In the context of plate tectonics it is classified as a forearc basin. Through the structural mapping of an uplifted forearc basin, i conclude that rapid rollback is characterized by tectonic quiescence in the calabrian forearc when it is located far from collision from 12 ma 5 ma. First, setting a baseline of deformation is important when studying plate boundaries. Emplacement of the resurrection peninsula ophiolite in the. Analysis of normal fault populations in the kumano forearc basin, nankai trough, japan. The bellingham basin is the northern of four basins of the actively deforming northern cascadia forearc. Microbial communities from methane hydratebearing deep. This proximity, as well as the similarity in morphology between the reentrant and an indentation in the lower arc slope. The relationship between the lesser antilles island arc, the tobago forearc basin, and the barbados accretionary prism.
Forearc structures of the eastern sunda arc are studied by new multichannel reflection seismic profiling. The forearc basin in myanmar is significant in understanding the development of continental forearc basins. The arauco basin is a sedimentfilled depression a sedimentary basin in southcentral chile. Department of earth and environmental sciences, california state university, fresno, 2576 e. Over geological time there is constant recycling of the forearc deposits due to erosion. Turonian, oceanic anoxic event, cool seep carbonate, cretaceous forearc basin, hokkaido introduction carried cretaceous to paleocene sediments and sumi. All three major components of the arctrench system franciscan subduction com plex, great valley forearc basin and sierra. The results of this study provide important clues to further our understanding of dynamic interactions between forearc basins and subduction zone processes. The basin contains 4 km of middle jurassic to late cretaceous sedimentary strata, and is part of a series. Basin formation in the nias area of the sumatra forearc, western indonesia 287 moore, the seismic stratigraphy of the northern sumatra forearc had been discussed by beaudry and moore 1985, who recognised three main neogene sequences which they assigned to the pleistocene unit 4, the pliocene and uppermost.
But implicit in the concept of a sedimentary basin is the existence of. Forearc basins are marine depositional basins on the trench side of arcs, and they vary in size and abundance with the evolutionary stage of an arc. Variation in forearc basin configuration and basinfilling. The birth of the xigaze forearc basin in southern tibet. The alkalic intrusions include nepheline syenite, camptonite, and. Nature of an inner trench slope on an accretionary prism, with the many slope basins formed by the intersection of thrust faults with the prism surface. Resolving the architecture and early evolution of a. The lower nanaimo group was deposited in the forearc georgia basin, canada and records the basin s initiation and early depositional evolution.
Sediment is delivered into the basin via a submarine turbidite system. Morphology and tectonics of the andaman forearc, northeastern. Analysis of normal fault populations in the kumano forearc. Trenchslope basin trench forearc basin intraarc basin backarc basin trenches. From published and unpublished sources, eleven seismic images have been compiled across the indo australiansunda plate margin from sumatra, where a subduction margin is generally recognized, through the andaman islands india, to myanmar where the nature of margin is subject to debate. Late tertiary neogene sediments deposited in the sunda forearc reveal the stratigraphic and structural evolution of this active plate margin. Resolving the architecture and early evolution of a forearc. Analysis of the upper cretaceoustertiary fill of the great valley forearc basin of california reveals a complicated history of subsidence partitioned in time and space. These faults have been active since the late miocene and are driven by detachment and extension of the underlying overpressured melange and broken formation. Nanaimo group strata are subdivided into 11 lithostratigraphic units, which are identified based on lithology, paleontology, texture and position relative to both the basal nonconformity and to each. In this paper we discuss the age, origin, and deformation of the late miocene unconformity and incorporate this information with the stratigraphy of the forearc basin, adjacent accretionary wedge, and abyssal plain to document the neogene evolution of the cascadia margin. Initiation and evolution of the great valley forearc basin of northern. Basin stratigraphy includes a regional late miocene unconformity that may coincide with a worldwide hiatus ca.
