Conference Presentations by Kamal Haji Karim
Contemporary Approaches in Advanced Research , 2023
In the Iraqi Northern Iraq, the Mawat-Chwarta area is well known, for its Ophiolite Complex and i... more In the Iraqi Northern Iraq, the Mawat-Chwarta area is well known, for its Ophiolite Complex and igneous rocks. Tens of studies investigated its petrology, geochemistry and tectonics under the name of Mawat Ophiolite Complex (MOC). According to these studies, MOC is a large part of the oceanic crust which was thrusted hundreds of kilometers as allochthonous sheets and obducted on the passive margin of the Arabian plate during the Late Cretaceous. In the present study, conjugate signals of stratigraphy, structure, rock texture, topography, type of weathering, remote sensing data, boundary condition, fossils hosting, and literature on marl metamorphism, indicated the sedimentary origin of the MOC. These signals confirm the autochthonous nature of MOC and all of its rocks have resulted from the crystallization of two types of sedimentary rocks. The claimed gabbro of the complex (here called Mawat gabbro) is a regional metamorphism of the marl of the Shiranish Formation (hemipelagite of Late Campanian). The second rocks are the claimed peridotite, volcanic rocks and others that resulted from the metamorphism of greywackes and mafic and felsic volcaniclastic arenite of the Walash Formation (Paleocene). The outcrops of the metamorphosed sediments of the latter formation are partially covering the former formation. These results are supported by detailed geologic maps, cross-sections, tectonic models, thin sections and GPS data. These results do not aid the presence of ophiolite and igneous rocks in the Mawat area and introduce significant changes to the geology of the whole Zagros collisional belt.
7th World Multidisciplinary Earth Sciences Symposium (WMESS 2021)
Mawat Ophiolite Complex is located about 36 km to the northeast of Sulaimani city and directly t... more Mawat Ophiolite Complex is located about 36 km to the northeast of Sulaimani city and directly to the east- northeast of Mawat town near the border of Iran in the northeastern Iraq. The complex has about 600-km2 surface area and consists of high mountain terrains that subjected to
intense geological investigations from the fiftieth of previous century till now. According to previous studies, the complex contains tens of igneous rocks such as basalt, metabasalt, tuff, diabase, metadiabase, diorite dykes, periodotite, serpentinite, serpentinite-matrix mélange, gabbro, metagabbro, harzbergite, pyroxenite, plagiogranite, pegmatite, granitiod rocks and dunite. They added occurrences of the volcanic and subvolcanic rocks in the form of dykes or basaltic flows. The present study tries to change the petrology and tectonics of whole complex from Ophiolite Complex
to Metamorphic Core Complex. The revision includes refusal of all the above igneous rocks, instead they considered as medium grade regional metamorphism of different types of volcaniclastic sandstones (volcanic wackes), arenites and greywackes (impure sandstones) which sourced
predominantly from remote volcanic source area inside Iran. The revision depended on several conjugate field and laboratory evidences inside the complex. These evidences such as absence of pillow basalt, volcanic flows, glass shards, volcanic cones, dykes, sills, contact metamorphism, dilatational structures and flow structures. Other evidences are presence of cross beddings, erosional surfaces, lensoidal channel fills, metamorphosed conglomerate, exposures of thousands of laminated planar beds and transition from fresh volcaniclastic sandstones to its medium grade metamorphosed counterparts, which previously considered as igneous rocks of ophiolite types. Another, evidence, in contrast to ophiolite section, the basalt location is at the base of the claimed ophiolite section while plutonic (dunite and peridotite) rocks located at its top. These locations of the two rocks contradict the definition of ophiolites. Accordingly, the present study changed the geological map of the whole Mawat area from igneous outcrops to metamorphosed volcaniclastic sandstones, arenites and greywackes that belong to Walash-Naoperdan Series. The parent rocks of the series transformed to different types of regionally metamorphosed rocks by deep burial during Eocene. During the burial, diageneses and metamorphisms enhanced by complex mixture of
materials from different source areas and seawaters environments. Later, they uplifted, unroofed and exhumed during Pliocene as a core complex
The Zagros Mountain Belt (ZMB) elongates between Arabian and Iranian plate from Turkey to Oman an... more The Zagros Mountain Belt (ZMB) elongates between Arabian and Iranian plate from Turkey to Oman and passes through a part of both Iran and Iraq. The Iraqi part consists of tens of series of anticlines consisting mainly of Tertiary and Cretaceous rocks. The anticlines are mainly trending NW-SE and deeply dissected by v-shaped valleys across the strike of their limbs and plunge areas. The present study focused on roles of the valleys on development of non-tectonic (release) diagonal (hko) joints in a part of the Kurdistan Region, Northeast Iraq. Previously, oil companies and Academicians achieved, in the area, extensive joint analyses and they attributed their origins to tectonic stresses resulting from colliding of Arabian and Iranian plates. Conversely, in the present study, the hko and ac joint sets, as the main joint sets of ZMB, are attributed to non-tectonic and local unloading (release) stresses associated with the development of the valleys. These valleys dissected the anticlines during Quaternary and they developed the associated joints on the surface nearly parallel to the free faces of the valley sides and valley heads, which are approximately coincide with hko joint sets. These sets are similar to fracture (slab) formed parallel to free face during tunnel excavation. The present study analyzed by photos, sketches, stereonets many fields joint sets and their growth depicted parallel to valley sides and heads. Additionally, the analysis includes rare joint sets that are bending parallel to the valley sides (bending in response to free surfaces of the valley sides). For further justification for the non-tectonic hko joint sets, the study compared them with two joints sets formed along the tree barks that formed by growth (thickening, lengthening and desiccation) of the tree trunks. These joints, being surficial, do not coincide with those of deep wells in the same area, therefore, the oil companies do not necessarily depend on surface joint analysis to find porosity in deep oil wells.
