Geology of the Cayman Islands: Evolution of Complex Carbonate Successions on Isolated Oceanic Islands

Preface
Contents
1 Introduction
	1.1 Introduction
	1.2 Physiography of the Cayman Islands
	1.3 Cayman Research—University of Alberta
	1.4 Methods
		1.4.1 Field Work and Drilling
		1.4.2 Thin Sections
		1.4.3 Scanning Electron Microscopy
		1.4.4 X-Ray Diffraction Analysis
		1.4.5 Electron Microprobe
		1.4.6 Stable Isotope Analyses
		1.4.7 87Sr/86Sr Analyses
		1.4.8 Elemental and Rare Earth Elements
		1.4.9 U/Th Dating
	References
2 Tectonic Setting of the Cayman Islands
	Abstract
	2.1 Introduction
	2.2 Earthquakes and Tsunamis
	2.3 Tectonic Elements on the Cayman Islands
	2.4 Conclusions
	References
3 Bluff Group—the Brac Formation
	Abstract
	3.1 Introduction
	3.2 Distribution
	3.3 Lower Boundary
	3.4 Upper Boundary
	3.5 Thickness
	3.6 Lithology
		3.6.1 Cayman Brac
			Lepidocyclina Facies
			Mollusc Facies
			Foraminifera Facies
			Fabric Retentive Dolomite Facies
			Fabric Destructive Finely Crystalline Dolomite Facies
			Sucrosic Dolomite Facies
		3.6.2 Grand Cayman
	3.7 Porosity
	3.8 Diagenesis
	3.9 Dolomite Stoichiometry
	3.10 Stable Isotopes
	3.11 87Sr/86Sr Geochronology
	3.12 Age
	3.13 Depositional Regimes
	3.14 Conclusions
	References
4 Bluff Group—The Cayman Formation
	Abstract
	4.1 Introduction
	4.2 Distribution
	4.3 Lower Boundary
	4.4 Upper Boundary
	4.5 Thickness
	4.6 Limestone—Dolostone Distribution
	4.7 Biota
	4.8 Facies
		4.8.1 Grand Cayman
		4.8.2 Cayman Brac
	4.9 Depositional Regimes
	4.10 Porosity and Permeability
	4.11 Stable Isotopes
	4.12 87Sr/86Sr Ratios
	4.13 Age
		4.13.1 Fossils
		4.13.2 87Sr/86Sr Geochronology
		4.13.3 Sea Level
	4.14 Conclusions
	References
5 Bluff Group—Pedro Castle Formation
	Abstract
	5.1 Introduction
	5.2 Distribution
	5.3 Lower Boundary
	5.4 Upper Boundary
	5.5 Thickness
	5.6 Lithology
		5.6.1 Grand Cayman
		5.6.2 Cayman Brac
	5.7 Stable Isotopes
	5.8 Porosity and Permeability
	5.9 87Sr/86Sr Geochronology
	5.10 Age
	5.11 Depositional Regimes
	5.12 Conclusions
	References
6 Diagenesis–Bluff Group
	Abstract
	6.1 Introduction
	6.2 Dolostones of the Bluff Group
		6.2.1 Dolomite Crystals
			Crystal Size
			Internal Structures and Compositional Zoning in Dolomite of the Cayman Islands
			Hollow Dolomite Crystals
		6.2.2 Low and High Calcian Dolomite
		6.2.3 Distribution of Low and High Calcian Dolomite
			Cayman Brac
			Grand Cayman
		6.2.4 Stable Isotopes
			Brac Formation
			Cayman Formation
			Pedro Castle Formation
		6.2.5 Trace Elements
			Na in Dolomite/Limestones
			Mn in Dolostones/Limestones
			Fe in Dolostones/Limestones
			Sr in Dolostones/Limestones
			Rare Earth Elements in Dolostones/Limestones
		6.2.6 87Sr/86Sr Ratios
			Brac Formation
			Cayman Formation
			Pedro Castle Formation
			Modern Seawater
			Potential Problems with 87Sr/86Sr Ratios
			Brac Formation
			Cayman Formation and Pedro Castle Formation
			Comparison with Other Island Dolostones
	6.3 Discussion
	6.4 Conclusions
	References
7 Ironshore Formation
	Abstract
	7.1 Introduction
	7.2 Distribution
	7.3 Lower Boundary
	7.4 Upper Boundary
	7.5 Thickness
	7.6 Internal Stratigraphy
		7.6.1 Lithological and Biological Characteristics of Units A to F
	7.7 The 6 m Sea Level Notch
	7.8 Key Exposures of the Ironshore Formation
		7.8.1 Grand Cayman
			Salt Creek
			Canary Lane Quarry
			Boat Launch, Northwest Coast
		7.8.2 Cayman Brac
		7.8.3 Little Cayman
			Little Cayman Quarry
			Salt Rocks
			Unnamed Hill
	7.9 Biota of the Ironshore Formation
		7.9.1 Corals
		7.9.2 Rhodolites
		7.9.3 Stromatolites
		7.9.4 Bivalves and Gastropods
	7.10 Trace Elements
	7.11 Diagenesis in the Ironshore Formation
		7.11.1 Alteration of Skeletal Material
			Strombus Gigas Shells
			Corals
		7.11.2 Calcretes
		7.11.3 Rhizoliths
		7.11.4 Roots and Caliche
		7.11.5 Roots and Peloids
