Description

Developments in Petrology, 6: Trondhjemites, Dacites, and Related Rocks focuses on the geology, geochemistry, and petrology of several kinds of trondhjemites, dacites, and genetically related rocks. The selection first elaborates on the definition, environment, and hypotheses of origin of trondhjemite; a review of the mineralogy and chemistry of tertiary-recent dacitic, latitic, rhyolitic, and related salic volcanic rocks; and some trace elements in trondhjemites and their implications to magma genesis and paleotectonic setting. Discussions focus on tectonic environments and trace element patterns, selection and reliability of trace elements, interrelationships between mineralogy and chemistry, and regional variations of dacitic and rhyolitic magmas. The publication then tackles strontium isotope geochemistry of late Archean to late Cretaceous tonalites and trondhjemites; Archean gray gneisses and the origin of the continental crust in West Greenland; and metamorphic development of early Archean tonalitic and trondhjemitic gneisses in Saglek Area, Labrador. The book examines the petrology, geochemistry, and origin of the Sparta quartz dioritetrondhjemite complex; reconnaissance geochemistry of Devonian island-arc volcanic and intrusive rocks in West Shasta District, California; and origin of the Twillingate trondhjemite in North-Central Newfoundland. The selection is highly recommended for geologists and geochemists wanting to explore trondhjemites, dacites, and genetically related rocks.

Table of Contents


Preface

Contributors

Chapter 1. Trondhjemite: Definition, Environment and Hypotheses of Origin

Abstract

Trondhjemite: Definition

Major-Element Character

Occurrence

Hypotheses of Origin

Comments on Archean Gray Gneiss Complexes

Relation to Subduction

Acknowledgments

References

Chapter 2. A Review of the Mineralogy and Chemistry of Tertiary-Recent Dacitic, Latitic, Rhyolitic, and Related Salic Volcanic Rocks

Abstract

Introduction

Chemistry

Phenocryst Mineralogy

Interrelationships Between Mineralogy and Chemistry

Regional Variations of Dacitic and Rhyolitic Magmas

Acknowledgments

References

Appendices

Chapter 3. Some Trace Elements in Trondhjemites - Their Implications to Magma Genesis and Paleotectonic Setting

Introduction

Selection and Reliability of Trace Elements

Tectonic Environments and Trace Element Patterns

Models of Trondhjemite Genesis

Conclusions

References

Chapter 4. Strontium Isotope Geochemistry of Late Archean to Late Cretaceous Tonalites and Trondhjemites

Abstract

Introduction

Samples and Criteria

Data

Results

Conclusions

Acknowledgments

References

Chapter 5. Oceanic Plagiogranite Revisited

Abstract

Introduction

Keratophyre and Plagiogranite

Nomenclature

Petrography

Intergrowths

Chemistry

Summary

References

Chapter 6. Archean Gray Gneisses and the Origin of the Continental Crust: Evidence from the Godthåb Region, West Greenl

Details

Language:
English
Copyright:
© 1979
Published:
Imprint:
Elsevier Science
Print ISBN:
9780444417657
Electronic ISBN:
9781483289601

Reviews

@qu:...future workers on trondhjemite will find this volume indispensable. @source: Mineralogical Magazine