Petrogenesis of Syenitic Magmatism in the Neo-Tethyan Zagros Suture Zone, Bulfat Complex, Kurdistan Region of NE Iraq: Insights into Tectonic Setting and Crustal Contamination

Quartz syenite and nepheline syenite occur as massive bodies and dikes within the Bulfat complex in the Zagros Suture Zone, located in the Kurdistan region of northeastern Iraq, within the Penjween-Walash Subzone. This study examines the petrogenesis, geochemistry, and tectonic implications of these rocks. Petrographic analysis identified two intrusions: quartz syenite, which is silica-saturated, dominated by alkali feldspar, plagioclase, quartz, and garnet, with inequigranular, porphyritic, poikilitic, myrmekitic, and perthitic intergrowth textures. Nepheline syenite is silica-undersaturated, containing a significant amount of feldspar and feldspathoid, and mafic minerals such as amphibole, biotite, and aegirine-augite. It displays holocrystalline, inequigranular, poikilitic, and perthitic intergrowth textures, with alterations including cancrinite pseudomorphs, albitization, and sericitization. Whole-rock geochemistry classifies both as alkaline, characterized by higher SiO2 content in quartz syenite (64.2 to 68 wt.%) compared to nepheline syenite (57 to 59.3 wt.%), and elevated alkalis. Both show enrichment in Light Rare Earth Elements relative to Heavy Rare Earth Elements, but quartz syenite has a higher total ∑REE =106.6–383 ppm than nepheline syenite, 7.7–145.3 ppm. Negative Eu anomalies indicate plagioclase fractionation and limit crustal contamination, while two nepheline syenite samples show positive Eu anomalies, indicating plagioclase accumulation. High Rb/Sr ratios suggest that the crust was contaminated from pelitic and psammitic sources. Tectonic discriminant diagrams reveal a volcanic arc field, characterized by enrichment in large ion lithophile elements, reflecting mantle-derived magmas modified by subduction during the closure of the Neo-Tethys. The elevated Zr/Y ratio further supports a continental arc setting, reflecting partial melting and magmatic differentiation. This study highlights the roles of magmatic fractionation, crustal assimilation, and subduction-related processes in the formation of nepheline syenite and quartz syenite.

• Publication year

  2026

• Venue

  Iraqi Geological Journal

• Publication date

  2026-01-31

• Fields of study

  Not labeled

• Identifiers
  DOI 10.46717/igj.2026.59.1a.6
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar

• No claims are published for this paper.

• No concepts are published for this paper.

• Late Cretaceous-Paleocene Arc and Back-Arc System in the Neotethys Ocean, Zagros Suture Zone

  2023cited by this paper
• Mineralogy and geochemistry of nepheline syenite from the Bang Phuc massif of the alkaline Cho Don complex in north-eastern Vietnam – implications for magma evolution and fluid-rock interactions

  2023cited by this paper
• Petrogenesis and tectonic setting of Shakha Rash granitoid, Bulfat intrusive complex, northeastern Iraq

  2022cited by this paper
• The early Eocene (48 Ma) Qaladeza trondhjemite formed by wet partial remelting of mafic crust in the arc-related Bulfat Igneous Complex (Kurdistan, Iraq): constraints on the timing of Neotethys closure

  2022cited by this paper
• Remote sensing techniques and geochemical constraints on the formation of the Wadi El-Hima mineralized granites, Egypt: new insights into the genesis and accumulation of garnets

  2022cited by this paper
• The composition of garnet in granite and pegmatite from the Gangdese orogen in southeastern Tibet: Constraints on pegmatite petrogenesis

  2021cited by this paper
• Assessment of magmatic versus post-magmatic processes in the Mueilha rare-metal granite, Eastern Desert of Egypt, Arabian-Nubian Shield

  2020cited by this paper
• Petrogenesis of scapolite-rich gabbro from the alkaline Cho Don complex in north-eastern Vietnam - mineralogical and geochemical implications

  2020cited by this paper
• Origin and Petrogenetic Implications of Spessartine Garnet in Highly‐Fractionated Granite from the Central Eastern Desert of Egypt

  2020cited by this paper
• U–Pb geochronology and Hf isotope data from the Late Cretaceous Mawat ophiolite, NE Iraq

  2019cited by this paper
• LA-ICP-MS trace element geochemistry of garnets: Constraints on hydrothermal fluid evolution and genesis of the Xinqiao Cu–S–Fe–Au deposit, eastern China

  2017cited by this paper
• 39 Ma U-Pb zircon age for the Shaki-Rash gabbro in the Bulfat igneous complex, Kurdistan region, Iraqi Zagros Suture zone: rifting of an Intra-Neotethys Cenozoic arc

  2017influential reference
• Highly fractionated granites: Recognition and research

  2017cited by this paper
• Mineralogy and Origin of Exsolution in Ti-rich Magnetite from Different Magmatic Fe-ti Oxide-bearing Intrusions

  2016cited by this paper
• Tectono-stratigraphy and general structure of the northwestern Zagros collision zone across the Iraq-Iran border

  2014cited by this paper
• Evidence for Paleocene-Eocene evolution of the foot of the Eurasian margin (Kermanshah ophiolite, SW Iran) from back-arc to arc: Implications for regional geodynamics and obduction

  2013cited by this paper
• Pre-collisional Intrusive Magmatism in the Bulfat Complex, Wadi Rashid, Qala Deza, NE Iraq: Geochemical and Mineralogical Constraints and Implications for Tectonic Evolution of Granitoid-gabbro Suites