WMESS 2021 (7th World Multidisciplinary Earth Sciences Symposium 6th-10th September 2021, 2021
View the article online for updates and enhancements. Content from this work may be used under th... more View the article online for updates and enhancements. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
The 1st International Conference for Natural Resources Research Center
The study focuses on description, analysis and mapping of the thick succession of calciturbidites... more The study focuses on description, analysis and mapping of the thick succession of calciturbidites facies for the first time on the Early Cretaceous Arabian Platform Passive Margin from Western Zagros Fold-Thrust belt, Northeastern Iraq (Kurd-istan Region). Along the margin, the study revealed active source of shedding voluminous calciturbidites sediments to the periplatform and deep basin of Neo-Tethys sea during the Early Cretaceous. Turbidity currents reworked pure coarse and fine detrital carbonates, from the platform, and transported long distance to the basin passing through the slope of the basin. Along this distance, the sediments crossed the marginal slope scoring submarine channels and depositing megabreccias in addition to coarse detrital carbonates (rudstone) before reaching the basin plain. On the plain mostly the fine grain facies of calciturbidites lay down and mixed with pelagic sediments such as radiolarias and calcispheres. The calciturbidite evidence can be tracked for more than 50 km in the studied area from platform to the basin across the slope. These latter facies are occasionally graded, laminated and cross-laminated with deep basin fossil such as planktonic foraminifera, and radiolarians. Stratigraphically, Qamchuqa, as carbonate factory, and Balambo Formations represent the platform and the basin facies, respectively. The periplatform (slope) was northeastward-facing and its toe was the depositional locus of shared lithology between the two aforementioned units. These formations are two Early Cretaceous rocks successions that crop out in Zagros Fold-Thrust Belt and occur in most famous oil fields in Middle East. These calciturbidites are keys for picturing boundary condition of the Passive Arabian Continental (platform) Margin, which is proved to be dynamic, stormy and with contrasted bathymetry (high topography). The study totally changes all characteristics of Balambo Formation from bathyal fine grain deposits to mixture of different carbonate grain of calciturbidite and pelagic origins.
The Mawat and Bulfat Igneous Complexes are two neighboring areas in the extreme northeastern Iraq... more The Mawat and Bulfat Igneous Complexes are two neighboring areas in the extreme northeastern Iraq near the border with Iran. Each complex has about 250 square kilometers in surface area and their stratigraphic and tectonic settings are nearly identical. These settings are established in the seventieth of the last century and since that time no significant changes are introduced till now although tens of the studies achieved on them. Here we introduce dramatic changes in the stratigraphy and tectonics of the two complexes depending on field mapping, eye witness and correlations in addition to applying petrographical, paleontological and boundary conditional studies. The two igneous complexes are changed to metamorphic core complexes by changing the previous ophiolite to metamorphosed greywackes and volcaniclastic sandstones. Additionally the previous three allochthonous sheets are considered to be autochthonous sedimentary stratigraphic units which include non-metamorphosed greywackes and limestone (Walash-Naoperdan Series) metamorphosed greywackes (previous ophiolite sheet) and metamorphosed Naoperdan Series (previous Gimo thrust Sheet). The deposition timing, source areas and their relation with other units of the Paleocene-Eocene are clarified and their boundaries are changed from tectonic to depositional. These attributes are linked with historical development of Sanandij-Sirjan Zone as the main part of Neo-Tethys sedimentary basin. It is concluded also that these sedimentary rocks are buried deeply during Late Eocene and metamorphosed regionally then uplifted as Core Complex during Pliocene bringing up with them self-Cretaceous units such a Shiranish Formation.
