Geology na Tsibirin Cook

Akwai Tsibirin Cook goma sha biyar, duk suna da alaƙa da tsaunuka masu fitattun wuta waɗanda suka fashe  babbar hanyar zafi ta kudu maso tsakiyar Tekun Pacific. Ƙananan tsibirai sun haɗa da shida daga cikin tsibirai na arewa waɗanda ke da tsibirai, da kuma hudu daga cikin tsibirin kudancin da ke da Tsibirin murjani. Rarotonga, tsibirin mafi girma na rukuni tsibiri ne mai tsaunuka. Tsarin dutse sun haɗa da marigayi Pliocene zuwa mafi yawan dutsen wuta na baya-bayan nan, Oligocene da Miocene reefs da tsakiyar Tertiary limestone underlying atolls  Bayyanar kwanan nan na coral reefs ana nuna su a lokuta da yawa daidai da faduwar sealevel a Mangaia, na akalla    in) a cikin shekaru 3400 da suka gabata.  Yankin arewacin Suwarrow Atoll yana da ɓangarorin reef da aka tsara tsakanin shekaru 4680 da 4310 BC kuma a arewa maso gabashin tsibirin an tsara tuddai uku daga ƙasar a shekaru 4220 BC, shekaru 3420 BC kuma daga shekaru 1250 BC. A kan Mitiaro cibiyar reef flat tana da yankuna da aka rubuta shekaru 5140-3620 BC.

## Rarotonga
Duk da yake ba dukkan tsibiran ke da tabbataccen kwanakin don dalilai na fasaha bayan abubuwan da suka shafi zamani da sake nazarin karatun da aka fi fahimta. Rarotonga ya barke tsakanin 1 · 697 zuwa 1 · 157 shekaru miliyan da suka wuce don haka ba za a iya sanya shi a ce Macdonald hotspot wanda ya shiga cikin wannan yanki shekaru 20 da suka wuce kuma ya bayyana Mangaia kusa. Idan samuwarsa ya fara ne da wannan wuri zai zama misali na sake fasalin wutar lantarki maimakon yadda aka saba da shi zuwa wurin Rarotonga mai zafi wanda ba tabbace ba. Babban sama da nau'in dutsen teku shine basalt, galibi basalt olivine amma phonolite da trachyte eruptives suma na kowa a kusa da tsakiyar caldera. Akwai tsakuwa na bakin teku da yashi da kuma murjani adibas. An haɓaka ajiyar murjani 6 ft (1.8m) kusa da filin jirgin sama a shekaru 43,000 da suka gabata.

## Mangaia
An yi nazarin tsaunuka masu tsaunuka na basaltic masu shekaru miliyan 18  saboda nau'in tafkin basaltic da aka sake amfani da shi wanda aka yi imanin yana da abubuwa sama da shekaru miliyan 500 wanda aka sani da HIMU (high μ = 238/204). 

## Aitutaki
Aitutaki, wanda ya fashe a kwanan nan akan dandamalin carbonate na atoll da ke kusa, yanzu an kwatanta shi azaman misali na sake fasalin volcanism tare da shekaru daga 1,941 zuwa 1 · 382 shekaru miliyan da suka wuce maimakon aikin al'ada ga abin da ake kira Rarotonga hotspot. Sai dai dutsen mai aman wuta na tushe ya kasance dutsen mai aman wuta wanda ya barke 9 · 39 shekaru miliyan da suka gabata a cikin jerin lokutan da aka sa ran a jerin tsaunukan Arago. Aitutaki, babban tsibiri, an kwatanta shi a matsayin kusa-toll, tare da kashi 85% na yankin da ke cikin reef a matsayin tafki, wanda a tsakiyar tsibiri ya ƙunshi manyan duwatsu masu aman wuta..

## Tsibirin Arago hotspot
Daga dazuzzukan dajin Arago wanda ke da wa fuskar arewa ta yan Cook yana haskakami, kuna son yanki a cikin Pacific, da teburan zinare na masu aman don yin saurayi da nuna ga samuwar yawan tsibiran kudanci Cook. Tsibirin Cook na Arago sune:

# Palmerston
# Aitutaki (9·39 Ma) 
# Atiu (7.44 zuwa 7·20 Ma) 
# Manaue
# Takutea
# Atiu
# Mitiaro
# Mauke

## Ƙungiyar Tsibirin Arewa
Tsibiran Manihiki, Nassau, Penrhyn Atoll, Pukapuka, Rakahanga da Suwarrow mai yiwuwa su sami manyan duwatsun farar ƙasa zuwa manyan tsaffin tsaunuka da ke tasowa daga farkon Babban Jami'in da ke yanzu murjani atolls. Dutsen dutse mafi girma shine Penrhyn yana tashi 16,000 ft (4,900 m) daga benen teku.