scholarly journals Aptian faulting in the Haushi-Huqf (Oman) and the tectonic evolution of the southeast Arabian platform-margin

GeoArabia ◽  
2003 ◽  
Vol 8 (4) ◽  
pp. 643-662 ◽  
Author(s):  
Christian Montenat ◽  
Pascal Barrier ◽  
Henri J. Soudet
Keyword(s):  
Strike Slip ◽  
Coarse Grained ◽  
Normal Faults ◽  
Third Order ◽  
Lower Aptian ◽  
Platform Margin ◽  
Platform Carbonates ◽  
Transform Margin ◽  
Order Sequence ◽  
Arabian Platform

ABSTRACT A major upper Aptian unconformity is recorded on the eastern Arabian Platform, between the lower Aptian Qishn limestone and the Albian Nahr Umr marls. The study of this hiatus, in the western homocline of the Haushi-Huqf Uplift (Eastern Central Oman) provides new data about the evolution of the eastern Arabian Platform during middle Cretaceous times. The limestones of the Qishn formed a shoaling sequence, mainly composed of matrix-rich, coarse-grained sediment with small rudistids and algal build-ups, that led to a subemergent environment. A third-order sequence is recognized in the Qishn platform carbonates, which is partitioned into three minor sequences. The Qishn carbonate was subjected to pre-lithification normal faulting. A thick ferrugineous crust (hardground) covered the top surface of the Qishn as well as the faultscarps before they were buried under the Albian Nahr Umr marls. The faults are dominantly NW-trending, SW-facing, normal faults. The significance of the faulting remains hypothetical. The syndiagenetic NW-SE normal faults may correspond to ‘en-echelon’ faults, combined with a sinistral movement of the Haushi-Nafun Fault (HNF). The HNF acted as a left-lateral, strike-slip fault during late Cretaceous, pre-Maastrichtian times. This movement possibly began earlier, during the late Aptian. It could be related to the dynamics of the eastern Arabian margin during the Cretaceous (Masirah transform margin). There are some indications testifying to the activity of the Masirah transform fault during the early-middle Cretaceous. The margin kinematics may be responsible for the reactivation of nearby large faults affecting the platform basement (for instance the HNF). A slight sinistral reactivation of the HNF may have induced the development of the Aptian NW-trending normal faults. Moreover, the occurrence of early Cretaceous strike-slip movements in the Arabian Platform have already been envisaged, at a plate-scale, as a consequence of the South Atlantic extension. On this assumption, the Aptian fault blocks may have resulted from the development of a sinistral transtension along the HNF.

scholarly journals Sequence stratigraphy of the Late Campanian – Early Maastrichtian Shiranish Formation, Jabal Sinjar, northwestern Iraq

GeoArabia ◽  
2010 ◽  
Vol 15 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Nabil Yousif Al-Banna
Keyword(s):  
Facies Analysis ◽  
Planktonic Foraminifera ◽  
Geological Time ◽  
Third Order ◽  
Lower Eocene ◽  
Shallow Marine ◽  
The Core ◽  
Aruma Formation ◽  
Order Sequence ◽  
Arabian Platform

ABSTRACT The Late Campanian – Maastrichtian Shiranish Formation consists of deep-marine marls and limestones that were deposited in northern and central Iraq. In northwestern Iraq, in the core of EW-trending Jabal Sinjar, a 430-m-thick section of the Shiranish Formation crops out. The base of the Shiranish section is not exposed here. It is unconformably overlain by Paleocene – Lower Eocene formations: Sinjar Formation along the northern part of the Jabal, and Aaliji Formation along its eastern side. Eighty samples were collected from the section and used for facies analysis and biostratigraphic calibration. Previous studies of planktonic foraminifera recognized four biozones, which were confirmed in the present study: Globotruncanita calcarata Interval Zone, Globotruncanella havanensis-Rosita fornicata Partial Range Zone, Globotruncana aegyptiaca Interval Zone and Gansserina gansseri Interval Zone. These zones are here calibrated in several geological time scales. Six facies were distinguishable throughout the section, representing shallow-marine, middle-shelf, outer-shelf and upper-bathyal environments. These environments were used to interpret six depositional sequences. The older five Shiranish sequences are fourth order and grouped into one third-order sequence, while the sixth and youngest Shiranish Sequence was of third order. This suggests that the studied section was deposited in about 5 million years between ca. 76.0–74.4 and 69.5–69.8 Ma. The correlation between the Shiranish sequences and those of the Aruma Formation in Saudi Arabia implies that the northern Arabian Platform was regionally flooded starting in the Late Campanian and ending in the Maastrichtian. In the study area, an unconformity straddles the Cretaceous – Tertiary (K/T) boundary and represent a hiatus of ca. 10 or more million years.

