Sediment thickness and crustal structure of offshore western New Zealand from 3D gravity modelling

Wood, Ray; Woodward, D. J.

doi:10.1080/00288306.2002.9514971

Cited by 27 publications

(34 citation statements)

References 23 publications

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“…Wandres and Bradshaw, 2005). All these regions show similar crustal thickness (Sundaralingham and Denham, 1987;Trey et al, 1999;Wood and Woodward, 2002). Underplating is interpreted to have occurred beneath Lord Howe Rise and the Challenger Plateau (Wood and Woodward, 2002), and the crust of the Ross Sea is interpreted to be intruded by mafic rocks (Trey et al, 1999).…”

Section: Origin Of Cmas and Smasmentioning

confidence: 91%

“…All these regions show similar crustal thickness (Sundaralingham and Denham, 1987;Trey et al, 1999;Wood and Woodward, 2002). Underplating is interpreted to have occurred beneath Lord Howe Rise and the Challenger Plateau (Wood and Woodward, 2002), and the crust of the Ross Sea is interpreted to be intruded by mafic rocks (Trey et al, 1999). For this reason, we assume that crustal thinning and underplating beneath the four formerly adjacent areas are related to one event, which we identify as Early Cretaceous or Jurassic thinning prior to the break-up (Uruski and Wood, 1991;Wood, 1993).…”

Section: Origin Of Cmas and Smasmentioning

confidence: 99%

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Extensional and magmatic nature of the Campbell Plateau and Great South Basin from deep crustal studies

et al. 2009

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Section: Origin Of Cmas and Smasmentioning

confidence: 91%

Section: Origin Of Cmas and Smasmentioning

confidence: 99%

Extensional and magmatic nature of the Campbell Plateau and Great South Basin from deep crustal studies

et al. 2009

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“…Crustal models based on bathymetry, gravity, and sediment thickness data predict that the Lord Howe Rise has a crustal thickness of 15–30 km and is inferred to be a continental prolongation of New Zealand and that the New Caledonia Trough has a crustal thickness of 5–15 km [ Klingelhoefer et al , 2007; Uruski and Wood , 1991; Wood and Woodward , 2002; Woodward and Hunt , 1971]. In the region that is southwest of New Caledonia, seismic reflection and refraction data confirm that the Lord Howe Rise has a crustal thickness of 23 km and the New Caledonia Trough has a crustal thickness of 6–8 km [ Klingelhoefer et al , 2007].…”

Section: Offshore Crust Type and Thicknessmentioning

confidence: 99%

Lithosphere delamination with foundering of lower crust and mantle caused permanent subsidence of New Caledonia Trough and transient uplift of Lord Howe Rise during Eocene and Oligocene initiation of Tonga-Kermadec subduction, western Pacific

et al. 2010

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We use seismic reflection and rock sample data to propose that the first‐order physiography of New Caledonia Trough and Norfolk Ridge formed in Eocene and Oligocene time and was associated with the onset of subduction and back‐arc spreading at the Australia‐Pacific plate boundary. Our tectonic model involves an initial Cretaceous rift that is strongly modified by Cenozoic subduction initiation. Hence, we are able to explain (1) complex sedimentary basins of inferred Mesozoic age; (2) a prominent unconformity and onlap surface of middle Eocene to early Miocene age at the base of flat‐lying sediments beneath the axis of New Caledonia Trough; (3) gently dipping, variable thickness, and locally deformed Late Cretaceous strata along the margins of the trough; (4) platform morphology and unconformities on either side of the trough that indicate a phase of late Eocene to early Miocene uplift to near sea level, followed by rapid Oligocene and Miocene subsidence of ∼1100–1800 m; and (5) seismic reflection facies tied to boreholes that suggest absolute tectonic subsidence at the southern end of New Caledonia Trough by 1800–2200 m since Eocene time. The Cenozoic part of the model involves delamination and subduction initiation followed by rapid foundering and rollback of the slab. This created a deep (>2 km) enclosed oceanic trough, ∼2000 km long and 200–300 km across, in Eocene and Oligocene time as the lower crust detached, with simultaneous uplift and local land development along basin flanks. Disruption of Late Cretaceous and Paleogene strata was minimal during this Cenozoic phase and involved only subtle tilting and local reverse faulting or folding. Basin formation was possible through the action of at least one detachment fault that allowed the lower crust to either be subducted into the mantle or exhumed eastward into Norfolk Basin. We suggest that delamination of the lithosphere, with possible mixing of the lower crust back into the mantle, is more widespread than previously thought and may be commonly associated with subduction initiation, such as Cenozoic events in the Mediterranean and western Pacific.