Papers by Kamal Haji Karim
Inżynieria Mineralna, Jun 22, 2024
Mağallaẗ Tikrīt li-l-ʻulūm al-ṣirfaẗ, Dec 24, 2023
Advances in science, technology & innovation, Dec 31, 2023
The oil companies worked in Iraq, drew and published
the time-expanded chronostratigraphic colum... more The oil companies worked in Iraq, drew and published
the time-expanded chronostratigraphic column (Wheeler
diagram) of Iraq in the fifties of the last century. During
this long time, the column remained without significant
changes. Therefore, the present study tries to modify and
update the column according to the recent sedimentological
developments and traditional and sequence stratigraphies.
Moreover, the modification is based on more than
50 published papers by the author and more than 20 years
of fieldwork in northern Iraq. The significant updates
include removing previous unconformities between formations,
such as Qamchuqa with Dokan and Bekhme,
Gulneri with Dokan and Kometan, and the latter Formation
with Shiranish Formation. This is true for the
unconformity between Tanjero and Kolosh Formations.
Thus, the article changed the contacts between the above
units to conformable ones, and their boundary is assigned
as gradational in the new chronostratigraphic column. The
column also includes the lateral merging of the Kolosh
Formation and the lower part of the Red Bed Series with
the Walash Formation (Group). The study considers these
three units as deposits of a large foreland basin, and their
sediments derived from a volcanic arc inside Iran during
the Paleocene. On the new column, the ophiolites and
basaltic rocks are assigned as metamorphosed greywackes
(volcaniclastic sandstones) of the Walash Formation. The
column manifests the tectonic setting and location of each
Formation according to the present tectonic zones (Low
and High Folded, Imbricated, Thrust, and Sanandaj-Sirjan
Zones) of Iraq instead of the previous general geographic
positions of the formations. According to fossils and
sedimentary structures, it shows the stratigraphic units in
their proper environmental settings, such as the Cretaceous
Arabian Platform Margin and the coastal areas of
the Zagros Foreland Basin, where the coarse clastic units
rested near the source areas during the Tertiary. Similarly,
it indicated the deep facies (marls and shales) near the
basin plains. The column is associated with models for
showing some of the stratigraphic units in their paleogeographic
and tectonic settings in basins during the latter
two ages. Establishing a new Iraqi time-expanded
stratigraphic column has applications in exploring oil and
other natural resources. It also enables a better understanding
of the stratigraphy and tectonic setting of the
Arabian plate and Zagros collisional belt.
The Piramagroon anticline (or Pira Magrun Mountain) elongates directly to the northwest of Sulaim... more The Piramagroon anticline (or Pira Magrun Mountain) elongates directly to the northwest of Sulaimani city, Northeast Iraq and its southeastern part contains two other anticlines, named Harmetool and Yakhyian anticlines in addition to their complementary synclines and many other smaller folds. The anticline has experienced intense search for oil in the last few years and a well is drilled to a depth of 3000 meters but, any evidence of oil or gas wasn't found. In the present study, the southeastern part has been studied stratigraphically and structurally and the previous studies have been critically reviewed which may help to reason about the absence of oil in the area. In this study the stratigraphy of the anticline has been determined and Kometan, Gulneri, Dokan, Balambo and Sarmord formations have been plotted on a geological map and stratigraphic column and the nannofossils have been used for the aging of intervals with undetermined ages. The thickness of the Gulneri Formation is 2-4 m and by the analysis of nannofossils its age was identified as Late Cenomanian-Early Turonian. Lithology and bedding styles of the Dokan and Upper part of the Balambo formations are very similar to Kometan Formation and they can be determined either by fossils or by using Gulneri Formation as marker bed. The outcrop of the Gulneri Formation is helpful for differentiation since it is soft and can be recognized easily in the field by its darker color. The structure of the anticline is relatively complex as it consists of asymmetrical anticlines with southwest plunge mainly in few places while it changes to overturned fold in others and is deformed by reverse fault. The anticlines are shaped by detachments on the Gulneri and Sarmord formations and by the other older soft rocks. The newly formed anticlines have the style of multi-detachment fold or multi-detachment faulted fold.
