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REVISED PROOF
ORIGINAL ARTICLE
1
2Microfacies and depositional environments of Jurassic (Callovian)
3Tuwaiq Mountain Formation in central Saudi Arabia
4Abdel Galil A. Hewaidy
1
•Mohamed W. Abd El-Moghny
1
•Sherif Farouk
2
•
5Khalid El Kahtani
3
6Accepted: 29 April 2016
7ÓSpringer-Verlag Berlin Heidelberg 2016
8Abstract Three stratigraphic sections of the Callovian
9Tuwaiq Mountain Formation at Shaib El-Hisyan, Khashm
10 Al-Giddayah and Dirab, near Riyadh City, central Saudi
11 Arabia have been studied to distinguish their microfacies
12 features and the equivalent probable depositional environ-
13 ments. Lithostratigraphically, the Tuwaiq Mountain For-
14 mation is subdivided into two lower and upper Tuwaiq
15 members. The part that informally is known as upper
16 Tuwaiq Member is subdivided from base to top into T1,
17 T2, and T3 members, respectively. The microfacies anal-
18 ysis of the Tuwaiq Mountain Formation led to the recog-
19 nition of 12 microfacies types (FT1–FT12) that are
20 grouped into three associations: (1) open platform facies
21 association (FT1–FT5); (2) high-energy shoals of ooids and
22 patch reefs facies association (FT6–FT9); and (3) restricted
23 carbonate platform facies association (FT10, FT12). The
24 lower part of the Tuwaiq Mountain Formation is charac-
25 terized by relative abundance of wackestone and
26 wacke/packstone facies that are capped by thin peloidal
27 molluscan floatstone facies. The former indicates a quiet
28 open platform environment with periodic agitation, while
29 the later indicates deposition in a sand shoal environment.
30 The facies of basal unit of the upper Tuwaiq Mountain
31 Formation, T1, are enriched with dense micrite matrix and
32 shell fragments of epifaunal and deep infaunal organisms
33
(e.g., Pholadomya spp.). The microfacies pattern of Bal-
34
adiyah Member (T1) indicates a quiet open platform with
35
low and sometimes high water circulation. The Maysiah
36
Member (T2) is composed of hard limestone with abun-
37
dance of coralline microfacies in framestone, grainstone,
38
and packstone textures suggesting a high-energy shallow
39
reefal environment with periods of quiet open platform
40
conditions. This shallow reefal environment becomes more
41
restricted southward, where shales and algal dolomitic
42
grainstones were formed. The Daddiyah Member (T3) that
43
made up of chalky limestone with chert intercalations is
44
predominated by matrix-support lime mudstone, wacke-
45
stone, and packstone facies. These microfacies reflect open
46
platform with slightly low circulation below fair-weather
47
wave base with period of restricted marine conditions
48
forming rudstone microfacies. Southward, these environ-
49
ments became shallower and subjected to considerable
50
quartz influx in an agitated sand shoal. 51
52
Keywords Microfacies Depositional environments 53
Tuwaiq mountain Jurassic Saudi Arabia
54
Introduction
55
Jurassic strata in Saudi Arabia consist mostly of carbonates
56
and evaporites that are mapped collectively as the Shaqra
57
Group, which is subdivided into the following seven for-
58
mations (from older to younger): the Marrat Formation, the
59
Dhruma Formation, the Tuwaiq Mountain Formation, the
60
Hanifa Formation, the Jubaila Formation, the Arab For-
61
mation, and the Hith Formation. The Shaqra Group is of
62
economic importance, because it hosts 12 hydrocarbon
63
reservoirs, including the Arab-D Reservoir within the
64
Ghawar Field (the largest oil field in the world).
A1 &Sherif Farouk
A2 geo.sherif@hotmail.com
A3
1
Geology Department, Faculty of Science, Al-Azhar
A4 University, Nasr City, Cairo, Egypt
A5
2
Exploration Department, Egyptian Petroleum Research
A6 Institute, Nasr City, Cairo, Egypt
A7
3
Geology Department, King Saud University, Riyadh, Saudi
Arabia
123
Carbonates Evaporites
DOI 10.1007/s13146-016-0310-9
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REVISED PROOF
65 Because of the presence of the main oil-producing beds
66 with in the middle–upper Jurassic strata in eastern pro-
67 vinces of Saudi Arabia (Fig. 1), many studies have dealt
68 with the microfacies characteristics and depositional
69 environments of the strata (e.g., Steineke and Bramkamp
70 1952; Steineke et al. 1958; Moshrif and Al-Asaad 1984;
71 Okla 1986; Enay et al. 1986; El As’aad 1989; Basyoni and
72 Khalil 2011). Biostratigraphy and micropalaeontology of
73 Jurassic carbonates in Saudi Arabia were studied to
74 determine ages and paleoenvironments (e.g., Hughes
75 2004a,b,2009; Galal and Kamel 2004; Al-Husseini 2009;
76 El-Sorogy et al. 2014).
77 Materials and methods
78 To accomplish this aim, three surface sections (Fig. 1) are
79 measured, sampled, and correlated in the area near Riyadh;
80 Shaib El-Hisyan (lat. 24°390N, long. 46°170E), Khashm Al-
81 Giddiyah (lat. 24°380N, long. 46°460E), and Dirab (lat
82
24°3102700N, long. 46°3703500E). Thirty-six thin sections (4
83
from Shaib El-Hisyan, 20 from Khashm Al-Giddiyah, and
84
12 from Dirab) are prepared and examined for the micro-
85
facies analysis. Thirty-six thin sections are investigated for
86
the microfacies analysis, including different skeletal and
87
non-skeletal particles, textures, grain-sizes, and cementing
88
materials. The carbonate rocks were classified in following
89
the schemes of Dunham (1962), and the equivalent envi-
90
ronments of the identified microfacies types were deter-
91
mined following Wilson (1975) and Flu
¨gel (2004). In
92
addition, the macrofaunal content of the Tuwaiq Mountain
93
Formation, including brachiopods, bivalves, gastropods,
94
corals, and echinoids, was studied carefully for the pale-
95
oecologic interpretations (Fig. 2).
96
Lithostratigraphy
97
Middle Jurassic strata in central Saudi Arabia are repre-
98
sented by the Dhruma and Tuwaiq Mountain Formations.
99
The stratigraphic nomenclature of these units has varied
Fig. 1 Generalized geologic
map of the Arabian Peninsula
(modified after Powers et al.
1966). The location of the
studied sections is 1Shaib El-
Hisyan, 2Khashm Al-
Giddayah, and 3Dirab
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REVISED PROOF
100 since they were first described. The term ‘‘Tuwaiq For-
101 mation’’ was introduced by Burchfiel and Hoover (1935)to
102 refer to all sediments below the ‘‘Nubian Sandstone’’ (now
103 referred to as the Cretaceous Biyadh and Wasia forma-
104 tions) in central Saudi Arabia. Steineke 1937 (cited in
105 Powers 1968) for the first time subdivided the ‘‘Tuwaiq
106 Formation’’ into the Marrat, Dhruma, Tuwaiq Mountain,
107 Hanifa and Jubaila Members (in ascending order). Bram-
108 kamp (1945) (cited in Powers 1968) raised these members
109 to formation rank, and the Tuwaiq Formation was desig-
110 nated the Tuwaiq Group (although the Group designation
111 was discarded later by Steineke and Bramkamp (1952).
