Tag Archives: hawaii

Hawaiian volcano rift zones

In Hawaii, volcanoes form over a hot spot, an area where magma rises from the mantle and breaks through the crust. The Pacific plate moves northwest over the hot spot—which remains stationary—eventually carrying the old volcano away from the hotspot. A new volcano then begins to form, with repeated basaltic eruptions building a broad shield volcano. Read more

Basalt types: tholeiites vs alkali basalts

Essentially, tholeiites are less evolved. They have different normalized rare earth element REE signatures: when normalized by chondrites, the more primitive tholeiites have flatter REE patterns, while calc-alkalis show enrichment in the light REEs (LREE). Tholeiites are associated with oceanic spreading centers (shallow), while alkali basalts are associated with collisional zones (deeper). Read more

Geology of Hawaiian Coral Reefs

HAWAIIAN CORAL REEFS
Cortney Cameron
EOS 402S, Duke University

I. Introduction

He pūko‘a kani ‘āina.
A coral reef grows into an island (from small beginnings come great things).

Part animal, part plant, and part mineral, corals sit at the crossroads of biology and geology. In the Hawaiian Islands, geographic isolation and hot spot volcanism have created a uniquely trying environment for coral reef development. This paper will summarize the biology and ecology of Hawaiian corals, as well as their economic and cultural importance, in order to understand the geologic contributions that corals make in producing carbonate and aiding the interpretation of igneous features. Read more