Inżynieria Mineralna, 2024
In the Iraqi Zagros, there are ten ophiolites and basaltic bodies, the famous ones are Penjween, ... more In the Iraqi Zagros, there are ten ophiolites and basaltic bodies, the famous ones are Penjween, Mawat, Bulfat and Peshashan Ophiolite complexes in addition to basaltic bodies such as Kata Rash, Avroman, Gercus, Chalki, and Hamrin basaltic bodies. The present study describes more than 12 significant problems concerning the previous assigning of the bodies as igneous rocks. These problems are observable in the field, laboratory, and in most previous works of literature that oppose the magmatic origin of these bodies. Our study explicated all aspects of each problem and clarified how the problems contradict magmatic crystallization and aid the sedimentary origin of these claimed igneous bodies. Finally, the interpretations of all the problems were collected as conjugate pieces of evidence for appraisal of the new origin of all igneous bodies in the Iraqi and Iranian Zagros belt. The outcomes consider the ophiolitic and basaltic rocks metamorphosed volcaniclastic sandstones (greywackes or mafic sandstone). These sandstones belong to fresh or metamorphosed greywackes of stratigraphic units of the Paleocene-Eocene Walash Formation (as distal facies) and Kata Rash Conglomerate (as proximal facies) which were previously considered volcanic rocks. These sediments are sourced originally from Urumeiah-Dokhtur Magmatic Arc (ADMA) and deposited inside Neo-Tethys, present Sanandaji-Sirjan Zone (SSZ), during the Jurassic-Early Cretaceous. Later, the sediments were metamorphosed and uplifted during the Paleocene and deposited inside the Iraqi Zagros belt by turbidity currents inside the Zagros Foreland basin. These ideas are shown in detail by tectonic and paleogeographic models.
Kurdistan Journal of Applied Research (KJAR)
This study unveils new considerations regarding the dolomitization
of the Bekhme and Qamchuqa for... more This study unveils new considerations regarding the dolomitization
of the Bekhme and Qamchuqa formations (BQFs), two reefal Cretaceous units
in the Iraqi Zagros collisional belt. Previous studies proposed the dolomitization
of these formations due to the ascent of Mg-rich hydrothermal solutions
through deep faults but lacked substantial supporting evidence. This paper
present new considerations suggesting that the dolomitization of the BQFs
resulted from the Cretaceous environmental conditions and basin paleogeographic
setting of the platform on which these formations were deposited. To
justify this consideration, seven proofs presented. First is the occurrence of
dolomite as vast layers extending tens of kilometers laterally and bounded
between limestone beds, which resemble a strata-bound occurrence. Second
is the absence of vertical selective dolomitization such as, hydrothermal mineralization,
vertical dolomite dykes, hydrothermal vents, tubes, or zones.
Third is the barrenness of most of the fault surfaces and their surrounding
rocks with selective dolomitization. Fourth is the sharp boundary between the
dolomite and limestone layers, indicating a sudden environmental change
from lagoon to reef or forereef. Fifth is the record of dolomitization in the sediments
reworked by bioturbation, evident in thalassinoides burrows. Sixth is
the succession of BQFs underlain by limestone and green marl devoid of dolomitization
and hydrothermal upward movement. Seventh is the contradictory
notion of hydrothermal dolomitization among the most recent study
published in the Science journal which atributed dolomitization to normal
temperate on earth surface. In the present study, the source of the Mg is argued
and its presence is attributed to the warmth of the Arabian platform
(plate) near the equator during the Cretaceous period. Another source is the
connection of the Arabian platform with the Neo-Tethys Sea, which was the
locus of Mg-rich mafic volcanism in the form of arcs and mid-oceanic ridge
topography, which supplied a voluminous amount of Mg to the Arabian carbonate platform through ocean currents.
The present study focuses on finding the relations between the Walash and
Naopurdan formations in... more The present study focuses on finding the relations between the Walash and
Naopurdan formations in the thrust zone of the Soran area with the Kolosh
and Khurmala Formations in High-Folded Zones of the Shaqlawa area. The
study also tries to indicate the relation of these four units with the Iraqi
ophiolite, volcanic rocks and Gimo sequence in the Soran area. The present
study modeled and reconstructed the tectonic setting and depositional
environment of the above units in a single foreland basin. The present study
changed the Walash and Naopurdan Groups to formations and indicated that
the type sections of the claimed two groups belong to the same succession.
The main difference between the two type sections is the metamorphism of
the type section of Walash Group. same as whereas the Walash Formation
consists of conglomerate, sandstone and siliceous shale south of Soran town.
The Naopurdan Formation consists of two parts, the lower part contains
sparse nummulite and alveolinas while the upper part is mainly comprised of
coralline limestone and the thickness of the two parts are about 100 m thick.
To the north, and northwest the Walash and Naopurdan formations are
metamorphosed regionally which is previously called the ophiolite and Gimo
sequence. We documented that the ophiolite is the regionally
metamorphosed felsic and mafic volcaniclastic sandstone (greywackes) of
the Walash Formation and deposited inside the shelf of the foreland basin.
While the Kolosh Formation is indicated as basinal facies of the Walash
Formation and it represents the fine siliciclastic sediments (shale and
sandstone) that are transported to a deep basin of the foreland basin by a
turbidity current. In the basin, Naopurdan and Khurmala Formations are
deposited as reefal facies on the top of the Walash and Kolosh Formations
during the Early Eocene.