112
Powers et al. (1966) proposed the term ‘‘Tuwaiq Mountain
113
Limestone’’ of these units and considered it of middle
114
Callovian at the lower part and of Oxfordian age at the
115
middle and upper parts. Pollastro (2003) following many
116
others back to the old terminology and included these five
117
formations in the Tuwaiq Group, while the Arab and Hith
118
formations were included in the Riyadh Group. The
119
Dhruma Formation was subdivided by Manivit et al. (1990)
120
into seven informal units D1–D7. The unit 7 represents the
121
upper Dhruma and includes the Atash Member at base and
122
Hisyan Member at the top (Powers et al. 1966). Recent
123
reexamination was carried by Hughes (2004a,b,2009) and
Fig. 2 Generalized
stratigraphic column for the
Jurassic sediments in Saudi
Arabia (after El-Asmar et al.
2015)
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REVISED PROOF
124 placed the mud-dominated D7 unit of the Dhruma For-
125 mation genetically within the basal Tuwaiq Mountain
126 Formation.
127 In coincidence with Hughes (2006), the Tuwaiq
128 Mountain Formation in the study area is consists mostly of
129 shallow-marine lagoon and stromatoporoid carbonates of
130 middle-to-late Callovian age, and lies unconformably upon
131 unit D6 from the Dhruma Formation without a clear
132 boundary. In addition, the formation, Tuwaiq Mountain, is
133 overlain disconformably by muddy carbonate, stromato-
134 poroid and lagoonal carbonate lithofacies of the upper
135 Jurassic Hanifa Formation. The upper boundary, in con-
136 trast, is placed at the change from light colored, massive,
137 resistant, coral-bearing, dense, and homogeneous micritic
138 limestone of the Tuwaiq Mountain Formation at the base to
139 brown, soft, thin-bedded, non-coraliferous, and homoge-
140 neous micritic and calcarenitic limestone of the overlying
141 Hanifa Formation at the top.
142 In this study, the Tuwaiq Mountain Formation is sub-
143 divided informally into lower and upper parts. The lower
144 part includes the Hisyan Member, while the upper part
145 includes the old known Tuwaiq Mountain Limestone and
146 can be divided into Baladiyah, Maysiyah, and Daddiyah
147 members. The newly defined Tuwaiq Mountain Formation
148 (Hughes 2006) consists mostly of stromatoporoid carbon-
149 ates of middle-to-upper Callovian age with a combined
150 thickness of 295 m. Middle Jurassic deposits of Saudi
151 Arabia show distinct lateral facies variation, and carbonate
152 deposits in the north are replaced by fluvial siliciclastic
153 sediments (mainly sandstones with minor shale and silt-
154 stone) to the south (Al-Aswad 1995).
155 The lower Tuwaiq Mountain (Hisyan Member)
156 The Hisyan Member is known as a ‘‘mud-dominated’’ unit
157 or the shale unit within the Jurassic section in central Saudi
158 Arabia. At its type locality, the Hiysan Member was
159 described by Powers (1968) as (tan to olive-tan shale
160 intercalated with thin limestone beds). In Shaib El-Hisyan
161 section, the Hisyan Member is composed of about 50 m
162 thick green shale successions that change upwardly into
163 greenish marl and have intercalations of grayish limestone
164 beds.
165 In the studied area, the Hisyan Member is represented
166 by about 45 m thick at the Shaib El-Hisyan section (Fig. 3)
167 with an exposed base and discontinuous upper boundary.
168 Among the dominating fossil-species in the member are
169 Africogryphea costellata Douville
´,Homomya vezalayi (D0
170 Archiac), Daghanirhynchia? triangulata Cooper, and
171 Daghanirhynchia angulocostata Cooper. Powers (1968)
172 attributed a middle Callovian age for this member based on
173 its faunal content.
174
The upper Tuwaiq Mountain Formation
175
In the present work, the upper Tuwaiq Mountain Formation
176
is referring all together to the three members (T1) or Bal-
177
adiyah, (T2) or Maysiyah, and (T3) or Daddiyah that given
178
by Vaslet et al. (1983) for the upper Tuwaiq Mountain
179
Formation from base to top. The member comprises about
180
175 and 139 m thick at Khashm Al-Giddiyah and Dirab
181
sections, respectively (Figs. 4,5). The member varies
182
lithologically from yellowish-green marls dissected by
183
gypsum vienlets and intercalated with thin fossiliferous
184
limestones in its lower part to a limestone succession that
185
topped by conglomeratic limestone with abundant silicified
186
corals in the middle part then followed by massive-bedded,
187
and chalky limestones intercalated with chert bands and
188
lenses at the upper part. It is important to mention that the
189
uppermost bed (2 m thick) of the unit is composed of
190
concretional and bedded limestone with burrowing and
191
bioturbation activities. This member is attributed to the
192
middle–upper Callovian age (Powers 1968).
193
Age assignment of the Tuwaiq Mountain Formation
194
Ammonites are rare in the Tuwaiq Mountain Formation.
195
Only Erymnoceras philbyi (Arkell 1956) recorded at the top
196
part of the Tuwaiq Mountain Formation in Dirab section
197
reflects middle-to-late Callovian age (Arkell 1956; Lewy
198
1982). The Hisyan Member of the lower Tuwaiq Mountain
199
Limestone was assigned to different ages in Saudi Arabia.
200
Powers et al. (1966) and Powers (1968) observed the
201
absence of ammonites in accurate positions within the
202
Hisyan Member. They split the member into two for-
203
aminiferal zones; Praekurnubia crusei at base and Kurnu-
204
bia bramkampi Zone at the top and noted that the aminiferal
205
faunas of the member are so closely related to those of the
206
immediately overlying middle Callovian beds of the
207
Tuwaiq Mountain Limestone. They considered the Hisyan
208
Member will prove to be no older than Callovian. Powers
209
(1968) and Hughes (2006) attributed the Hisyan Member to
210
the Coronatum Zone of middle Callovian age based on
211
ammonites, nautiloids, brachiopods, and nannoflora.
212
Four biostratigraphic units were recognized based upon
213
the vertical distribution of macrofaunal species intercalated
214
with two barren intervals (Al-Gahtani 2013). These are
215
from base upwards: the Pholadomya (Bucardiomya)lirata
216
Zone, Barren interval (1), Sphringanaria capax Zone,
217
Pholadomya (Pholadomya)inornata Zone, Coral Zone,
218
and Barren interval (2). They suggested a middle Callovian
219
age for the major part of the Tuwaiq Mountain Formation;
220
in addition, a probable Upper Callovian of the upper part of
221
the Tuwaiq Mountain Formation, which is found barren of
222
any macrofauna in central Saudi Arabia.
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REVISED PROOF
223 Description of measured sections
224 This study presents three measured sections of Callovian
225 strata near the city of Riyadh. These three sections, which
226 are described below, are designated as the Shaib El-Hisyan
227 section, the Khashm Al-Giddiyah section, and the Dirab
228 section (Fig. 1). At these sections, the exposed Callovian
229 Tuwaiq Mountain Formation have been measured and
230 sampled in detail. The lithologic characteristics of these
231 measured sections are described as follows:
232 Shaib El-Hisyan section
233 The Shaib El-Hisyan section is located approximately
234 45 km west of the city of Riyadh and 20 km north of Al
235 Muzahimiyah, at 24°390N latitude and 46°170E longitude.
236
This section is 45 m thick and is subdivided into three
237
lithologic units which are described below from base to top
238
(Fig. 3).