	7.12 Conclusions
	References
8 Modern Carbonate Environments
	Abstract
	8.1 Introduction
	8.2 The Coastal Shelves of the Cayman Islands
	8.3 Corals and Coral Reefs
		8.3.1 Modern Corals of the Cayman Islands
		8.3.2 Shelf-Edge Reef of Grand Cayman
	8.4 Lagoons of Grand Cayman
		8.4.1 North Sound
			The Fresh-Brackish Water Association
			The Marine Facies Association
			Rare Earth Elements
			Age
			Facies Architecture
		8.4.2 South Sound
			Facies
			Age of Sediments
			Facies Changes Through Time
			Sedimentary Processes
		8.4.3 Frank Sound and Pease Bay
			Facies
			Facies Changes Through Time
			Foraminifera in Frank Sound
		8.4.4 East Sound
	8.5 Bioerosion
	8.6 Temporal Changes in Surface Seawater Temperatures
	8.7 The Critical Role of Thalassia in the Lagoons of the Cayman Islands
	8.8 Impact of Storms on the Coastal Areas of the Cayman Islands
		8.8.1 Storm Boulders
		8.8.2 Boulder Ramparts
		8.8.3 Storm Impact on Lagoonal Sediments
	8.9 Vermetid Buildups
	8.10 Beachrock
	8.11 Conclusions
	References
9 Karst on the Cayman Islands
	Abstract
	9.1 Introduction
	9.2 Modern Karst of the Cayman Islands
		9.2.1 Phytokarst
		9.2.2 Caves and Speleothems on Cayman Brac
			Caves in the Brac Formation
			Caves in the Cayman Formation
			Cave Speleothems
			Notch Speleothems
		9.2.3 Caves and Speleothems on Grand Cayman
			The Twilight Zone
			Stalactites and Stalagmites
			Cave Pearls
			Calcite Versus Aragonite Precipitation
			Comparison of Notch Speleothems and Cave Speleothems
	9.3 Vertebrate Fossils
	9.4 Paleokarst on the Cayman Islands
		9.4.1 Paleokarst Surfaces
			The Brac Unconformity
			The Cayman Unconformity
			The Pedro Castle Unconformity
	9.5 Subsurface Paleokarst Features
		9.5.1 Caymanite
		9.5.2 Paleo-Caves
		9.5.3 Sinkholes, Joints, and Other Cavities
	9.6 Conclusions
	References
10 Terra Rossa, Phosphate, and Mangrove Swamps
	Abstract
	10.1 Introduction
	10.2 Terra Rossa
		10.2.1 Stratigraphic Distribution of Lithified Terra Rossa on the Cayman Islands
		10.2.2 Composition
			Clays, X-ray Amorphous Material, Anatase, Hematite, Goethite, and Manganese Precipitates
			Biofragments
			Glaebules
			Clay-Coated Grains and Terra Rossa Ooids
			Fractures
		10.2.3 Stable Isotopes
		10.2.4 Rare Earth Elements
		10.2.5 Origin of Terra Rossa on the Cayman Islands
	10.3 Phosphate Deposits
		10.3.1 Composition of Phosphatic Limestone
		10.3.2 Petrography of Phosphatic Limestones
			Lithoclasts and Detrital Phosphate Grains
			Glaebules
			Phosphate Rafts
			Matrix
			Microbes
			Calcite Cement
		10.3.3 Stable Isotopes
		10.3.4 Rare Earth Elements
		10.3.5 Origin of Phosphate Deposits
	10.4 Mangrove Deposits
		10.4.1 Barkers Peninsula and West Bay Peninsula
		10.4.2 Barkers Peninsula and West Bay Peninsula
			Laminated and Non-laminated Crusts
			Plastic Mud
			Peat
		10.4.3 South Sound
		10.4.4 Age and Development of Mangrove Swamps
	10.5 Conclusions
	References
11 Hydrogeology
	Abstract
	11.1 Introduction
		11.1.1 Stage I
		11.1.2 Stage II
		11.1.3 Stage III
	11.2 Bedrock Geology
	11.3 Porosity and Permeability
	11.4 Rainfall
	11.5 Freshwater Lenses
		11.5.1 Joints, Factures, and Water Lenses
		11.5.2 Groundwater on the Cayman Islands
			Seawater
			Rainwater
			Pond Water
			Water in Sinkholes
			Cave Water
			Groundwater—Perched Water Zone
			Groundwater—Highly Brackish to Saline Water
		11.5.3 Hydrochemical Facies
			Chloride Ions
			Bicarbonate Ions
			Calcium and Magnesium Ions
	11.6 Groundwater Calcite and Dolomite Saturation States
		11.6.1 Rainwater
		11.6.2 Perched Water
		11.6.3 Groundwater—Fresh Water Zone
		11.6.4 Groundwater—Lightly Brackish Water Zone
		11.6.5 Groundwater—Types I and II
	11.7 Groundwater and Bedrock in and Around the East End Freshwater Lens
	11.8 Development of Reverse Osmosis Plants
	11.9 Conclusions
	References
Appendix_1