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The architecture of lacustrine systems is the result of the complex interaction between tectonics, climate and environmental parameters, and constitute the main forcing parameters on the lake dynamics. Field analogue studies have been performed to better assess such interactions, and their impact on the facies distribution and the stratigraphic architecture of lacustrine systems. The Yacoraite Formation (Late Cretaceous/Early Palaeocene), deposited during the sag phase of the Salta rift basin in Argentina, is exposed in world‐class outcrops that allowed the dynamics of this lacustrine system to be studied through facies analysis and stratigraphic evolution. On the scale of the Alemania‐Metán‐El Rey Basin, the Yacoraite Formation is organized with a siliciclastic‐dominated margin to the west, and a carbonate‐dominated margin to the east. The Yacoraite can be subdivided into four main 'mid‐term' sequences and further subdivided into 'short‐term' sequences recording high frequency climate fluctuations. Furthermore, the depositional profiles and identified system tracts have been grouped into two end‐members at basin scale: (a) a balanced 'perennial' depositional system for the lower part of the Yacoraite Formation and (b) a highly alternating 'ephemeral' depositional system for the upper part of the Yacoraite Formation. The transition from a perennial system to an ephemeral system indicates a change in the sedimentary dynamics of the basin, which was probably linked with the Cretaceous/Tertiary boundary that induced a temporary shutdown of carbonate production and an increase in siliciclastic supply. [ABSTRACT FROM AUTHOR]

Models to explain alluvial system development in rift settings commonly depict fans that are sourced directly from catchments formed in newly uplifted footwalls, which leads to the development of steep‐sided talus‐cone fans in the actively subsiding basin depocentre. The impact of basin evolution on antecedent drainage networks orientated close to perpendicular to a rift axis, and flowing over the developing hangingwall dip slope, remains relatively poorly understood. The aim of this study is to better understand the responses to rift margin uplift and subsequent intrabasinal fault development in determining sedimentation patterns in alluvial deposits of a major antecedent drainage system. Field‐acquired data from a coarse‐grained alluvial syn‐rift succession in the western Gulf of Corinth, Greece (sedimentological logging and mapping) has allowed analysis of the spatial distribution of facies associations, stratigraphic architectural elements and patterns of palaeoflow. During the earliest rifting phase, newly uplifted footwalls redirected a previously established fluvial system with predominantly southward drainage. Footwall uplift on the southern basin margin at an initially relatively slow rate led to the development of an overfilled basin, within which an alluvial fan prograded to the south‐west, south and south‐east over a hangingwall dip slope. Deposition of the alluvial system sourced from the north coincided with the establishment of small‐scale alluvial fans sourced from the newly uplifted footwall in the south. Deposits of non‐cohesive debris flows close to the proposed hangingwall fan apex pass gradationally downstream into predominantly bedload conglomerate deposits indicative of sedimentation via hyperconcentrated flows laden with sand‐ and silt‐grade sediment. Subsequent normal faulting in the hangingwall resulted in the establishment of further barriers to stream drainage, blocking flow routes to the south. This culminated in the termination of sediment supply to the basin depocentre from the north, and the onset of underfilled basin conditions as signified by an associated lacustrine transgression. The evolution of the fluvial system described in this study records transitions between three possible end‐member types of interaction between active rifting and antecedent drainage systems: (a) erosion through an uplifted footwall, (b) drainage diversion away from an uplifted footwall and (c) deposition over the hangingwall dip slope. The orientation of antecedent drainage pathways at a high angle to the trend of a developing rift axis, replete with intrabasinal faulting, exerts a primary control on the timing and location of development of overfilled and underfilled basin states in evolving depocentres. [ABSTRACT FROM AUTHOR]

