Bio-electrosequence interpretation of late cretaceous sediments of the Southern Bornu Basin, Nigeria

Abstract. Integrated analysis of foraminiferal and palynological data from the Duljan-1 well, Central Indus Basin, Pakistan, is used to identify critical surfaces (candidate sequence boundaries (SB) and maximum flooding surfaces (MFS)) and construct a biosequence stratigraphical framework. Within the Barremian through Bartonian–Priabonian? succession 15 depositional sequences have been recognized, each with a candidate MFS. These biosequences are shown to equate with the local lithostratigraphy and tentatively with the ‘global’ large-scale depositional cycles of Haq et al. (1987). Detailed dating has enabled seven candidate MFS to be tentatively equated with MFS identified on the nearby Arabian plate (Sharland et al., 2001). A combination of detailed age dating and palaeobathymetric determinations indicates significant basin uplift and erosion at end Cretaceous and end Eocene times, the latter coinciding with closure of Neo-Tethys. Smaller-scale unconformities are also noted. Multi-disciplinary palaeoenvironmental interpretations enable recognition of detailed changes in water mass conditions. Palynological data suggest these changes result from variations in terrestrial/freshwater input, though evidence of periodically low oxygen bottom water conditions/shallowing of the oxygen minimum zone, possibly ‘Oceanic Anoxic Event-2’ (OAE-2; late Cenomanian–Turonian) is suggested as a further control.

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Last Cretaceous Geology of Taranaki Basin, New Zealand

10.26686/wgtn.16945621.v1 ◽

2021 ◽

Author(s):

◽

Glenn Paul Thrasher

Keyword(s):

New Zealand ◽

Late Cretaceous ◽

Coastal Plain ◽

New Caledonia ◽

Strike Slip ◽

Source Rocks ◽

Petroleum Exploration ◽

Petroleum Reservoir ◽

The North ◽

Potential Source Rock

Taranaki Basin is a large sedimentary basin located along the western side of New Zealand, which contains all of this countries present petroleum production. The basin first formed as the late-Cretaceous Taranaki Rift, and the first widespread sediments are syn-rift deposits associated with this continental rifting. The Taranaki Rift was an obliquely extensional zone which transferred the movement associated with the opening of the New Caledonia Basin southward to the synchronous Tasman Sea oceanic spreading. Along the rift a series of small, en-echelon basins opened, controlled by high-angle normal and strike-slip faults. These small basins presently underlie the much larger Taranaki Basin. Since the initial rift phase, Taranaki Basin has undergone a complex Cenozoic history of subsidence, compression, additional rifting, and minor strike-slip faulting, all usually involving reactivation of the late-Cretaceous rift-controlling faults. One of the late-Cretaceous rift basins is the Pakawau Basin. Rocks deposited in this basin outcrop in Northwest Nelson as the Pakawau Group. Data from the outcrop and from wells drilled in the basin allow the Pakawau Group to be divided into two formations, the Rakopi Formation and the North Cape Formation, each with recognizable members. The Rakopi Formation (new name) is a sequence of terrestrial strata deposited by fans and meandering streams in an enclosed basin. The North Cape Formation is a transgressive sequence of marine, paralic and coastal-plain strata deposited in response to regional flooding of the rift. The coal-measure strata of the Rakopi Formation are organic rich, and are potential petroleum source rocks where buried deeply enough. In contrast, the marine portions of the North Cape Formation contain almost no organic matter and cannot be considered a potential source rock. Sandy facies within both formations have petroleum reservoir potential. The Rakopi and North Cape formations can be correlated with strata intersected by petroleum exploration wells throughout Taranaki Basin, and all syn-rift sediments can be assigned to them. The Taranaki Rift was initiated about 80 Ma, as recorded by the oldest sediments in the Rakopi Formation. The transgression recorded in the North Cape Formation propagated southwards from about 72 to 70 Ma, and the Taranaki Rift remained a large marine embayment until the end of the Cretaceous about 66.5 Ma. Shortly thereafter, a Paleocene regression caused the southern portions of Taranaki Basin to revert to terrestrial (Kapuni Group) sedimentation. The two distinct late Cretaceous sedimentary sequences of the Rakopi and North Cape formations can be identified on seismic reflection data, and the basal trangressive surface that separates them has been mapped throughout the basin. This horizon essentially marks the end of sedimentation in confined, terrestrial subbasins, and the beginning of Taranaki Basin as a single, continental-margin-related basin. Isopach maps show the Rakopi Formation to be up to 3000m thick and confined to fault- controlled basins. The North Cape Formation is up to 1500m thick and was deposited in a large north-south embayment, open to the New Caledonia basin to the northwest. This embayment was predominantly a shallow-marine feature, with shoreline and lower coastal plain facies deposited around its perimeter

