Sabbatical Report- Alham Al-langawi 2004 Sabbatical Report 2004... · 2014. 12. 8. · Sabbatical Report- Alham Al-langawi 2004 9 1. Preparation for ICP by Manchester University-Earth

Sabbatical Report- Alham Al-langawi 2004

1

SABBATICAL REPORT

PETROGRAPHIC AND GEOCHEMICAL INVESTIGATION OF PRE-PERMIAN

KHARUS FORMATION

Dr. Alham Jassim Al-langawi

Presented to

The Authority for Applied Education and Training

College of Basic Education-Science Department

September 2004


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Table Of Content

Page

Abstract…………………………………………………………………….. 3

Acknowledgments…………………………………………………………… 4

Work Procedure………………………………………………………….…. 5

I Field Work………………………………………………………………….. 5

II Petrography………………………………………………………………….. 6

1 Sample Preparation………………………………………………………….. 6

2 Petrographic Analysis By The Polarizing Microscope……………………... 6

3 Petrographic Analysis By Cathodoluminescence…………………………… 7

4 Petrographic Study By Using The SEM…………………………………….. 8

III Geochemical Investigations………………………………………………. 8

1 Preparation for ICP by Manchester University-Earth Science Department-

The United Kingdom………………………………………………………...

9

2 Wet Chemical Analysis By The ICP………………………………………... 9

3 Quantitative-Chemical Analysis By Using The SEM………………………. 9

4 Quantitative-Chemical Analysis By Using The Micro-Probe………………. 10

IV Tables………………………………………………………………………… 11

V Figures………………………………………………………………………... 14

VI Appendix1: Quantitative Chemical Analysis by The SEM……………….. 20

Benefits Gained From This Sabbatical Leave………………………………. 27


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Abstract

The Pre-Permian formations are the oldest rocks in the Oman mountain belt, which consists

of shallow marine and terrestrial sediments of Late Proterozoic to Early Paleozoic age, and

group of metamorphic rocks consisting of schists and mylonites of various origins (Glennie,

1977; Glennie et al, 1974; Lippard, 1983; Mann and Hanna, 1990; Ogasawara, et al, 2000;

Robertson et al, 1990). This study will be based on field, petrographic and geochemical

investigations of the top part of the Pre-Permian rocks called the Kharus Formation that is

unconformably covered by Akhdar Group (Permian-Triassic). The Pre-Permian rocks are

exposed in series of erosional windows beneath the Hajar Supergroup in central Oman

Mountains. The major exposure is at Saih Hatat window eastern Oman Mountains, other

smaller exposures are at central Oman Mountains which are: Sahtan, Kharus and Mistal

windows at Jebel Akhdar, and very small exposures at the core of Jebel Nakhal (Figure 1).

The Kharus Formation is formed during the Cambrian and is about 180 meters thick (Mann

and Hanna, 1990). The lower part of the Kharus Formation consists of laminated lime

mudstones, while the upper portion is composed of massive carbonate unit with local

stromatolites, chert nodules and oolitic limestones (Mann and Hanna, 1990). The

petrographic investigation will be carried out by using transmission light microscope,

scanning electron microscope, and cathodoluminescence. The petrographic investigations

will be supplemented by geochemical analysis, using microprobe, X-ray diffraction, atomic

absorption, and quantitative analysis by the scanning electron microscope.


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Acknowledgments

The completion of this report would not have been possible without the help and support of a

large number of people whose contribution I would like to acknowledge.

I wish to thank Dr. Hamoud Fahd Al-Modhaf, Director General for The Authority for Applied

Education and Training (PAAET), for granting me with a sabbatical leave to accomplish this

work.

The author would like to thank also Dr. Tony Adams lecturer- Earth Science Department-

Manchester University for his valuable scientific contributions regarding the petrography of

the samples. My thanks are also due to Mr. Alastair Bewsher, Mr. Paul Lythgoe and Mr. Tim

Jenson-Earth Science Department-Manchester University for chemical analysis of the coral

samples. My thanks are also due to Chief Technician at the Electron Microscope Unit- Earth

Science Department-Manchester University, Mr. Steve Caldwell for the quantitative and

qualitative analysis of the samples.