The changing of the ophiolite to metamorphosed Walash Formation is
based on many signals which are finding pervasive laminations, granular
textures, planar bedding surfaces, erosional surfaces, and lensoidal
submarine channels, in the rocks that are previously considered ophiolite in
Soran areas. All the grains of the claimed igneous rocks are angular and
show breakage edges and pitted surfaces which show that the grains are
crystalloclasts and volcanic lithic fragments deposited by water currents.
Other evidence for the absence of ophiolite and igneous rocks in northern
Iraq are the absence of dykes, pillow lava, volcanic flow, contact
metamorphism, sheet -channalized lava flows and mineralization. Another
piece of evidence is the similarity between Kolosh and Walash Formations
in mineralogy, and ages, and both formations consist mainly of fragments of plagioclase, hornblende, and pyroxene with miner olivine. The stratigraphic columns, depositional models and geologic cross section are drawn for the Soran area which are relevant to the Mawat and Chwarta areas.
Iraqi Bulletin of Geology and Mining, 2008
WIT transactions on engineering sciences, Dec 4, 2012
Iraqi Geological Journal
Cenomanian-Turonian (C/T boundary) is globally foci of intense geological study in the most part ... more Cenomanian-Turonian (C/T boundary) is globally foci of intense geological study in the most part of the world due its organic matter content. In Iraq, the representative of the boundary is defined previously as bituminous black shale and named “Gulneri Formation” which is about 2.5 meters thick. In the country, the boundary is controversial both stratigraphically and lithologically; since it is assumed that its top and base are bounded by unconformity and deposited in euxinic and small relic basin. In the present study, the previous studies are critically evaluated and many new results and new fact are documented about the formation through studying of nine sections. The new results include changing of the lithology and boundary condition (rejecting of underlying and overlying previously indicated unconformities). The lithology has amended to marl and marly limestone and the depositional basin is changed to large open basin in which Balambo and Kometan formations are deposited. Addi...
Journal of Sedimentary Environments, Jan 14, 2023
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Conference Presentations by Kamal Haji Karim
intense geological investigations from the fiftieth of previous century till now. According to previous studies, the complex contains tens of igneous rocks such as basalt, metabasalt, tuff, diabase, metadiabase, diorite dykes, periodotite, serpentinite, serpentinite-matrix mélange, gabbro, metagabbro, harzbergite, pyroxenite, plagiogranite, pegmatite, granitiod rocks and dunite. They added occurrences of the volcanic and subvolcanic rocks in the form of dykes or basaltic flows. The present study tries to change the petrology and tectonics of whole complex from Ophiolite Complex
to Metamorphic Core Complex. The revision includes refusal of all the above igneous rocks, instead they considered as medium grade regional metamorphism of different types of volcaniclastic sandstones (volcanic wackes), arenites and greywackes (impure sandstones) which sourced
predominantly from remote volcanic source area inside Iran. The revision depended on several conjugate field and laboratory evidences inside the complex. These evidences such as absence of pillow basalt, volcanic flows, glass shards, volcanic cones, dykes, sills, contact metamorphism, dilatational structures and flow structures. Other evidences are presence of cross beddings, erosional surfaces, lensoidal channel fills, metamorphosed conglomerate, exposures of thousands of laminated planar beds and transition from fresh volcaniclastic sandstones to its medium grade metamorphosed counterparts, which previously considered as igneous rocks of ophiolite types. Another, evidence, in contrast to ophiolite section, the basalt location is at the base of the claimed ophiolite section while plutonic (dunite and peridotite) rocks located at its top. These locations of the two rocks contradict the definition of ophiolites. Accordingly, the present study changed the geological map of the whole Mawat area from igneous outcrops to metamorphosed volcaniclastic sandstones, arenites and greywackes that belong to Walash-Naoperdan Series. The parent rocks of the series transformed to different types of regionally metamorphosed rocks by deep burial during Eocene. During the burial, diageneses and metamorphisms enhanced by complex mixture of
materials from different source areas and seawaters environments. Later, they uplifted, unroofed and exhumed during Pliocene as a core complex
Papers by Kamal Haji Karim
the time-expanded chronostratigraphic column (Wheeler
diagram) of Iraq in the fifties of the last century. During
this long time, the column remained without significant
changes. Therefore, the present study tries to modify and
update the column according to the recent sedimentological
developments and traditional and sequence stratigraphies.
Moreover, the modification is based on more than
50 published papers by the author and more than 20 years
of fieldwork in northern Iraq. The significant updates
include removing previous unconformities between formations,
such as Qamchuqa with Dokan and Bekhme,
Gulneri with Dokan and Kometan, and the latter Formation
with Shiranish Formation. This is true for the
unconformity between Tanjero and Kolosh Formations.
