Kaikohe-Bay of Islands volcanic field

Coordinates35°20′54″S 173°50′55″E / 35.348316°S 173.848686°E / -35.348316; 173.848686

Rock age20–0.0013 Ma

PreꞒ

Ꞓ

O

S

D

C

P

T

J

K

Pg

N

Last eruption1300 to 1800 years ago

Kaikohe-Bay of Islands volcanic field
Te Ahuahu, looking from Waimate North
Highest point
Coordinates	35°20′54″S 173°50′55″E / 35.348316°S 173.848686°E / -35.348316; 173.848686
Geography
Kaikohe-Bay of Islands volcanic field
Geology
Rock age	20–0.0013 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Last eruption	1300 to 1800 years ago

The recently active basaltic Kaikohe-Bay of Islands volcanic field in the Northland region of New Zealand is associated geographically with an older region of extinct volcanism to its north the Wairakau Volcanic Centre, meaning eruptions in this region have occurred over the last 20 million years.^[1] All the cones older than 2 million years have eroded away, leaving plateaus from Ōkaihau to Kerikeri and north to Whangaroa from the old andesite/dacite stratovolcanoes of the Wairakau Volcanic Centre and the ten million year old or more recent volcanoes in field towards the south. In the southern part of the field, around 12 small basaltic scoria cones, and a rhyolite dome erupted in the last 500,000 years around Kaikohe. The field is considered dormant, rather than extinct.^[2]

Map to emphasise selected recent surface volcanic features of the dormant Kaikohe volcanic field.

Legend

• '"`UNIQ--templatestyles-00000011-QINU`"'  Scoria vents (large squares) less than a million years old
• '"`UNIQ--templatestyles-00000012-QINU`"'  eroded vents (small squares) from about 20 million years ago
• '"`UNIQ--templatestyles-00000013-QINU`"'  lava fields less than a million years old
• '"`UNIQ--templatestyles-00000014-QINU`"'  ancient volcanic deposits associated with the stratovolcanoes of the Wairakau Volcanic Centre are to the north in red and are from about 20 million years ago
• To enlarge the map and enable mouseover of volcano feature/wikilinks click on the rectangle shape.'"`UNIQ--ref-00000015-QINU`"''"`UNIQ--ref-00000016-QINU`"''"`UNIQ--ref-00000017-QINU`"''"`UNIQ--ref-00000018-QINU`"'

Map of more detailed volcanic features of the dormant Kaikohe volcanic field allowing wider context.

Legend

• Key for the volcanics that are shown with panning is:
• '"`UNIQ--templatestyles-0000001A-QINU`"'  basalt (shades of brown/orange)
• '"`UNIQ--templatestyles-0000001B-QINU`"'  monogenetic basalts
• '"`UNIQ--templatestyles-0000001C-QINU`"'
    undifferentiated basalts of the Tangihua Complex in Northland Allochthon
• '"`UNIQ--templatestyles-0000001D-QINU`"'  arc basalts
• '"`UNIQ--templatestyles-0000001E-QINU`"'  arc ring basalts
• '"`UNIQ--templatestyles-0000001F-QINU`"'
    dacite
• '"`UNIQ--templatestyles-00000020-QINU`"'  andesite (shades of red)
• '"`UNIQ--templatestyles-00000021-QINU`"'  basaltic andesite
• '"`UNIQ--templatestyles-00000022-QINU`"'
    rhyolite (ignimbrite is lighter shades of violet)
• '"`UNIQ--templatestyles-00000023-QINU`"'  plutonic
• White shading is selected caldera features.
• Clicking on the rectangle icon enables full window and mouse-over with volcano name/wikilink and ages before present.