Last but not least, my special thanks are due to my family, especially to my husband and my

sister Eng. Huda Al-langawi for their support, consideration and making my life easier in the

U.K.


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WORK PROCEDURE

I. FIELD WORK

Fieldwork was conducted in August 2003, before starting the sabbatical leave, so as all the

samples needed for the research will be sent to the university of Manchester for thin

sectioning. The top 36 meters of the Pre-Permian Kharus formation was sampled from Wadi

Hijir a tributary of Wadi Bani Kharus- Jabal Nakhal (Figure 1). Kharus Formation is

unconformabley covered by the Permian-Triassic Autochthonous Akhdar Group (Figure 2).

The top 2 meters are composed of thickly bedded dark gray coarse crystalline dolomite. This

layer is underlined by thinly laminated light gray dolomite, which is 10 meters thick. This

layer is underlined by thickly bedded coarse crystalline dolomite of about 5 meters thick,

which is light gray and crosscut by various cemented veins. The previous layer is underlined

by 4 meters of a very hard light gray dolomite bed that is composed of 10-15 cm thick layers.

A very thinly laminated (6 meters) stromatolitic dolomite, which is dark gray and contain

scattered fossils lies beneath the previous layer. This bed is succeeded by 3 meters of light

gray dolomite, which is crosscut by veins of calcite. The previous layer is underlined by a 3-

meter thick dolomite that is thinly laminated and composed of alternating gray and beige

color dolomite layers. The older exposed part of the Kharus Formation is composed of 1

meter of stromatolitic limestone, which is dark gray and thinly laminated.

After returning from Oman, the samples were sent to the department of Earth Sciences-

Manchester University in September 2003 for the preparation of polished thin sections and

normal thin sections, for the use in petrographic study.


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II. PETROGRAPHY

1. Sample Preparation.

Careful examination of the samples obtained from fieldwork was conducted in order to

choose the portion that is going to be used for cutting and preparation of thin sections. These

desirable parts were marked and labeled, then the samples were sent to the Department of

Earth Sciences-Manchester University in September 2003 for the preparation of polished thin

sections which is going to be used in the analysis by the Electron Scanning Microscope-

quantitative and qualitative analysis (SEM), qualitative analysis by the cathodoluminescence

microscope (CL), and quantitative analysis by the Micro-Probe, and normal thin sections for

the use in petrographic study by the polarizing microscope. Total number of prepared thin

section is 22 (11 polished thins, and 11 normal thin sections). Alizarin Red S and Potassium

Ferricyanide solution was used to stain the normal thin sections.

1. Petrographic Analysis By The Polarizing Microscope.

The petrographic study indicates that the lower part of the exposed section of the Kharus

formation at Wadi Hijir start with microcrystalline cloudy limestone-dolostone unit that is

crosscut by several thick fractures micro-fractures cemented by dolomite spars. The previous

unit is covered by a thinly laminated bed composed of alternating layers which are either

microcrystalline or medium crystalline. This layer is also crosscut by several fractures, but

cemented by calcite crystals. Layer three is composed of fine-medium crystalline dolomite,

which is overlain by two layers of coarse crystalline dolomites. All these units are crosscut


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by micro fractures and thick fractures cemented by dolomite spars. Layer 6 is composed of

microcrystalline dolomite, which is crosscut by several fractures that are cemented with

rhombic dolomites and coarse crystalline calcite. The three layers covering layer 6 is

composed of medium crystalline dolomites, which are crosscut by several fractures that are

cemented by dolomite, calcite and iron oxides. Layer 10 is composed of a laminated dolomite

unit, some of the layers are composed of fine cloudy dolomite crystals, and others of medium

crystalline dolomites. This unit is includes also some fractures which are cemented by

dolomite and calcite spars. The last (top) layer of the Kharus formation is composed of coarse

crystalline dolomite intercalated by several dolomite fractures. Figure 3, show some chosen

photomicrographs taken form the upper part of Kharus Formation.

