Ionium dating of acidic volcanic rocks.

Generalized Titanomagnetite in Hawaiian Volcanic Rocks'

A ferromagnetic oxide mineral with spinel structure was separated from Hawaiian volcanic rocks ranging from basalt to trachyte . The chemical compositions of all the specimens have been arranged on an oxygen reaction line, and can safely be interpreted as the result of a process of either oxidation or reduction of material with composition on or near this line. In the trachyte the mineral was f...

Dating species divergences using rocks and clocks.

Groundwater in Sedimentary, Metamorphic and Volcanic Rocks

Geochemical Character of Neogene Volcanic Rocks of the Central Beetle-

Vol ca nic rocks have formed along the length of the North Amer i can Cor dil lera dur ing the Neo gene and Qua ter nary pe ri ods. Vol ca nism of this age is dom i nantly al ka line and ex tends through out cen tral Brit ish Co lum bia and the south ern Yu kon Ter ri tory. Dis tinct prov inces of al ka line magmatism have been iden ti fied in BC, in clud ing the north ern Cor dil lera vol ca n...

Petrogenesis of alkalic and calcalkalic volcanic rocks of Mormon Mountain Volcanic Field, Arizona

The Cenozoic Mormon Mountain Volcanic Field (MMVF) of northern Arizona is situated in the transition zone between the Basin and Range and the Colorado Plateau. It is composed of alkalic to sub-alkalic basalts and calcalkalic andesites, dacites, and rhyodacites. Despite their spatial and temporal association, the basalts and the calcalkalic suite do not seem to be co-genetic. The petrogenesis of...