shallow water beach to intertidal and lagoonal facies, while highstand systems tracts (HST) show shallowing upward trends in which deep water facies are overlain by shallow water facies. All sequence boundaries (except at the base of the stratigraphic column) are of the no erosional (SB2) types. We conclude eustatic rather than tectonic factors played a dominant role in controlling carbonate depositional environments in the study area.

Multistage dolomitization in the Qal'eh Dokhtar Formation (Middle‐Upper Jurassic), Central Iran: petrographic and geochemical evidence

“…The upper part (upper carbonate unit) is represented by medium-to thick-bedded limestone, dolomitic limestone and dolomite, which form the main types of dolomite present in this formation. The facies and depositional environments of the Qal'eh Dokhtar Formation in the study area are described in detail by Sabbagh Bajestani et al (2016). Litho-and microfacies characteristics of the Qal'eh Dokhtar Formation indicate that these sedimentary successions were deposited in low-to highenergy environments of a mixed carbonate-siliciclastic ramp; the facies range from tidal flat to beach to intertidal, lagoon, barrier, and open marine (Sabbagh Bajestani et al, 2016).…”

“…The facies and depositional environments of the Qal'eh Dokhtar Formation in the study area are described in detail by Sabbagh Bajestani et al (2016). Litho-and microfacies characteristics of the Qal'eh Dokhtar Formation indicate that these sedimentary successions were deposited in low-to highenergy environments of a mixed carbonate-siliciclastic ramp; the facies range from tidal flat to beach to intertidal, lagoon, barrier, and open marine (Sabbagh Bajestani et al, 2016). The limestone lithofacies include mudstone, wackestone, packstone and grainstone (Sabbagh Bajestani et al, 2016).…”

High‐Frequency Sequence Stratigraphy and Fine‐Scale Reservoir Characterization of the Devonian Sandstone, Donghe Formation, North Uplift of the Tarim Basin

“…Using sequence stratigraphy to understand hydrocarbon reservoir has been studied for long (Leckie and Walker, 1982;Cattaneo and Steel, 2003;Al-Ramadan et al, 2005;Zecchin, 2007;Jackson et al, 2009;Cheng Yongsheng, 2015;Xian Benzhong et al, 2017). It is crucial to use high -resolution sequence stratigraphy in reservoir characterization because sequence stratigraphy can predict facies and grain size distribution in order to understand the reservoir heterogeneity (Zecchin, 2007;Guo Wei et al, 2015;Zecchin and Catuneanu, 2015;Lai Jin et al, 2016;Li Weiqiang et al, 2017;Mei Mingxiang and Liu Shaofeng, 2017;Sabbagh Bajestani Mahnaz et al, 2017;Zhang et al, 2017b). The fine-scaled reservoir is defined as reservoirs within high-frequency sequence scale (Zecchin and Catuneanu, 2015).…”