2. Petrographic Analysis By Cathodoluminescence

Cathodoluminescence photomicrographs are used to show the differences in dolomites and

calcite trace elements composition and to determine the crosscutting relationship between the

different fabric components in the samples. It should be noted that the zoned

cathodoluminescence patterns in the crystals, especially void filling crystals, indicate

fluctuations in the Mn and Fe values. Also difference in luminescence colors of the rock

forming crystals indicate different crystallization stages that these rocks underwent. Figure 4,

show some examples on different fabric components found within the upper part of Kharus

Formation as seen by cathodoluminescence microscope.


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3. Petrographic Study By Using The SEM

Backscattered images from the scanning electron microscope are important for the study of

carbonate rocks, especially in determining the relationships between dolomite and calcite

within any particular rock. The difference in atomic weight between calcite (heavier) and

dolomite crystals is reflected in the images, giving more brighter (light gray) shades for

calcite. The backscattered images revealed the existence of calcite-cemented fractures, and

intercrystalline porosity between the rock forming dolomite crystals as well as the fracture

filling calcite and dolomite crystals. These images were also important in revealing the

existence of zoning in the rhombic dolomite crystals, where they include alternating zones of

dolomite and calcite. In addition, these images indicated the existence of heavy minerals,

which give very bright shades. Figure 5, show some examples on the above findings for the

Kharus Formation dolomites and limestones.

III. GEOCHEMICAL INVESTIGATIONS.

The major elements and the trace elements were analyzed by using Inductive Coupled

Plasma-optical emission spectrometric method (ICP) at the Chemical Labs-Department of

Earth Sciences-Manchester University. After reaching Manchester, a portion of each sample

was cut by the electric saw by the researcher, then each sample was crushed and powdered

manually by using an agate mortar to prepare for the wet chemical analysis (ICP). As for the

quantitative analysis by the SEM and Micro-Probe, the polished thins were used.


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1. Preparation for ICP by Manchester University-Earth Science Department- The

United Kingdom.

1. Weighing approximately 0.1 gm of each sample, and each were put in separate vessels.

2. Adding 10 ml concentrated HCl with 10 ml distilled water to dissolve each sample.

3. The samples then filtered to remove any particles > 0.45 m.

3. The digested samples were then made up to 100 ml with distilled water in volumetric flask.

4. The vessels were sealed, and then analyzed by Inductive Coupled Mass Spectrometer (VG

Elemental Plasmaquad 2 STE).

2. Wet Chemical Analysis By The ICP.

Table 1, show the data gained from the analysis by using ICP for trace elements. Table 2,

show data for major elements also gained from the analysis by using ICP. It is important to

know that the analysis is on bulk rock powder that was grinded as in the above-mentioned

procedure.

3. Quantitative-Chemical Analysis By Using The SEM.

The Jeol-6400 Scanning Electron Microscope (SEM) fitted with a link analytical quantitative

X-ray energy spectrometer (EDS) was used for analyzing the polished thins. This analysis is

important in order to specify the type of rock forming minerals and void filling minerals, and

to obtain trace and major element concentrations on the micron level in individual crystals.

Figure 6 and Appendix 1, are example on some of the quantitative analysis by using the SEM.


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4. Quantitative-Chemical Analysis By Using The Micro-Probe.

Dolomite and calcite crystals from all fabric components were analyzed by the microprobe in

order to obtain trace and major element concentrations on the micron level in individual

crystals. All trace elements within the dolomites and the calcites were analyzed by wave

despersive spectrometers (WDS) during the investigations by the microprobe. In addition,

element maps were formed for some samples to show the distribution and concentration of the

major and trace elements in the samples (Figure 7). Table 3 and 4, list some of the data

gained from point analysis for two polished thins by the micro probe.


