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Table T5. Structural identifier checklist used for spreadsheet comments associated with each structural identifier.

Structural identifier Observations included
Subhorizontal microcracks (Shm) Drilling-induced fractures
Joints (J) Joint density

Plume structures on joint surface
Veins (V) Hydrothermal (Vh), fault with fibrous mineral (Vf), with cataclasis (Vc)

Orientation of veins and vein-array boundaries
Width and length
Magnitude and nature of offset: n = normal, r = reverse, ss = strike slip
Density of vein network (N/10 cm)
Array characteristics
Sense of shear: d = dextral, s = sinistral
Angle between new vein segments and array boundary (measure of array dilatation)
Internal structure of fibers
Crack-seal structures and number of vein-opening events
Wallrock alteration and shape—sharp or diffuse boundaries
Vein terminations (splayed or tapered)
Vein mineralogy
Magmatic vein (Vm)
Alteration vein (Va)
Faults (F) Fault-zone thickness, orientation, and density

Movement sense: r = reverse, n = normal, d = dextral, s = sinistral
Movement offset (displacement, millimeters)
Intensity of cataclastic fabric (Cf)
Cataclastic foliation (Scc)
Matrix material (gouge or secondary minerals)
Overprinting of preexisting fabric
Breccias (B) Hydrothermal (Bh), Magmatic (Bm),Cataclastic (Bc)
  Clast size and shape, matrix composition, relative proportions
Serpentinization foliation (S) Strength of foliation
  Orientation of foliation in core reference frame
Brittle-plastic fabrics (Bp) Intensity of fabric

Orientation of foliation
Intensity of fabric
Crystal-plastic fabrics (CPf) Intensity of fabric in retrograde assemblage

Orientation of foliation (Sp) and lineation (Lp)
L-, LS-, and S-tectonite
Shear sense indicators: block-rotated porphyroclasts, asymmetric augen, SC fabrics, discrete shear bands, mica-fish, and tension gash arrays: r = reverse, n = normal, d = dextral, s = sinistral
Mineralogical segregation or banding
Intensity and orientation of foliations (Sm) and lineations (Lm)
Magmatic fabrics (Mf) Minerals that define the shape and/or crystallographic preferred orientations

Angle between crystallographic and shape fabrics
Orientation of subfabrics
Compositional layering (Cl) Type of layering (e.g., igneous cumulate, alteration, etc.); orientation, thickness, and density of layers

Grain size layering (Gs), compositional "modal" layering (Cl)
Orientation and density
Igneous contacts (Ic) Concordant or discordant
Crosscutting relationships Intrusive relationships, relative chronology of the different fabrics
  Angle between compositional layering and magmatic or crystal-plastic fabric

Notes: This checklist notes structural characteristics that were searched for in macroscopic core samples. These characteristics supplement the information required by the spreadsheet and were noted in the comments section of the spreadsheet. The abbreviations for these features were used to document crosscutting relationships on the structure section of the visual core descriptions.

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