Pdf recent observations of an association between forearc basins and slip during subduction thrust earthquakes suggest a link between processes. In continental margin arcs, such as the sunda arc in indonesia, forearc basins range up to 700 km in strike length. A very different aspect of cenozoic history is exposed on simeulue to the nw of nias, including an oligomiocene erosional unconformity comparable with sections reported from wells in the forearc basin karig et al. Seismic imaging of forearc backthrusts at northern sumatra. This region of the forearc is partly to wholly decoupled from convergencedriven compression which dominates deformation elsewhere in the forearc. Pdf ophiolitic basement to the great valley forearc. Nature and distribution of slabderived fluids and mantle. Structure and stratigraphy of the barbados accretionary prism and the tobago forearc basin n. In most subduction zones, formation of backarc basin bab and arc magmas depletes the mantle source toward the trench, resulting in more depleted mantle beneath the forearc.
Forearc basins are one of the fundamental sedimentary basins, and they preserve various geological phenomena arising from dynamic interactions between subducting and overriding plates along convergent plate boundaries. Forearc basins lie between the axes of trenchslope breaks or trenches and the magmatic arcs. Earthquake rupture would be expected along the thrust where temperatures are low enough for seismogenic failure to occur. The basin is interpreted as being part of an uplifted part of the continental shelf. The early oligocene oregon coast range intrusions ocri consist of gabbroic rocks and lesser alkalic intrusive bodies that were emplaced in marine sedimentary units and volcanic sequences within a tertiary cascadia forearc basin. Previous studies have proposed descriptive classification schemes for such basins and performed analog experiments. Further south, to the west of sumatra, kieckhefer et al. By integrating recent results from the basement study by mora et al. Structure of the hawkes bay forearc basin and north island shear belt, eastern north island, new zealand ministry of business, innovation and employment, new zealand, unpublished petroleum report pr4884, 36 p. The profile clearly demarcates the backthrust branches at the seaward edge of the aceh forearc basin, along which the inner forearc continues to evolve. The stratigraphic succession of a forearc basin provides crucial information on the history of a convergent plate margin.
The palaeogene forearc basin of the eastern alps and western. Pdf holocene faulting in the bellingham forearc basin. Seabeam data reveal two deep subcircular reentrants in the lower arc slope of the new hebrides island arc that may illustrate two stages in the development of a novel type of forearc basin. Condie, in earth as an evolving planetary system third edition, 2016. Pdf evolution of the ecuador offshore forearc basin and. Interpretation of new multichannel seismic reflection data from the andaman forearc basin afb in the northern indian ocean is presented here. Geological survey the undiscovered oil and gas of antarctica by john kingston open file report 91597 this report is. Ophiolitic basement to the great valley forearc basin, california, from seismic and gravity data. Formation of forearc basins by collision between seamounts.
A dense grid of multichannel seismic reflection data and information from 17 exploratory wells were used to establish a detailed seismicstratigraphic framework of the forearc region from 0 to 6n. Modification of continental forearc basins by flat. Thermal basin modelling of the arauco forearc basin, south. Stratigraphic evolution and reservoir quality in a neogene. Due to tectonic stresses as one tectonic plate rides over another, forearc regions are sources for great thrust earthquakes. The malekula reentrant lies just south of the partly subducted bougainville seamount. A new approach uses the compositional variability of detrital clinopyroxenes and. Pdf formation of forearc basins and their influence on subduction. Because the ggtb is a promis ing site of hydrocarbon resources, to understand processes at the origin of this escapeinduced forearc basin has a major economic interest. Graduate thesis or dissertation structure and seismic.
