scholarly journals Significance of angular unconformities between Cretaceous and Tertiary strata in the northwestern segment of the Zagros fold–thrust belt, Kurdistan Region, NE Iraq

2011 ◽  
Vol 148 (5-6) ◽  
pp. 925-939 ◽  
Author(s):  
KAMAL H. KARIM ◽  
HEMIN KOYI ◽  
MUSHIR M. BAZIANY ◽  
KHALED HESSAMI
Keyword(s):  
Lower Cretaceous ◽  
Foreland Basin ◽  
Geological Mapping ◽  
Passive Margin ◽  
Arabian Plate ◽  
Thrust Belt ◽  
Kurdistan Region ◽  
Stratigraphic Position ◽  
First Time ◽  
Red Bed

AbstractIn this study, two angular unconformities are found and analysed for the first time in the Mesozoic–Cenozoic succession in the northwestern segment of the Zagros fold–thrust belt (ZFTB) in the Kurdistan Region. The first unconformity exists between Lower Cretaceous and Paleocene–Eocene rocks and the second between the Campanian Shiranish Formation and the Maastrichtian Tanjero Formation. Each of these unconformities is found in two different localities in the Zagros Imbricate Zone (i.e. the highly deformed zone immediately SW of the Zagros Suture) of the ZFTB of the Kurdistan Region near the border with Iran. The study uses recent geological mapping, structural and stratigraphic analyses in addition to using previous biozonation of the stratigraphic units that bound the two unconformities. The first unconformity was initiated with obduction of the ophiolite and Lower Cretaceous radiolarite onto the passive margin of the Arabian plate. This unconformity formed during an early phase of the Zagros orogeny, which is associated with the developing of a foreland basin, and resulted in the folding of the radiolarites and their uplift to form high-relief land. The erosion of this high-relief land resulted in the formation of the Paleocene–Eocene Red Bed Series and their deposition on the folded radiolarite. The timing of the deformation that caused this unconformity is hard to determine; however, its stratigraphic position may suggest that it possibly is related to post-Cenomanian movements. The second unconformity is between the tilted Campanian Shiranish Formation (hemipelagite) and Tanjero Formation (500 m of conglomerate in the more proximal area). These unconformities indicate that deformation and uplift of the sedimentary units was variable during ophiolite obduction in this part of the ZFTB. We argue that deformation, ophiolite obduction and collision are likely to have varied in space and time along the c. 2000 km long ZFTB.

scholarly journals Geodynamics and Oil and Gas Potential of the Yenisei-Khatanga Basin (Polar Siberia)

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 510 ◽  
Author(s):  
Valery Vernikovsky ◽  
Georgy Shemin ◽  
Evgeny Deev ◽  
Dmitry Metelkin ◽  
Nikolay Matushkin ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Oil And Gas ◽  
Foreland Basin ◽  
Gas Reservoirs ◽  
The North ◽  
Western Arctic ◽  
Folded Structures ◽  
Gas Potential ◽  
First Time ◽  
North Western

The geodynamic development of the north–western (Arctic) margin of the Siberian craton is comprehensively analyzed for the first time based on our database as well as on the analysis of published material, from Precambrian-Paleozoic and Mesozoic folded structures to the formation of the Mesozoic-Cenozoic Yenisei-Khatanga sedimentary basin. We identify the main stages of the region’s tectonic evolution related to collision and accretion processes, mainly subduction and rifting. It is demonstrated that the prototype of the Yenisei-Khatanga basin was a wide late Paleozoic foreland basin that extended from Southern Taimyr to the Tunguska syneclise and deepened towards Taimyr. The formation of the Yenisei-Khatanga basin, as well as of the West-Siberian basin, was due to continental rifting in the Permian-Triassic. The study describes the main oil and gas generating deposits of the basin, which are mainly Jurassic and Lower Cretaceous mudstones. It is shown that the Lower Cretaceous deposits contain 90% of known hydrocarbon reserves. These are mostly stacked reservoirs with gas, gas condensate and condensate with rims. The study also presents data on oil and gas reservoirs, plays and seals in the Triassic, Jurassic and Cretaceous complexes.

