Palaeoenvironmental Interpretation of the Upper Triassic Baluti Formation in two selected sections at Amediya District, Kurdistan Region- Iraq: Insights from Palynofacies Study

Abstract

Palynofacies analysis was carried out on 28 outcrop samples from the Upper Triassic Baluti Formation from Zewa and Sararu Sections in south and northwestern of Amediya District respectively, Kurdistan Region- Iraq. Based on the studied palynofacies, both sections are quite different in terms of depositional environment. Four types of palynofacies were recognized as following: the palynofacies type IV (Pl.1) is observed in the lower, middle and upper portions of upper part of Zewa Section in which, is characterized by high amount of phytoclasts, medium percentage of amorphous organic matter (AOM) and palynomorphs. This facies is referred to a depositional area that is located relatively nearshore with an arid hinterland, the palynofacies type V (Pl.2) was observed in lowermost and middle portions of upper part of Zewa Section, which is characterized by high domination of palynomorphs (mainly bisaccates and monosaccate pollen grains) and a less amount of phytoclasts and AOM. This facies indicates the domination of shallow marine to continent environment. The palynofacies type VI (Pl.3) was observed in middle and upper portions of upper part of the Zewa Section and lower and upper parts of the Sararu Section. This facies showed less amount or absence of palynomorphs, and relatively high amount of AOM and phytoclasts. In addition to this, a remarkable percentage of dinoflagellate cysts in Sararu Section has been found in this facies. This facies indicates proximal suboxic-anoxic shelf, and palynofacies type IX (Pl.4) was observed in middle to upper part of Sararu Section and characterized by less amount or absence of palynomorphs with high amounts of AOM and phytoclasts, which represents a deep environment of deposition.

The Middle to Late Triassic of Central Saudi Arabia with emphasis on the Jilh Formation. Part II: sequence stratigraphy, depositional and structural history, correlations and paleogeography

“…Palynological data for this "Shale 2" in Well Atrush-1-location on Figure 12 Hanna [2007], stated a Julian (Early Carnian) age for the basal Baluti at the same locality with a possible Norian age for the uppermost beds of the formation. Azo [2020] also interprets the Baluti shales as being partially of Julian age. Thus, the biostratigraphic data available to date remains equivocal and does not refute our interpretation that the "Marker Dolomite" that underlies the Baluti Formation is older than previously interpreted and of Julian (Early Carnian) age, and therefore equivalent to the Jilh Dolomite of Saudi Arabia and neighbouring countries, as proposed by Lunn et al [2019].…”

“…Figure 11. Distribution of Ladinian conodonts throughout the Mediterranean Tethyan domain [palaeogeographical base-map modified fromDercourt et al, 2000a,b, Barrier andVrielynck, 2008].…”

Depositional Environment of the Upper Triassic Baluti Formation in Gara Anticline, Kurdistan Region, North Iraq: Insight from Microfacies and Biomarker Characteristics

“…The dolomites of the Baluti were formed as early diagenetic at the tidal-subtidal environment and as a late diagenetic at the shallow-deep burial depths (Al-Mashaikie and Razzak, 2017). Azo et al (2020) studied the palynofacies analysis of the Baluti Formation in the Zewa section at Gara Anticline. Based on their findings, the paleoenvironmental deposition of the formation was probably shelf to basin transition and mud-dominated oxic shelf.…”

Sedimentology of the Baluti Formation (Late Triassic) in the Warte area, northeastern Iraqi Kurdistan region

“…Since the first description of the Baluti Formation by Bellen et al (1959) in it is type section, there have been several published articles on the Baluti Formation in the outcrops of Northern Iraq. This includes the works of Buday (1980), Jassim and Goff (2006), Hanna (2007), Aqrawi, Goff, Horbury, and Sadooni (2010), Al‐Juboury and McCann (2015), Shingaly (2016), Al‐Mashaikie, Abdul‐Razzak, and Naser (2016), Al‐Mashaikie (2017), Al‐Mashaikie and Abdul‐Razzak (2017), Asaad (2019), Asaad and Omer (2019), Lunn, Miller, and Samarrai (2019), Azo, Hanna, and Edilbi (2020), and Asaad and Omer (2020), which have all focused mainly on the stratigraphy, sedimentology and palaeontology of the studied formation. The main aim of this article is a detailed investigation of the sedimentological aspect of the Baluti Formation in the studied section in terms of lithostratigraphy, petrography, diagenesis, mineralogy, facies analysis, and subdivisions, in order to understand further the lateral continuity of its depositional environment in areas that have not been studied previously.…”