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LATE CRETACEOUS PONDED TURBIDITE SYSTEMS: A NEW STRATIGRAPHIC PLAY FAIRWAY IN THE BROWSE BASIN

The APPEA Journal ◽

10.1071/aj03010 ◽

2004 ◽

Vol 44 (1) ◽

pp. 269 ◽

Cited By ~ 2

Author(s):

J.M. Benson ◽

S.J. Brealey ◽

C.W. Luxton ◽

P.F. Walshe ◽

N.P. Tupper

Keyword(s):

Late Cretaceous ◽

Small Area ◽

Source Rocks ◽

Hydrocarbon Migration ◽

Sequence Stratigraphic ◽

Trapping Mechanism ◽

Stratigraphic Analysis ◽

Wireline Logs ◽

Net To Gross ◽

Set Up

Regional seismic and sequence stratigraphic analysis of the Browse Basin identified a new Late Cretaceous play fairway involving ponded turbidite systems deposited within confined basins. This work highlighted the potential for isolated sandstone reservoirs in the Middle Campanian sequence of the Caswell Sub-basin. Extensional faults were expected to provide vertical conduits for charge from underlying Early Cretaceous source rocks.The play concept was tested by the drilling of two exploration wells in 2001. The Carbine prospect was a potential stratigraphic trap involving deposition of turbidite sandstones within a localised basin set up by slumping in an intra-slope setting. Carbine–1 penetrated a 77 m thick section of high quality, 100% net-to-gross sandstone but failed to encounter hydrocarbons.A similar ponded turbidite model was invoked for the Marabou prospect although in this case the confined basin was controlled by pre-existing topography at the toe of the slope. The trapping mechanism for Marabou was largely stratigraphic although a small area of anticlinal closure was present. Marabou–1 penetrated 102 m of good quality sandstone with elevated gas readings over the uppermost 22 m. Borehole problems prevented the acquisition of wireline logs or testing but it appears likely that the well penetrated a sub-commercial hydrocarbon column restricted to the four-way dip closure.The well results confirmed the presence of ponded turbidite systems with excellent reservoir characteristics. Further work is required, however, to address the critical risks associated with hydrocarbon migration and updip seal. Nevertheless, ponded turbidite systems remain attractive exploration targets particularly in basins where updip seal is assisted by structuring and where the reservoirs are intercalated with prolific source rocks.

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Biostratigraphic signature of sequence boundaries, maximum flooding surfaces, condensed sections, and depositional systems tracts – with examples from the gulf of mexico plio-pleistocene

The Paleontological Society Special Publications ◽

10.1017/s2475262200005694 ◽

1992 ◽

Vol 6 ◽

pp. 9-9

Author(s):

John M. Armentrout

Keyword(s):