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V. TABLES.

1. Geochemical analysis by the ICP:-

Table 1: Analysis of bulk rock samples by the ICP for Kharus formation, showing trace

element concentrations.

Sample Al Fe K Na Sr

No. ppm ppm pmm pmm ppm

WHK1 89.73 765.70 102.69 83.75 600.20

WHK2 301.05 7185.04 297.22 175.46 129.43

WHK3 410.06 910.06 236.94 208.90 55.13

WHK4 262.14 537.86 131.07 193.20 37.86

WHK5 236.28 208.37 136.74 209.30 35.35

WHK6 174.24 1232.32 207.91 140.57 37.88

WHK7 71.71 793.82 74.70 153.39 26.89

WHK8 110.26 228.19 188.88 216.68 36.43

WHK9 98.98 726.18 195.19 174.84 24.05

WHK10 153.23 587.81 215.05 223.12 26.88

WKH11 49.63 103.86 13.79 191.18 27.57

Table 2: Analysis of bulk rock samples by the ICP for Kharus formation, showing major

element concentrations.

Sample Ca Mg Ca Mg CaCO3 MgCO3

No. ppm ppm Elm% Elm% Mole % Mole %

WHK1 282053.8 9961.117 28.205 0.996 94.50 5.50

WHK2 177235.9 74629.91 17.724 7.463 59.03 40.97

WHK3 182286.3 99686.65 18.229 9.969 52.59 47.41

WHK4 162284.5 103944.7 16.228 10.394 48.64 51.36

WHK5 154127.4 99263.26 15.413 9.926 48.50 51.50

WHK6 156155.7 86160.77 15.616 8.616 52.37 47.63

WHK7 118202.2 78014.94 11.820 7.801 47.89 52.11

WHK8 120732.5 73738.26 12.073 7.374 49.83 50.17

WHK9 121729.9 73510.64 12.173 7.351 50.11 49.89

WHK10 121822.6 76557.35 12.182 7.656 49.12 50.88

WKH11 123078.1 79624.08 12.308 7.962 48.39 51.61


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2. Geochemical analysis by the Microprobe:-

Table 3: Point analysis by the Microprobe for Kharus formation- sample No (WHK1),

showing major and trace element concentrations.