Thus, the article changed the contacts between the above
units to conformable ones, and their boundary is assigned
as gradational in the new chronostratigraphic column. The
column also includes the lateral merging of the Kolosh
Formation and the lower part of the Red Bed Series with
the Walash Formation (Group). The study considers these
three units as deposits of a large foreland basin, and their
sediments derived from a volcanic arc inside Iran during
the Paleocene. On the new column, the ophiolites and
basaltic rocks are assigned as metamorphosed greywackes
(volcaniclastic sandstones) of the Walash Formation. The
column manifests the tectonic setting and location of each
Formation according to the present tectonic zones (Low
and High Folded, Imbricated, Thrust, and Sanandaj-Sirjan
Zones) of Iraq instead of the previous general geographic
positions of the formations. According to fossils and
sedimentary structures, it shows the stratigraphic units in
their proper environmental settings, such as the Cretaceous
Arabian Platform Margin and the coastal areas of
the Zagros Foreland Basin, where the coarse clastic units
rested near the source areas during the Tertiary. Similarly,
it indicated the deep facies (marls and shales) near the
basin plains. The column is associated with models for
showing some of the stratigraphic units in their paleogeographic
and tectonic settings in basins during the latter
two ages. Establishing a new Iraqi time-expanded
stratigraphic column has applications in exploring oil and
other natural resources. It also enables a better understanding
of the stratigraphy and tectonic setting of the
Arabian plate and Zagros collisional belt.
of the Bekhme and Qamchuqa formations (BQFs), two reefal Cretaceous units
in the Iraqi Zagros collisional belt. Previous studies proposed the dolomitization
of these formations due to the ascent of Mg-rich hydrothermal solutions
through deep faults but lacked substantial supporting evidence. This paper
present new considerations suggesting that the dolomitization of the BQFs
resulted from the Cretaceous environmental conditions and basin paleogeographic
setting of the platform on which these formations were deposited. To
justify this consideration, seven proofs presented. First is the occurrence of
dolomite as vast layers extending tens of kilometers laterally and bounded
between limestone beds, which resemble a strata-bound occurrence. Second
is the absence of vertical selective dolomitization such as, hydrothermal mineralization,
vertical dolomite dykes, hydrothermal vents, tubes, or zones.
Third is the barrenness of most of the fault surfaces and their surrounding
rocks with selective dolomitization. Fourth is the sharp boundary between the
dolomite and limestone layers, indicating a sudden environmental change
from lagoon to reef or forereef. Fifth is the record of dolomitization in the sediments
reworked by bioturbation, evident in thalassinoides burrows. Sixth is
the succession of BQFs underlain by limestone and green marl devoid of dolomitization
and hydrothermal upward movement. Seventh is the contradictory
notion of hydrothermal dolomitization among the most recent study
published in the Science journal which atributed dolomitization to normal
temperate on earth surface. In the present study, the source of the Mg is argued
and its presence is attributed to the warmth of the Arabian platform
(plate) near the equator during the Cretaceous period. Another source is the
connection of the Arabian platform with the Neo-Tethys Sea, which was the
locus of Mg-rich mafic volcanism in the form of arcs and mid-oceanic ridge
topography, which supplied a voluminous amount of Mg to the Arabian carbonate platform through ocean currents.
Naopurdan formations in the thrust zone of the Soran area with the Kolosh
and Khurmala Formations in High-Folded Zones of the Shaqlawa area. The
study also tries to indicate the relation of these four units with the Iraqi
ophiolite, volcanic rocks and Gimo sequence in the Soran area. The present
study modeled and reconstructed the tectonic setting and depositional
environment of the above units in a single foreland basin. The present study
changed the Walash and Naopurdan Groups to formations and indicated that
the type sections of the claimed two groups belong to the same succession.
The main difference between the two type sections is the metamorphism of
the type section of Walash Group. same as whereas the Walash Formation
consists of conglomerate, sandstone and siliceous shale south of Soran town.
The Naopurdan Formation consists of two parts, the lower part contains
sparse nummulite and alveolinas while the upper part is mainly comprised of
coralline limestone and the thickness of the two parts are about 100 m thick.
To the north, and northwest the Walash and Naopurdan formations are
metamorphosed regionally which is previously called the ophiolite and Gimo
sequence. We documented that the ophiolite is the regionally
metamorphosed felsic and mafic volcaniclastic sandstone (greywackes) of
the Walash Formation and deposited inside the shelf of the foreland basin.
While the Kolosh Formation is indicated as basinal facies of the Walash
Formation and it represents the fine siliciclastic sediments (shale and
sandstone) that are transported to a deep basin of the foreland basin by a
turbidity current. In the basin, Naopurdan and Khurmala Formations are
deposited as reefal facies on the top of the Walash and Kolosh Formations
during the Early Eocene.