  2013cited by this paper
• The tectonic evolution of a Neo‐Tethyan (Eocene–Oligocene) island‐arc (Walash and Naopurdan groups) in the Kurdistan region of the Northeast Iraqi Zagros Suture Zone

  2013cited by this paper
• Principles Of Igneous And Metamorphic Petrology 2nd Edition

  2013cited by this paper
• Tectonostratigraphic overview of the Zagros Suture Zone, Kurdistan Region, Northeast Iraq

  2012influential reference
• Cr-spinel compositions in serpentinites and their implications for the petrotectonic history of the Zagros Suture Zone, Kurdistan Region, Iraq

  2011cited by this paper
• A Geochemical Classification for Feldspathic Igneous Rocks

  2008cited by this paper
• Garnet-bearing rhyolite from Deh-Salm area, Lut block, Eastern Iran: anatexis of deep crustal rocks

  2008cited by this paper
• Internally consistent solution models for Fe-Mg-Mn-Ti oxides: Fe-Ti oxides

  2007cited by this paper
• Magmatic evolution of the Peñón Rosado granite: Petrogenesis of garnet-bearing granitoids

  2007cited by this paper
• Calcite twinning constraints on late Neogene stress patterns and deformation mechanisms in the active Zagros collision belt

  2007cited by this paper
• Deciphering the source and contamination history of peraluminous magmas using δ18O of accessory minerals: examples from garnet-bearing plutons of the Sierra Nevada batholith

  2006cited by this paper
• Petrogenesis of Cogenetic Nepheline and Quartz Syenites and Granites (Northern Damara Orogen, Namibia): Enriched Mantle versus Crustal Contamination

  2005cited by this paper
• The Ti-saturation surface for low-to-medium pressure metapelitic biotites: Implications for geothermometry and Ti-substitution mechanisms

  2005influential reference
• The Sodalite Family – A Simple but Versatile Framework Structure

  2005cited by this paper
• Convergence history across Zagros (Iran): constraints from collisional and earlier deformation

  2005influential reference
• Regional stratigraphy of the Zagros fold-thrust belt of Iran and its proforeland evolution

  2004cited by this paper
• Seismological constraints on the crustal structure beneath the Zagros Mountain belt (Iran)

  2003cited by this paper
• COMPOSITION OF BIOTITE FROM GRANITIC ROCKS OF THE CANADIAN APPALACHIAN OROGEN: A POTENTIAL TECTONOMAGMATIC INDICATOR?

  2003cited by this paper
• Cretaceous–Tertiary convergence and continental collision, Sanandaj–Sirjan Zone, western Iran

  2003cited by this paper
• A Geochemical Classification for Granitic Rocks

  2001influential reference
• THE SIGNIFICANCE OF STRIKE‐SLIP FAULTING IN THE BASEMENT OF THE ZAGROS FOLD AND THRUST BELT

  2001cited by this paper
• Application of new experimental and garnet Margules data to the garnet-biotite geothermometer

  2000cited by this paper
• Post-collisional strongly peraluminous granites

  1998influential reference
• Nomenclature of the Micas

  1998cited by this paper
• Report. Nomenclature of Amphiboles: Report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on New Minerals and Mineral Names

  1997cited by this paper
• TECTONICS OF THE ZAGROS OROGENIC BELT OF IRAN - NEW DATA AND INTERPRETATIONS

  1994cited by this paper
• Using Geochemical Data: Evaluation, Presentation, Interpretation

  1994influential reference
• Formation of cogenetic quartz and nepheline syenites

  1993cited by this paper
• Geochemical discrimination between shoshonitic and potassic volcanic rocks in different tectonic settings: A pilot study

  1992cited by this paper
• Non-ideal mixing in the phlogopite-annite binary: constraints from experimental data on Mg−Fe partitioning and a reformulation of the biotite-garnet geothermometer

  1992cited by this paper
• Garnet compositions and their use as indicators of peraluminous granitoid petrogenesis — southeastern Arabian Shield

  1988cited by this paper
• Crustal contributions to arc magmatism in the Andes of Central Chile

  1988cited by this paper
• Nomenclature of Pyroxenes

  1988cited by this paper
• Metasomatic origin of spessartine-rich garnet in the South Mountain Batholith, Nova Scotia

  1988cited by this paper
• A-type granites: geochemical characteristics, discrimination and petrogenesis

  1987cited by this paper
• The Cameroon line, West Africa: a comparison between oceanic and continental alkaline volcanism

  1987cited by this paper
• Geochemical characteristics of collision-zone magmatism

  1986cited by this paper
• Error estimation and empirical geothermobarometry for pelitic systems.

  1985influential reference
• Role of the sub-continental lithosphere in magma genesis at active continental margins

  1983influential reference
• The mineralogy of peraluminous granites; a review

  1981cited by this paper
• The Role of Manganese in the Paragenesis of Magmatic Garnet: An Example from the Old Woman-Piute Range, California

  1981cited by this paper
• The interpretation of igneous rocks

  1979influential reference
• Geochemistry of eocene calc-alkaline volcanic rocks from the Kastamonu area, Northern Turkey

  1976cited by this paper
• A Guide to the Chemical Classification of the Common Volcanic Rocks

  1971cited by this paper
• The sodalite group of minerals

  1967cited by this paper
• An Introduction to the Rock-Forming Minerals

  1966cited by this paper
• Composition of the Earth

  1966influential reference

• No citing papers are available for this paper.