WKH1 Element %

Point No. Ca S Mg Na K Si Al Mn Fe Sr O Total%

#1 40.42 0.01 0.28 0.00 0.00 0.00 0.00 0.01 0.02 0.03 16.35 57.11

#2 40.26 0.04 0.19 0.02 0.00 0.00 0.00 0.00 0.02 0.02 16.25 56.80

#3 40.49 0.02 0.17 0.00 0.00 0.00 0.00 0.00 0.02 0.09 16.32 57.12

#4 40.37 0.01 0.10 0.00 0.00 0.01 0.00 0.01 0.00 0.05 16.21 56.76

#5 40.04 0.00 0.39 0.00 0.00 0.00 0.00 0.01 0.04 0.00 16.25 56.73

#6 40.46 0.02 0.11 0.02 0.00 0.00 0.00 0.01 0.02 0.04 16.27 56.96

#7 40.18 0.02 0.30 0.01 0.00 0.00 0.00 0.01 0.02 0.00 16.27 56.81

#8 40.14 0.00 0.38 0.00 0.00 0.00 0.00 0.01 0.03 0.01 16.28 56.84

#9 39.88 0.01 0.21 0.01 0.00 0.00 0.00 0.00 0.03 0.03 16.08 56.23

#10 40.03 0.01 0.12 0.00 0.00 0.00 0.00 0.01 0.03 0.07 16.09 56.35

#11 40.03 0.01 0.21 0.00 0.00 0.00 0.00 0.00 0.03 0.01 16.15 56.44

#12 40.22 0.00 0.25 0.01 0.00 0.00 0.00 0.01 0.01 0.02 16.24 56.76

#13 40.20 0.02 0.23 0.01 0.00 0.00 0.00 0.01 0.03 0.03 16.23 56.75

#14 40.23 0.03 0.29 0.01 0.00 0.00 0.00 0.02 0.01 0.01 16.30 56.91

#15 40.53 0.03 0.03 0.00 0.00 0.00 0.00 0.01 0.01 0.12 16.26 57.00

#16 40.25 0.01 0.21 0.00 0.00 0.00 0.00 0.02 0.01 0.00 16.23 56.73

#17 40.38 0.03 0.02 0.00 0.00 0.01 0.00 0.00 0.00 0.27 16.22 56.93

#18 40.12 0.00 0.22 0.00 0.00 0.00 0.00 0.02 0.01 0.00 16.17 56.55

#19 40.16 0.01 0.21 0.01 0.00 0.00 0.00 0.03 0.05 0.01 16.21 56.69

#20 40.61 0.01 0.07 0.01 0.00 0.01 0.00 0.00 0.03 0.14 16.31 57.17

#21 40.34 0.01 0.02 0.02 0.00 0.00 0.00 0.00 0.01 0.14 16.16 56.70

#22 40.05 0.00 0.08 0.00 0.00 0.00 0.00 0.01 0.01 0.17 16.08 56.41

#23 40.20 0.02 0.22 0.01 0.00 0.00 0.00 0.02 0.03 0.00 16.22 56.71

#24 40.27 0.00 0.26 0.01 0.00 0.00 0.00 0.01 0.03 0.00 16.26 56.84

#25 40.24 0.01 0.20 0.00 0.00 0.01 0.00 0.03 0.00 0.00 16.22 56.71

#26 39.90 0.00 0.22 0.00 0.00 0.00 0.00 0.03 0.03 0.01 16.09 56.27

#27 39.90 0.00 0.19 0.00 0.00 0.00 0.00 0.02 0.01 0.01 16.07 56.21

#28 39.90 0.06 0.36 0.00 0.00 0.03 0.00 0.00 0.03 0.12 16.28 56.77

#29 39.46 0.02 0.30 0.01 0.00 0.02 0.00 0.00 0.01 0.11 16.02 55.96

#30 32.97 0.01 5.25 0.00 0.00 0.01 0.00 0.17 0.02 0.00 16.70 55.13

#31 39.56 0.03 0.22 0.00 0.00 0.03 0.00 0.01 0.02 0.09 16.03 56.00

#32 39.53 0.06 0.26 0.00 0.01 0.09 0.00 0.02 0.01 0.10 16.14 56.22

#33 39.86 0.02 0.39 0.00 0.00 0.03 0.00 0.00 0.00 0.20 16.26 56.76

#34 39.77 0.00 0.27 0.00 0.00 0.02 0.00 0.01 0.03 0.00 16.09 56.18

#35 39.72 0.02 0.33 0.02 0.01 0.04 0.00 0.02 0.02 0.12 16.18 56.48

#36 39.74 0.03 0.31 0.00 0.01 0.03 0.00 0.01 0.01 0.08 16.15 56.35

#37 40.00 0.06 0.34 0.00 0.00 0.04 0.00 0.01 0.02 0.14 16.34 56.95

#38 38.51 0.03 0.35 0.02 0.13 0.37 0.25 0.01 0.02 0.12 16.34 56.15

#39 39.49 0.02 0.30 0.02 0.00 0.00 0.00 0.01 0.00 0.00 16.00 55.85


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Table 4: Point analysis by the Microprobe for Kharus formation-sample No (WHK6),

showing major and trace element concentrations.