VULCAN SUB-BASIN FAULT STYLES — IMPLICATIONS FOR HYDROCARBON MIGRATION AND ENTRAPMENT

1992 ◽  
Vol 32 (1) ◽  
pp. 138 ◽  
Author(s):  
E.P. Woods
Keyword(s):  
Late Stage ◽  
Structural Complexity ◽  
Strike Slip ◽  
Normal Faults ◽  
Third Order ◽  
Hydrocarbon Migration ◽  
Structural Domains ◽  
The North ◽  
Hydrocarbon Traps ◽  
Timor Sea

Several structural domains are recognised within the Vulcan Sub-basin, Timor Sea. These domains developed during the Jurassic rifting phase and are separated by major transfer zones which trend in a northwest-southeast direction. Within each domain are frequent third order transfers which sub-divide the main northeast trending fault blocks into numerous compartments. These enable structural hydrocarbon traps to be formed, despite a predominant regional dip. They also affect migration pathways.Jurassic fault styles include detached rotational blocks, salt-associated features, tilted fault blocks and 'hourglass' horsts and grabens. These generally have a northeast-southwest orientation. The transfer faulting complicates these features and forms zones of structural complexity with associated poor seismic data quality. A separate fault episode in the north of the sub-basin during the Tithonian resulted in an east-west fault set overprinting the earlier structuring.Intra-Cretaceous fault movement is also recognised and has an important role in early hydrocarbon entrapment.Structural reactivation during the Late Miocene/Early Pliocene of the earlier fault sets modified the geometry of many existing traps. Numerous new traps may also have formed as a result of this tectonism. In many places the resulting geometry is complex, particularly where the younger fault orientation is at an angle to the main Oxfordian fault set. The late-stage movement is primarily extensional, manifested by predominantly normal faults; overall, however, a varying component of strike slip is likely. A divergent strike-slip zone is recognised at the southwest end of the Cartier Trough.The effects of the late stage tectonism tend to mask the seismic expression of Mesozoic hydrocarbon traps resulting in many wells being drilled off-structure at the target horizon. An understanding of the deeper structuring should result in further discoveries in this prospective basin.

Rampart seismic zone of central Alaska

1983 ◽  
Vol 73 (3) ◽  
pp. 813-829
Author(s):  
P. Yi-Fa Huang ◽  
N. N. Biswas
Keyword(s):  
Main Shock ◽  
Fault Plane ◽  
B Value ◽  
Aftershock Sequence ◽  
Strike Slip ◽  
Lithospheric Plate ◽  
Normal Faults ◽  
Seismic Zone ◽  
The West ◽  
Fault Plane Solutions

abstract This paper describes the characteristics of the Rampart seismic zone by means of the aftershock sequence of the Rampart earthquake (ML = 6.8) which occurred in central Alaska on 29 October 1968. The magnitudes of the aftershocks ranged from about 1.6 to 4.4 which yielded a b value of 0.96 ± 0.09. The locations of the aftershocks outline a NNE-SSW trending aftershock zone about 50 km long which coincides with the offset of the Kaltag fault from the Victoria Creek fault. The rupture zone dips steeply (≈80°) to the west and extends from the surface to a depth of about 10 km. Fault plane solutions for a group of selected aftershocks, which occurred over a period of 22 days after the main shock, show simultaneous occurrences of strike-slip and normal faults. A comparison of the trends in seismicity between the neighboring areas shows that the Rampart seismic zone lies outside the area of underthrusting of the lithospheric plate in southcentral and central Alaska. The seismic zone outlined by the aftershock sequence appears to represent the formation of an intraplate fracture caused by regional northwest compression.

