Table T12. Structural geology checklist used during Leg 183.

Structural geology checklist
Fractures:
Fracture density per section (1.5 m)
Veins:
Vein orientation
Average vein width
Mineral infilling
Vein fabric
Crack seal events (number of events)
Vein density per section
Wall rock alteration (width and characteristics of halo)
Crosscutting relations of veins
Vein array
Array thickness
Number of veins in array
Composition of veins
Orientation
Shear Zones:
Shear zone thickness
Lineations
Deformation bands
Color
Thickness
Mineral composition
Number of bands within array
Faults:
Orientation of fault zone
Fault zone thickness
Shear sense (offset, Riedel shears, mineral lineation)
Amount of offset
Nature of gouge
Composition of mineral infilling
Slickenside orientation
Cataclasites:
Clast size
Clast shape
Clast composition
Matrix composition (gouge or secondary minerals)
Breccias:
Matrix or clast supported
% matrix
Matrix composition
Clast size
Angular vs. rounded clasts
Clast composition
Origin (hydraulic vs. fault)
Sedimentary structures:
Layering (spacing between laminae)
Clastic dikes
Igneous contacts:
Chilled margins
Dike width
Crosscutting relations