Sea Level ◽

Sediment Accumulation ◽

Relative Sea Level ◽

Faunal Abundance ◽

Condensed Section ◽

Wireline Logs ◽

Depositional Systems ◽

Abundance And Diversity ◽

Sequence Boundaries ◽

Maximum Flooding Surface

The primary horizons utilized in sequence stratigraphic analysis are the sequence boundary, and the maximum flooding surface which occurs within the condensed section in areas of low sediment accumulation rates. These regionally correlative surfaces can be identified on seismic reflection profiles, on wireline logs, in stratigraphic sections, and from checklists of fossil abundance and diversity. Both surfaces are time-transgressive but nevertheless can be used as correlation horizons for partitioning depositional cycles into discrete phases of relative sea-level rise and fall. Sediments deposited during rising and falling phases of sea-level form depositional systems tracts that consist of all correlative deposits of lowstand, of transgressive or of highstand phases of relative sea level.The sequence boundary is an unconformity formed during relative lowering of and during lowstand of sea level. The unconformity correlates into basinal areas of continuous sedimentation where the age of the unconformity is determined biostratigraphically. The unconformity surface is usually recognized because of erosional truncation of underlying strata and the onlap of overlying strata of the next sequence. The sequence boundary may be represented by a marked shift in biofacies assemblages from deeper below to shallower above. It may be marked also by an increase in reworked or displaced fossils, and by a decrease in both fossil abundance and diversity due to rapid accumulation of sediment in the shallow water, high-energy environments associated with the erosional unconformity.The maximum flooding surface is defined by, and can be identified by, the most landward onlap of marine strata immediately below the progradational unit with downlapping onto the flooding surface. The precise age of this surface will vary along any basin margin because of the interplay of sediment supply and accommodation space. Away from the locus of major input of sediment this surface is a clay-rich condensed section formed by slow accumulation of sediment. This interval is often represented by significant increase in fossil abundance and by the deepest-water biofacies assemblage of the transgressive-regressive cycle. Despite their lateral variabilities, the seismic, lithologic and biostratigraphic signatures of the condensed section and of the associated maximum flooding surface are generally the most easily recognized and precisely dated regional correlative surfaces.Within the axis of the depocenter, the highstand systems tract typically consists of forestepping coarsening-upward cycles deposited above the maximum flooding surface and below the sequence boundary. Fossil assemblages of the highstand systems tract reflect shallowing upward neritic conditions, with intervals in which faunal abundance decreases upwards. Transgressive systems tracts are backstepping coarsening-upward cycles deposited above the regional transgressive surface and below the maximum flooding surface. Fossil assemblages in transgressive systems tracts show deepening-upward biofacies and an increase in faunal abundance upward. Lowstand systems tracts are most significant seaward of the shelf-edge, and consist of depositional thicks with low fossil abundance. These lowstand systems tracts are separated by highly fossiliferous condensed sections containing the distal aspects of the transgressive and highstand systems tracts.Identification of each sequence boundary and its correlative conformity, and of each maximum flooding surface is achieved by careful recognition of patterns of stratal terminations, by correlation of those stratal surfaces of discontinuity with measured sections or wireline logs, and by biostratigraphic correlation between these sections and logs. If the discontinuity surfaces correlate throughout the depositional basin or subbasin, they should be considered sequence boundaries and maximum flooding surfaces. If the surfaces are limited to local areas and are not coeval, they are probably local discontinuities associated with local structural events or with autocyclic shifting of sediment accumulation.

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Last Cretaceous Geology of Taranaki Basin, New Zealand

10.26686/wgtn.16945621 ◽

2021 ◽

Author(s):

◽

Glenn Paul Thrasher

Keyword(s):

