LEG 185 PRELIMINARY REPORT

IZU-MARIANA MARGIN

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TABLE OF CONTENTS

Title Page
Disclaimer
Shipboard Scientific Party

Scientific Report

• Abstract
• Introduction
• Historical Perspectives
• Izu-Mariana Arc
• Western Pacific Stratigraphy
• Scientific Objectives
• Site 801
• Site 1149
• Microbiology Objectives for Both Sites
• Drilling Strategy
• Site 801 Principal Results
• Basement Stratigraphy and Geochemistry
• Basement Alteration
• Calculating Element Budgets
• Character of the Jurassic Quiet Zone
• Site 1149 Principal Results
• Introduction
• Site 1149 Geophysics
• Site 1149 Sediments
• Site 1149 Basement
• Sampling the Deep Biosphere
• Shipboard Sampling
• Tracer Tests
• Summary
• A Legacy Site into Pacific Jurassic Crust
• A Complete Sedimentary Sequence in the Nadezhda Basin, Western Pacific
• Early Cretaceous Seafloor Subducting at the Izu-Bonin Trench
• A Mass Balance Equation for Crustal Recycling at the Mariana Arc
• Comparisons of the Input and the Output at the Mariana and Izu Arcs
• The Jurassic Quiet Zone
• Deep Biosphere
• Calibrating Magnetic Anomaly M11
• Mesozoic and Cenozoic Pelagic Sequences
• Petrology of Mesozoic Crust
• Architecture of Fast-Spreading Crust
• Continued Diffusive Exchange between Basement and Sediments
• Discussion of Sampling Strategy
• Communal and Composite Geochemical Samples
• Glass Samples
• Analysis of Logs
• Paleomagnetic and Paleointensity Analysis
• Microbiology
• References
• Table Captions (1-4)
• Figure Captions (1-18)

Operations Synopsis

• Site 801
• Hole 801D
• Hole 801C
• Diamond Core Barrel System Test
• Site 1149
• Hole 1149A
• Hole 1149B
• Hole 1149C
• Hole 1149D

Date posted: 28 September 1999

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