Coals within the forearc basin sedimentary succession exhibit the highest thermal maturity of all chilean coal helle et al. In particular, it helps to establish the origin of the underlying ophiolites and to unravel the earliest evolutionary stage of arctrench systems, which remain poorly understood. Stratigraphic evolution and reservoir quality in a neogene accretionary forearc setting. Repeated tectonic inversions of simeulue may be related in part to transpression and transtension stresses generated by. Basins that may have formed by seamount collision lie within the accretionary wedge adjacent to the aleutian trenches. The wrangell mountains basin is a mesozoic forearc basin that developed during a period of accretionary tectonics in the northwestern cordillera. Forearc basins containing thick sediments are important features of continental margin arctrench systems with high sedimentation rates dickinson and seely. The arauco forearc basin of south central chile is situated in a rather cold active margin setting at the edge of the continental shelf close to the chileperutrench figure 1. The basin has an approximate area of 8,000 square kilometres and at its deeper parts the surface of its sedimentary fill reaches 200 metres below sealevel. Structure and stratigraphy of the barbados accretionary. Types, geometries, and relationships to subduction zone dynamics article pdf available in geological society of america bulletin 12856. Forearc basins are marine depositional basins on the trench side of arcs figure 3.
Oblique strikeslip faulting of the cascadia submarine. Seismic stratigraphy and cenozoic evolution of west sumatra forearc basin article pdf available in aapg bulletin 695 may 1985 with 376 reads how we measure reads. An increase or decrease of the sediment flux may change the type, geometry, and deformation manner of the forearc basin. The east java forearc preserves a record of cenozoic sedimentation and tectonic history, and information about the character of the deeper crust. Oct 25, 2019 resolving the architecture and early evolution of a forearc basin georgia basin, canada using detrital zircon skip to main content thank you for visiting. Initiation and evolution of forearc basins in the central. These processes could result in a roughly circular forearc basin. The highquality multichannel seismic data from the andaman forearc region enable us to examine the seismic characters and to demarcate seismic sequences bounded by distinct unconformities. We highlight ongoing tectonic activity of the entire outer arc high.
Kumano basin geology and seismic evidence of gas hydrates the kumano basin is the largest forearc basin in the nankai trough and lies at about 2000 m water depth. The great valley forearc basin widened during the cretaceous as a result of two processes. Farther landward, the surface rises again, reaching a maximum at the forearc high. The nature of the crust under the andaman forearc basin is not known curray 2005, basically for lack of data.
The evolution of sediment flow routing during complete evolution of the kumano forearc basin is determined through integration of stratigraphic and sediment provenance analyses in the upper nankai forearc. Pdf forearc basins are one of the fundamental sedimentary basins, and they preserve various geological phenomena arising from dynamic interactions. Structure of the hawkes bay forearc basin and north. Structure and stratigraphy of forearc regions aapg datapages. Forearc basin evolution along accretionary convergent margins, wrangell mountains, alaska. The northsouth contractional strain in the forearc manifests in upperplate faults active during the holocene, the northernmost components of which are faults within the bellingham basin. Combined with other evidence, we further infer that the carboniferous. The architecture of sw ecuador is typical of a forearc basin setting including an accretionary prism and an outer forearc high such as those observed in the kumano japan and the coast range and. Basins associated with subduction processes prepared by dr. Roughtextured areas in eastern part of image result from noisy data. Eel river basin of coastal northwestern california gregory s. The basin has an approximate area of 8,000 square kilometres 3,100 sq mi and at its deeper parts the surface of its sedimentary fill reaches 200 metres 660 ft below sealevel. Specifically, uplift in the forearc basin corresponds to the onset of the laramide orogeny and inferred low angles of subduction. The convergent margin of northwest colombia where the san jacinto and lower magdalena valley forearc basins are located, offers a unique opportunity to study.
