Early growth of Kohala volcano and formation of long Hawaiian rift zones

Geology
By:  and 

Links

Abstract

Transitional-composition pillow basalts from the toe of the Hilo Ridge, collected from outcrop by submersible, have yielded the oldest ages known from the Island of Hawaii: 1138 ± 34 to 1159 ± 33 ka. Hilo Ridge has long been interpreted as a submarine rift zone of Mauna Kea, but the new ages validate proposals that it is the distal east rift zone of Kohala, the oldest subaerial volcano on the island. These ages constrain the inception of tholeiitic volcanism at Kohala, provide the first measured duration of tholeiitic shield building (≥870 k.y.) for any Hawaiian volcano, and show that this 125-km-long rift zone developed to near-total length during early growth of Kohala. Long eastern-trending rift zones of Hawaiian volcanoes may follow fractures in oceanic crust activated by arching of the Hawaiian Swell in front of the propagating hotspot.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Early growth of Kohala volcano and formation of long Hawaiian rift zones
Series title Geology
DOI 10.1130/G31929.1
Volume 39
Issue 7
Year Published 2011
Language English
Publisher Geological Society of America
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center, Volcano Science Center
Description 4 p.
First page 659
Last page 662
Country United States
State Hawai'i
Google Analytic Metrics Metrics page
Additional publication details