Late Pleistocene extension and strike-slip in the Dead Sea Basin

2004 ◽  
Vol 141 (5) ◽  
pp. 565-572 ◽  
Author(s):  
YUVAL BARTOV ◽  
AMIR SAGY
Keyword(s):  
Internal Structure ◽  
Slip Rate ◽  
Dead Sea ◽  
Strike Slip ◽  
Normal Faults ◽  
Small Scale ◽  
Dead Sea Basin ◽  
Pull Apart Basin ◽  
Western Border ◽  
The Dead

A newly discovered active small-scale pull-apart (Mor structure), located in the western part of the Dead Sea Basin, shows recent basin-parallel extension and strike-slip faulting, and offers a rare view of pull-apart internal structure. The Mor structure is bounded by N–S-trending strike-slip faults, and cross-cut by low-angle, E–W-trending normal faults. The geometry of this pull-apart suggests that displacement between the two stepped N–S strike-slip faults of the Mor structure is transferred by the extension associated with the normal faults. The continuing deformation in this structure is evident by the observation of at least three deformation episodes between 50 ka and present. The calculated sinistral slip-rate is 3.5 mm/yr over the last 30 000 years. This slip rate indicates that the Mor structure overlies the currently most active strike-slip fault within the western border of the Dead Sea pull-apart. The Mor structure is an example of a small pull-apart basin developed within a larger pull-apart. This type of hierarchy in pull-apart structures is an indication for their ongoing evolution.

scholarly journals Development of fault and vein networks in a carbonate sequence near Hayl al-Shaz, Oman Mountains

GeoArabia ◽  
2013 ◽  
Vol 18 (2) ◽  
pp. 99-136
Author(s):  
Simon Virgo ◽  
Max Arndt ◽  
Zoé Sobisch ◽  
Janos L. Urai
Keyword(s):  
United Arab Emirates ◽  
Coarse Grained ◽  
Normal Faults ◽  
Structural Elements ◽  
High Angle ◽  
Oman Mountains ◽  
Bedding Planes ◽  
Fracture Systems ◽  
Calcite Veins ◽  
Al Jabal Al Akhdar

ABSTRACT We present a high-resolution structural study on the dip slope of the southern flank of Jabal Shams in the central Oman Mountains. The objectives of the study were: (1) to test existing satellite-based interpretations of structural elements in the area; (2) prepare an accurate geological map; and (3) collect an extensive structural dataset of fault and bedding planes, fault throws, veins and joints. These data are compared with existing models of tectonic evolution in the Oman Mountains and the subsurface, and used to assess the applicability of these structures as analogs for fault and fracture systems in subsurface carbonate reservoirs in Oman. The complete exposure of clean rock incised by deep wadis allowed detailed mapping of the complex fault, vein and joint system hosted by Member 3 of the Cretaceous Kahmah Group. The member was divided into eight units for mapping purposes, in about 100 m of vertical stratigraphy. The map was almost exclusively based on direct field observations. It includes measurement of fault throw in many locations and the construction of profiles, which are accurate to within a few meters. Ground-truthing of existing satellite-based interpretations of structural elements showed that faults can be mapped with high confidence using remote-sensing data. The faults range into the subseismic scale with throws as little as a few decimeters. However, the existing interpretation of lineaments as cemented fractures was shown to be incorrect: the majority of these are open fractures formed along reactivated veins. The most prominent structure in the study area is a conjugate set of ESE-striking faults with throws resolvable from several centimeters to hundreds of meters. These faults contain bundles of coarse-grained calcite veins, which may be brecciated during reactivation. We interpret these faults to be a conjugate normal- to oblique fault set, which was rotated together with bedding during the folding of the Al Jabal al-Akhdar anticline. There are many generations of calcite veins with minor offset and at high-angle-to-bedding, sometimes in en-echelon sets. Analysis of clear overprinting relationships between veins at high-angle-to-bedding is consistent with the interpretations of Holland et al. (2009a); however we interpret the anticlockwise rotation of vein strike orientation to start before and end after the normal faulting. The normal faults post-date the bedding-parallel shear veins in the study area. Thus these faults formed after the emplacement of the Semail and Hawasina Nappes. They were previously interpreted to be of the same age as the regional normal- to oblique-slip faults in the subsurface of northern Oman and the United Arab Emirates, which evolved during the early deposition of the Campanian Fiqa Formation as proposed by Filbrandt et al. (2006). We interpret them also to be coeval with the Phase I extension of Fournier et al. (2006). The reactivation of these faults and the evolution of new veins was followed by folding of the Al Jabal al-Akhdar anticline and final uplift and jointing by reactivation of pre-existing microveins. Thus the faults in the study area are of comparable kinematics and age as those in the subsurface. However they formed at much greater depth and fluid pressures, so that direct use of these structures as analogs for fault and fracture systems in subsurface reservoirs in Oman should be undertaken with care.