New Zealand ◽

Late Cretaceous ◽

Coastal Plain ◽

New Caledonia ◽

Strike Slip ◽

Source Rocks ◽

Petroleum Exploration ◽

Petroleum Reservoir ◽

The North ◽

Potential Source Rock

Taranaki Basin is a large sedimentary basin located along the western side of New Zealand, which contains all of this countries present petroleum production. The basin first formed as the late-Cretaceous Taranaki Rift, and the first widespread sediments are syn-rift deposits associated with this continental rifting. The Taranaki Rift was an obliquely extensional zone which transferred the movement associated with the opening of the New Caledonia Basin southward to the synchronous Tasman Sea oceanic spreading. Along the rift a series of small, en-echelon basins opened, controlled by high-angle normal and strike-slip faults. These small basins presently underlie the much larger Taranaki Basin. Since the initial rift phase, Taranaki Basin has undergone a complex Cenozoic history of subsidence, compression, additional rifting, and minor strike-slip faulting, all usually involving reactivation of the late-Cretaceous rift-controlling faults. One of the late-Cretaceous rift basins is the Pakawau Basin. Rocks deposited in this basin outcrop in Northwest Nelson as the Pakawau Group. Data from the outcrop and from wells drilled in the basin allow the Pakawau Group to be divided into two formations, the Rakopi Formation and the North Cape Formation, each with recognizable members. The Rakopi Formation (new name) is a sequence of terrestrial strata deposited by fans and meandering streams in an enclosed basin. The North Cape Formation is a transgressive sequence of marine, paralic and coastal-plain strata deposited in response to regional flooding of the rift. The coal-measure strata of the Rakopi Formation are organic rich, and are potential petroleum source rocks where buried deeply enough. In contrast, the marine portions of the North Cape Formation contain almost no organic matter and cannot be considered a potential source rock. Sandy facies within both formations have petroleum reservoir potential. The Rakopi and North Cape formations can be correlated with strata intersected by petroleum exploration wells throughout Taranaki Basin, and all syn-rift sediments can be assigned to them. The Taranaki Rift was initiated about 80 Ma, as recorded by the oldest sediments in the Rakopi Formation. The transgression recorded in the North Cape Formation propagated southwards from about 72 to 70 Ma, and the Taranaki Rift remained a large marine embayment until the end of the Cretaceous about 66.5 Ma. Shortly thereafter, a Paleocene regression caused the southern portions of Taranaki Basin to revert to terrestrial (Kapuni Group) sedimentation. The two distinct late Cretaceous sedimentary sequences of the Rakopi and North Cape formations can be identified on seismic reflection data, and the basal trangressive surface that separates them has been mapped throughout the basin. This horizon essentially marks the end of sedimentation in confined, terrestrial subbasins, and the beginning of Taranaki Basin as a single, continental-margin-related basin. Isopach maps show the Rakopi Formation to be up to 3000m thick and confined to fault- controlled basins. The North Cape Formation is up to 1500m thick and was deposited in a large north-south embayment, open to the New Caledonia basin to the northwest. This embayment was predominantly a shallow-marine feature, with shoreline and lower coastal plain facies deposited around its perimeter

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An integrated life cycle and water footprint assessment of nonfood crops based bioenergy production

Scientific Reports ◽

10.1038/s41598-021-83061-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jun Li ◽

Fengyin Xiong ◽

Zhuo Chen

Keyword(s):

Life Cycle ◽

Environmental Sustainability ◽

Large Scale ◽

Water Footprint ◽

Arable Land ◽

Integrated Analysis ◽

Actual Performance ◽

Bioenergy Production ◽

Trade Offs ◽

Hybrid Pennisetum

AbstractBiomass gasification, especially distribution to power generation, is considered as a promising way to tackle global energy and environmental challenges. However, previous researches on integrated analysis of the greenhouse gases (GHG) abatement potentials associated with biomass electrification are sparse and few have taken the freshwater utilization into account within a coherent framework, though both energy and water scarcity are lying in the central concerns in China’s environmental policy. This study employs a Life cycle assessment (LCA) model to analyse the actual performance combined with water footprint (WF) assessment methods. The inextricable trade-offs between three representative energy-producing technologies are explored based on three categories of non-food crops (maize, sorghum and hybrid pennisetum) cultivated in marginal arable land. WF results demonstrate that the Hybrid pennisetum system has the largest impact on the water resources whereas the other two technology options exhibit the characteristics of environmental sustainability. The large variances in contribution ratio between the four sub-processes in terms of total impacts are reflected by the LCA results. The Anaerobic Digestion process is found to be the main contributor whereas the Digestate management process is shown to be able to effectively mitigate the negative environmental impacts with an absolute share. Sensitivity analysis is implemented to detect the impacts of loss ratios variation, as silage mass and methane, on final results. The methane loss has the largest influence on the Hybrid pennisetum system, followed by the Maize system. Above all, the Sorghum system demonstrates the best performance amongst the considered assessment categories. Our study builds a pilot reference for further driving large-scale project of bioenergy production and conversion. The synergy of combined WF-LCA method allows us to conduct a comprehensive assessment and to provide insights into environmental and resource management.