WKH6 Element %

Point No. Ca S Mg Na K Si Al Mn Fe Sr O Total%

#40 39.76 0.01 0.17 0.00 0.00 0.01 0.00 0.04 0.00 0.00 16.02 56.00

#41 39.68 0.00 0.06 0.01 0.00 0.01 0.00 0.08 0.01 0.00 15.92 55.75

#42 39.72 0.00 0.06 0.00 0.00 0.01 0.00 0.02 0.01 0.00 15.91 55.73

#43 39.63 0.00 0.06 0.00 0.00 0.00 0.00 0.06 0.00 0.00 15.88 55.62

#44 47.64 0.00 0.09 0.02 0.00 0.00 0.00 0.05 0.01 0.00 19.10 66.91

#45 38.74 0.00 0.05 0.00 0.00 0.00 0.00 0.08 0.02 0.00 15.53 54.43

#46 39.59 0.02 0.07 0.00 0.00 0.00 0.00 0.01 0.01 0.00 15.87 55.55

#47 40.27 0.02 0.07 0.04 0.00 0.01 0.00 0.03 0.00 0.00 16.17 56.62

#48 40.23 0.03 0.07 0.00 0.00 0.00 0.00 0.03 0.00 0.00 16.15 56.52

#49 22.73 0.02 12.15 0.02 0.00 0.00 0.00 0.13 0.33 0.00 17.23 52.62

#50 22.38 0.00 12.29 0.00 0.00 0.00 0.00 0.14 0.28 0.00 17.15 52.24

#51 22.64 0.02 12.18 0.00 0.00 0.00 0.00 0.12 0.09 0.01 17.14 52.21

#52 22.05 0.00 12.18 0.01 0.00 0.00 0.00 0.16 0.27 0.01 16.96 51.64

#53 22.08 0.00 12.25 0.00 0.00 0.01 0.02 0.14 0.35 0.00 17.05 51.90

#54 22.15 0.01 12.56 0.02 0.00 0.00 0.00 0.06 0.08 0.00 17.16 52.04

#55 22.53 0.01 12.26 0.02 0.00 0.02 0.00 0.10 0.18 0.00 17.19 52.31

#56 23.48 0.02 11.34 0.00 0.00 0.00 0.01 0.12 0.28 0.00 16.99 52.25

#57 22.71 0.00 12.23 0.01 0.00 0.00 0.00 0.08 0.13 0.01 17.19 52.36

#58 22.11 0.01 12.38 0.00 0.00 0.00 0.00 0.14 0.26 0.00 17.10 52.01

#59 22.87 0.00 12.33 0.01 0.00 0.00 0.03 0.05 0.05 0.00 17.31 52.65

#60 22.10 0.00 12.46 0.00 0.00 0.01 0.02 0.09 0.24 0.00 17.15 52.06

#61 21.77 0.00 13.09 0.04 0.00 0.01 0.00 0.02 0.05 0.00 17.35 52.33

#62 21.91 0.01 13.18 0.02 0.00 0.00 0.00 0.01 0.00 0.00 17.44 52.57

#63 21.76 0.01 13.08 0.01 0.00 0.01 0.00 0.01 0.00 0.00 17.33 52.22

#64 21.09 0.01 12.48 0.04 0.43 1.14 0.36 0.01 0.03 0.00 18.37 53.95

#65 22.12 0.00 13.11 0.01 0.00 0.01 0.00 0.02 0.01 0.00 17.48 52.76

#66 21.74 0.09 12.88 0.05 0.02 0.37 0.03 0.02 0.01 0.00 17.72 52.92

#67 21.74 0.01 12.99 0.00 0.00 0.01 0.00 0.02 0.00 0.00 17.25 52.03

#68 22.24 0.02 13.02 0.02 0.00 0.02 0.00 0.01 0.00 0.00 17.50 52.82

#69 21.75 0.01 13.01 0.00 0.00 0.01 0.00 0.02 0.03 0.00 17.29 52.14

#70 21.56 0.00 12.92 0.02 0.02 0.11 0.05 0.02 0.02 0.00 17.31 52.04


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V. FIGURES.