239
Unit 1 is at least 7 m thick, and is composed of green,
240
friable to hard and thinly bedded limestone. Macro-
241
fossils include brachiopods and pelecypods. A contact
242
of Unit 1 with underlying units is not exposed. The
243
upper contact of Unit 1 is placed immediately below a
244
bed of massive limestone, which is described below as
245
Unit 2.
246
Unit 2 is 26 m thick, and is composed of white, semihard
247
limestone at base that grades up to brownish yellow marl
248
and topped by green shale bed. It is characterized by the
249
presence of \20 % carbonate grains (e.g., pelecypod
250
and oolites). The upper contact of Unit 2 is placed
Member
H i s y a n
Time unit M I d d l e C a l l o v i a n
Lower T u w a i q M o u n t a i n Formation
Early
Callovian
Dhruma
Atash
Limestone
Legend
Marly Limestone
Fig. 3 Stratigraphic column of the lower Tuwaiq Mountain Formation at Shaib El-Hisyan section showing microfacies types, particles, and
depositional environments
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REVISED PROOF
251 immediately below a bed of yellowish-green massive
252 limestone, which is described below as Unit 3
253 Unit 3 is 12 m thick, is composed of yellowish-green,
254 massive, fossiliferous limestone, and is the uppermost
255 part of the measured section. The carbonate grains are
256 well developed, sometimes in large size, and represented
257 by brachiopods, pelecypods, peloids, and oolites.
258 Khashm Al-Giddiyah section
259 The Khashm Al-Giddiyah section is located within the city
260 of Riyadh, at 24°3605200N latitude and 46°4703700E
261
longitude (Fig. 4). This section is about 175 m thick at this
262
section is divided into 12 lithologic units, which are
263
described below from base to top (Fig. 4).
264
Unit 1 is represented by 45 m thick of yellowish-gray,
265
fossiliferous, friable to hard limestone. The bioclastics
266
are represented by pelecypod, gastropod, and brachiopod
267
shell fragments.
268
Unit 2 is a pale yellow, massive, fossiliferous marl. The
269
thickness of this unit reaches about 22 m. Gastropod
270
shell fragments are the main observed fossils in this unit.
271
Unit 3 is 55 m thick of yellowish-brown, very hard,
272
coralline dolomitic limestone intercalated with
U p p e r C a l l o v i a n
Unit 6
Unit 5
4Unit 3
Unit 2
Unit 1 Units
Member
Formation
U p p e r T u w a i q M o u n t a i n
M i d d l e C a l l o v i a n Time unit
Daddiyah
Maysiah Baladiyah
Oxfordian
Hanifa
Limestone Fragmental
Limestone Shale
Legend
Fig. 4 Stratigraphic column of
the upper Tuwaiq Mountain
Formation at Khashm Al-
Giddiyah section showing
microfacies types, particles, and
depositional environments
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REVISED PROOF
273 yellowish-green, friable, fossiliferous, thin-bedded marly
274 limestone. The faunal content in this unit is represented
275 by coralline algae and benthonic foraminifera.
276 Unit 4 is 12 m thick and composed of pale yellow to
277 yellowish-green, massive to friable, bioturbated, fossil-
278 iferous limestone. Its upper contact is eroded and capped
279 by conglomeratic sediments.
280 Unit 5 is well-defined pale green fragmental limestone
281 (about 20 m thick) with subangular gravely conglomer-
282 ate in the uppermost part. These conglomerates are
283 composed of carbonate clastics.
284 Unite 6 attains about 21 m thick of yellowish-green,
285 massive, fossiliferous marly limestone. The upper con-
286 tact of this unit has an irregular surface as a result of
287 erosion. This unit is capped by fossiliferous limestone,
288 intercalated with shale thin beds that are mapped as the
289 Oxfordian Hanifa Formation. The base of the Hanifa
290 Formation is picked at the base of the lowermost shale
291 bed that is at least 10 m thick.
292
Dirab section
293
The Dirab section is located approximately 15 km south-
294
west of the city of Riyadh and 37 km east-northeast of Al
295
Muzahimiyah, at 24°3102700N latitude and 46°3703500E
296
longitude. This section is 140 m thick, and is divided into 6
297
units, which are described below from base to top (Fig. 5).
298
Unit 1 is 29 m thick and composed of yellow, argilla-
299
ceous limestone rich in brachiopod and gastropod
300
interacted with a thin bed (1 m thick) of yellowish-
301
green, friable, fossiliferous marl. Bioclastic grains in this
302
unit are well developed and represented by brachiopod,
303
pelecypod, and gastropod. This unit is topped by hard
304
yellowish-white limestone. The lower contact is
305
unexposed.
306
Unit 2 is 8 m thick and made up of pale yellow, friable,
307
argillaceous, non-fossiliferous marly limestone.
308
Unit 3 consists of yellowish-gray, massive, fossiliferous,
309
dolomitic limestone. It attains about 5 m thick.
Member
Formation
U p p e r T u w a i q M o u n t a i n
M i d d l e C a l l o v i a n U p p e r C a l l o v i a n Time unit
Daddi ah
Ma siah Baladi ah
Limestone Fragmental
Limestone Shale
Legend
Fig. 5 Stratigraphic column of
the upper Tuwaiq Mountain
Formation at Dirab section
showing microfacies types,
particles, and depositional
environments
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310 Bioclastic grains in this unit are represented by coralline
311 algae, pelecypod, and some gastropod.
312 Unit 4 is 10 m thick and composed of varicolored; green,
313 yellowish gray and reddish brown, fissile, slope-forming,
314 calcareous shales with thin gypsum vienlets. They are
315 also highly ferruginous and partly glauconitic.
316 Unit 5 is made up of pale brown, yellow, hard, algal
317 coralline limestone with 15 m thick.
318 Unit 6 is the uppermost unit in this stratigraphic section
319 with thickness reaching about 73 m. It composed of
320 yellowish-gray, massive sandy limestone that topped by
321 reefal limestone.
322 Microfacies analysis and depositional environments
323 Thirty-six thin sections (4 from Shaib El-Hisyan, 20 from
324 Khashm Al-Giddiyah, and 12 from Dirab) are investigated
325 for the microfacies analysis, including different skeletal
326 and non-skeletal particles, textures, grain sizes, and
327 cementing materials. The carbonate rocks were classified
328 in following the schemes of Dunham (1962) and the
329 equivalent environments of the identified microfacies
330 types were determined following Wilson (1975) and
331 Flu
¨gel (2004). Twelve microfacies types grouped into
332 three major facies associations are recognized in the
333 present study as follows:
334 Open platform facies association: this facies association
335 includes five facies types
336 1. Foraminiferal lime-mud/wackestone (FT1).
337 2. Foraminiferal bioclastic wackestone (FT2).
338 3. Molluscan bioclastic packstone (FT3).
339 4. Algal sponge wacke/packstone (FT4).
340 5. Foraminiferal algal packstone (FT5).
341 High-energy shoals of ooids and patch reef facies
342 association: this facies association includes four facies
343 types:
344 6. Sandy biopeloidal grainstone (FT6).
345 7. Pelloidal oolitic oyster floatstone (FT7).
346 8. Coralline framestone/bindstone (FT8).
347 9. Coralline dolomitic grainstone (FT9).
348 Restricted carbonate platform facies association: this
349 facies association includes three facies types:
350 10. Algal dolomitic grainstone (FT10).
351 11. Rudstone (FT11).
352 12. Shale/mudstone (FT12).
353 The following paragraphs summarize the description
354 and probable environments of deposition of these facies
355 types.