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Invasive Cereal Aphids of North America: Ecology and Pest Management

Annual Review of Entomology ◽

10.1146/annurev-ento-011118-111838 ◽

2019 ◽

Vol 64 (1) ◽

pp. 73-93 ◽

Cited By ~ 10

Author(s):

Michael J. Brewer ◽

Frank B. Peairs ◽

Norman C. Elliott

Keyword(s):

North America ◽

Pest Management ◽

Great Plains ◽

Large Scale ◽

Production Systems ◽

Cereal Crops ◽

Cereal Aphids ◽

Sugarcane Aphid ◽

Cereal Production ◽

Abundance And Diversity

Aphid invasions of North American cereal crops generally have started with colonization of a new region or crop, followed by range expansion and outbreaks that vary in frequency and scale owing to geographically variable influences. To improve understanding of this process and management, we compare the invasion ecology of and management response to three cereal aphids: sugarcane aphid, Russian wheat aphid, and greenbug. The region exploited is determined primarily by climate and host plant availability. Once an area is permanently or annually colonized, outbreak intensity is also affected by natural enemies and managed inputs, such as aphid-resistant cultivars and insecticides. Over time, increases in natural enemy abundance and diversity, improved compatibility among management tactics, and limited threshold-based insecticide use have likely increased resilience of aphid regulation. Application of pest management foundational practices followed by a focus on compatible strategies are relevant worldwide. Area-wide pest management is most appropriate to large-scale cereal production systems, as exemplified in the Great Plains of North America.

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Dynamics of Genome Architecture in Rhizobium sp. Strain NGR234

Journal of Bacteriology ◽

10.1128/jb.184.1.171-176.2002 ◽

2002 ◽

Vol 184 (1) ◽

pp. 171-176 ◽

Cited By ~ 62

Author(s):

Patrick Mavingui ◽

Margarita Flores ◽

Xianwu Guo ◽

Guillermo Dávila ◽

Xavier Perret ◽

...

Keyword(s):

Large Scale ◽

Insertion Sequence ◽

Biological Significance ◽

Genome Architecture ◽

Bacterial Genomes ◽

Symbiotic Plasmid ◽

Sequence Elements ◽

Dynamic Structures ◽

Genome Analyses ◽

Insertion Sequence Elements

ABSTRACT Bacterial genomes are usually partitioned in several replicons, which are dynamic structures prone to mutation and genomic rearrangements, thus contributing to genome evolution. Nevertheless, much remains to be learned about the origins and dynamics of the formation of bacterial alternative genomic states and their possible biological consequences. To address these issues, we have studied the dynamics of the genome architecture in Rhizobium sp. strain NGR234 and analyzed its biological significance. NGR234 genome consists of three replicons: the symbiotic plasmid pNGR234a (536,165 bp), the megaplasmid pNGR234b (>2,000 kb), and the chromosome (>3,700 kb). Here we report that genome analyses of cell siblings showed the occurrence of large-scale DNA rearrangements consisting of cointegrations and excisions between the three replicons. As a result, four new genomic architectures have emerged. Three consisted of the cointegrates between two replicons: chromosome-pNGR234a, chromosome-pNGR234b, and pNGR234a-pNGR234b. The other consisted of a cointegrate of the three replicons (chromosome-pNGR234a-pNGR234b). Cointegration and excision of pNGR234a with either the chromosome or pNGR234b were studied and found to proceed via a Campbell-type mechanism, mediated by insertion sequence elements. We provide evidence showing that changes in the genome architecture did not alter the growth and symbiotic proficiency of Rhizobium derivatives.

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Source rock characterization of mesozoic to cenozoic organic matter rich marls and shales of the Eratosthenes Seamount, Eastern Mediterranean Sea

Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles ◽

10.2516/ogst/2018036 ◽

2018 ◽

Vol 73 ◽

pp. 49 ◽

Cited By ~ 8

Author(s):

Sebastian Grohmann ◽

Susanne W. Fietz ◽

Ralf Littke ◽

Samer Bou Daher ◽

Maria Fernanda Romero-Sarmiento ◽

...

