Lau-Colville Ridge

The Lau-Colville Ridge is an extinct oceanic ridge located in the Pacific Ocean, on the oceanic Australian Plate in the southwest Pacific Ocean. It extends about 2,700 km (1,700 mi) from the southeast of Fiji to the continental shelf margin of New Zealand's North Island.

 Geography 
The Lau-Colville Ridge is divided into two segments:

 The northern Lau Ridge forms the western boundary of the Lau Basin and contributed to the formation of several islands southeast of Fiji.
 The southern Colville Ridge forms the western boundary of the Havre Trough.

To the west of the ridge lies the South Fiji Basin, whose bedrock is of Oligocene origin.https://ruor.uottawa.ca/bitstream/10393/43523/3/Gray_Alexandra_2022_thesis.pdf

 Geology 
The ridge is composed primarily of mafic picro-basalts to dacite with underlying diverse rocks that are over 100 million years old. Volcanic activity along the Lau Ridge occurred mainly between 14 and 6 million years ago, while the Colville Ridge experienced volcanism between 7.5 and 2.6 million years ago.http://oceanrep.geomar.de/46263/6/Timm_REVISED.pdfhttp://igppweb.ucsd.edu/~dbassett/Publications_files/Timm_Louisville_seamount_subduction_NatureComm_2013.pdf

 Tectonics 
The Lau-Colville Ridge was once a subduction boundary between the Australian Plate and the Pacific Plate. The ridge is now the inactive part of a 100 million-year-old arc/back-arc system. The adjacent Lau Basin contains active spreading centers that continue to evolve today.https://www.researchgate.net/publication/248257025https://hal.archives-ouvertes.fr/hal-00407049/file/2001GC000261.pdf

 Related pages 

 Lau Basin
 Havre Trough
 Plate tectonics

 References 

Category:Pacific Ocean