1/2/2024 0 Comments Define submerge![]() The Glossary of Geology defines a continent as “one of the Earth’s major land masses, including both dry land and continental shelves” (Neuendorf et al., 2005). Selected microcontinents and continental fragments shown by black dotted lines: Md-Madagascar Mt-Mauritia D-Gulden Draak T-East Tasman G-Gilbert B-Bollons O-South Orkney. Large igneous province (LIP) submarine plateaus shown by blue dashed lines: AP-Agulhas Plateau KP-Kerguelen Plateau OJP-Ontong Java Plateau MP-Manihiki Plateau HP-Hikurangi Plateau. Continental shelf areas shown in pale colors. Simplified map of Earth’s tectonic plates and continents, including Zealandia. 1)? Continents are Earth’s largest surficial solid objects, and it seems unlikely that a new one could ever be proposed. But what about the major continents (Fig. Simultaneously, there have been advances in our understanding of continental rifting, continent-ocean boundaries (COBs), and the discovery of a number of micro-continental fragments that were stranded in the ocean basins during supercontinent breakups (e.g., Buck, 1991 Lister et al., 1991 Gaina et al., 2003 Franke, 2013 Eagles et al., 2015). In the past 50 years there has been great emphasis and progress in measuring and modeling aspects of plate tectonics at various scales (e.g., Kearey et al., 2009). In combination, these divisions provide a powerful descriptive framework in which to understand and investigate Earth’s history and processes. 2017Įarth’s surface is divided into two types of crust, continental and oceanic, and into 14 major tectonic plates (Fig. Zealandia provides a fresh context in which to investigate processes of continental rifting, thinning, and breakup. The identification of Zealandia as a geological continent, rather than a collection of continental islands, fragments, and slices, more correctly represents the geology of this part of Earth. Today it is 94% submerged, mainly as a result of widespread Late Cretaceous crustal thinning preceding supercontinent breakup and consequent isostatic balance. Its isolation from Australia and large area support its definition as a continent-Zealandia. The region has elevated bathymetry relative to surrounding oceanic crust, diverse and silica-rich rocks, and relatively thick and low-velocity crustal structure. A 4.9 Mkm 2 region of the southwest Pacific Ocean is made up of continental crust.
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