356
Open platform facies association
357
1. Foraminiferal lime-mud/wackestone (FT1): This micro-
358
facies type is recorded in the upper Tuwaiq Mountain For-
359
mation in Dirab section, in its middle part, and Khashm Al-
360
Giddiyah section, in its upper part. The rocks of this facies
361
are pale yellow marly limestone. This microfacies is com-
362
posed mainly of badly preserved bioclastic grains (e.g.,
363
benthonic foraminifera; calcareous algae; echinoids) form-
364
ing less than 10 % of the studied microfacies (Fig. 6a, b).
365
The bad preservation of the fossils is due to their micriti-
366
zation as a diagenetic process. The foraminiferal shell
367
fragments are usually micritized and filled with microcrys-
368
talline calcite cement. Variable size, thin-walled calcisphers
369
are well developed in spherical egg shapes. These allochems
370
are embedded in dense micrite matrix (up to 90 %) that may
371
be recrystallized forming small patches of spary calcite.
372
Patchy recrystallization of micrite to microspar and in places
373
to pseudospar is formed during shallow and deep burial
374
diagenetic environments (Flu
¨gel 2004).
375
Associated macrofauna: This microfacies is character-
376
ized by its rare macrofaunal content of benthonic for-
377
aminifera, calcareous algae, and echinoids.
378
Interpretation: The abundance of carbonate mud in this
379
microfacies indicates the deposition in open platform
380
environment below normal wave base with low-energy
381
conditions is suggested as indicated by abundance of car-
382
bonate mud. This interpretation of depositional environ-
383
ment coincides with that of Wilson (1975) to his FZ7
384
microfacies.
385
2. Foraminiferal bioclastic wackestone (FT2): This
386
microfacies is recorded in the Hisyan Member at the Shaib
387
El-Hisyan section and in the upper Tuwaiq Mountain at the
388
Khashm Al-Giddiyah section. It is composed of yellowish
389
limestone, massive ledge-marker changed to friable greenish
390
argillaceous limestone. Microscopically, FT2 is forming less
391
than 20 % of the rock and is made up of moderately sorted
392
skeletal particles of benthonic foraminifera, pelecypod, and
393
echinoid fragments (Fig. 6c, d). These bioclastic grains are
394
loosely packed in a dense micritic matrix (up to 75 %) that
395
becomes, in parts, granular or mosaic sparry calcite. Synaxi al
396
calcite overgrowth cement is made by an inclusion-rich
397
single crystal with cloudy appearance and occurs around
398
echinoid host grains. Quartz grains that forming only less
399
than 3 % of the rock are in the size of very fine sand, and are
400
detected in minor quantities.
401
Associated macrofauna: There is a notable absence of
402
macrofaunal elements in the sediments of this microfacies
403
in Khashm Al-Giddiyah section. On the other hand, only
404
two pelecypod species (Pholadomya aubryi and Pho-
405
ladomya inornata) were recorded in Shaib El-Hisyan sec-
406
tion that have a facultative mobile deep infaunal
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407 suspension feeder mode of life denoting living in a shallow
408 water depth (Table 1).
409 Interpretation: Based on the enrichment of dense
410 micritic matrix and its limited faunal content, this micro-
411 facies type could be deposited in a quite open-marine
412 platform interior below fair-weather wave base with low
413 circulation conditions.
414
3. Molluscan bioclastic packstone (FT3): This micro-
415
facies type is recorded in the Hisyan Member at Shaib El-
416
Hisyan section and upper Tuwaiq Mountain Formation at
417
the lower part of Khashm Al-Geddiyah and Dirab sections.
418
This microfacies type is made up of skeletal components
419
(60–70 %) and dense micrite matrix (30–40 %). The bio-
420
clastic grains are represented by fragments that vary in
Fig. 6 Open platform
microfacies associations in the
Tuwaiq Mountain Formation: a,
bForaminiferal lime-mud/
wackestone (FT1)inupper
Tuwaiq Mountain at: aKhashm
Al-Giddiyah section and bin
Dirab section; c,
dForaminiferal bioclastic
wackestone (FT2) at cKhashm
Al-Giddiyah section and in d
lower Tuwaiq Mountain
(Hisyan Member),Bbrachiopod
fragment; e,fMolluscan
bioclastic packstone (FT3) at
eKhashm Al-Giddiyah section;
fShaib El-Hisyan section;
gAlgal sponge
wacke/packstone (FT4) in
upper Tuwaiq Mountain at
Dirab section; hForaminiferal
algal packstone (FT5) in upper
Tuwaiq Mountain at Khashm
Al-Giddiyah section, abundant
benthic foraminiferal tests and
calcareous algae (T) randomly
disseminated in a dense lime-
mud matrix. Bar scale 250 lm
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421 shape and size of bivalves, brachiopods, gastropods,
422 echinoderms, and benthonic foraminifera (Fig. 6e, f). The
423 majority of the pelecypod bioclastic grains are moderately
424 sorted, coarse to fine sand-size, recrystallized and trans-
425 formed into spary calcite. It worthy to mention that
426 microbial pelloidal microcrystalline calcite is sometimes
427 recorded in reasonable amounts (7 %) that may be attrib-
428 uted to biological activity (Flu
¨gel 2004). Some echinoid
429 spines of different sizes and septal pattern cross sections
430 exhibit a radial pattern around a hollow or irregularly
431 fabricated center are recorded.
432 Associated macrofauna: the most common fauna asso-
433 ciated with this microfacies are brachiopod species;
434 Daghanirhynchia? triangulata,Eurysites rotundus and
435 Daghanirhynchia angulocostata, and the pelecypod species
436 Pholadomya (Bucardiomya) aubryi and Pholadomya
437 inornata (Table 1). The brachiopod association lived as a
438 stationary epifaunal, suspension feeders, while the pele-
439 cypod species were facultatively mobile deep infaunal
440 forms.
441 Interpretation: The predominance of mud-supported
442 textures, the diverse faunal association content, and the
443 absence of terrigenous influx suggest a deeper open-marine
444
platform interior environment with open circulation, nor-
445
mally above fair-weather wave base.
446
4. Algal sponge wacke/packstone (FT4): This microfa-
447
cies type is recorded in the upper Tuwaiq Mountain For-
448
mation at Dirab section. It consists of hard reefal
449
limestones. The allochems constitute about 20–40 % of
450
this microfacies and are made up of sponge spicules, cal-
451
careous algae, and pelecypod and gastropod fragments.
452
Sponge spicules are recrystallized and transformed into
453
macrocrystalline spary calcite (Fig. 6g). The monoaxon
454
and tetraxon sponge spicules are well preserved, which
455
indicates a slow dissolution and rapid cementation. Silica
456
minerals (chalcedony) occupy bivalve debris as well as
457
unidentified bioclastic grains due to the transformation of
458
carbonate minerals into chalcedony. The allochems are
459
embedded in dense micrite matrix (up to 70 % of the
460
microfacies).