The changing of the ophiolite to metamorphosed Walash Formation is
based on many signals which are finding pervasive laminations, granular
textures, planar bedding surfaces, erosional surfaces, and lensoidal
submarine channels, in the rocks that are previously considered ophiolite in
Soran areas. All the grains of the claimed igneous rocks are angular and
show breakage edges and pitted surfaces which show that the grains are
crystalloclasts and volcanic lithic fragments deposited by water currents.
Other evidence for the absence of ophiolite and igneous rocks in northern
Iraq are the absence of dykes, pillow lava, volcanic flow, contact
metamorphism, sheet -channalized lava flows and mineralization. Another
piece of evidence is the similarity between Kolosh and Walash Formations
in mineralogy, and ages, and both formations consist mainly of fragments of plagioclase, hornblende, and pyroxene with miner olivine. The stratigraphic columns, depositional models and geologic cross section are drawn for the Soran area which are relevant to the Mawat and Chwarta areas.
intense geological investigations from the fiftieth of previous century till now. According to previous studies, the complex contains tens of igneous rocks such as basalt, metabasalt, tuff, diabase, metadiabase, diorite dykes, periodotite, serpentinite, serpentinite-matrix mélange, gabbro, metagabbro, harzbergite, pyroxenite, plagiogranite, pegmatite, granitiod rocks and dunite. They added occurrences of the volcanic and subvolcanic rocks in the form of dykes or basaltic flows. The present study tries to change the petrology and tectonics of whole complex from Ophiolite Complex
to Metamorphic Core Complex. The revision includes refusal of all the above igneous rocks, instead they considered as medium grade regional metamorphism of different types of volcaniclastic sandstones (volcanic wackes), arenites and greywackes (impure sandstones) which sourced
predominantly from remote volcanic source area inside Iran. The revision depended on several conjugate field and laboratory evidences inside the complex. These evidences such as absence of pillow basalt, volcanic flows, glass shards, volcanic cones, dykes, sills, contact metamorphism, dilatational structures and flow structures. Other evidences are presence of cross beddings, erosional surfaces, lensoidal channel fills, metamorphosed conglomerate, exposures of thousands of laminated planar beds and transition from fresh volcaniclastic sandstones to its medium grade metamorphosed counterparts, which previously considered as igneous rocks of ophiolite types. Another, evidence, in contrast to ophiolite section, the basalt location is at the base of the claimed ophiolite section while plutonic (dunite and peridotite) rocks located at its top. These locations of the two rocks contradict the definition of ophiolites. Accordingly, the present study changed the geological map of the whole Mawat area from igneous outcrops to metamorphosed volcaniclastic sandstones, arenites and greywackes that belong to Walash-Naoperdan Series. The parent rocks of the series transformed to different types of regionally metamorphosed rocks by deep burial during Eocene. During the burial, diageneses and metamorphisms enhanced by complex mixture of
materials from different source areas and seawaters environments. Later, they uplifted, unroofed and exhumed during Pliocene as a core complex
the time-expanded chronostratigraphic column (Wheeler
diagram) of Iraq in the fifties of the last century. During
this long time, the column remained without significant
changes. Therefore, the present study tries to modify and
update the column according to the recent sedimentological
developments and traditional and sequence stratigraphies.
Moreover, the modification is based on more than
50 published papers by the author and more than 20 years
of fieldwork in northern Iraq. The significant updates
include removing previous unconformities between formations,
such as Qamchuqa with Dokan and Bekhme,
Gulneri with Dokan and Kometan, and the latter Formation
with Shiranish Formation. This is true for the
unconformity between Tanjero and Kolosh Formations.
Thus, the article changed the contacts between the above
units to conformable ones, and their boundary is assigned
as gradational in the new chronostratigraphic column. The
column also includes the lateral merging of the Kolosh
Formation and the lower part of the Red Bed Series with
the Walash Formation (Group). The study considers these
three units as deposits of a large foreland basin, and their
sediments derived from a volcanic arc inside Iran during
the Paleocene. On the new column, the ophiolites and
basaltic rocks are assigned as metamorphosed greywackes
(volcaniclastic sandstones) of the Walash Formation. The
column manifests the tectonic setting and location of each
Formation according to the present tectonic zones (Low
and High Folded, Imbricated, Thrust, and Sanandaj-Sirjan
Zones) of Iraq instead of the previous general geographic
positions of the formations. According to fossils and
sedimentary structures, it shows the stratigraphic units in
their proper environmental settings, such as the Cretaceous
Arabian Platform Margin and the coastal areas of
the Zagros Foreland Basin, where the coarse clastic units
rested near the source areas during the Tertiary. Similarly,
it indicated the deep facies (marls and shales) near the
basin plains. The column is associated with models for
showing some of the stratigraphic units in their paleogeographic
and tectonic settings in basins during the latter
two ages. Establishing a new Iraqi time-expanded
stratigraphic column has applications in exploring oil and
other natural resources. It also enables a better understanding
of the stratigraphy and tectonic setting of the
Arabian plate and Zagros collisional belt.
