TY - JOUR
T1 - Melanesian back-arc basin and arc development
T2 - constraints from the eastern Coral Sea
AU - Seton, Maria
AU - Mortimer, Nick
AU - Williams, Simon
AU - Quilty, Patrick
AU - Gans, Phil
AU - Meffre, Sebastien
AU - Micklethwaite, Steven
AU - Zahirovic, Sabin
AU - Moore, Jarrod
AU - Matthews, Kara J.
PY - 2016/11/1
Y1 - 2016/11/1
N2 - The eastern Coral Sea is a poorly explored area at the north-eastern corner of the Australian Tectonic Plate, where interaction between the Pacific and Australian plate boundaries, and accretion of the world's largest submarine plateau – the Ontong Java Plateau – has resulted in a complex assemblage of back-arc basins, island arcs, continental plateaus and volcanic products. This study combines new and existing magnetic anomaly profiles, seafloor fabric from swath bathymetry data, Ar–Ar dating of E-MORB basalts, palaeontological dating of carbonate sediments, and plate modelling from the eastern Coral Sea. Our results constrain commencement of the opening of the Santa Cruz Basin and South Rennell Trough to c. 48 Ma and termination at 25–28 Ma. Simultaneous opening of the Melanesian Basin/Solomon Sea further north suggests that a single > 2000 km long back-arc basin, with at least one triple junction existed landward of the Melanesian subduction zone from Eocene–Oligocene times. The cessation of spreading corresponds with a reorganisation of the plate boundaries in the area and the proposed initial soft collision of the Ontong Java Plateau. The correlation between back-arc basin cessation and a widespread plate reorganisation event suggests that back-arc basins may be used as markers for both local and global plate boundary changes.
AB - The eastern Coral Sea is a poorly explored area at the north-eastern corner of the Australian Tectonic Plate, where interaction between the Pacific and Australian plate boundaries, and accretion of the world's largest submarine plateau – the Ontong Java Plateau – has resulted in a complex assemblage of back-arc basins, island arcs, continental plateaus and volcanic products. This study combines new and existing magnetic anomaly profiles, seafloor fabric from swath bathymetry data, Ar–Ar dating of E-MORB basalts, palaeontological dating of carbonate sediments, and plate modelling from the eastern Coral Sea. Our results constrain commencement of the opening of the Santa Cruz Basin and South Rennell Trough to c. 48 Ma and termination at 25–28 Ma. Simultaneous opening of the Melanesian Basin/Solomon Sea further north suggests that a single > 2000 km long back-arc basin, with at least one triple junction existed landward of the Melanesian subduction zone from Eocene–Oligocene times. The cessation of spreading corresponds with a reorganisation of the plate boundaries in the area and the proposed initial soft collision of the Ontong Java Plateau. The correlation between back-arc basin cessation and a widespread plate reorganisation event suggests that back-arc basins may be used as markers for both local and global plate boundary changes.
KW - Back-arc basin
KW - Eastern Coral Sea
KW - Melanesia
KW - Subduction
KW - SW Pacific
UR - http://www.scopus.com/inward/record.url?scp=84992630103&partnerID=8YFLogxK
U2 - 10.1016/j.gr.2016.06.011
DO - 10.1016/j.gr.2016.06.011
M3 - Article
AN - SCOPUS:84992630103
VL - 39
SP - 77
EP - 95
JO - Gondwana Research
JF - Gondwana Research
SN - 1342-937X
ER -