IRAQI BULLETIN OF GEOLOGY AND MINING
مجلة الجيولوجيا والتعدين العراقية
ISSN 1811 - 4539
اهداف ومجال النشر تعليمات النشر للمؤلفات البحوث المنشورة هيئة التحرير
BIOSTRATIGRAPHY OF THE Cretaceous/ PALEOGENE boundary in DOKAN AREA, SuLAIMANIYAH, Kurdistan region, NE Iraq
Khalid M. Sharbazheri, Imad M. Ghafor and Qahtan A. Muhammed
Received: 05/ 12/ 2010, Accepted: 04/ 05/ 2011
Key words: Biostratigraphy, Cretaceous/ Paleogene boundary, Sulaimaniyah, Kurdistan Region, Iraq
(p. 1 – 24)
ABSTRACT
The studied area is located within the High Folded Zone in Dokan area, northeastern Iraq. The Cretaceous/ Paleogene boundary consists of flysch clastic beds of Tanjero and Kolosh formations, interbedded with marl. The study is achieved on the outcrops of the uppermost part of the Late Cretaceous successions (upper part of Tanjero Formation) and the Early Paleogene (lowermost part of Kolosh Formation). Based on identified planktonic foraminiferal assemblages, five biozones were recorded from the upper part of the Tanjero Formation, these zones are from bottom to top: Pseudotextularia intermedia Interval Zone (CF5), Racemiguembelina fructicosa Interval Zone (CF4), Pseudoguembelina hariaensis Interval Zone (CF3), Pseudoguembelina palpebra Interval Zone (CF2), Plummerita hantkeninoides Total Range Zone (CF1) and two biozones were recorded from the lower part of Kolosh Formation, which are: (P1a) Parvularugoglobigerina eugubina – Subbotina triloculinoides Interval Zone and (P1b) Subbotina triloculinoides – Globanomalina compressa/ Praemurica inconstans Interval Zone.
The result of the present study (in contrast to previous studies) shows that the Early Danian is found for the first time in the sediments of the Kolosh Formation. It is possible that the other two zones: P0 (Guembelitria cretacea Zone), and Pα (Parvularugoglobigerina eugubina Zone) were not recorded completely or continuously in the studied area. The biostratigraphic correlations; based on planktonic foraminiferal zonations showed a comparison between the biostratigraphic zones, which were established in this study with other equivalents of the commonly used planktonic zonal scheme around the Cretaceous/ Paleogene boundary, in and outside Iraq.
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MICROFACIES AND BIOSTRATIGRAPHY OF BABA FORMATION (LATE OLIGOCENE) IN BAI HASSAN, OIL WELL-25, KIRKUK AREA, CENTRAL NORTH IRAQ
Imad M. Ghafor
Received: 15/ 08/ 2010, Accepted: 16/ 06/ 2011
Key words: Larger Foraminifera, Baba Formation, Late Oligocene, Chattian, Kirkuk, Iraq
(p. 25 – 32)
ABSTRACT
Larger Foraminifera in the Baba Formation (Middle Oligocene) are discussed. The investigation is based on a well sequence of limestone in Bai Hassan oil well -25, Kirkuk area central northern part of Iraq. Baba Formation is subdivided into three microfacies, which are: Fine to very coarse larger Foraminifera packstone, Fine bioclastic smaller Foraminiferal packstone and Fine bioclastic smaller Foraminiferal wackestone. The depositional environment of Oligocene Carbonate may be a part of an attached platform area, where more or less open marine prevailed through out.
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Interpretation OF NEW FACIES IN THE PILA SPI FORMATION (MIDDLE – LATE EOCENE), IN SULAIMANIYAH, NE IRAQ
Polla A. Khanaqa
Received: 15/ 09/ 2010, Accepted: 30/ 01/ 2011
Key words: Eocene, Pila Spi Fn., Avanah Fn., Sagrma Mountain, Limestone, Ramp, Coral, Bryozoa
(p. 33 – 45)
ABSTRACT
The Pila Spi Formation (Middle – Late Eocene) was previously assigned as lagoonal crystallized limestone and poorly fossiliferous, including gastropods, miliolids and algae. Conversely, during fieldwork new facies and lithologies were observed in outcrop sections. These sections contain intervals (10 – 40 m thick) that are characterized by massiveness and high fossils content; such as: algae, corals and bryozoans and their bioclasts. These constituents can be identified only in polished slab, while in thin section they are hardly identifiable due to diagenetic processes. These constituents form several facies such as: floatstone, bindstone, framestone, bafflestone and rudstone.