461
Associated macrofauna: The macrofauna associated
462
with this microfacies include: Toxonelasma arabicum
463
(brachiopod), Eligmus aualites (pelecypod), Pholadomya
464
inornata (pelecypod), Ceratomyopsis Arabica (pelecypod),
465
Pachymya (Arcomya)deserti (pelecypod), Pholadomya
466
(Bucardiomya) somaliensis (pelecypod), Pseudomelania
Table 1 Modes of life and feeding types of the identified Callovian macrofaunal species in the Tuwaiq Mountain Formation
Species Mode of life Feeding type Associated facies
Bivalve
Africogryphea costellata Stationary epifaunal Suspension feeder FT7
Homomya vezalayi Facultatively mobile deep infaunal Suspension feeder FT7
Pholadomya (Bucardiomya) aubryi Facultatively mobile deep infaunal Suspension feeder FT3
Pholadomya inornata Facultatively mobile deep infaunal Suspension feeder FT3
Eligmus aualites Stationary epifaunal Suspension feeder FT4
Pholadomya (Bucardiomya) somaliensis Facultatively mobile deep infaunal Suspension feeder FT4
Pachymya (Arcomya) deserti Epifaunal Suspension feeder FT4
Ceratomyopsis arabica Stationary semi-infaunal Suspension feeder FT4
Brachiopod
Sphriganaria capax Stationary epifaunal Suspension feeder FT7
Daghanirhynchia? triangulata Stationary epifaunal Suspension feeder FT3, FT7
Eurysites rotundus Stationary epifaunal Suspension feeder FT3, FT7
Daghanirhynchia angulocostata Stationary epifaunal Suspension feeder FT3, FT7
Toxonelasma arabicum Stationary epifaunal Suspension feeder FT4
Gastropods
Pseudomelania (Rhabdoconcha) raabi Epifaunal Herbivore FT4
Phyllocheilus sp. Epifaunal Herbivore FT4
Corals
Actinastrea crassoramosa Stationary intermediate-level epifaunal Photosymbiotic-suspension feeder FT8, FT10
Astroconian sp. Stationary epifaunal Photosymbiotic-suspension feeder FT10
Ovalastrea michelini Stationary intermediate-level epifaunal Photosymbiotic-suspension feeder FT10
Favian sp. Stationary epifaunal Photosymbiotic-suspension feeder FT10
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467 (Rhabdoconcha) raabi (gastropod), and Phyllocheilus sp.
468 (gastropod). These species range in their mode of life from
469 stationary epifaunal to facultatively mobile deep infaunal
470 (Table 1).
471 Interpretation: The predominance of mud-supported
472 texture and the faunal content reflect low-agitated, deep
473 open platform. The abundance of monoaxon and tetraxon
474 sponge spicules and calcareous algae suggests deposition in
475 a deep platform during period of sea level rise (Hughes
476 2006).
477 5. Foraminiferal algal packstone (FT5): This microfa-
478 cies type occurs in the upper Tuwaiq Mountain Formation
479 at Khashm Al-Giddiyah section. It is made up of few
480 millimeters thick smooth and crinkled laminae of yellow-
481 ish-green, massive marl that alternating with micrite and
482 microsparite laminae. The voids and microfractures within
483 the matrix are almost completely filled with sparry calcite.
484 The bioclasts in this microfacies represented by benthonic
485 foraminifera and calcareous green algae are well developed
486 to constitute up to 60 % of the rock that cemented by
487 crypyocrysalline calcite (about 30 %). Spherical hollow
488 calcitic bodies (calcisphers) are observed as aggregates or
489 in clusters and similar to the planktonic green algae. The
490 chambers of benthic foraminiferal tests are filled mainly by
491 spary calcite, while the test walls are completely micritized
492 (Fig. 6h). The micritic matrix may be formed by the dis-
493 integration of the algae.
494 Associated macrofauna: This microfacies type is found
495 barren of any macrofaunal elements.
496 Interpretation: The presence of the benthic foraminiferal
497 species (e.g., Kurnubia sp), calcareous green algae (e.g.,
498 Teutloporella nodosa), mud-supported texture, and the
499 absence of macrofaunal content reflect a slightly deep
500 platform environment. The green algae are one of the most
501 effective carbonate producers in modern tropical and sub-
502 tropical reefs and lagoons (Flu
¨gel 2004).
503 High-energy shoals of ooids and patch reef facies
504 association
505 6. Sandy biopeloidal grainstone (FT6): This microfacies
506 type is composed of hard fossiliferous limestone and occurs
507 in the upper Tuwaiq Mountain Formation at the Dirab
508 section. The allochems in this microfacies constitute about
509 70 % of the rock (Fig. 7a) and are cemented by crystalline
510 spary calcite (up to 25 %). Carbonate grains are repre-
511 sented mainly by rounded, spherical, and oval micritic
512 pellets of different sizes. However, the majority of these
513 allochems are of a 0.5 mm common size. The micrite in
514 pellets is recrystallized and transformed into microsparite.
515 The faunal content is less than 10 % and represented by
516 calcareous algae, bivalve debris, and foraminifera. Algal
517 and trace bivalve remains are transformed into spary
518
calcite. Some quartz grains are dispersed with medium to
519
fine sand size. Few of these quartz grains are encrusted
520
with thin rim of carbonate-forming oolitic structure.
521
Associated macrofauna: This microfacies type is found
522
barren of any macrofaunal elements.
523
Interpretation: The sediments of this microfacies were
524
deposited in agitated platform sand shoals above the fair-
525
weather wave base that similar to FZ6 of Wilson model
526
(1975). The abundance of rounded, well-sorted peloids and
527
rarely bioclastic grains may reflect moderate circulation
528
conditions and efficiency of winnowing by wave currents.
529
7. Pelloidal oolitic oyster floatstone (FT7):This
530
microfacies type consists of massive, hard, fossiliferous
531
limestone and recorded in the Hisyan Member at Shaib El-
532
Hisyan section. Oolites and large shell fragments of bra-
533
chiopods and pelecypods (Fig. 7b) are the main compo-
534
nents forming about 73 % of this microfacies and
535
cemented by crystalline calcite (up to 25 %). Oolitic grains
536
that constitute about 75 % of carbonate grains may have
537
radial structure and vary in their size from 0.3 to 1 mm.
538
They are mostly moderately sorted, well-rounded, and of
539
spherical shapes. Radial ooids are in the form of laminae
540
that made up of radially arranged crystals. Micritic pellets
541
in this microfacies vary in shape, where the spherical and
542
oval ones are more common. Another significant feature in
543
this microfacies is that the allochems are cemented together
544
by microsparite.
545
Associated macrofauna: The macrofauna associated
546
with this microfacies include the brachiopod species
547
Daghanirhynchia? triangulata,Eurysites rotundus,
548
Daghanirhynchia angulocostata, and Sphriganaria capax.
549
Besides, some pelecypod species, such as Africogryphea
550
costellata and Homomya vezalayi, are recorded in this
551
microfacies.
552
Interpretation: The abundant occurrence of carbonate
553
skeletal grains (e.g., ooids; pellets; large shell fragments)
554
with less micrite matrix is attributed to sand shoal envi-
555
ronment along platform margin. Grade of sorting of the
556
oolites may reflect moderate current turbulence. The
557
presence of the above-mentioned oyster and brachiopod
558
fauna reflects stationary epifaunal to facultatively mobile
559
deep infaunal mode of life (Table 1).
560
8. Coralline framestone/bindstone (FT8). This microfa-
561
cies type is consists of lightcolored, massive, reefal lime-
562
stone and occurs in the upper Tuwaiq Mountain Formation
563
at the middle part of Khashm Al-Giddiyah section. The
564
coral fragments, which are the principal component (up to
565
80 %) of this microfacies, were strongly recrystallized by
566
diagenetic process. The intergranular pores are filled by
567
microcrystalline calcite (Fig. 7c,d). Corals trapped many
568
other organisms, such as benthonic foraminifera.