Lacustrine rift basins commonly preserve a fairly complete record of the sediment source‐to‐sink (S2S) system, and consequently may form an ideal natural laboratory for establishing quantitative relationships between the various elements within the S2S system. The tectonic‐activity rate in the source (e.g., fault‐growth rate and fault‐activity rate), accommodation space and depositional system in the sink (e.g., areal extent and volume, as well as the depositional dip of the fan‐ and braid‐deltas) are genetically related and their quantitative correlations are explored. The Palaeogene succession on the southwestern margin of the Huanghekou Depressionin the Bohai Bay Basin, one of the largest lacustrine rift basins in eastern China, was chosen to study these relationships, using 3‐D seismic, core and well‐log data. The tectonic activity was strongly related to the sediment supply, accommodation space and morphology of the sink area. Three different rates of tectonic activity are identified; these led to changes in the basic features of the S2S system that influenced each other. In Members 4 and 3 (lower unit) of the Shahejie Fm. (40.44–44.7 Ma), strong tectonic activity led to significant uplift, resulting in the widest exposure of the provenance area to erosion, to a high sediment‐supply rate, to a steep slope and to a large accommodation space which controlled the development of several fan‐deltas with steep progradational angles. In Member 3 (upper unit) of Shahejie Fm. (37.89–40.44 Ma) and Member 3 of Dongying Fm. (30.2–33.28 Ma), decreased tectonic activity led to slower uplifting, resulting in a wider alluvial plain, longer transport distances, a lower sediment‐supply rate and less accommodation space, so that braid‐deltas with larger volumes and a gentler slope developed; In Members 1 and 2 of Shahejie Fm. (33.28–37.89 Ma) and Member 2 of Dongying Fm. (26.71–30.2 Ma), still further decreasing tectonic activity led to a still lower sediment‐supply rate, a more gentle depositional slope, less accommodation space, and the development of several braid‐deltas with a gentle angle. The quantitative relationships established here advance our understanding of the relationships within lacustrine source‐to‐sink systems, especially for tectonically controlled rift basins. [ABSTRACT FROM AUTHOR]

The dynamics of sediment feeding into rift basins and the geomorphologic nature of source areas are critical elements in understanding the evolution of rifted basins. This study integrates seismic, well and geochronologic data on the western dipslope of the Raoyang Sag, a rift associated sub‐basin to the larger Bohai Bay Basin of China to define the history of drainage development for the basin and to assess the sedimentologic response to drainage evolution events. In the Paleogene‐age Lixian Slope, as indicated by paleo‐drainage configuration, progradational seismic geometries, compositional maturity and zircon‐tourmaline‐rutile maturity index trends, three drainages; the paleo‐Daqing River, paleo‐Tang River and paleo‐Dasha River drainages were feeding three closely spaced hanging wall deltaic depositional systems; Delta A fed from the northwest, Delta B fed from the west and Delta C fed from the southwest, respectively. From the late Eocene to early Oligocene, a decrease in sediment‐flux into the hanging wall is documented and petrographic analysis is used to link these changes to stream‐capture in the upstream catchment of the Daqing River. This change is coupled with morphologic changes in the geometries of Deltas A and C, both of which show decreasing deltaic areas, changes in lobe geometry and changes in distributary channel sizes. In addition, the progradational direction of Delta C changes from perpendicular‐to‐the‐rift axis to prograding oblique‐to‐the‐rift axis. It is apparent that the progradation and retrogradational changes in rift margin deltas do not happen in isolation, but such changes can affect growth and progradation direction in adjacent deltas. This work shows that the decrease in sediment‐flux, caused by a drainage capture, will result in a decrease in distributary channel size and delta size and may result in upstream deltas taking advantage of such decreasing confinement to prograde more obliquely to the rift axis. [ABSTRACT FROM AUTHOR]