Keyword(s):

Organic Matter ◽

Mediterranean Sea ◽

Source Rock ◽

Eastern Mediterranean ◽

Source Rocks ◽

Eastern Mediterranean Sea ◽

Potential Source Rock ◽

Levant Basin ◽

Rock Characterization ◽

Rock Eval

Several significant hydrocarbon accumulations were discovered over the past decade in the Levant Basin, Eastern Mediterranean Sea. Onshore studies have investigated potential source rock intervals to the east and south of the Levant Basin, whereas its offshore western margin is still relatively underexplored. Only a few cores were recovered from four boreholes offshore southern Cyprus by the Ocean Drilling Program (ODP) during the drilling campaign Leg 160 in 1995. These wells transect the Eratosthenes Seamount, a drowned bathymetric high, and recovered a thick sequence of both pre- and post-Messinian sedimentary rocks, containing mainly marine marls and shales. In this study, 122 core samples of Late Cretaceous to Messinian age were analyzed in order to identify organic-matter-rich intervals and to determine their depositional environment as well as their source rock potential and thermal maturity. Both Total Organic and Inorganic Carbon (TOC, TIC) analyses as well as Rock-Eval pyrolysis were firstly performed for the complete set of samples whereas Total Sulfur (TS) analysis was only carried out on samples containing significant amount of organic matter (>0.3 wt.% TOC). Based on the Rock-Eval results, eight samples were selected for organic petrographic investigations and twelve samples for analysis of major aliphatic hydrocarbon compounds. The organic content is highly variable in the analyzed samples (0–9.3 wt.%). TS/TOC as well as several biomarker ratios (e.g. Pr/Ph < 2) indicate a deposition under dysoxic conditions for the organic matter-rich sections, which were probably reached during sporadically active upwelling periods. Results prove potential oil prone Type II kerogen source rock intervals of fair to very good quality being present in Turonian to Coniacian (average: TOC = 0.93 wt.%, HI = 319 mg HC/g TOC) and in Bartonian to Priabonian (average: TOC = 4.8 wt.%, HI = 469 mg HC/g TOC) intervals. A precise determination of the actual source rock thickness is prevented by low core recovery rates for the respective intervals. All analyzed samples are immature to early mature. However, the presence of deeper buried, thermally mature source rocks and hydrocarbon migration is indicated by the observation of solid bitumen impregnation in one Upper Cretaceous and in one Lower Eocene sample.

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Environment of Deposition and Paleogeography of the Late Cretaceous Glenburn Formation, Eastern North Island, New Zealand

10.26686/wgtn.17071979 ◽

2021 ◽

Author(s):

◽

James McClintock

Keyword(s):

New Zealand ◽

Late Cretaceous ◽

Large Scale ◽

East Coast ◽

Three Dimensional ◽

Depositional Environments ◽

Tectonic Deformation ◽

Turbidity Currents ◽

Submarine Fan ◽

Submarine Channels

The Glenburn Formation of the East Coast of New Zealand is a Late Cretaceous sedimentary formation consisting of alternating layers of sandstone, mudstone and conglomerate. The Glenburn Formation spans a depositional timeframe of over 10 Ma, is over 1000 m thick, is regionally extensive and is possibly present over large areas offshore. For these reasons, it is important to constrain the paleoenvironment of this unit. Late Cretaceous paleogeographic reconstructions of the East Coast Basin are, however, hampered by a number of factors, including the pervasive Neogene to modern tectonic deformation of the region, the poorly understood nature of the plate tectonic regime during the Cretaceous, and a lack of detailed sedimentological studies of most of the region’s Cretaceous units. Through detailed mapping of the Glenburn Formation, this study aims to improve inferences of regional Cretaceous depositional environments and paleogeography. Detailed facies based analysis was undertaken on several measured sections in eastern Wairarapa and southern Hawke’s Bay. Information such as bed thickness, grain size and sedimentary structures were recorded in order to identify distinct facies. Although outcrop is locally extensive, separate outcrop localities generally lie in different thrust blocks, which complicates comparisons of individual field areas and prevents construction of the large-scale, three-dimensional geometry of the Glenburn Formation. Glenburn Formation consists of facies deposited by sediment gravity flows that were primarily turbidity currents and debris flows. Facies observed are consistent with deposition on a prograding submarine fan system. There is significant variation in facies both within and between sections. Several distinct submarine fan architectural components are recognised, such as fan fringes, fan lobes, submarine channels and overbank deposits. Provenance and paleocurrent indicators are consistent with deposition having occurred on several separate submarine fans, and an integrated regional paleogeographic reconstruction suggests that deposition most likely occurred in a fossil trench following the mid-Cretaceous cessation of subduction along the Pacific-facing margin of Gondwana.

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