569
Associated macrofauna: The coral Actinastrea crasso-
570
ramosa with a stationary intermediate-level epifaunal
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571 mode of life is the main macrofaunal element recorded in
572 this microfacies (Table 1).
573 Interpretation: The abundant occurrence of corals, the
574 high shell fragmentation of most fossils, and the poor
575 sorting of the matrix suggest a shallow water environment
576
of deposition, close to a platform-patch reefal environment,
577
with moderate to high turbulence.
578
9. Coralline dolomitic grainstone (FT9): This microfa-
579
cies type consists of yellowish-brown, hard limestone rich
580
in large corals at the top and is recorded in the upper
Fig. 7 High-energy shoals of
ooids and patch reef (a–e) and
restricted carbonate platform (f–
h) microfacies associations in
the Tuwaiq Mountain
Formation: aSandy biopeloidal
grainstone (FT6) in upper
Tuwaiq Mountain at Dirab
section; bPelloidal oolitic
oyster floatstone (FT7) of lower
Tuwaiq Mountain at Shaib El-
Hisyan section; c,dCoralline
framestone/bindstone (FT8) in
upper Tuwaiq Mountain at
cDirab section and dKhashm
Al-Giddiyah section;
eCoralline dolomitic grainstone
(FT9) in upper Tuwaiq
Mountain at Khashm Al-
Giddiyah section; fAlgal
dolomitic grainstone (FT10) in
upper Tuwaiq Mountain at
Dirab section; g,hRudstone
(FT11) in upper Tuwaiq
Mountain at gKhashm Al-
Giddiyah section and hDirab
section. Bar scale 250 lm
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581 Tuwaiq Mountain Formation at Khashm Al-Giddiyah
582 section. Petrographically, this microfacies is composed of
583 corals (65 %) that are recrystallized and transformed into
584 granular spary calcite (Fig. 7e). Ostracods and brachiopods
585 can be observed (\10 %), where their wall is completely
586 recrystallized and transformed into sparite. Besides the
587 above-mentioned elements, silica minerals of the chal-
588 cedony type and dolomite crystals (up to 25 %) with partial
589 neomorphism are well observed in this microfacies type.
590 That may due to siliceous corals or replacement of car-
591 bonate minerals to chalcedony.
592 Associated macrofauna: Only some coral elements and
593 few brachiopods are recorded.
594 Interpretation: This coralline-grainstone facies can be
595 formed along platform margin and as reefal patches in
596 high-energy shallow inner neritic environment. It may be
597 corresponding to facies zone FZ5 of Wilson (1975) that is
598 characterized by water depth generally some meters, and
599 the deposited facies are mainly represented by massive
600 limestone and dolomite.
601 Restricted carbonate platform facies association
602 10. Algal dolomitic grainstone (FT10): It consists of hard,
603 fossiliferous, dolomitic limestone and recorded in the upper
604 Tuwaiq Mountain Formation at the middle part of Dirab
605 section. The allochems constitute about 40–60 % of this
606 microfacies and are embedded in dolomitized spary calcite
607 enriched with iron oxides (up to 50 %). The faunal content
608 is represented by calcareous algal debris of variable shapes
609 and sizes, foraminifera, pelecypod fragments, corals,
610 echinoids, and some gastropods (Fig. 7f). The majority of
611 algae debris that constitute about 75 % of the bioclastic
612 grains is recrystallized and transformed into granular spary
613 calcite subjected to dolomitzation process. Other fossil
614 groups particularly echinoids, bryozoans, and corals are
615 less common than algae in this facies. Some of the echinoid
616 shells in this microfacies have a well-developed calcite
617 overgrowth. In addition, microbial dense pelloidal micrite
618 of different sizes is well developed in this microfacies.
619 Furthermore, quartz grains of medium to very fine sand-
620 size constitute smaller portion (\5 %) of this microfacies.
621 All carbonate and non-carbonate grains are embedded in
622 dolomitized spary calcite enriched with iron oxides.
623 Associated macrofauna: Rich coral content with a
624 variety of species (e.g., Actinastrea crassoramosa; Astro-
625 conian sp.; Ovalastrea michelini; Favian sp.) of stationary
626 intermediate-level epifaunal mode of life (Table 1).
627 Interpretation: The fossil assemblage and the low ter-
628 rigenous content in this microfacies may indicate the
629 deposition in restricted fore-reef environment with mod-
630 erate energy conditions. Dasyclad algae occur as rock-
631 building in restricted environments, and their distribution is
632
controlled by water temperature (warm waters, mostly
633
within the 208), substrate (sand and mud), salinity (normal
634
marine), water energy (low, generally subtidal), and depth
635
(below low tide down to about 30 m, commonly \5m)
636
(Flu
¨gel 2004).
637
11. Rudstone (FT11): This microfacies consists of light
638
olive, gray fragmental limestone with granule-pebble
639
grained conglomerate and recorded in the upper Tuwaiq
640
Mountain Formation at the lower part of Dirab and in the
641
upper part of Khashm Al-Giddiyah sections. These are
642
50 % of subrounded to subangular lithoclastics that are
643
resulted from postdepositional reworking of carbonate
644
substrate, including some shell fragments (e.g., echinoids
645
and foraminifera) (Fig. 7g, h). The lithoclasts, range in
646
their size from fine sand (62.5–125 lm) to very fine gravel
647
(3 mm), in this lithofacies are either embedded in micritic
648
matrix as in Khashm Al-Giddiyah section or cemented
649
together by macrocrystalline sparite as in Dirab section (up
650
to 45 %). This may reflect shallower depositional condi-
651
tions at Dirab section towards south than that of Khashm
652
Al-Giddiyah section towards north in the studied area.
653
Associated macrofauna: This microfacies type is found
654
barren of any macrofaunal elements.
655
Interpretation: The co-existence of the carbonate litho-
656
clastics with micrite matrix can be attributed to the
657
reworking of nearby pre-existing carbonates by storm
658
waves and their redeposition in agitated water. This litho-
659
facies can be formed as lagoonal deposits along restricted
660
platform interior usually landward in high-energy water
661
conditions.
662
12. Shale/siliciclastic mudstone (FT12): This lithofacies
663
is recorded as intercalations within the limestones in all the
664
measured sections (Figs. 3,4,5). The shale is fissile, slope-
665
forming, calcareous, sticky, soapy, gypsiferous, sandy,
666
unfossiliferous, and varicolored; grayish gray, yellowish
667
gray, and reddish brown. They are also highly ferruginous
668
and partly glauconitic.
669
Associated macrofauna: This microfacies type is found
670
barren of any macrofaunal elements.
671
Interpretation: This microfacies can be deposited in a
672
shallow, restricted platform environment with low-energy
673
conditions. The paucity of fauna reflects the deposition
674
under low-oxygen water conditions and/or high argilla-
675
ceous input during the deposition.
676
Discussion
677
The present study discusses the lithofacies, microfacies,
678
and biofacies characters of the Tuwaiq Mountain Forma-
679
tion to help in developing a meaningful depositional model
680
for this unit in central Arabia area. This formation consists
681
of build shoals, patch reefs, shoreface deposits, and
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682 bioclastic microfacies. The lateral and vertical changes of
683 these microfacies reflect a carbonate ramp depositional
684 environment (Fig. 8).