Interpretation of gravity, magnetotelluric, and aeromagnetic data in conjunction with geologic constraints reveals details of basin geometry, thickness, and spatiotemporal evolution of the southern San Luis Basin, one of the major basins of the northern Rio Grande rift. Spatial variations of low-density basin-fill thickness are estimated primarily using a 3D gravity inversion method that improves on previous modeling efforts by separating the effects of the low-density basin fill from the effects of pre-rift rocks. The basin is found to be significantly narrower--and more complex in the subsurface--than indicated or implied by previous modeling efforts. The basin is also estimated to be significantly shallower than previously estimated. Five distinct subbasins are recognized within the broader southern San Luis Basin. The oldest and shallowest subbasin is the Las Mesitas graben along the northwestern basin margin, formed during the Oligocene transition from Southern Rocky Mountain volcanic field magmatism to rifting. In this subbasin, sediments are estimated to reach a maximum thickness of ~400 m within a north-south elongated structural depression. Other subbasins that likely initially developed during the Miocene are the dominant tectonic features in the southern San Luis Basin. This includes the Tres Orejas subbasin, which formed in the southwestern portion of the basin by the Embudo fault zone and a hypothesized fault zone along its western margin. This subbasin reaches a maximum thickness of ~2 km, as indicated by magnetotelluric and gravity modeling. The Sunshine Valley, Questa, and Taos subbasins occupy the eastern part of the southern San Luis Basin. The southern Sangre de Cristo fault zone is the dominant tectonic feature that controlled their development after ~20 Ma. The east-down Gorge fault zone controlled the western margins of significant parts of these eastern subbasins, although much of the Taos subbasin may be superimposed on the Tres Orejas subbasin. Maximum low-density basin-fill thicknesses are estimated to be 1.2 km for the Sunshine Valley subbasin, 800 m for the Questa subbasin, and 1.8 km for the Taos subbasin. Subbasin-forming tectonic activity along the Gorge fault zone and within the Tres Orejas subbasin ceased by the end of the development of the largely Pliocene Taos Plateau volcanic field. After that, rift-related subsidence became more narrowly centered on the eastern margin of the basin, controlled mainly by the linked Embudo and southern Sangre de Cristo fault zones. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Songkhla basin has four phases of tectonic activity. • Eocene – boundary faults conformed to a coherent fault model. • Oligocene – Miocene – boundary faults switched to an isolated fault model. Abstract The Cenozoic N-S trending Songkhla rift basin, located in the southwest Gulf of Thailand, is a half-graben structure. The boundary fault zone on the western side of the basin is formed from a series of N-S to NNE-SSW, east-dipping normal faults. The Songkhla basin is an example of a predominantly orthogonal extended half graben that developed in phases between the Late Eocene and the early Middle Miocene, and appears to be little affected by pre-existing fabrics. The rift spans two phases of rifting: the Eocene-Oligocene phase that is present in the eastern, and the Oligocene-Miocene phase that is present in the western Gulf of Thailand and onshore areas. 2D and 3D seismic data shows that the tectonic phases within the Songkhla basin are slightly different from the overall regional pattern and comprises: (1) an early rift stage in the Eocene; (2) a late rift stage from Oligocene to Early Miocene (3) a post-rift Middle Miocene stage, possibly with minor inversion; and, (4) continuation of post-rift subsidence from the Pliocene to recent. The early rift stage is marked by numerous relatively small extensional faults. Many of these faults became inactive during the later extensional episodes, when extension was focused on the boundary fault system. The region of the boundary fault investigated here is composed of five large segments (F1-F5). During the Eocene, the segments, except for F5, became hard linked, and generally by the end of the Eocene, throw conformed to a coherent model. However, despite the boundary fault segments becoming linked during the Oligocene to Miocene, where extensional throws were relatively low, the throw patterns along the fault zone started to change to an isolated fault model, where several throw highs and lows are present along the fault trace. [ABSTRACT FROM AUTHOR]