Figure 1: Simplified geologic map of the central Oman Mountains showing the

distribution of Pre-Permian rocks (after Glennie et al. 1974).

Figure 2: Field photomicrograph showing the top part of Kharus Formation that is

unconformably overlain by the Permian Saiq Formation.

Permian Saiq Formation-

Akhdar Group

Pre-Permian Kharus

Formation

Angular Unconformity


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WHK1 WHK6

WHK2 WHK7

WHK3 WHK8

WHK4 WHK10

WHK5 WHK11

Figure 3: Photomicrographs taken under plain polarized light for some samples.


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WHK10: ppl

Polycrystalline dolomite

WHK10: Cl

First stage dolomite (yellow luminescence),

aggraded dolomite crystals (red luminescence)

WHK10: ppl

Polycrystalline dolomite (laminated part)

WHK10: CL

Medium crystalline dolomite (yellow

luminescence), aggraded (coarse crystalline

dolomite crystals (red luminescence)

WHK1: ppl

Limestone affected by fracturing, which are

cemented by calcite and dolomite.

WHK1: CL

Rock forming calcite (dark gray luminescence)

calcite cementing crystals(yellowish-green) and

dolomite cementing crystals (dark green).

WHK6: ppl

Microcrystalline dolomite, and fracture filling

calcite and dolomite crystals.

WHK6: ppl

Microcrystalline dolomite (dark gray

luminescence), and fracture filling calcite (yellow)

and rhombic zoned dolomite (alternating bands of

red-yellow-dark gray)

Figure 4: show some examples on different fabric components found within the upper

part of Kharus Formation as seen by cathodoluminescence and polarizing microscope.


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WHK1: Limestone

Fracture filling dolomite (dark gray) and rock forming

calcite (light gray)

WHK6: Dolomite

Rock forming dolomite (dark gray), alternating zones

of fracture filling dolomite (medium gray) and calcite

(light gray)

WHK4: Dolomite

Rock forming dolomite (dark gray), zoned fracture

filling dolomite that includes calcitic rims (light gray)

WHK9: Dolomite

Intercrystalline and intracrystalline porosity (black

areas) within the rock forming dolomite crystals

WHK4: Dolomite

Rock forming dolomite (dark gray), fracture filling

calcite (light gray), fracture filling dolomite (medium

gray)

WHK11: Dolomite

Filling of intercrystalline pore spaces by calcite (light

gray)

WHK6: Dolomite

Crosscutting fracture: first stage (dolomitic-medium

gray) second stage calcitic (light gray)

WHK4: Dolomite

Occurrence of heavy minerals (white spots) within the

dolomite (gray)

Figure 5: Backscattered images from SEM showing some examples on the relationship

between fabric components within the dolomites and limestones from Kharus F

backscattered images Formation.


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Figure 6: Backscattered image from SEM showing fracture filling calcite (light gray)

and fracture filling Quartz (smooth-with no intracrystalline porosity), within a dolomite

(WHK11). Quantitative data on the points are displayed in appendix1.

Void filling

Quartz

Void filling

calcite

Rock forming

dolomite 6

3

9

4

5 2

1

7

8 10

11

12

13

Rock forming

dolomite


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Distribution of Ca within void filling and

rock forming dolomites, and void filling

calcite.

Distribution of Mg within void filling and


calcite.

Distribution of Fe within void filling and


calcite.

Distribution of Mn within void filling and


calcite.

Figure 7: Photomicrographs by the Probe showing the distribution and concentration of

the major and trace elements in the one of the samples from the top part of Kharus

Formation (WHK6). The scale on the right side indicates the concentration in (ppm).

Photomicrograph under

plain polarized light for

the same section that

was scanned by the

microprobe

Documents

Sabbatical Report- Alham Al-langawi 2004 Sabbatical Report 2004... · 2014. 12. 8. · Sabbatical Report- Alham Al-langawi 2004 9 1. Preparation for ICP by Manchester University-Earth