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Table of Contents - Special Paper 400Collisional Delamination in New Guinea: The Geotectonics of Subducting Slab Breakoffby Mark Cloos, Benyamin Sapiie, Andrew Quarles van Ufford, Richard J. Weiland, Paul Q. Warren, and Timothy P. McMahon |
Abstract | 1 | |
Chapter 1. Geology of the Central Range of Western New Guinea |
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Introduction | 3 | |
Geology of Western New Guinea | 4 | |
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Geologic Framework | 4 |
Cenozoic Plate-Tectonic Setting | 4 | |
Active Tectonism | 4 | |
Magmatism in the Highlands | 7 | |
New Guinea Trench — A Reactivating Relict | 9 | |
Geologic Transect — Western Central Range | 10 | |
Foreland Basin — Buried Continental Shelf | 10 | |
Foothills — Leading Edge of Central Range Orogenic Belt | 13 | |
Mapenduma Anticline — Thick-Skinned Deformation | 13 | |
Folds in the Southern Central Range — Thin-Skinned Deformation | 14 | |
Ruffaer Metamorphic Belt — Metamorphosed Passive Margin Strata | 16 | |
Irian Ophiolite Belt — Accreted Oceanic Lithosphere | 16 | |
Shortening Estimates and Plate-Tectonic Rates | 17 | |
Chapter 2. Mechanics of Subducting Slab Breakoff by Collisional Delamination |
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Lithospheric Delamination | 19 | |
Rupture of the Lithosphere | 20 | |
Fracture and Flow | 20 | |
Plastic and Viscous Flow | 21 | |
The Lithosphere: Brittle/Plastic Behavior | 22 | |
The Asthenosphere: Viscous Response | 22 | |
Peak Strength in the Crust and Mantle | 23 | |
Force Transmission | 24 | |
Plate Bending during Subduction | 25 | |
Buoyancy of the Lithosphere | 26 | |
Chapter 3. Palinspastic Reconstruction of Collisional Delamination in New Guinea |
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Collisional Delamination — Scaled Cross Sections | 29 | |
25 Ma: Intraoceanic Subduction | 31 | |
15 Ma: Emergence of Isolated Islands | 32 | |
12 Ma: Beginning of the Central Range Orogeny | 33 | |
10 Ma: Thin-Skinned Deformation | 34 | |
8 Ma: Collisional Delamination Begins | 35 | |
6 Ma: Thick-Skinned Deformation and Magmatism | 37 | |
4 Ma: Collisional Delamination Is Complete | 37 | |
2 Ma: Postcollision | 39 | |
Present Day | 40 | |
Collisional Delamination and Induced Magmatism | 40 | |
Collisional Delamination and Sedimentation | 42 | |
Time-Transgressive Orogenesis: Propagating Tear | 42 | |
Along-Strike Variations in Structural Style | 44 | |
Lithospheric Healing after Delamination | 45 | |
Plate Tectonic Changes Related to the Collision Forming New Guinea: Nearby and Transoceanic | 45 | |
Conclusions | 46 | |
Acknowledgments | 46 | |
References Cited | 46 |