Some potentially attractive reservoirs, containing anomalously thick (10s to a few 100 m), cross-stratified sandstone, have been locally encountered within both the classic regressive (lower Brent) and the transgressive (upper Brent) segments of the Brent Delta. Three documented cases of these sandstone bodies are re-examined. They are internally dominated by simple or compound dunes, and typified by two types of deepening-upward succession, recording a retrogradational or transgressive shoreline history. Type I is expressed as a single estuarine succession changing upwards from erosive, coarse-grained channelized deposits into outer estuary tidal bar deposits. The estuary is underlain and overlain by deltaic deposits. Type II lacks significant basal river deposits but is composed by stacked mixed-energy and tide-dominated estuarine deposits. It is underlain by deltaic deposits and overlain by open marine sediments. Considering the structural evolution in the northern North Sea basin, we suggest (as did some earlier researchers) that these sandstone bodies were local, but sometimes broad transgressive estuaries, formed at any time during large-scale Brent Delta growth and decay. The estuary generation was likely triggered by fluvial incision coupled with active faulting, producing variable accommodation embayments, where tidal currents became focused and deposition became transgressive. The spatial variations of the interpreted estuary deposits were linked with variable, fault-generated accommodation. The relatively simple, lower Brent estuarine units were created by short-lived, fault activity in places, whereas the complex, stacked upper-Brent estuarine units were likely a result of more long-lived, punctuated fault-induced subsidence leading into the northern North Sea main rifting stage. The thick cross-stratified units potentially accumulated in the hangingwall of large bounding faults. [ABSTRACT FROM AUTHOR]

Continental 'overfilled' conditions during rift initiation are conventionally explained as due to low creation of accommodation compared with sediment supply. Alternatively, sediment supply can be relatively high from the onset of rifting due to an antecedent drainage system. The alluvial Lower Group of the western Plio-Pleistocene Corinth rift is used to investigate the interaction of fluvial sedimentation with early rifting. This rift was obliquely superimposed on the Hellenide mountain belt from which it inherited a significant palaeorelief. Detailed sedimentary logging and mapping of the well-exposed syn-rift succession document the facies distributions, palaeocurrents and stratigraphic architecture. Magnetostratigraphy and biostratigraphy are used to date and correlate the alluvial succession across and between fault blocks. From 3·2 to 1·8 Ma, a transverse low sinuosity braided river system flowed north/north-east to east across east-west-striking active fault blocks (4 to 7 km in width). Deposits evolved downstream from coarse alluvial conglomerates to fine-grained lacustrine deposits over 15 to 30 km. The length scale of facies belts is much greater than, and thus not directly controlled by, the width of the fault blocks. At its termination, the distributive river system built small, stacked deltas into a shallow lake margin. The presence of a major antecedent drainage system is supported by: (i) a single major sediment entry point; (ii) persistence of a main channel belt axis; (iii) downstream fining at the scale of the rift basin. The zones of maximum subsidence on individual faults are aligned with the persistent fluvial axis, suggesting that sediment supply influenced normal fault growth. Instead of low accommodation rate during the early rift phase, this study proposes that facies progradation can be controlled by continuous and high sediment supply from antecedent rivers. [ABSTRACT FROM AUTHOR]

Abstract: High-resolution three-dimensional seismic data show that fault distribution and evolution in rift basins can be very complicated and inconsistent with the classic model of fault formation and propagation. Fault development in the presence of multiple pre-existing weaknesses is still not clearly studied. Trying to understand the role of multiple pre-existing weaknesses in sand models, two series of experiments were prepared. In the first series of models, the mechanical properties of pre-existing weaknesses were the same but their orientations were different, whereas in the second series of models, both mechanical properties and orientations were different. The basic characteristics of fault formation and evolution in a rift basin revealed by the models are as follows: 1) weakness-reactivated faults (faults that formed directly along and above the pre-existing weaknesses) and weakness-related faults (faults which are not located above the pre-existing weaknesses, but have similar orientation) form much earlier than weakness-unrelated faults. The order of formation of different weakness-reactivated faults is determined by the relative reactivation tendency factors (f a) of the weaknesses; 2) weakness-reactivated faults and weakness-related faults develop mainly along or parallel to pre-existing weaknesses. In contrast, weakness-unrelated faults develop nearly perpendicular to the extension direction; 3) a complicated fault system can form during a single extension phase in the presence of multiple pre-existing weaknesses; and 4) the mode of fault formation and propagation and the increase in length and number of faults have close ties to the nature of pre-existing weaknesses. Fault displacement and length do not have a power law relationship for the majority of faults, and there is no unique relationship for different kinds of faults. In addition to providing new insights to the formation of complex fault systems, the experiment results presented here could be reasonably explained using the Reactivation Tendency Theory. They can also be applied to the complicated fault system in rift basin. [Copyright &y& Elsevier]

