Map helps unravel complexities of the southwestern Pacific Ocean

Abstract

The southwestern Pacific Ocean region hosts submerged continental margins, ridges, sedimentary basins, and volcanic arcs located around Papua New Guinea, New Zealand, Australia, and Fiji. The geological history of this vast region has remained controversial, and to improve understanding of the processes that controlled its geodynamical evolution, it is essential to place each piece of available data in a regional spatiotemporal framework. To this end, a new map, entitled “Structural Provinces of the Southwest Pacific,” was released by the Geological Survey of New Caledonia in May 2011. The publication consists of two parts: (1) a 40‐page booklet of geological notes, which documents the nature and age of each structure and contains an associated list of references; and (2) a 3‐ x 4‐foot poster of a structural map revealing the nature of the basement, location, and type of the main structural features (see simplified version in Figure 1) and the age of formation using the international standards for geological color codes established by the Commission for the Geological Map of the World (CGMW) (see http://ccgm.free.fr/index.html).

Tasman Frontier Subduction Initiation and Paleogene Climate

“…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 velocity, and gravity and magnetic anomalies (Collot et al, 2012;Klingelhoefer et al, 2007;Mortimer, 2004aMortimer, , 2004bMortimer et al, 2008;Sutherland, 1999;Tulloch et al, 1991;Wood and Woodward, 2002). Lord Howe Rise and Challenger Plateau ( Figures 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).…”

Crustal Structure Across the Lord Howe Rise, Northern Zealandia, and Rifting of the Eastern Gondwana Margin

“…Extinct seafloor spreading in the Tasman Basin is from Gaina, Müller, et al (); Gaina, Roest, et al (). (b) Bathymetric map of the studied area showing key domains of the northern Lord Howe rise, with the major tectonic boundaries (Collot et al, ; Stagg et al, ). Positions of the Ocean Bottom Seismometers (OBSs) deployed during the KR16–05/GA0354 survey are shown by the white ticks and the black line shows the air gun shooting.…”

Episodic behavior of Gondwanide deformation in eastern Australia: Insights from the Gympie Terrane

“…(a) Late Paleozoic configuration of Gondwana [ Domeier and Torsvik , ] showing the approximate extent of the Terra Australis Orogen. Latitude and longitude grid spacing is 30°; (b) crustal elements of Australia and peri‐Gondwanan terranes of the SW Pacific [after Collot et al ., ]. Gympie Terrane and suggested correlatives highlighted in blue; (c) simplified geological map of eastern Australia (data from Geoscience Australia).…”