The discovery of these facies revealed new environmental and paleogeographic setting for the Middle – Late Eocene in the northeastern part of Iraq. The depositional environment is a carbonate ramp with low topographic patchy reef, back reef and lagoon. The evidences for ramp are gradual changes of the facies and absence of high energy facies. The new facies of the Pila Spi Formation and Avanah Formation are deposited on back reef and reef environments, respectively. The ramp is bordered from south and southwest by open marine basin where Jaddala Formation was deposited, while it is limited from the north by paleohigh, which separates the ramp from Walash – Naopurdan Group.
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GENESIS AND AGE ESTIMATION OF THE THARTHAR DEPRESSION, CENTRAL WEST IRAQ
Varoujan K. Sissakian
Received: 22/ 03/ 2011, Accepted: 28/ 07/ 2011
Key words: Tharthar Depression, Doline, Karstification, Graben, Iraq
(p. 47 – 62)
ABSTRACT
Tharthar Depression is one of the largest closed depressions in Iraq; it is located in the central western part of Iraq, between the Jazira and Mesopotamia Plains, west of the Tigris River. It covers about 2050 Km2, oriented almost N – S, then changes to N35° W – S35° E, with a bowl shape, the base being in the south. The exposed rocks in the near surroundings of the depression belong to Fatha and Injana formations, with Al-Fatha Alluvial Fan sediments in its eastern bank. Tectonically, it is located in the Mesopotamia Foredeep of the Unstable Shelf, forming the contact between the Jazira and Mesopotamia Plains. Geomorphologically, it is a large depression with a floor of – 3 m, above the sea level. The maximum length and width of the depression are 120 and 48 Km, respectively. The eastern rim of the depression is higher than the western one; the heights of both rims are 90 and 75 m, respectively.
The Tharthar Depression since 1956 is changed to an artificial reservoir to collect the over flooded water of the Tigris River, during flood seasons, therefore was called Tharthar Lake. The Tigris and Euphrates Rivers, however, link the reservoir, by means of artificial canals. The inlet canal, however, is from the Tigris River, regulated by Samarra Dam, which controls the divergent excess water from the Tigris River, by means of the inlet canal.
The genesis of the Tharthar Depression is a matter of debit, since 1959, many ideas explain the origin of the depression. The aim of this study is to deduce the origin of the depression. This study proves that the depression is of multi genesis, closed depression formed mainly by karstification, due to dissolving of gypsum rocks of the Fatha Formation. The measured parameters, depth/ width ratio, length/ width ratio and width at top/ width at bottom ratio range from 0.017 to 0.125, 27.6 to 300, and 2 to 4.5, respectively. Such ratios assume either collapse or solution doline, of multi origin. The age of the Tharthar Depression is most probably Holocene.
