Table of Contents - SPE233: Synextensional Magmatism in the Basin and Range Province; A Case Study from the Eastern Great Basin


Acknowledgments

Abstract

Introduction

Geologic setting
Previous work
Methods

Tertiary Stratigraphy

Older andesites and rhyolites Northern Egan Range
Conners Pass area, central Schell Creek Range
Northernmost Schell Creek Range
Southwestern Deep Creek Range
Other areas

Kalamazoo volcanic rocks

Kalamazoo Tuff Distribution, volume, and source area
Cooling units, lithic content, and mineralogy
Hornblende dacite lavas
Distribution, volume, and source area(s)
Textural variations and modal mineralogy
Tuff of North Creek
Distribution, volume, and source area(s)
Cooling units, lithic content, and mineralogy

Younger sedimentary and volcanic sequences

Duck Creek Valley
Sacramento Pass
Confusion Range
Northernmost Snake Range
Pleasant Valley

Relative Timing of Faulting and Volcanism

The onset of extensional faulting
Faulting associated with the Kalamazoo volcanic rocks
Faulting associated with the younger sedimentary and volcanic sequences
Duck Creek Valley
Sacramento Pass and Confusion Range
Northernmost Snake Range
Tectonic-stratigraphic summary

Geochemistry of synextensional volcanic rocks in east-central Nevada

Major- and trace-element compositions
Early andesites and rhyolites
Kalamazoo volcanic rocks
Sr and Nd isotopic compositions
Discussion
Chemical evidence for the sources of crustal melts
Proportions of mantle and crustal components
Assimilation-fractional-crystallization modeling of isotopic data
Summary

Eruptive histories of some other highly extended regions

Yerington District, west-central Nevada
Death Valley, southeastern California
Socorro, New Mexico
Eldorado Mountains, southern Nevada
Whipple Mountains and environs, southeastern California-western Arizona
Chocolate Mountains, southeastern California Summary

Discussion: Extension and magmatism in the Basin and Range Province

Driving mechanisms
Space-time distributions of extension and volcanism
Active versus passive rifting
A model for Basin and Range extension and magmatism
Implications and unresolved problems

References