Geometry, kinematics and dynamic characteristics of a compound transfer zone: the Dongying anticline, Bohai Bay Basin, eastern China
5
Citation
39
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract The Dongying anticline is an E-W striking complex fault-bounded block unit which located in the central Dongying Depression, Bohai Bay Basin. The anticline covers an area of approximately 12 km 2 . The overlying succession, which is mainly composed of Tertiary strata, is cut by normal faults with opposing dips. In terms of the general structure, the study area is located in a compound transfer zone with major bounding faults to the west (Ying 1 fault) and east (Ying -8 and -31 faults). Using three-dimensional seismic data, wireline log and checkshot data, the geometries and kinematics of faults in the transfer zone were studied, and fault displacements were calculated. The results show that when activity on the Ying 1 fault diminished, displacement was transferred to the Ying -8, Ying -31 and secondary faults so that total displacement increased. Dynamic analysis shows that the stress fields in the transfer zone were complex: the northern portion was a left-lateral extensional shear zone, and the southern portion was a right-lateral extensional shear zone. A model of potential hydrocarbon traps in the Dongying transfer zone was constructed based on the above data combined with the observed reservoir rock distribution and the sealing characteristics of the faults. The hydrocarbons were mainly expulsed from Minfeng Sag during deposition periods of Neogene Guantao and Minghuazhen Formations, and migrated along major faults from source kitchens to reservoirs. The secondary faults acted as barriers, resulting in the formation of fault-bound compartments. The high points of the anticline and well-sealed traps near secondary faults are potential targets. This paper provides a reservoir formation model of the low-order transfer zone and can be applied to the hydrocarbon exploration in transfer zones, especially the complex fault block oilfields in eastern China.Keywords:
Anticline
Growth fault
Echelon formation
Neogene
Outcrop
Fault block
ABSTRACT North central Gulf Coast Middle Mesozoic zones of crustal weakness, caused by transform faulting associated with plate separation and rifting, became ideal loci for subsequent tectonic adjustments. Several lines of evidence - manifested in wrench faulting - point toward the existence of such adjustments occurring in the Upper Jurassic, Cretaceous, and Tertiary strata of this area. Eight lines of evidence suggest that there are at least four zones of faulting in the region that have been affected by lateral (and vertical) fault movements and associated extension fracturing. Isopach maps, en echelon fault/fold patterns, location of time-specific igneous activity, offset basement features, anomalous saltwater incursions into freshwater aquifers, offset surface geomorphic features, surface lineaments, and regional hydrocarbon migration patterns are all suggestive of dominant lateral motion along the affected zones in the subsurface and/or surface. Two main results of the region's wrench faulting are evident in (1) the development of vertical pathways or conduits facilitating hydrocarbon migration from deep, thermally mature source rocks to shallower reservoirs located in non-mature source rock zones; and (2) the development of extension fractures that enhance reservoir porosity. Both results have created the potential for increasing hydrocarbon source volumes available for migration and reservoiring.
Lineament
Echelon formation
Isopach map
Fault block
Anticline
Growth fault
Monocline
Cite
Citations (5)
This paper describes normal growth faults at the base of the Ferron Sandstone exposed along the highly accessible walls of Muddy Creek Canyon in central Utah. Although there have been several studies of growth faults in outcrops this is the first that integrates detailed sedimentological measured sections with fault kinematics and section restorations. We measured 20 sedimentological sections and interpreted a photomosaic covering approximately 200 m (550 ft) lateral distance. The outcrop is oriented parallel to depositional dip and perpendicular to the general strike of the faults. Distinctive pre-growth, growth, and post-growth strata indicate a highly river-dominated crevasse delta, that prograded northwest into a large embayment of the Ferron shoreline. The growth section comprises medium- to large-scale cross stratified sandstones deposited as upstream and downstream accreting mouth bars in the proximal delta front. Deposition of mouth bar sands initiates faults. Because depositional loci rapidly shift, there is no systematic landward or bayward migration of fault patterns. During later evolution of the delta, foundering of fault blocks creates an uneven sea-floor topography that is smoothed over by the last stage of deltaic progradation. Faults occur within less than 10 m (30 ft) water depths in soft, wet sediment. Detailed examination of the fault zones shows that deformation was largely by soft-sediment mechanisms, such as grain rolling and by lubrication of liquefied muds, causing shale smears. Mechanical attenuation of thin beds occurs by displacement across multiple closely spaced small throw faults. Analogous river-dominated deltaic subsurface reservoirs may be compartmentalized by growth faults, even in shallow-water, intracratonic, or shelf-perched highstand deltas. Reservoir compartmentalization would occur where thicker homogenous growth sandstones are placed against the muddy pre-growth strata and where faults are shale-smeared, and thus potentially sealing.
Outcrop
Growth fault
Anticline
Progradation
Lithology
Bedding
Fault block
Syncline
Cite
Citations (0)
Abstract Growth faulting is a common feature of many deltaic environments and is vital in determining local sediment dispersal and accumulation, and hence in controlling the resultant sedimentary facies distribution and architecture. Growth faults occur on a range of scales, from a few centimetres to hundreds of metres, with the largest growth faults frequently being under‐represented in outcrops that are often smaller than the scale of feature under investigation. This paper presents data from the exceptionally large outcrops of the Cliffs of Moher, western Ireland, where a growth‐fault complex affects strata up to 60 m in thickness and extends laterally for ≈ 3 km. Study of this Namurian (Upper Carboniferous) growth‐fault system enables the relationship between growth faulting and sedimentation to be detailed and permits reconstruction of the kinematic history of faulting. Growth faulting was initiated with the onset of sandstone deposition on a succession of silty mudstones that overlie a thin, marine shale. The decollement horizon developed at the top of the marine shale contact for the first nine faults, by which time aggradation in the hangingwall exceeded 60 m in thickness. After this time, failure planes developed at higher stratigraphic levels and were associated with smaller scale faults. The fault complex shows a dominantly landward retrogressive movement, in which only one fault was largely active at any one time. There is no evidence of compressional features at the base of the growth faults, thus suggesting open‐ended slides, and the faults display both disintegrative and non‐disintegrative structure. Thin‐bedded, distal mouth bar facies dominate the hangingwall stratigraphy and, in the final stages of growth‐fault movement, erosion of the crests of rollover structures resulted in the highest strata being restricted to the proximity of the fault. These upper erosion surfaces on the fault scarp developed erosive chutes that were cut parallel to flow and are downlapped by the distal hangingwall strata of younger growth faults.