scholarly journals Tectono-Stratigraphic Note: Time calibration of late Carboniferous, Permian and Early Triassic Arabian stratigraphy to orbital-forcing predictions

GeoArabia ◽  
2005 ◽  
Vol 10 (2) ◽  
pp. 189-192 ◽  
Author(s):  
Moujahed Al-Husseini ◽  
Robley K. Matthews
Keyword(s):  
Second Order ◽  
Late Carboniferous ◽  
Orbital Forcing ◽  
Third Order ◽  
Depositional Sequence ◽  
Sequence Stratigraphic ◽  
Rosetta Stone ◽  
Time Calibration ◽  
Sequence Boundaries ◽  
Order Sequence

The recent publication of GTS 2004 (Gradstein et al., 2004) provides an opportunity to recalibrate in time the late Carboniferous, Permian and Early Traissic Arabian Stratigraphy (GeoArabia Special Publication 3, Edited by Al-Husseini, 2004) as represented by the rock units in subsurface Interior Oman (Osterloff et al., 2004a, b) and the Haushi-Huqf Uplift region (Angiolini et al., 2004) (Figure). Additionally, sequence stratigraphic models of orbital forcing (Matthews and Frohlich, 2002; Immenhauser and Matthews, 2004) provide new insights in regards to the time calibration of depositional sequences: the “Rosetta Stone” approach. The Rosetta Stone approach predicts that the period of a third-order depositional sequence is 2.430 ± 0.405 my (denoted DS3 and here adjusted to increase the fourth-order ‘geological tuning fork’ from 0.404 to 0.405 my based on Laskar et al., 2004). The present calibration is also tied to the orbital-forcing model developed by R.K. Matthews (in Al-Husseini and Matthews, 2005; this issue of GeoArabia) that predicts that a second-order depositional sequence (denoted DS2) consists of six DS3s that were deposited in a period of about 14.58 my (6 x 2.430 my); the DS2 being bounded by two regional second-order sequence boundaries (SB2) corresponding to sea-level maximum regression surfaces.

scholarly journals Cenozoic tectonic model of the Bohai Bay Basin in China

2016 ◽  
Vol 153 (5-6) ◽  
pp. 866-886 ◽  
Author(s):  
FUSHENG YU ◽  
HEMIN KOYI
Keyword(s):  
Data Interpretation ◽  
Strike Slip ◽  
Normal Faults ◽  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Basin Inversion ◽  
Tectonic Model ◽  
Early Oligocene ◽  
Anticlockwise Rotation ◽  
Partial Inversion

AbstractModelling results and seismic interpretation illustrate that the Cenozoic evolution of the Bohai Bay Basin (BBB) can be divided into different stages. A transtensional phase during Paleocene – early Oligocene time created NE-trending strike-slip faults and E–W-trending normal faults which were driven roughly by N–S–extension, making an angle of 25° with the strike-slip faults. Seismic data interpretation yields evidence that inversion phases occurred within the NE Xialiaohe Depression of the greater Bohai Bay Basin. This inversion phase is attributed to rotation and partial inversion that occurred during late Oligocene time, leading to formation of inversion structures along the NE part of Tanlu Fault. This episode is attributed to an anticlockwise rotation of the eastern part of the BBB driven by the convergence between the Pacific and Eurasian plates. The tectonic scenario described was simulated in scaled analogue models, which were extended by pulling two basement plates away from each other. Partial inversion was simulated by rotation of one of the plates relative to the other. Model results show many of the features observed in the BBB. Our model results are used to argue that, unlike the two-episode extension and whole-basin inversion models previously proposed for the BBB, a single N–S-aligned extension followed by anticlockwise rotation accounts for the Cenozoic evolution of the BBB and produces some of the structural complexities observed in the basin.