Abstract: Displacement ratio (D r) is the ratio between salt thickness (T v) and sub-salt normal fault displacement (D) (D r = T v/D), and it is typically used to predict the degree of geometric and kinematic linkage between sub- and supra-salt fault populations, and the overall structural style in salt-influenced extensional settings. However, we currently lack natural examples of how D r and the underlying geological controls vary, and how these may control the three-dimensional geometry and evolution of salt-influenced normal fault systems. Furthermore, it is currently unknown if kinematic coherence in salt-influenced extensional settings can be maintained over relatively long length-scales (101–103 m) and for relatively long timeframes, and how this may impact the growth and geometry of large-throw (>500 m), salt-influenced normal fault systems. In this paper we use a 3600 km2, high-quality 3D seismic reflection dataset and borehole data from the Stavanger Fault System (SFS), Egersund Basin, eastern North Sea Basin to investigate; (i) how pre-rift salt thickness (T v) and sub-salt fault throw (T) control the structural style and evolution of a basin-bounding, salt-influenced normal fault system; and (ii) the role salt plays in maintaining kinematic coherence in normal fault systems. We demonstrate that; (i) pre-rift salt distribution (T v), specifically its presence in the proto-footwall (i.e., when T v > 0), is the primary control on partitioning of faulting and (forced) folding along the fault system, and the style of linkage (i.e., hard- or soft-linkage) between sub- and supra-salt fault populations; and (ii) sub- and supra-salt fault populations represent brittle elements of a single, geometrically and kinematically coherent structure, the geometry and evolution of which is related to the ductile translation of strain on a scale (up to 8 km) and duration (c. 65 Myr) that believe is significantly greater and longer than previously documented. [Copyright &y& Elsevier]

The Hailar-Tamtsag Basin is a typical rift basin where two sets of regional caprocks are developed, i.e., mudstone caprocks (containing a small amount of tuff) developed in strong rifting stage and fault-depression stage, respectively. The caprocks have a cumulative thickness of 50-120 m in general, and a single-layer thickness of 20-50 m, interbedded with sandstone about 1-2 m thick. The large set of mudstone is distributed continuously, as pure mudstone caprock. Forty-three mudstone and tuff samples were taken to perform displacement pressure test with our independently developed displacement pressure tester. Test result shows that the displacement pressure is 0.04-10.00 MPa, which is equivalent to 0.09-20.01 MPa after being corrected to the actual burial depth. As the burial depth increases, the displacement pressure rises gradually, and is 1-10 times greater than that of oil-bearing sandstone or conglomerate reservoir at the same burial depth. The difference between displacement pressure of mudstone caprock and sandstone or conglomerate reservoir increases greatly if the burial depth exceeds 1000 m. Because of the displacement pressure difference between caprock and reservoir, the maximum height of hydrocarbon column sealed by the caprock ranges from 300 m to 2000 m, much higher than the height of the trap closure at the same burial depth. No hydrocarbons will leak through such caprocks. Analysis of the reservoir GOI, homogeneous temperature, and crude maturity of both deep and shallow reservoirs in Well Wu-20 in the Wuerxun Depression shows that Damoguaihe II Member reservoir is a secondary reservoir developed during adjustment of early reservoir. It is mainly distributed in inverted structures. Faulting is one of the main factors breaking the integrity of caprocks. Three kinds of faults are often related to the migration of hydrocarbons across regional caprocks: the first type refers to the positive inverted faults breaking the early sealing conditions and making the hydrocarbons accumulated in the early period re-migration; the second type refers to the faults with shear mudstone smear structures which lose their continuity and open vertically when the fault throws exceed 5 times of the mudstone thickness; the third type refers to the normal faults developed in the structural inversion stage, which have a typical cataclastic structure and are easy to cause vertical migration of hydrocarbons. Hydrocarbon enriched horizons of the rift basins are co-controlled by 'fault-caprock'. Specifically, 95% of the geological reserve is controlled by regional caprocks, and only 5% is controlled by open faults, secondary oil/gas reservoirs are developed over regional caprocks. [ABSTRACT FROM AUTHOR]