Growth fault
Outcrop
Aggradation
Fault block
Onlap
Thrust fault
Geologic time scale
Cite
Citations (30)
Abstract The Burgos Basin in northeastern Mexico as shown in Fig. 1 produces from the clastic Paleocene in the western portion of the basin to the Miocene in the east. Fig. 2 is a stratigraphic chart of the Tertiary. As different Tertiary formations exhibit different structural styles, the primary structural style of each major formation will be discussed and compared. Structural features across the Burgos Basin are not uniform, but complex. Interpretation on 2D and 3D seismic data, on both regional and field development scales, has revealed faults and structures that result not only from extensional forces, but also from compressional or transverse forces. The purpose of this paper is to give a general synopsis of many of the structural styles that have been observed in the Burgos Basin. A common perception that structuring in Burgos is similar to South Texas may limit a more complete understanding of the basin's true potential. A majority of the faults are normal faults. Fault displacements range from a few meters to greater than 2000m (along the major growth fault systems). The extensional normal faults found in the basin have listric and high angle fault planes, syndepositional and post-depositional movement. Generally, synthetic faults are down-to-the-east and antithetic faults are down-to-the-west. Extensional structures include anticlines, synclines and graben systems. While most of the structuring is consistent with traditional Gulf of Mexico basin extensional tectonics, faults with reverse throw, normal faults along which there has been subsequent reverse movement, and anticlinal folds have been observed. These features may be related to deformation occurring in the mountains to the west of the Burgos Basin and result from transverse movement that extends as far to the east as the border with the United States. These anomalous structures are strikingly visible on 3D seismic data. A northeast-southwest or northwest-southeast trend is observed in non-extensional faults and may influence producing trends through the formation of natural fracture systems.
Anticline
Extensional fault
Growth fault
Syncline
Echelon formation
Fault block
Extensional tectonics
Cite
Citations (1)
Abstract The Dongying anticline is an E-W striking complex fault-bounded block unit which located in the central Dongying Depression, Bohai Bay Basin. The anticline covers an area of approximately 12 km 2 . The overlying succession, which is mainly composed of Tertiary strata, is cut by normal faults with opposing dips. In terms of the general structure, the study area is located in a compound transfer zone with major bounding faults to the west (Ying 1 fault) and east (Ying -8 and -31 faults). Using three-dimensional seismic data, wireline log and checkshot data, the geometries and kinematics of faults in the transfer zone were studied, and fault displacements were calculated. The results show that when activity on the Ying 1 fault diminished, displacement was transferred to the Ying -8, Ying -31 and secondary faults so that total displacement increased. Dynamic analysis shows that the stress fields in the transfer zone were complex: the northern portion was a left-lateral extensional shear zone, and the southern portion was a right-lateral extensional shear zone. A model of potential hydrocarbon traps in the Dongying transfer zone was constructed based on the above data combined with the observed reservoir rock distribution and the sealing characteristics of the faults. The hydrocarbons were mainly expulsed from Minfeng Sag during deposition periods of Neogene Guantao and Minghuazhen Formations, and migrated along major faults from source kitchens to reservoirs. The secondary faults acted as barriers, resulting in the formation of fault-bound compartments. The high points of the anticline and well-sealed traps near secondary faults are potential targets. This paper provides a reservoir formation model of the low-order transfer zone and can be applied to the hydrocarbon exploration in transfer zones, especially the complex fault block oilfields in eastern China.
Anticline
Growth fault
Echelon formation
Neogene
Outcrop
Fault block
Cite
Citations (5)
Anticline
Bedrock
Neogene
Surface exposure dating
Optically stimulated luminescence
Thrust fault
Landform
Cite
Citations (26)
Anticline
Anomaly (physics)
Lithology
Syncline
Cite
Citations (69)
The July oil field is a major normal-fault–bounded structural block in the Suez rift basin, Egypt. It is adjacent to a major structural transfer zone, which has controlled sediment influx to the rift basin center for the past 20 m.y. The lower to middle Miocene Upper Rudeis Formation, part of the synrift stratigraphic sequence, records deformation of the July structural block. The formation contains abrupt lateral changes in thickness and facies, which record earlier phases of fault movement and deformation in the July field area that do not conform to the present-day structural configuration.The Upper Rudeis Formation was deposited as turbidites in a submarine-fan system sourced from the western rift shoulder. It was deposited over and around bathymetric highs created by coeval fault displacement in the July field area. By studying thickness and facies patterns, we have determined that the present-day main bounding fault to the July block consisted of a series of unlinked fault segments, which linked after Upper Rudeis deposition. A subsidiary fault west of the block exerted the most control on thickness patterns, not the present-day main bounding fault. Thus, commonly used models of deposition in active half grabens are difficult to apply at July field.
Fault block
Growth fault
Echelon formation
Half-graben
Horst and graben
Rift zone
Horst
Anticline
Cite
Citations (27)