Lau-Colville Ridge

Lau-Colville Ridge
Lau-Colville Ridge
Stratigraphic range: 14–2.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Fiji Lau; Basin Tonga-; Kermadec; Ridge Lau-; Col-; ville; Ridge Tonga; Trench Kermadec; Trench Osbourn Trough Louisville Seamount Chain Hikurangi Trough South; Fiji; Basin New Zealand . The extinct Lau-Colville Ridge is to the west of more geologically active Pacific Ocean seafloor features.
Type	Igneous
Lithology
Primary	mafic picro-basalts to dacite
Other	Underlying diverse subduction and other rocks >100 Ma old
Location
Coordinates	27°06′S 179°12′W / 27.1°S 179.2°W
Region	South Pacific
Country	New Zealand
Type section
Named for	Lau Islands and Cape Colville
	Approximate surface projection on Pacific Ocean of the Coville Ridge (brown). Clicking on the map enlargement icon shows also the Lau Ridge (orange) and the northern portion of the Lau Ridge which as it widens and flattens is shown as a band shaded light orange from south of the Lau Islands that is essentially illustrative.

The Lau-Colville Ridge is an extinct oceanic ridge located on the oceanic Australian Plate in the south-west Pacific Ocean extending about 2,700 km (1,700 mi)^[3] from the south east of Fiji to the continental shelf margin of the North Island of New Zealand. It was an historic subduction boundary between the Australian Plate and the Pacific Plate and has important tectonic relationships to its east where very active spreading and subduction processes exist today. It is now the inactive part of an eastward-migrating, 100 million year old Lau-Tonga-Havre-Kermadec arc/back-arc system or complex^[4] and is important in understanding submarine arc volcanism because of these relationships.^[5] To its west is the South Fiji Basin whose northern bedrock is Oligocene in origin.^[6]

^ Cite error: The named reference MGCR was invoked but never defined (see the help page).
^ Cite error: The named reference MGLR was invoked but never defined (see the help page).
^ Ruellan et al. 2003, Section:1.Introduction
^ Ewart et al. 1998, Introduction, p. 332
^ Timm et al. 2019, Section:Introduction
^ Timm et al. 2019, abstract

[MGCR-1] Cite error: The named reference MGCR was invoked but never defined (see the help page).

[MGLR-2] Cite error: The named reference MGLR was invoked but never defined (see the help page).

[3] Ruellan et al. 2003, Section:1.Introduction

[4] Ewart et al. 1998, Introduction, p. 332

[Timm2019intro-5] Timm et al. 2019, Section:Introduction

[Timm2019abstract-6] Timm et al. 2019, abstract

[1]

[2]

[3]

[4]

[5]

[6]

Lau-Colville Ridge
Stratigraphic range: 14–2.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fiji Lau Basin Tonga- Kermadec Ridge Lau- Col- ville Ridge Tonga Trench Kermadec Trench Osbourn Trough Louisville Seamount Chain Hikurangi Trough South Fiji Basin New Zealand . The extinct Lau-Colville Ridge is to the west of more geologically active Pacific Ocean seafloor features.
Type	Igneous
Lithology
Primary	mafic picro-basalts to dacite
Other	Underlying diverse subduction and other rocks >100 Ma old
Location
Coordinates	27°06′S 179°12′W / 27.1°S 179.2°W / -27.1; -179.2
Region	South Pacific
Country	New Zealand
Type section
Named for	Lau Islands and Cape Colville
Approximate surface projection on Pacific Ocean of the Coville Ridge (brown).^[1] Clicking on the map enlargement icon shows also the Lau Ridge (orange) ^[2] and the northern portion of the Lau Ridge which as it widens and flattens is shown as a band shaded light orange from south of the Lau Islands that is essentially illustrative.