Abstract: The Billefjorden fault zone (BFZ) of Svalbard, Norway, is a long-lived major tectonic lineament with significant influence on the structural style of the northwestern Barents Shelf. The fault zone can be traced for around 2–300km in an N-S direction, where it is made up of three major fault strands, all dipping 50–70° to the east. Field and seismic data delineate gradual shifts in displacement between master faults (northern Odelfjellet, Balliolbreen, and southern Drønbreen faults) and suggest that two c. 20km long, 2–3km wide relay zones exist along strike. The western fault strand consistently has a pre-Carboniferous reverse character; placing basement on top of Devonian sedimentary units with a throw estimated at 10km. Subsequent Carboniferous extensional reactivation of segments of the BFZ resulted in formation of the Billefjorden Trough, with a rift basin showing a fairly consistent polarity for its length. This suggests a profound control by the older, Devonian reverse faults on the extensional structural style. The Billefjorden Trough extends for a minimum of 110km along strike, and is 20–30km wide at the most. A gentle north plunge of the basin axis in the south is mirrored by an opposite plunge in the north, offering a depth/thickness of around 2000m in the central realm, diminishing to 500m in the south. Geometries of the trough suggest sedimentary response to fault-growth, with weak lithologies such as evaporites promoting fault-monocline formation and associated lenticular basin geometries. On the contrary, wedged shaped fill geometries toward major faults is consistent with significant fault movement and growth sequences. Subsequent mild Tertiary reactivation of fault segments of the BFZ is suggested by local reverse faults and deep-seated anticline-syncline pairs. [Copyright &y& Elsevier]

Abstract: Three-dimensional seismic and well data from the South Viking Graben, northern North Sea Basin, is used to investigate the temporal and spatial development of a gravity-driven normal fault array above an evaporite-rich detachment. Two moderate throw (500–900m), Middle to Upper Jurassic normal faults (the Gudrun and Brynhild Faults) are developed within the study area. Both faults die-out laterally and tip-out upwards at different structural levels within the syn-rift succession. Both faults terminate downwards into Late Permian evaporites (Zechstein Group) and do not offset pre-evaporite basement units. This thin-skinned fault array developed in response to westwards tilting of the hangingwall of the South Viking Graben during Late Jurassic rifting, and consequent westward gliding and extensional break-up of units above the mechanically-weak evaporite horizon. Isochron mapping and well-based correlation of Middle to Upper Jurassic syn-rift units allow constraints to be placed on the temporal evolution of the fault array. Several stages of structural development are observed which document; (i) a period of relatively minor, early (i.e. pre-rift) halokinesis; (ii) variable spatial activity on individual faults within the array; and (iii) the progressive upslope migration of active faulting within the array as a whole. The progressive upslope migration of fault activity is interpreted to reflect progressive “unbuttressing” and extensional faulting of upslope, post-evaporite units. The overall structural style and kinematic evolution identified here shares many characteristics with both ‘rift–raft tectonics’ documented in other rifts developed above an evaporitic sub-stratum and ‘raft tectonics’ described from passive margin basins containing thick mobile salt or shale intervals. This style of fault array evolution differs from that observed in rifts lacking mobile layers at-depth and highlights the importance of these units in the structural development of rifts. [Copyright &y& Elsevier]