of the Bekhme and Qamchuqa formations (BQFs), two reefal Cretaceous units
in the Iraqi Zagros collisional belt. Previous studies proposed the dolomitization
of these formations due to the ascent of Mg-rich hydrothermal solutions
through deep faults but lacked substantial supporting evidence. This paper
present new considerations suggesting that the dolomitization of the BQFs
resulted from the Cretaceous environmental conditions and basin paleogeographic
setting of the platform on which these formations were deposited. To
justify this consideration, seven proofs presented. First is the occurrence of
dolomite as vast layers extending tens of kilometers laterally and bounded
between limestone beds, which resemble a strata-bound occurrence. Second
is the absence of vertical selective dolomitization such as, hydrothermal mineralization,
vertical dolomite dykes, hydrothermal vents, tubes, or zones.
Third is the barrenness of most of the fault surfaces and their surrounding
rocks with selective dolomitization. Fourth is the sharp boundary between the
dolomite and limestone layers, indicating a sudden environmental change
from lagoon to reef or forereef. Fifth is the record of dolomitization in the sediments
reworked by bioturbation, evident in thalassinoides burrows. Sixth is
the succession of BQFs underlain by limestone and green marl devoid of dolomitization
and hydrothermal upward movement. Seventh is the contradictory
notion of hydrothermal dolomitization among the most recent study
published in the Science journal which atributed dolomitization to normal
temperate on earth surface. In the present study, the source of the Mg is argued
and its presence is attributed to the warmth of the Arabian platform
(plate) near the equator during the Cretaceous period. Another source is the
connection of the Arabian platform with the Neo-Tethys Sea, which was the
locus of Mg-rich mafic volcanism in the form of arcs and mid-oceanic ridge
topography, which supplied a voluminous amount of Mg to the Arabian carbonate platform through ocean currents.
Naopurdan formations in the thrust zone of the Soran area with the Kolosh
and Khurmala Formations in High-Folded Zones of the Shaqlawa area. The
study also tries to indicate the relation of these four units with the Iraqi
ophiolite, volcanic rocks and Gimo sequence in the Soran area. The present
study modeled and reconstructed the tectonic setting and depositional
environment of the above units in a single foreland basin. The present study
changed the Walash and Naopurdan Groups to formations and indicated that
the type sections of the claimed two groups belong to the same succession.
The main difference between the two type sections is the metamorphism of
the type section of Walash Group. same as whereas the Walash Formation
consists of conglomerate, sandstone and siliceous shale south of Soran town.
The Naopurdan Formation consists of two parts, the lower part contains
sparse nummulite and alveolinas while the upper part is mainly comprised of
coralline limestone and the thickness of the two parts are about 100 m thick.
To the north, and northwest the Walash and Naopurdan formations are
metamorphosed regionally which is previously called the ophiolite and Gimo
sequence. We documented that the ophiolite is the regionally
metamorphosed felsic and mafic volcaniclastic sandstone (greywackes) of
the Walash Formation and deposited inside the shelf of the foreland basin.
While the Kolosh Formation is indicated as basinal facies of the Walash
Formation and it represents the fine siliciclastic sediments (shale and
sandstone) that are transported to a deep basin of the foreland basin by a
turbidity current. In the basin, Naopurdan and Khurmala Formations are
deposited as reefal facies on the top of the Walash and Kolosh Formations
during the Early Eocene.
The changing of the ophiolite to metamorphosed Walash Formation is
based on many signals which are finding pervasive laminations, granular
textures, planar bedding surfaces, erosional surfaces, and lensoidal
submarine channels, in the rocks that are previously considered ophiolite in
Soran areas. All the grains of the claimed igneous rocks are angular and
show breakage edges and pitted surfaces which show that the grains are
crystalloclasts and volcanic lithic fragments deposited by water currents.
Other evidence for the absence of ophiolite and igneous rocks in northern
Iraq are the absence of dykes, pillow lava, volcanic flow, contact
metamorphism, sheet -channalized lava flows and mineralization. Another
piece of evidence is the similarity between Kolosh and Walash Formations
in mineralogy, and ages, and both formations consist mainly of fragments of plagioclase, hornblende, and pyroxene with miner olivine. The stratigraphic columns, depositional models and geologic cross section are drawn for the Soran area which are relevant to the Mawat and Chwarta areas.