scholarly journals Detrital zircon provenance record of the Zagros mountain building from the Neotethys obduction to the Arabia-Eurasia collision, NW Zagros fold-thrust belt, Kurdistan region of Iraq

2021 ◽  
Author(s):  
Renas I. Koshnaw ◽  
Fritz Schlunegger ◽  
Daniel F. Stockli
Keyword(s):  
Detrital Zircon ◽  
Upper Cretaceous ◽  
Foreland Basin ◽  
Source Area ◽  
Late Eocene ◽  
Thrust Belt ◽  
Kurdistan Region ◽  
Angular Unconformity ◽  
Tectonic Processes ◽  
Provenance Data

Abstract. Recognition of new angular unconformity and synthesizing of new detrital zircon U-Pb and (U-Th)/He provenance records, including zircon (U-Th)/(He-Pb) double dating, from the NW Zagros elucidate the basin dynamics of the foreland wedge-top and intermontane units, as well as the tectonic processes in the source terranes in response to different geodynamic phases. In this contribution, we present field observations and detrital zircon provenance data from hinterland basins to reconstruct the basin dynamics and the underlying tectonic controls in the NW Zagros in the Kurdistan region of Iraq. Results reveal that the deposition of the suture zone units of the Red Beds Series (RBS; Suwais Group, Govanda Formation, Merga Group) occurred in an intermontane basin on top of folded Upper Cretaceous units with an angular unconformity. The RBS provenance data point at the Paleogene Walash-Naopurdan-Kamyaran (WNK) arc-related complex as a source area and show substantial decrease of magmatism by ~ 36 Ma, as reflected by the youngest ages peaks. New detrital zircon provenance data from the hinterland wedge-top units of the proto-Zagros foreland basin (the Tanjero, Kolosh, and Gercus Formations) exhibit exclusive derivation from the Upper Cretaceous Neotethys ophiolitic terranes, different from the provenance of the older Lower Cretaceous and Paleozoic units that are dominated by the Paleozoic and Neoproterozoic age spectra. These shifts in provenance between different tectonostratigraphic units argue for sediment route reversal from E to W in response to ophiolite obduction, arrival of the WNK complex and commencement of the continental collision during the late Eocene, followed by deposition of the RBS in the hinterland of the proto-Zagros fold-thrust belt, and paleodrainage connection with the post-collisional Neogene foreland basin.

scholarly journals Provenance of Paleocene–Eocene red beds from NE Iraq: constraints from framework petrography

2014 ◽  
Vol 151 (6) ◽  
pp. 1034-1050 ◽  
Author(s):  
MUATASAM MAHMOOD HASSAN ◽  
BRIAN G. JONES ◽  
SOLOMON BUCKMAN ◽  
ALI ISMAEL AL-JUBORY ◽  
FAHAD MUBARAK AL GAHTANI
Keyword(s):  
Foreland Basin ◽  
Source Area ◽  
Coarse Grained ◽  
Arabian Plate ◽  
Red Beds ◽  
Northern Iraq ◽  
Rock Fragments ◽  
Clastic Rocks ◽  
The North ◽  
Red Bed

AbstractThe red-bed deposits in northern Iraq are situated in an active foreland basin adjacent to the Zagros Orogenic Belt, bound to the north by the Iranian plate thrust over the edge of the Arabian plate. The red-bed successions are composed of alternating red and brown silty mudstones, purplish red calcareous siltstone, fine- to coarse-grained pebbly sandstone and conglomerate. The red beds in the current study can be divided into four parts showing a trend of upward coarsening with fine-grained deposits at the top. A detailed petrographic study was carried out on the sandstone units. The clastic rocks consist mainly of calcite cemented litharenite with rock fragments (volcanic, metamorphic and sedimentary), quartz and minor feldspar. The petrographic components reflect the tectonic system in the source area, laterally ranging from a mixed orogenic and magmatic arc in Mawat–Chwarta area to recycled orogenic material rich in sedimentary rock fragments in the Qandel area. The Cretaceous–Palaeogene foreland basin of northern Iraq formed to the southwest of the Zagros Suture Zone and the Sanandaj–Sirjan Zone of western Iran. During Palaeogene time deposition of the red beds was caused by renewed shortening in the thrust sheets overlying the Arabian margin with uplift of radiolarites (Qulqula Formation), resulting in an influx of radiolarian debris in addition to continuing ophiolitic detritus. Mixed sources, including metamorphic, volcanic and sedimentary terranes, were present during deposition of the upper part of the red beds.

