|Posted on February 23, 2022 at 7:40 AM|
Zealandia illustrates that the large and the obvious in natural science can be overlooked. Based on various lines of geological and geophysical evidence, particularly those accumulated in the last two decades, we argue that Zealandia is not a collection of partly submerged continental fragments but is a coherent 4.9 Mkm2 continent (Fig. 1). Currently used conventions and definitions of continental crust, continents, and microcontinents require no modification to accommodate Zealandia.
Satellite gravity data sets, New Zealand’s UNCLOS program, and marine geological expeditions have been major influences in promoting the big picture view necessary to define and recognize Zealandia (Fig. 2). Zealandia is approximately the area of greater India and, like India, Australia, Antarctica, Africa, and South America, was a former part of the Gondwana supercontinent (Figs. 3 and 5). As well as being the seventh largest geological continent (Fig. 1), Zealandia is the youngest, thinnest, and most submerged (Fig. 4). The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list. That a continent can be so submerged yet unfragmented makes it a useful and thought-provoking geodynamic end member in exploring the cohesion and breakup of continental crust.
We thank Belinda Smith Lyttle for GIS work and Patti Durance, Ron Hackney, and Brendan Murphy for comments. Formal reviews by Peter Cawood, Jerry Dickens, and an anonymous referee greatly improved the focus and content. This paper is based on work supported by New Zealand Government core funding grants to GNS Science.
Adams, C.J., and Griffin, W.L., 2012, Rodinian detrital zircons in Late Cretaceous sandstones indicate a possible Precambrian basement under southern Zealandia: Precambrian Research, v. 212–213, p. 13–20, doi: 10.1016/j.precamres.2012.04.003.
Bache, F., Mortimer, N., Sutherland, R., Collot, J., Rouillard, P., Stagpoole, V.M., and Nicol, A., 2014, Seismic stratigraphic record of transition from Mesozoic subduction to continental breakup in the Zealandia sector of eastern Gondwana: Gondwana Research, v. 26, p. 1060–1078, doi: 10.1016/j.gr.2013.08.012.
Beggs, J.M., Challis, G.A., and Cook, R.A., 1990, Basement geology of the Campbell Plateau: Implications for correlation of the Campbell Magnetic Anomaly System: New Zealand Journal of Geology and Geophysics, v. 33, p. 401–404, doi: 10.1080/00288306.1990.10425696.
Bird, P., 2003, An updated digital model of plate boundaries: Geochemistry Geophysics Geosystems, v. 4, p 1027, doi: 10.1029/2001GC000252.
Blewett, R.S., editor, 2012, Shaping a Nation:
A Geology of Australia: Canberra, Geoscience Australia and ANU Press, 571 .......
Indexed for Geological Society Of America by Dragonfly Kingdom Library
Categories: Underground Intelligence Media: World News - World History, Self Improvement - Spiritual Evolution - Transcendence - (B.S.S.I), DK Travel Agency: Marco's Fitness Travel, Limo & Car Transportation Service