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HYDROGEOCHEMISTRY AND GEOMICROBIOLOGY OF DARZILA SPRING IN SANGAW, SULAIMANIYAH, NE IRAQ
Polla A. Khanaqa and Diary A. Al-Manmi
Received: 22/ 03/ 2011, Accepted: 06/ 10/ 2011
Key words: Sulphide spring, Geomicrobiology, Hypogenic cave, Karst
(p. 63 – 79)
ABSTRACT
Darzila is a hypogenic cave located in Sangaw near Sulaimaniyah; Northeast of Iraq, offers a remarkable opportunity to observe microbial interactions within environment, which is related to the karst aquifers. Both water and atmosphere in the cave are rich in hydrogen sulphide. The predominant cation in the cave's water sample is Ca2+ and anion is SO42-. The chemical speciation shows that samples 1 and 3 are supersaturated with gypsum. The high ionic ratio values of Ca/ Mg and Ca/ SO4 indicates further dissolution of anhydrite and calcite. While the high ratio value of Na/ Cl, in sample 4 is attributed to ionic exchange inside the cave. Redox reactions in the cave appear to be microbially mediated. Bacteriological analysis of water samples shows that there are three Thiobacilli species, a genus that often obtains its energy from the oxidation of sulphur compounds. Oxidation of hydrogen sulphide to sulphuric acid, and hence the cave enlargement, is probably enhanced by these bacteria. Two cave-enlargement processes were identified: i) Sulphuric acid derived from oxidation of the hydrogen sulphide converts subaerial limestone surfaces to gypsum. The gypsum falls into the cave stream and dissolves. ii) Strongly acidic droplets form on the gypsum and on microbial filaments, dissolving the limestone, where they drip onto the cave floors. The possible source of organic matter is from deep oil-rich reservoirs (or bitumen occurrences within the limestone), the presence of organic matter at the bank of Awa Spi stream support this idea.
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THESIS ABSTRACTS:
SEQUENCE STRATIGRAPHY OF THE QAMCHUQA SUCCESSION, NORTHEASTERN IRAQ
Basma A.A. Al-Samarraie
Earth Science – M.Sc. Thesis – College of Science – University of Baghdad, (July, 2011)
(p. 81)
ABSTRACT
The Qamchuqa Formation in the study area was deposited on a shallow carbonate platform with distally steepened ramp setting. Five facies associations were distinguished in the Qamchuqa Formation. These include, shallow restricted environment, shallow semi restricted, shallow open marine, shoal, and deep outer ramp. The intertounged Balambo beds within the lower part of Qamchuqa Formation at Zewe section are characterized by planktonic foraminifera wackestone to packestone, Radiolarian wackestone and black shale. This association reflect basinal environment.
Several diagenetic processes affected the Qamchuqa succession. They include micritization, neomorphism, dissolution, cementation, dolomitization, silicification, compaction, and dedolomitization. These processes were related to four main diagenetic environments; marine phreatic, mixing, meteoric phreatic and deep burial. In the present study, the main diagenetic processes affecting the Qamchuqa Formation are dolomitization (pervasive, selective), dissolution, and cementation. Detailed petrographic study of the dolomite suggests that the dolomitization of the Qamchuqa Formation occurred in the mixing zone.
The Qamchuqa Formation is represented by four third order cycles, which can be divided in to two of fourth order cycles. These cycles where deposited during episodes of relative sea level rises and stillstands. They are characterized in general by a keep up carbonate deposits. Tectonic subsidence was the main controlling factor, which affects the paleogeography of the Qamchuqa basin; producing different rate of accommodation and consequently the nature of facies stacking pattern.
The relative sea level fluctuation has a great effect on the diagenetic development of carbonate succession.
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البحوث العربي
سعة التبادل الأيوني في أطيان المونتمورلونايت الصناعية العراقية واعتمادها لتقدير محتوى المونتمورلونايت في الطين المنتج
خلدون صبحي البصام، شيماء محمد عبد الرحمن وسلامه جلوب رشيد
الاستلام: 03/ 12/ 2008، القبول: 30/ 04/2009
الكلمات الدالة: مونتمورلونايت، سعة التبادل الأيوني، العراق
(p. 1 – 17)
CATION EXCHANGE CAPACITY IN IRAQI INDUSTRIAL MONTMORILLONITIC CLAYSTONES AND THEIR USE IN THE ESTIMATION OF MONTMORILLONITE CONTENT IN THE PRODUCED CLAY
Khaldoun S. Al-Bassam, Shaima'a M. Abdul Rahman and Sallama Ch. Rashid
ABSTRACT
This work is concerned with cation exchange capacity (CEC) of the industrial montmorillonitic claystones produced by GEOSURV from Safra Mine in Western Desert and the possible use of CEC as a quantitative indicator of montmorillonite content as well as to study the effect of heating on the cation exchange capacity of these clays. Analyses and tests of about 375 samples of these clays, previously analyzed, were studied and processed. Moreover, a series of standards were prepared to support the ideas and aims of this work. The results show the possible use of CEC to estimate montmorillonite content with acceptable accuracy using Methylene Blue method. The accuracy of this method is comparable to the mineral estimation by XRD. The results can be controlled by comparison with alumina content of these clays.