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“…Continental "basement" beneath bathymetric rises in the region is inferred to be similar to rocks found in New Zealand, New Caledonia, and eastern Australia; this inference is supported by limited dredge samples and drilling (DSDP Site 207), seismic velocities, and gravity and magnetic anomalies Klingelhoefer et al, 2007;Mortimer, 2004aMortimer, , 2004bMortimer et al, 2008;Sutherland, 1999;Tulloch et al, 1991;Wood and Woodward, 2002). The Lord Howe Rise and Challenger Plateau ( Figure F3, F4) are probably composed of quartzose metasedimentary rocks and granitoids of Paleozoic age that represent the eastern edge of Gondwana (Mortimer et al, 2017).…”

Section: Geological Settingmentioning

confidence: 69%

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Sutherland¹,

Dickens²,

Blum³

et al. 2018

International Ocean Discovery Program Preliminary Report

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International Ocean Discovery Program (IODP) Expedition 371 drilled six sites in the Tasman Sea of the southwest Pacific between 27 July and 26 September 2017. The primary goal was to understand Tonga-Kermadec subduction initiation through recovery of Paleogene sediment records. Secondary goals involved understanding regional oceanography and climate since the Paleogene. Six sites were drilled, recovering 2506 m of cored sediment and volcanic rock in 36.4 days of on-site drilling during a total expedition length of 58 days. Wireline logs were collected at two sites. Shipboard observations made using cores and logs represent a substantial gain in fundamental knowledge about northern Zealandia, because only Deep Sea Drilling Project Sites 206, 207, and 208 had penetrated beneath upper Eocene strata within the region.The cored intervals at five sites (U1506-U1510) sampled nannofossil and foraminiferal ooze or chalk that contained volcanic or volcaniclastic intervals with variable clay content. Paleocene and Cretaceous sections range from more clay rich to predominantly claystone. At the final site (U1511), a sequence of abyssal clay and diatomite was recovered with only minor amounts of carbonate. The ages of strata at the base of each site were middle Eocene to Late Cretaceous, and our new results provide the first firm basis for defining formal lithostratigraphic units that can be mapped across a substantial part of northern Zealandia and related to onshore regions of New Caledonia and New Zealand.The material and data recovered during Expedition 371 enable primary scientific goals to be accomplished. All six sites provided new stratigraphic and paleogeographic information that can be put into context through regional seismic-stratigraphic interpretation and hence provide strong constraints on geodynamic models of subduction zone initiation. Our new observations can be directly related to the timing of plate deformation, the magnitude and timing of vertical motions, and the timing and type of volcanism. Secondary paleoclimate objectives were not all completed as planned, but significant new records of southwest Pacific climate were obtained.

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Sediment thickness and crustal structure of offshore western New Zealand from 3D gravity modelling

Cited by 27 publications

References 23 publications

Extensional and magmatic nature of the Campbell Plateau and Great South Basin from deep crustal studies

Extensional and magmatic nature of the Campbell Plateau and Great South Basin from deep crustal studies

Lithosphere delamination with foundering of lower crust and mantle caused permanent subsidence of New Caledonia Trough and transient uplift of Lord Howe Rise during Eocene and Oligocene initiation of Tonga-Kermadec subduction, western Pacific

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