Scientists study deep geological structure between New Hebrides Arc and Eastern Australian Margin

Lafoy, Y.; Beuque, Sabrina Van de; Bernardel, George; Missègue, François; Nercessian, A.; Auzende, J.M.; Symonds, P. A.; Exon, N. F.

doi:10.1029/98eo00441

Cited by 11 publications

(6 citation statements)

References 3 publications

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“…1971; Woodward & Hunt 1971). This origin was confirmed by the RV Rig Seismic's FAUST 1 deep multichannel seismic cruise, which was carried out in order to better understand the geology and evolution of the submarine features located between Australia and New Caledonia (Lafoy et al . 1998a, b).…”

Section: Introductionmentioning

confidence: 83%

Miocene volcanic seamounts on northern Lord Howe Rise: lithology, age and origin

et al. 2004

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Multibeam sonar swath-mapping has revealed small submarine volcanic cones on the northeastern Lord Howe Rise, a submerged ribbon continent. Two such cones, aligned north-northwest and 120 km apart, were dredged at 23-24 Њ S. Water depth is about 1150 m nearby: the southern cone rises to 750 m and the northern to 900 m. Volcanic rocks dredged from the cones are predominantly highly altered hyaloclastites with minor basalt. The clasts are mostly intensely altered vesicular brownish glass with lesser basalt, set in zeolitic, clayey, micritic, or ferruginous cement. Lavas and hyaloclastites contain altered phenocrysts of olivine and plagioclase, and fresh clinopyroxene. The latter have compositions between acmite and Ti-augite, matching clinopyroxene phenocrysts in undersaturated intraplate basanitic mafic lavas. Interbedded micrites in the volcaniclastics represent calcareous ooze that was deposited with (or later than) the volcanic pile. Foraminifers indicate that the micrite is dominantly Early Miocene ( ca 16 Ma), and that the ooze was deposited in cool water. Upper Miocene to Pliocene micrites, presumed to be later infillings, all contain warm-water forms. This evidence strongly suggests that both cones formed in pelagic depths in the Early Miocene. Ferromanganese crusts from the two cones are up to 7 cm thick and similar physically, but different chemically. The average growth rate is 4 mm/10 6 y. Copper, nickel, and cobalt content are relatively high in the north, but copper does not exceed 0.08 wt%, nickel 0.65%, and cobalt 0.25%. The Mn:Fe ratio is high in the south (average 13.7) suggesting strong hydrothermal influence. Such small volcanic cones related to intraplate hot-spot-type volcanism may occur in extensive fields on the Lord Howe Rise, like those off southern Tasmania. On the Lord Howe Rise, the known small volcanic cones coincide with broad gravity highs in areas of shallow continental basement. The highs are aligned parallel to the Lord Howe Rise margins, and it is probable that the Miocene volcanism is related to jostling on older faults. Other fields of small volcanic seamounts may occur on the Lord Howe Rise on such fractured gravity highs.

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Section: Introductionmentioning

confidence: 83%

Miocene volcanic seamounts on northern Lord Howe Rise: lithology, age and origin

et al. 2004

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“…These had acronyms such as Zonéco, Extraplac, Noucaplac and Austradec (for a compilation, see Sutherland et al 2012). These programmes produced essential contributions that led to the integration of the onshore and offshore geology of New Caledonia and a better appreciation of its context in the broader SW Pacific environment (Lafoy et al 1998(Lafoy et al , 2005Van De Beuque 1999;Auzende et al 2000;Collot 2009). The Pleistocene-Holocene lagoon-reef complex of New Caledonia was thoroughly investigated from the early 1990s to the early 2000s (Cabioch et al 2008a, b).…”

Section: Current Phase Of Workmentioning

confidence: 99%

Chapter 1 Introduction to New Caledonia: geology, geodynamic evolution and mineral resources

Maurizot

Robineau

Vendé‐Leclerc

et al. 2020

Memoirs

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This Memoir summarizes our current knowledge of New Caledonia geology, geodynamics and mineral resources based on published and unpublished information. Except for a short paper timed for the 34th International Geological Congress (Cluzel et al. 2012b), there has been no review of the geology of New Caledonia since Paris (1981)that is, for more than 35 years. As such, it is timely that this Memoir is published.This Memoir comprises a collection of ten self-contained chapters written by 28 researchers from New Caledonia, France, New Zealand, Australia and Papua New Guinea. This work is not simply a summation of the factual material acquired since Paris (1981). The purpose of each chapter is to present: (1) a data synthesis from which the reader can make his or her own interpretations and (2) an interpretation by the authors incorporating contemporary datasets and geoscientific concepts. Onshore-offshore connections are emphasized, as are the geological relations with New Zealand, Australia and Papua New Guinea, although this Memoir certainly is not a synthesis of the geodynamics of the SW Pacific.This introductory chapter is a starting point for understanding how the current state of geoscientific knowledge of New Caledonia was reached. It includes a small-scale geological map and proposes a general stratigraphic scheme for New Caledonia. It reviews the advances in knowledge of the geology of the country since the last synthesis of Paris (1981). It also summarizes current problems and issues and the analyses strengths and weaknesses in the state of knowledge of the country's geology.Chapter 2 reviews the geodynamics of the SW Pacific and its relations with New Caledonian geology (Collot et al. 2020). The onshore geology of New Caledonia cannot be separated from its regional and offshore context. This chapter identifies the major geological structures of the SW Pacific from the eastern Australian coast to the Tonga-Kermadec Trench. This mostly submerged system of basins, ridges and seamounts of various ages is interpreted as oceanic and thinned continental crust, continental ridges, volcanic arcs, intra-plate volcanic chains and oceanic plateaus. Part of this region, including New Caledonia, is a submerged continent referred to as Zealandia (Mortimer et al. 2017). This chapter presents and compares tectonic models that attempt to explain the formation and development of this complex area.Chapter 3 considers the Pre-Late Cretaceous basement terranes of the Gondwana active margin (Maurizot et al. 2020a).

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“…A bottom-simulating reflector (BSR, Fig. 2c) observed in the seismic data previously on the eastern flank of the LHR and the Fairway Basin (Ramsay et al, 1997;Exon et al, 1998Exon et al, , 2007Lafoy et al, 1998Lafoy et al, , 2005Bernardel et al, 1999;Auzende et al, 2000) led to speculation regarding the existence of methane hydrate resources underlying the area. However, the results of the AUSFAIR MD153 survey (2006), in conjunction with further analysis of seismic and DSDP 208 data, have subsequently indicated that the apparent BSR is more likely to be related to an Opal-A/Opal-CT transition front (Colwell et al, 2006;Nouzé et al, 2009).…”

Section: Previous Work In the Areamentioning

confidence: 94%

Seafloor features and fluid migration in the Capel and Faust basins, offshore eastern Australia

Rollet¹,

McGiveron²,

Hashimoto³

et al. 2012

Marine and Petroleum Geology

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Scientists study deep geological structure between New Hebrides Arc and Eastern Australian Margin

Cited by 11 publications

References 3 publications

Miocene volcanic seamounts on northern Lord Howe Rise: lithology, age and origin

Miocene volcanic seamounts on northern Lord Howe Rise: lithology, age and origin

Chapter 1 Introduction to New Caledonia: geology, geodynamic evolution and mineral resources

Seafloor features and fluid migration in the Capel and Faust basins, offshore eastern Australia

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