685 The lower member of the Tuwaiq Mountain Formation,
686 Hisyan Member, is dominated by mud and is composed of
687 green shale, which changes upwardly into greenish marl,
688 intercalated with hard limestone beds. The dominant car-
689 bonate microfacies in the lower Tuwaiq Mountain are
690 foraminiferal bioclastic wackestone (FT2) and molluscan
691 bioclastic packstone (FT3) capped by peloidal molluscan
692 floatstone microfacies (FT7) (Fig. 3). These microfacies
693 indicate the deposition in a quiet open platform environ-
694 ment that subjected to periodic agitation, while the peloidal
695 oolitic floatstone microfacies indicate the deposition in
696 high-energy sand shoal environments. Hughes (2004b)
697 based on the absence of ammonites suggested a shallow-
698 marine depositional environment for the Hisyan Member.
699 The basal unit (T1) of the upper Tuwaiq Mountain
700 Formation (Baladiyah Member) at Khashm Al-Giddiyah
701 section is composed of about 45 m thick yellowish-green
702 marl successions with gypsum vienlets and thin fossilifer-
703 ous hard limestone intercalations. The main microfacies of
704 this unit, foraminiferal bioclastic wackestone (FT2) and
705 molluscan bioclastic packstone (FT3), are characterized by
706 an enrichment of dense micrite matrix and by the presence
707 of epifaunal brachiopods as well as mobile deep infaunal
708
pelecypods (e.g., Pholadomya ssp). Based on these
709
microfacies types, it can be said that Baladiyah Member is
710
deposited in quiet open platform interior with low, and
711
sometimes high, water circulation (Fig. 4). On the other
712
hand, these facies types change into algal wacke/packstone
713
(FT4), pelloidal grainstone (FT6), and restricted rudstone
714
microfacies (FT11) in the southern part of the study area.
715
These microfacies changes indicate that the environment
716
changes southward from open deeper platform in Khashm
717
Al-Giddiyah section in the north to shallower restricted
718
platform environments in Dirab section (Fig. 5). The Bal-
719
adiyah Member was suggested to be deposited in a deep,
720
open-marine depositional environment in which a low
721
sedimentation rate prevailed, based on the presence of
722
abundant bivalves (Hughes 2004b,2008).
723
The middle unit of the formation, Maysiyah Member
724
T2, is composed of 70 m thick succession of ledge-forming
725
hard limestone that is abundant in coralline microfacies of
726
framestone and grainstone textures (FT8, FT9) as recorded
727
in Khashm Al-Giddiyah section. These microfacies change
728
into about 25 m thick succession of algal sponge
729
wacke/packstone (FT4), algal dolomitic grainstone (FT10),
730
and green shale intercalations (FT12) in Dirab section. It
731
can be suggested that these coralline microfacies associa-
732
tions were deposited in a shallow, reefal environment with
733
high-energy conditions interrupted by periodic quiet open-
Fig. 8 Block diagram showing the distribution of the sedimentary facies of the Callovian succession in the study area
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734 marine platform that caused the deposition of foraminiferal
735 packstone (FT5, Fig. 4). Southward in the study area, the
736 environment becomes more restricted to form shales and
737 algal dolomitic grainstone (Fig. 5).
738 The upper unit of the upper Tuwaiq Mountain Forma-
739 tion, Daddiyah Member (T3), is made up of 60 m of chalky
740 limestone with some ammonite fauna and chert intercala-
741 tions. This member is predominated by matrix-support
742 microfacies, such as foraminiferal lime mudstone (FT1),
743 foraminiferal bioclastic wackestone (FT2), and for-
744 aminiferal algal packstone (FT5). These microfacies types
745 reflect an open-marine platform environment with slightly
746 low circulation below fair-weather wave base. The area
747 was subjected to period of subaerial exposure and/or bio-
748 turbation and restricted marine conditions, where the car-
749 bonate intraclastics were deposited forming rudstone
750 microfacies (FT11) (Fig. 4). Towards the south in Dirab
751 section, the environment became shallower and subjected
752 to considerable quartz influx in agitated sand shoals, which
753 resulted in the deposition of thick ([90 m) succession of
754 sandy biopelloidal grainstone microfacies (FT6) (Fig. 5).
755 Hughes (2004b) suggested that the Daddiyah Member (T3)
756 may be deposited in a deeper maximum flooding stage
757 during the Tuwaiq Mountain Formation.
758 Conclusions
759 The lower Tuwaiq Mountain (Hisyan Member) is com-
760 posed mainly of mud-dominated and represented by for-
761 aminiferal bioclastic wackestone (FT2) and molluscan
762 bioclastic packstone (FT3) that are capped by thin peloidal
763 molluscan floatstone (FT7). These microfacies reflect quiet
764 open-marine environment that is subjected to periodic
765 agitation and a peloidal oolitic floatstone that had been
766 deposited in a high-energy sand shoal environment.
767 The basal unit of the upper Tuwaiq Mountain Limestone
768 (Baladiyah Member, T1) at Khashm Al-Giddiyah section is
769 composed of yellowish-green marl and intercalated with
770 thin fossiliferous hard limestone beds. The dominated
771 microfacies of this unit are foraminiferal bioclastic
772 wackestone (FT2) and molluscan bioclastic packstone
773 (FT3). These microfacies are characterized by an enrich-
774 ment of dense micrite matrix, and they are deposited in
775 quiet open-marine platform interior in low and sometimes
776 high water circulation. This environment is changed
777 southward in Dirab section and became shallower than in
778 Khashm Al-Giddiyah section, and the algal wacke/pack-
779 stone (FT4), pelloidal grainstone (FT6), and restricted
780 rudstone microfacies (FT11) had been deposited.
781 The middle member of the upper Tuwaiq Mountain
782 Limestone (Maysiah Member, T2) is composed of hard
783 coralline limestone. The microfacies of this unite is
784
framestone and grainstone textures (FT8, FT9) suggesting
785
deposition in shallow, high-energy reefal environment with
786
periodic quiet open-marine platform, where foraminiferal
787
packstone (FT5) was deposited. This environments pass
788
laterally into more restricted southward in Dirab section,
789
where shales and algal dolomitic grainstone had been
790
deposited.
791
The upper member of the upper Tuwaiq Mountain
792
Limestone (Daddiyah Member, T3) is made up of chalky
793
limestone with chert intercalation and characterized by
794
predominance of matrix-support microfacies as for-
795
aminiferal lime mudstone (FT1) and foraminiferal bioclastic
796
wackestone (FT2), as well as foraminiferal algal packstone
797
(FT5). These microfacies reflect open-marine platform with
798
slightly low circulation below fair-weather wave base. The
799
area of Khashm Al-Giddiyah section was subjected to period
800
of subaerial exposure, and rudstone microfacies was
801
deposited in restricted marine conditions (FT11). Towards
802
the south in Dirab section, these environments are shallower
803
than in Khashm Al-Giddiyah section with considerable
804
quartz influx in agitated sand shoals, and sandy biopelloidal
805
grainstone microfacies (FT6) were deposited.
806
Acknowledgments This project was supported by King Saud 807
University, Deanship of Scientific Research, College of Science 808
Research Center, Saudi Arabia.