This chapter aims to elucidate variation of forearc basins in terms of basin configurations and basin filling depositional systems with some examinations of their controlling factors, using actual examples from the cenozoic forearc basins along the northeast and southwest japan arcs. New geochronologic and thermochronologic data from rocks near hatcher pass, southwest talkeetna mountains, alaska, record earliest paleocene erosional and structural exhumation on the flank of the active cook inlet forearc basin. We present stratigraphic, sandstone petrographic, and upb detrital data from upper. Basin formation in the nias area of the sumatra forearc. Early tertiary exhumation of the flank of a forearc basin. Multiple orientations and generations of faults from 3d coherency mapping g. This belt may have grown by continued accretion at the toe of the wedge, by underplating beneath the reentrant, and by trapping of sediment shed from the island arc. Of particular interest are the tectonic and sedimentary interactions between the accretionary wedge and forearc basin and the influence of tectonics and eustatic sealevel fluctuations on sedimentation.
Sediment flow routing during formation of forearc basins. Forearc basins between the magmatic arc and the trench axis. Shaded relief bathymetry of the daisy bank fault and vicinity, central oregon continental slope and abyssal plain. The unconformity is angular and probably subaerially eroded on the inner and middle. A late oligocene age of the reef is attested by lbf assemblages occurring in two different facies. A forearc is the region between an oceanic trench and the associated volcanic arc. Forearc regions are found at convergent margins, and include any accretionary wedge and forearc basin that may be present. Late cenozoic seismic stratigraphy of the andaman forearc. In contrast, eastern, arcward parts of the basin display subsidence histories suggestive of thermal contraction and compatible with continentward migration of sierran arc magmatism in the late cretaceous. The relationship between the lesser antilles island arc, the tobago forearc basin, and the barbados accretionary prism shows classic convergent margin geometry. Drilling of sedimentary sequences down to the basin basement was recently carried out by deep sea. Subsidence isochrons indicate that oblique subduction of the european plate below the adriatic plate was responsible for forearc.
Western, oceanward parts of the basin record subsidence, then uplift, in apparent response to the angle and rate of descent of the underlying subducting plate. Pdf seismic stratigraphy and cenozoic evolution of west. In this study, we present a highresolution deep seismic reflection image of the northern sumatran subduction forearc, near the 2004 december 26 sumatra earthquake epicentral region. The active subduction thrust is located along the base of the model, extending from the trench landward. Until we can reconstruct how and why this happens, we cannot pretend to understand a wide range of important earth processes and properties, including lithospheric strength, composition, and density, and the driving force behind plate motions. To understand subduction initiation, study forearc crust. The talara basin is a sedimentary basin that is located along the northwestern coastline of peru that covers 1 mi 2. Importance of structural history integration on 1 and 2d basin and petroleum system models in hawke bay, north island, new zealand november 28th, 2012 blair burgreen, steve graham, and kris meisling the 5th. C g h d in the kumano forearc basin, nankai trough, japan. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere to bend, by a process known as lithospheric flexure. We image a high alongstrike variability of the subducting oceanic plate, the interface between subducting and overriding plate, the accretionary wedge, the outer arc high and forearc basins. Cretaceous plutons shed sediments to the south, forming the paleocene arkose ridge formation. A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt.
This study focuses on the oldest sedimentary strata preserved in the xigaze forearc basin to 1 document the relationship between the. Sedimentary evolution and provenance of the late permian. The great valley forearc basin widened during the cretaceous as a. Surya nugraha robert hall abstract cenozoic subduction of the indoaustralian plate beneath java began in the middle eocene. Structure, evolution and tectonic activity of the eastern.
The forearc region includes any forearc basin, outerarc high, accretionary prism and. A better understanding of the mechanisms by which new subduction zones form is critical for advancing the solid earth sciences. Structure and stratigraphy of the barbados accretionary prism. Matthews 2 convergentmargin basins cmbs are commonly associated with active arcs, and hence are rich in detrital zircon dz whose ages closely reect the timing of deposition. Triassic successions of the southern nqb were most likely deposited in a forearc basin under the in situ suture model, that is, the northward subduction of the longmu co. The kumano basin, located along the nankai margin, southwest japan fig. Forearc basin evolution along accretionary convergent margins.
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