scholarly journals Geochemical characterisation, volumetric assessment and shale-oil/gas potential of the Middle Jurassic–Lower Cretaceous source rocks of NE Arabian Plate

GeoArabia ◽  
2015 ◽  
Vol 20 (3) ◽  
pp. 99-140
Author(s):  
Adnan A.M. Aqrawi ◽  
Balazs Badics
Keyword(s):  
Lower Cretaceous ◽  
Middle Jurassic ◽  
Foreland Basin ◽  
Black Shales ◽  
Source Rocks ◽  
Arabian Plate ◽  
Shale Oil ◽  
Volumetric Assessment ◽  
System Tracts ◽  
Lower Berriasian

ABSTRACT The Middle Jurassic–Lower Cretaceous strata of the NE Arabian Plate contain several prolific source rocks providing the charge to some of the largest world-class petroleum systems. They are located within the Zagros Fold Belt and Mesopotamian Foreland Basins covering the northern, central and southeastern parts of Iraq, Kuwait and western and southwestern Iran, particularly the Lurestan and Khuzestan provinces. These source rocks include the Bajocian–Bathonian Sargelu, the Callovian–Lower Kimmeridgian Naokelekan and the Upper Tithonian–Lower Berriasian Chia Gara formations of Iraq and their chronostratigraphic equivalents in Kuwait and Iran. They have charged the main Cretaceous and Cenozoic (Tertiary) reservoirs throughout Iraq, Kuwait and Iran with more than 250 billion barrels of proven recoverable hydrocarbons. These formations represent the transgressive system tracts of sequences deposited within deep basinal settings and anoxic environments. They are dominated by black shales and bituminous marly limestones, with high total organic carbon (TOC) contents (ranging from 1–18 wt%), and by marine Type IIS kerogen. Their Rock-Eval S2 yields may reach up to 60 mg HC/g Rock, particularly along the depocentre of the Mesopotamian Foreland Basin. The immature hydrogen index (HI) values might have been up to 700 mg HC/g TOC, whereas the present-day observed values vary depending on the location within the basin and the present-day maturity. The Source-Potential Index (SPI; i.e. mass of hydrocarbons in tons, which could be generated from an area of 1 sq m in case of 100% transformation ratio) averages around 2–3, but can even reach up to 14–16 along the basins’ centres. The Sargelu and the overlying Naokelekan-basinal Najmah formations (and their equivalents) could represent the best potential shale-gas/shale-oil plays in Iraq, Kuwait and Iran, due to their organic richness, favourable maturity and the presence of regional upper and lower seals. The estimated oil-in-place for the potential Sargelu shale-oil play in Iraq only is around 1,300–2,500 billion barrel oil-equivalent (BBOE) and in Kuwait is about 7–150 BBOE.

Neogene shortening and exhumation of the Zagros fold-thrust belt and foreland basin in the Kurdistan region of northern Iraq

2017 ◽  
Vol 694 ◽  
pp. 332-355 ◽  
Author(s):  
Renas I. Koshnaw ◽  
Brian K. Horton ◽  
Daniel F. Stockli ◽  
Douglas E. Barber ◽  
Mazin Y. Tamar-Agha ◽  
...  
Keyword(s):  
Foreland Basin ◽  
Thrust Belt ◽  
Kurdistan Region ◽  
Northern Iraq
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