Sedimentary basin inversion, the shortening of formerly extensional basins, is accommodated mainly by compressional reactivation of extant faults and fractures across a wide range of scales. As such, inversion is a large-scale manifestation of Byerlee friction, the dynamic criterion for fault reactivation governing the effective shear strength of the shallow crust. Basin inversion generates distinctive deformational architecture, and it is implicated strongly in sedimentary basin exhumation. As a principal source of horizontal stress, inversion drives significant sedimentary porosity reduction and resultant fluid flow. Upper crustal deformation is critically dependent on fluid overpressure (i.e., pore fluid pressures greater than would be calculated from a hydrostatic gradient), and, perhaps more than in any other tectonic setting, overpressures are potentially large during sedimentary basin inversion. This review therefore includes discussion of the role of fluid overpressure in inversion and the evidence for it. Collectively, inversion has profound implications—good and bad—for the prospectivity of many petroliferous sedimentary basins. Thus, recognizing the evidence for basin inversion, quantifying its magnitude and understanding the mechanisms that accommodate inversion and other phenomena affected by it, have become essential components of the basin analyst''s remit. [Copyright &y& Elsevier]

Rift-related normal faults generally have various geometries, and cause the syn-rift stratigraphy in their hanging wall to be characterized by different infilling patterns. Our understanding of the tectonic control on the syn-rift stratigraphy mainly stems from the analysis of fault kinematics, stratigraphic styles and depositional facies. However, questions remain about how fault geometry, kinematics and slip rate influence the style of a rift-related half-graben and the syn-rift stratigraphy, and what enlightenment that relationship has for the hydrocarbon exploration in rifts. Using the 2D MOVE Software, this study attempts to simulate the development of a fault-bounded half-graben, with the aim of investigating the aforementioned questions. The modeling results show that, a planar, listric and ramp-flat-ramp border fault controls a tabular, wedged-shaped, and composite wedge-shaped growth package, respectively, but exceptionally, the planar fault bounds a wedge-shaped package if the fault rotates with movement. In addition, rollover structure forms when the border fault has a listric or ramp-flat-ramp shape, indicating that the fault geometry and kinematics dominate the syn-tectonic stratigraphic pattern. Besides, fault slip rate relative to sediment supply affects the scale, dip and infilling pattern of the syn-tectonic stratigraphy. In details, reduction of fault slip rate or increment of sediment supply results in: i) the extent of the syn-tectonic stratigraphy enlarging, ii) the dip angle of the syn-tectonic stratigraphy decreasing, and iii) the water depth in the related half-graben getting shallower. This study provides insights into understanding the origin of the variable styles of rift-related half-graben and syn-rift stratigraphy. Also, our modeling results have an important implication for evaluating source rock quality in rifts. Finally, we give a preliminary example of using the MOVE Software to investigate the geometry and evolution of fault-bounded basin, which is well worth being further explored. • MOVE Software is powerful for investigating syn-tectonic stratigraphic pattern. • Syn-tectonic stratigraphy is sensitive to fault geometry, activity and sedimentation rate. • Significant role of low angle basement fault on the Enping sag evolution. [ABSTRACT FROM AUTHOR]

Pliocene and Pleistocene sediments from West Turkana (Kenya, East African Rift System) form emblematic syn -rift successions for understanding the evolution of extensional basin and continental rifting. They also constitute world-renowned fossil-bearing strata from which >500 hominin fossils were discovered over the past decades, with >100 inventoried archeological sites. However, associated sedimentary dynamics and architectures as well as paleoenvironments are only partially reconstructed and the relative contribution of climate and tectonism to paleoenvironmental change over time remains unclear. Here, through the interpretation of sedimentary facies, the delineation of sequences and the analysis of δ13C in soil carbonates, we provide the first exhaustive reconstruction from ~ 4.00 to ~ 0.75 Ma of (i) fluctuations of the paleolake that occupied the Turkana Depression, (ii) the successive sedimentary dynamics and related paleolandscapes that characterized the West Turkana area and (iii) respective roles of climate and tectonism in the sedimentation. We show evidence for seven major transgression-regression (T-R) cycles between ~ 4.00 and ~ 0.75 Ma superimposed locally by lower amplitude T-R cycles. Comparing the sedimentological interpretations and the δ13C values in soil carbonates (literature data), we reveal that fluctuations of rainfall over the Ethiopian Dome, which hosts the drainage basin of the Omo River — the main tributary of Lake Turkana — controlled high-amplitude lake level fluctuations during the Plio-Pleistocene period. We also demonstrate that vegetation and tree cover evolved differently in the Omo Valley and West Turkana. Furthermore we outline that two different sedimentary systems reflecting two distinct modes of sedimentation alternated through times in the West Turkana area as a response to the variations in sediment supply coming from the western rift shoulder (i.e. Lapurr Range) that alternatively generated wave- or river-dominated sedimentary systems. In conclusion, we reveal that climate regulated water input, paleolake water-level fluctuations and vegetation. Tectonism determined sediment supply to the basin controlled in West Turkana by pulses of increased activity of the main border fault (i.e., the Murua Rith Lapurr Fault). [ABSTRACT FROM AUTHOR]