Quantifying fault reactivation risk in the western Gippsland Basin using geomechanical modelling

2013 ◽  
Vol 53 (1) ◽  
pp. 255 ◽  
Author(s):  
Ernest Swierczek ◽  
Cui Zhen-dong ◽  
Simon Holford ◽  
Guillaume Backe ◽  
Rosalind King ◽  
...  
Keyword(s):  
Structural Model ◽  
Strike Slip ◽  
Fault Reactivation ◽  
Fault System ◽  
Co2 Injection ◽  
Normal Faults ◽  
Surface Geometry ◽  
Northern Margin ◽  
Fault Surface ◽  
Gippsland Basin

The Rosedale Fault System (RFS) bounds the northern margin of the Gippsland Basin on the Southern Australian Margin. It comprises an anastomosing system of large, Cretaceous-age normal faults that have been variably reactivated during mid Eocene-Recent inversion. A number of large oil and gas fields are located in anticlinal traps associated with the RFS, and in the future these fields may be considered as potential storage sites for captured CO2. Given the evidence for geologically recent fault reactivation along the RFS, it is thus necessary to evaluate the potential impacts of CO2 injection on fault stability. The analysis and interpretation of 3D seismic data allowed the authors to create a detailed structural model of the western section of the RFS. Petroleum geomechanical data indicates that the in-situ stress in this region is characterised by hybrid strike-slip to reverse faulting conditions where SHmax (40.5 MPa/km) > SV (21 MPa/km) ~ Shmin (20 MPa/km). The authors performed geomechanical modelling to assess the likelihood of fault reactivation assuming that both strike-slip and reverse-stress faulting regimes exist in the study area. The authors’ results indicate that the northwest to southeast and east-northeast to west-southwest trending segments of the RFS are presently at moderate and high risks of reactivation. The authors’ results highlight the importance of fault surface geometry in influencing fault reactivation potential, and show that detailed structural models of potential storage sites must be developed to aid risk assessments before injection of CO2.

A SEQUENCE STRATIGRAPHIC STUDY OF THE CALLOVIAN FLUVIO-DELTAIC TO MARINE SUCCESSION WITHIN THE ZOCA REGION

1996 ◽  
Vol 36 (1) ◽  
pp. 269 ◽  
Author(s):  
P.A. Arditto
Keyword(s):  
Coastal Plain ◽  
Distribution Patterns ◽  
Zone Boundary ◽  
Third Order ◽  
Sediment Distribution ◽  
Sequence Stratigraphic ◽  
Modern Analogue ◽  
Delta System ◽  
Order Sequence ◽  
Reference Section

This paper presents the results and conclusions of an integrated sequence stratigraphic study of the Callovian marine succession across area 'A' of the Zone of Cooperation (ZOCA). This study utilised wireline log and conventional core data from within ZOCA 91–1 and ZOCA 91–12, and incorporated trade data from adjacent permits, to generate a rational depositional model for the succession. Three distinct third-order sequences have been recognised from the detailed correlation of regional flooding surfaces recognised on wireline log motifs calibrated against conventional core and biostratigraphy. The base of the oldest third-order sequence includes section previously referred to as Plover Formation, and roughly corresponds to the W.digitata/W.indotata zone boundary. The Callovian Unconformity within the ZOCA region is thus relegated to a third-order sequence boundary or disconformity. The term Elang Formation is proposed for this Callovian succession which comprises three third-order sequences mappable across ZOCA. The well-type section for the Elang Formation is Elang-1, and an additional well reference section would be Elang-2, as both these wells contain significant and complementary cored section.Detailed sedimentological studies on conventional core reveal that the Elang Formation comprises a succession of coastal plain to nearshore marine sediments, ranging from low sinuosity fluvial channel, fluvial-dominated deltaic, proximal low sinuosity estuarine channel and distal outer bay sediments. Only minor wave-dominated, open marine shoref ace intervals were interpreted, most of the cored intervals indicating a fluvially-domi-nated shoreline with minimal wave reworking. Isopach and per cent sand maps generated for each third-order sequence comprising the Elang Formation illustrate the successive sediment distribution patterns across ZOCA during the progressive marine transgression from the top of the fluvio-deltaic Plover Formation to the base of the offshore marine Lower Flamingo Group. The sand-trend maps for the three sequences which comprise the Elang Formation indicate a fluvial/estuarine-dominated delta system, sourced from the region of the Laminaria Field, AC/P8, building east and southeast out across the ZOCA region. A modern analogue of this delta system in both size and sedimentation style may be the Brahmaputra/Ganges Delta of East Bengal.

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