Orogenesis: The Making of Mountains

Cover
Orogenesis: The Making of Mountains
Title
Copyright
Contents
Preface
Acknowledgments
1: Major features of the Earth and plate tectonics
	Plate tectonics
		Mid Ocean Rises
		Plate boundaries
		Magnetic anomalies
		Lithospheric plates
	Orogens and plate tectonics
		Rheological control over continental break-up
	Dewey and Bird classification of orogens
	Ancient plates and orogeny
	Major features of orogens
	Orogenic deformation
	Mechanisms of lithospheric thickening
	Orogenic metamorphism
	Further reading
2: Driving mechanisms for plates, slab retreat and advance, and a cause of orogenesis
	Retreat and advance of subduction zones
	Gravity differences as driving forces in orogeny
	Applications of the Platt and England model
3: Physical and chemical principles: rock deformation, isostasy, geochronology and heat production in the lithosphere
	Rock deformation
	Coulomb fracture theory
	Stress and strain
	S- and L-tectonites
	Rotational and non-rotational strain
	Three-dimensional strain
	Rheology
	Controls of deformation
		Temperature
		Confining pressure
	Strain rate
	Fluids in rock deformation
	Permeability and non-permeability of rocks
	Enhanced pore fluid pressure
		Effective stress
	Fluids in earthquakes and in pathways in the crust
		Seismic pumping and valves
	Mechanisms of rock deformation
	Transformation and reaction-enhanced ductility
		Crystal plasticity
		Diffusive mass transfer
	Isostasy
	Geochronology and thermochronology
	Geotherms and thermal structure
	Heat transfer in the lithosphere
	Heat sources
	Heat advection
	Further reading
4: Large-scale features of orogens: thrusts and folds
	Arcuation of orogens and oroclines
	Physical properties of thrust faults
	Doubly vergent orogens
	Classification of thrusts
		(a) Gravity gliding or spreading/flow models
		(b) Extrusion of orogen-scale tectonic wedges
		(c) Dislocation model
		(d) 'Push-from-behind' model
	Detachment
	Time spans of thrusts
	Thrust systems
	Imbricates and duplexes
	Modelling
	Relationship between folds and thrusts
	Displacement on thrusts
	Restored sections
	Thrust terminations
	Transport direction in thrusting
	Thrust mechanics
	Orogenic wedge theory
	Ductile thrusts
	Internal strain in thrust sheets
	Folds in shear zones
	Rotation of thrust sheets about a vertical axis
	Further reading
5: Evolution of orogens
	The transition from passive margin to active margin
	Collision belts
	Mountain uplift
	Symmetry and asymmetry in orogens
	Strike-slip orogens
	Uplift and collapse of mountains
	Stages of collision
	Collision belts
		The Himalayan Karakoram and Tibetan orogen
	Mechanics of shortening in the Himalaya
		Indentation
		Thrusting
		The South Tibetan Detachment (STD)
		Underthrusting in the Himalaya
	Oroclines
	The metamorphic evolution of the Himalaya
	Karakoram
	The Tibetan Plateau
		Pre-Cenozoic thickening in Tibet?
	Deep crustal flow
		Differences between North and South Tibet
	N–S grabens
	Timing of Tibetan uplift
	The Alps
		Culminations and depressions
		Internal zone
		External zone
		The North Alpine Foreland Basin
		Jura mountains
		The Hinterland
		Evolution of the Alps
	Ultra-high-pressure metamorphism
		The depth of subduction
		Underplating and the orogenic wedge
		The current view on evolution
	Continent–continent convergence after final closure of the ocean:the late movements in the Alps
		Dextral strike-slip tectonics
		Indentation tectonics?
		Comparisons between the Alps and the Himalaya
	Cordilleran belts: the North and South American Cordillera
		Subduction of the Nazca plate
		Volcanism
	Sectors of the Andes
	Control over the upper slab deformation by the convergence direction of South America and Nazca
	Structural units and shortening in the Andean belt
	Thick-skinned or thin-skinned thrusts?
		Timing of crustal thickening
	Neotectonics
	High plateau
	Deep structure of the Andes
	The North American Cordillera
		Collision tectonics?
		Extensional tectonics
		The Canadian Cordillera
	Timing in orogeny
	Oblique collision belts
	Caledonides of the North Atlantic
	Caledonides in North America
	The British Caledonides
		The Grampian orogeny
		Obducted ophiolites
		The Scandian orogeny: closure of Iapetus
	Sinistral transpression during the Scandian orogeny
		Kinematic indicators of strike-slip movements
		Switch to orogen-parallel motion
		Sinistral transtensional regime
	Oblique collision in the Zagros
	Intraplate tectonics
	Further reading
6: Lateral spreading of orogens: foreland propagation, channel flow and weak zones in the crust
	Cause of orogenic spreading
	Orogenic collapse
	Metamorphic core complexes
	Channel flow
	Extrusion and channel flow
	Couette and Poiseuille flow
	Driving force for channel flow
	Channel flow and erosion
	Low-viscosity layers in the crust
	Tests for the channel flow model
	Deep crustal flow in Tibet
	Is channel flow a special case confined to the Himalaya?
