Petrography and Mineral Chemistry of Kolaka Podiform Chromitites, Mergasur District, Iraqi Kurdistan Region

Nawroz Jawad; Idrees N.  Ahmed

Article Details

Petrography and Mineral Chemistry of Kolaka Podiform Chromitites, Mergasur District, Iraqi Kurdistan Region

Authors:

Nawroz Jawad | Idrees N. Ahmed

Publisher:

Iraqi Geologists Union (Union of Iraqi Geologists)

Journal:

The Iraqi Geological Journal Vol.59 Issue 1A, pp.98-117

Document Type:

Article

Publication Date:

1/2026

Document Language:

English

Document ID (Org No.):

2001836965

pISSN:

2663-8754

Keywords:

Abstract:

 The newly discovered Kolaka chromitite pods hosted by serpentinized peridotite in the Zagros Suture Tectonic Zone of northeastern Iraq are studied petrographically and geochemically. Cr-spinel (magnesiochromite) is the essential mineral in these chromitites with lesser amounts of serpentine, olivine, pyroxene, and a few accessory minerals, and from accessory minerals in serpentinite. These chromitites display massive, disseminated, granular, brecciated, spongy, and pull-apart textures. The host serpentinite shows a mesh texture and retains some olivine and pyroxene grains. The magnesiochromites in chromitite consist of 57.80 wt.% Cr2O3, 14.72 wt.% FeOt, 14.11 wt.% MgO, and 12.00 wt.% Al2O3, minor amounts of TiO2 (0.12 wt.%), MnO (0.21 wt.%), NiO (0.17 wt.%), and trace amounts of ZnO, SiO2, Na2O, K2O, CaO, and V2O3; their average Cr#, Mg#, Al#, and Fe3+# values are 0.76, 0.68, 0.23, and 0.04, respectively. The accessory magnesiochromite in the serpentinized peridotite contains 48.39wt.% Cr2O3, 18.89 wt.% FeOt, 18.95 wt.% Al2O3, and 11.67 wt.% MgO, minor amounts of TiO2 (0.20 wt.%), MnO (0.29 wt.%), ZnO (0.17 wt.%), and trace amounts of SiO2, Na2O, K2O, CaO, V2O3, and NiO; their average Cr#, Mg#, Al#, and Fe3+# values are 0.63, 0.56, 0.36, and 0.03, respectively. Various tectonic discrimination diagrams, in addition to those based on the parental melt compositions of Al2O3, TiO2, and FeOt/MgO, indicate that the Kolaka chromitites are high-Cr, low-Ti, ophiolitic, originated from boninitic magmas within a suprasubduction zone as part of a Fore-arc tectonic setting during the development of the Taurus (Turkey)-Zagros (Iran/Iraq) Ophiolite Belt.

Article Details

Petrography and Mineral Chemistry of Kolaka Podiform Chromitites, Mergasur District, Iraqi Kurdistan Region

Authors:

Nawroz Jawad | Idrees N. Ahmed

Publisher:

Iraqi Geologists Union (Union of Iraqi Geologists)

Journal:

The Iraqi Geological Journal Vol.59 Issue 1A, pp.98-117

Document Type:

Article

Publication Date:

1/2026

Document Language:

English

Document ID (Org No.):

2001836965

pISSN:

2663-8754

Chromitite

Magnesiochromite

Serpentinized peridotite

Fore-arc

Zagros Suture Zone

Iraq

Issues

Article Details

Petrography and Mineral Chemistry of Kolaka Podiform Chromitites, Mergasur District, Iraqi Kurdistan Region

Authors: Nawroz Jawad | Idrees N. Ahmed

Publisher: Iraqi Geologists Union (Union of Iraqi Geologists)

Journal: The Iraqi Geological Journal Vol.59 Issue 1A, pp.98-117

Document Type: Article

Publication Date: 1/2026

Document Language: English

Document ID (Org No.): 2001836965

pISSN: 2663-8754

Chromitite

Magnesiochromite

Serpentinized peridotite

Fore-arc

Zagros Suture Zone

Iraq

Issues

Authors:

Nawroz Jawad | Idrees N. Ahmed

Publisher:

Iraqi Geologists Union (Union of Iraqi Geologists)

Journal:

The Iraqi Geological Journal Vol.59 Issue 1A, pp.98-117

Document Type:

Article

Publication Date:

1/2026

Document Language:

English

Document ID (Org No.):

2001836965

pISSN:

2663-8754