Organic-rich shale, the third member of the PaleogeneShahejie Formation (Es 3), is considered as an excellent lacustrine source rock in the Bohai Bay Basin. However, studies on how paleosedimentary environments affect organic matter enrichment are still lacking. In this study, cores of the Es 3 shale in the Dongpu Depression (DD) nearly 200 m in length were collected at well Pu 115 to investigate organic matter enrichment mechanism. Results suggest that the Es 3 shale was deposited under reductive conditions based on the redox index (V/(V + Ni)) and the large amount of pyrite. The Mg/Sr and Fe/Mn ratios indicate a generally arid climate with a frequently changing paleowater depth. The paleosalinity analyses indicate the Es 3 shale developed under fresh-brackish conditions. The Ba content ranges from 75 to 435 ppm (avg. 284 ppm), showing a moderate paleoproductivity. Correlation analyses among the total organic carbon (TOC) and major and trace element ratios show that the TOC rises with the increasing water reduction degree. With increasing water paleosalinity, the TOC increases initially and then decreases, reaching a maximum TOC at a paleosalinity of 11‰. In addition, the TOC increases initially and then decreases with increasing detrital input, indicating that a moderate detrital input would be beneficial for organic matter enrichment. The redox conditions, paleosalinity and quantity of detrital input are the key factors controlling the organic matter enrichment. Further analyses show that the redox conditions were controlled by the paleoclimate, and the paleosalinity and terrestrial detrital input quantity were affected by the paleowater depth. The root factors controlling the organic matter enrichment are paleoclimate and paleowater depth in the saline lacustrine rift basin. • Organic matter enrichment mechanism of saline lacustrine shale was analyzed by combing paleo-salinity, redox condition, terrestrial input, and paleo-productivity in response to paleo-sedimentary environment. • The Es 3 shale was developed in a fresh-brackish and reducing water body with changeable arid climate. • Reduction condition, paleosalinity, and terrestrial detrital input jointly controlled organic matter enrichment. [ABSTRACT FROM AUTHOR]

The spatial and temporal pattern of sedimentation in a rift basin is a result of complex interplay between tectonically induced vertical crustal movement and climatic condition. Though the conceptual and numerical models for tectono-sedimentary evolution of half grabens are available, the stratigraphic arrangement of lithofacies produced by the environments on hangingwall block is poorly documented till date. Additionally, the stratigraphic record resulting from the interactions between the hangingwall processes and those of the basin trough is less known. The purpose of this work is to delineate the tectonic and climatic factors controlling the distribution of sedimentary environments from the stratigraphic architecture of a Late Triassic to Early Jurassic syn -rift strata of a continental half-graben of India. This work also aims to characterize the deposits formed in the transitional environments that occur in between the fluvial system of the hangingwall dip slope and the lacustrine system at the basin trough. This work involves a detailed sedimentological study including facies analysis and palaeocurrent analysis. The studied syn -rift sediments record i) a changeover from axial to transverse fluvial system in the end of Triassic, ii) transition from fluvial to lake marginal environment in the Early Jurassic and iii) evolution of an extensive palustrine system in the Middle Jurassic. The corresponding changes in lithological and geochemical characters for the first change points towards incresed tectonic movement along the main boundary fault that caused the progradation of the hangingwall fans towards the basin trough. Later changes can be attributed to the reconfiguration of the sedimentary environments due to increase in aridity that influenced the introduction of coarse clastics to the basin. [ABSTRACT FROM AUTHOR]