	Further reading
7: Metamorphism in orogeny
	Introduction
	General characterisation of metamorphism
		Mapping metamorphism: from isograds to facies
		Facies series, progressive metamorphism and evaluation of regional P-T variations
	Early perspectives on metamorphism in relation to tectonics
	Metamorphism and thermal modelling
	Quantification of metamorphism: from mineral assemblages to P–T diagrams
		Composition-assemblage diagrams and projections
		Petrogenetic grids and Schreinemakers´ nets
		Divariant and multivariant equilibria – from Schreinemakers´ nets to pseudosections
		Geothermobarometry
	Crustal melting and orogeny
		Melting processes and temperature conditions
		Migmatites and migmatite terrains
		Partial melting, migmatites and the strength and behaviour of orogens
	The P–T realm of metamorphism: the current view
	Pressure-temperature (P–T) paths and pressure-temperature-time (P–T–t) paths
	Blueschist-eclogite and UHP metamorphism
		Background and P–T domain
		Timescales of HP/UHP metamorphism and rates of exhumation
		Models for UHP rock exhumation
	Collision and medium P/T metamorphism: Barrovian type metamorphism
		Barrovian facies series and the Himalayan case study
		Barrovian collisional metamorphism and inverted zones: models for orogen development
		Channel flow and Himalayan metamorphic zones: timing and P–T paths
		Problems with channel flow as a model for the Himalayan metamorphism
	Collision and medium P/T metamorphism: eclogite–high-pressure granulite (E-HPG)
		Background and P–T domain
		Pressure–temperature–time paths
		Formation and exhumation of E-HPG metamorphic rocks
		Bohemian Massif – rapid buoyancy-driven vertical extrusion of HPG?
		Caledonian E-HPG in Norway and Greenland
		The Grenville Province: heterogeneous ductile flow and exhumation of E-HPG rocks and deep orogen interiors
	Low P/T metamorphism: granulite and UHT metamorphism in orogeny
		Background and P–T domain (low P/T and UHT)
		Pressure–temperature–time paths in G-UHT
		Timescales of G-UHT metamorphism: orogenic and other settings
		Hot orogens and G-UHT metamorphism
	Gravitational spreading, core complexes and extensional metamorphism
	Concluding remarks
8: The erosion and exhumation of mountains
	Mountains as barriers
	Examples of the linkage between tectonics and erosion
	Dating the rates of exhumation and uplift in mountain belts
	The mass balance within an orogen
	Terminology
	The measurement of the rate of exhumation
	Orogenic history
		Exhumation of the Alps
		Exhumation of the Himalaya
	Further reading
9: Sedimentary history of the foredeep basins
	Isostasy and Bouguer anomalies
	Loading the lithosphere
	A classification of foreland basins
	Foredeeps and advancing thrust sheets
	Basin evolution
	Isostatic adjustments in foredeeps
	Thermochronology using detrital minerals
	Exhumation of orogens
		The exhumation and uplift of the Alps
		Unroofing the Himalaya
	Sediment budgets in SE Asia
10: Deep structure, mountain support and phase changes
	Rock densities and isostasy
	Support for the load of orogens
	Geophysical studies in the Himalaya–Tibet
	Recent geophysical work on the deep structure of Tibet
	Receiver function analysis and shear wave splitting detect the deep structure
	Phase changes in the deep structure
	Eclogitisation and the 'weighting of orogens'
	The Cz/lz ratio
	Eclogitisation and exhumation and collapse in other orogens
	The rapid phase change from granulite to eclogite facies and vice versa
	Basement control, reactivation and reworking
	Further reading
11: Mountains and climate
	Monsoons
	The significance of the Tibetan Plateau
	Climate change in the Cenozoic
	Evidence for global climate change in the late Miocene and Pliocene
	How does the Tibetan Plateau disrupt global circulation?
	A possible threshold height for the plateau
	A causal relation between plateau uplift and mantle dynamics
	When did the plateau attain its present elevation?
	Weakening of the monsoon at 8 Ma – a counter-argument
	Monsoon precipitation as a tectonic forcer
	Monsoon controls erosion in the Himalaya
	Himalayan uplift and the chemical composition of the oceans
		The 87Sr/86Sr plot
	Transport of calcium
	Drawdown of CO2
	Oxygen isotopes
	Proposed link between the Himalaya and chemical erosion
	Erosion in channel flow
	Further reading
12: Secular change in orogeny
	Secular change in heat production and the Earth´s thermal budget
	Modelling the onset of subduction and its consequences
	Secular change in metamorphism in orogenic belts
	Accretion, amalgamation and collision from the Palaeoproterozoic to NeoArchaean
		The Trans-Hudson Orogeny of Canada
		The Lewisian of northwest Scotland
		The Archaean Gneiss Complex of southwest Greenland
	Weak lithospheres and 'ultrahot' orogens
	Further reading
References
Index