809
References
810
Al-Aswad AA (1995) Middle Jurassic non-marine siliciclastic facies 811
in southern central Saudi Arabia. J Afri Sci 20(3–4):253–262 812
Al-Gahtani KM (2013) Stratigraphy, macrofaunal assemblages and 813
paleoenvironments of the Jurassic sequence (Callovian - Kim- 814
meridgian) of central Saudi Arabia. Ph.D, thesis, Al-Azhar 815
University, Cairo, Egypt, p 259 816
Al-Husseini MI (2009) Update to Late Triassic-Jurassic stratigraphy 817
of Saudi Arabia for the Middle East geologic time scale. 818
GeoArabia 14(2):145–186 819
Arkell WJ (1956) Jurassic geology of the world. Oliver & Boyd, 820
Geology, Stratigraphic, p 806 821
Basyoni M, Khalil M (2011) An overview of the diagenesis of the 822
Upper Jurassic carbonates of Jubaila and Hanifa formations, 823
central Saudi Arabia. Arab J Geosci: 1–16 824
Bramkamp R (1945) Unpublished report in Powers RW (1968) 825
Lexique stratigraphique international: Saudi Arabia: Vol. III, 826
Asie, fasc. 10b1: Centre National Recherche Scientifique, Paris, 827
p 177 828
Burchfiel HL, Hoover JW (1935) Unpublished report in Powers, RW 829
(1968) Lexique stratigraphique international: Saudi Arabia: Vol. 830
III, Asie, fasc. 10b1: Centre National Recherche Scientifique, 831
Paris, p 177 832
Dunham RJ (1962) Classification of carbonate rocks according to 833
depositional textures. In: Ham WE (ed), Classification of 834
carbonate rocks, Vol. 1. American Association Petroleum 835
Geologists Memoir, 108–121 836
El As’aad GMA (1989) Callovian colonial corals from the Tuwaiq 837
Mountan Limestone of Saudi Arabia. Paleontology 838
32(3):675–684
Carbonates Evaporites
123
Journal : Large 13146 Dispatch : 14-7-2016 Pages : 16
Article No. : 310 hLE hTYPESET
MS Code : CAEV-D-15-00010 hCP hDISK
44
REVISED PROOF
839 El-Asmar HM, Ehab M, Assal Abdelbaset S, El-Sorogy Mohamed
840 Youssef (2015) Facies analysis and depositional environments of
841 the Upper Jurassic Jubaila Formation, central Saudi Arabia. J Afr
842 Earth Sci 110(2015):34–51
843 El-Sorogy AS, Al-Kahtany KM, El-Asmar HM (2014) Marine benthic
844 invertebrates of the Upper Jurassic Tuwaiq Mountain Lime-
845 stone,Khashm Al-Qaddiyah, central Saudi Arabia. J Afr Earth
846 Sci 97:161–172
847 Enay R, Le Nindre YM, Mangold C, Manivit J, Vaslet D (1986). The
848 Jurassic of central Saudi Arabia: new data on lithostratigraphic
849 units, paleoenvironments, ammonite faunas, ages and correla-
850 tions. Deputy Ministry Mineral Resource, Jiddah, Technical
851 Record B.R.G.M.- TRO6-3: p 65
852 Flu
¨gel E (2004) Microfacies of carbonate rocks, analysis, interpre-
853 tation and application, 2nd edn. Springer-Verlag, Berlin, p 984
854 Galal G, Kamel SM (2004) Benthic foraminifera from the Callovian
855 (Middle Jurassic) Tuwaiq Formation, central Saudi Arabia:
856 Magallat Kulliyyat al-ulum. Gami’at imarat al-’arabiyyat al-
857 muttahidat =Journal of the Faculty of Science. UAE Univer-
858 sity, June, 2004, Vol. 13, pp 57–72
859 Hughes GW (2004a) Middle to Late Jurassic biofacies of Saudi
860 Arabia. Riv Ital Paleontol Stratigr 110:173–179
861 Hughes GW (2004b) Upper Jurassic Saudi Arabian carbonate
862 petroleum reservoirs; biostratigraphy, micropalaeontology, and
863 palaeoenvironments. GeoArabia 9(3):79–114
864 Hughes GW (2006) Biofacies and palaeoenvironments of the Jurassic
865 Shaqra group of Saudi Arabia. Volumina Jurassica VI, pp 33–45
866 Hughes GW (2008) Biofacies and palaeoenvironments of the Jurassic
867 Shaqra Group of Saudi Arabia. Volumina Jurassica, VI,
868 pp 33–45
869 Hughes GWAG (2009) Using Jurassic micropaleontology to deter-
870 mine Saudi Arabian carbonate paleoenvironments. Soc Sediment
871 Geol (SEPM) Special Publ 93:127–152
872 Lewy Z (1982) Gryphaeligmus n. gen. (Bivalvia; Malleidae) from the
873 Bathonian of the Middle East. J Paleontol 56(3):811815
874 Manivit J, Le Nindre YM, Vaslet D (1990) Histoire ge
´ologiquede la
875 bordure occidentale de la plate-forme arabe. Le Jurassique
876 d’Arabie Central e. Documents du Bureau de Recherches
877 Ge
´ologiqueset Minie
`res, Orle
´ans. Doc, 194: 560
878
Moshrif MA, Al-Asaad G (1984) Sedimentation environmental 879
interpretation of Hanifa Formation (Upper Jurassic), central 880
Saudi Arabia. J Coll Sci King Saud Univ 15(2):479–505 881
Okla SM (1986) Litho and microfacies of Upper Jurassic carbonate 882
rocks outcropping in central Saudi Arabia. J Petrol Geol 883
9(2):195–206 884
Pollastro RM (2003) Geologic and production characteristics utilized 885
in assessing the Barnett Shale continuous (unconven-tional) gas 886
accumulation, Barnett-Paleozoic total petroleum system, Fort 887
Worth Basin, Texas: Barnett Shale Symposium, Ellison Miles 888
Geotechnology Institute at Brookhaven College, Dallas, Texas, 889
November 12–13, 2003, p 6 890
Powers RW (1968) Lexique stratigraphique international. V. III, Asie, 891
10bl, Saudi Arabia. Centre National de la Recherche Scien- 892
tifique, Paris, pp 1–177 893
Powers RW, Ramirez LF, Redmond CD, Elberg EL (1966) Geology 894
of Arabian Peninsula, sedimentary geology of Saudi Arabia. Prof 895
Pap US geol Surv 560(D):1–147 896
Steineke M (1937) Unpublished ARAMCO report in Powers RW 897
(1968) Lexique stratigrapique international: Saudi Ara- 898
bia:Vol.III, Asia, fasc. 10b1: Centre National de la Recherche 899
Scientifique, Paris, p 177 900
Steineke M, Bramkamp RA (1952) Stratigraphical introduction. In: 901
Arkell W (ed) Jurassic ammonites from Jebel Tuwaiq, central 902
Arabia philosophical transactions Series B. 236. Royal Society, 903
London, pp 241–256 904
Steineke M, Bramkamp RA, Sanders NJ (1958) Stratigraphic 905
relations of Arabian Jurassic oil. In: Weeks LG (ed) Habitat of 906
oil. The American Association of Petroleum Geologist, Tulsa, 907
pp 1294–1329 908
Vaslet D, Delfour J, Manivit J, Le Nindre YM, Brosse JM, Fourniguc 909
J (1983) Geologic map of the Wadi a Rayn quadrangle, sheet 23 910
H., Kingdom of Saudi Arabia, Saudi Arabian Deputy Ministry 911
for Mineral Resources, Geoscience Map G.M.-63 Scale 912
1:250,000 with text, p 46 913
Wilson JL (1975) Carbonate facies in geological history. Springer- 914
Verlag, Berlin, p 471
915
Carbonates Evaporites
123
Journal : Large 13146 Dispatch : 14-7-2016 Pages : 16
Article No. : 310 hLE hTYPESET
MS Code : CAEV-D-15-00010 hCP hDISK
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