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دراسة طباقية لتكوين مساد (الطباشيري المتأخر) في منطقة شرق الرطبة – الكيلو 160، الصحراء الغربية العراقية
رضا محمد عامر
الاستلام: 28/ 12/ 2009، القبول: 28/ 07/2011
الكلمات الدالة: تكوين المساد، سينومينيان – تورونيان، الكريتاسي المتأخر، الصحراء الغربية العراقية
(p. 19 – 47)
STRATIGRAPHIC STUDY OF MS'AD FORMATION EAST OF RUTBAH – KILO 160 AREA, WESTERN DESERT, IRAQ
Reda M. Amer
ABSTRACT
The micropaleontological study and microfacies analysis of the collected rock samples from east of Rutbah – Kilo 160 area, in the Iraqi Western Desert, and the penetrated sequence in borehole A'awaj 1, revealed that the exposed sequence in the involved area belongs to Ms'ad Formation of Late Cenomanian - Turonian (Late Cretaceous) age. The penetrated sequence in the drilled borehole is 160 m thick, indicated that the sequence belongs to Ms'ad Formation; the difference in the known thickness of Ms'ad Formation and that indicated from the borehole will be a matter of discrepancy. However, the location of the drilled borehole, which is interpreted by means of geophysical methods as a graben, will explain the reason of such big difference in the thickness of the Ms'ad Formation. Meanwhile, this increase in thickness will support the geophysical interpretation of the graben.
The regional and detailed geological mapping of the Iraqi Western Desert during 1980 and 2005, respectively, revealed that the involved area is covered by many formations. Geological maps at scale of 1:25000 were complied during both stages of mapping, depending on the prepared lithofacies maps supported by paleontological studies of hundreds of rock samples collected from the outcrops. Those maps were used in compilation of geological maps at scale of 1:100000 and 1:250000, and finally the geological map of Iraq at scale of 1:1000000. The latter shows that the following formations are exposed in the involved area: Najmah, Nahr Umr, Mauddud, Rutbah and Ms'ad.
The Ms'ad Formation, in the studied sequence is composed mainly of dolomitic limestone, recrystallized dolomitic limestone, sandy limestone, clayey sandstone and sandy dolomite, with abundant planktonic and benthonic foraminiferal assemblages, like:
Rotalipora greenhornensis (MORROW), R. apenninica (RENZ), R. cushmani (MORROW), Helvetoglobotruncana helvetica (BOLLI), Whiteinella archaeocretacea PESSAGNO, W. baltica Douglas and Rankin, Dicarinella imbricata (MORNOD), Marginotruncana renzi (GANDOLFI), M. angusticarinata (GANDOLFI), M. marginata (REUSS), M. coronate (BOLLI), M. pseudolineana PESSAGNO, M. tricarinata QUEREAU, M. schneeganzi SIGAL, Preaglobotruncana stephani (GANDOLFI), Hedbergella delrioensis (CARSEY), Stomiosphaera sphaerica (KAUFMAN) and Pithonella ovalis (KAUFMAN).
Taberina KEIZER, Dicyclina MUNIER – CHALMAS, Pseudolituenella MARIE Meandropsina SCHLUMBERGER, Nezzazata OMARA, Qataria HENSON, Edomia HENSON, Cisalveolina REICHEL and Orbitolina D'Orbigny.
Two biozones were recognized, these are:
- Rotalipora greenhornensis Zone of Late Cenomanian age
- Helvetoglobotruncana helvetica Zone of Turonian age
Moreover, it was recognized that intertonging occurs between the upper part of Rutbah Formation and the lower part of Ms'ad Formation.
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