REVIEW
 
 

DEFINITIONS

anticlinorium and synclinorium: large-scale anticlines and synclines 10's of km wide formed of smaller-scale antiforms and synforms

 fold limb: flank of a fold on either side of a

fold hinge: zone of maximum curvature

 crest: highest point of a folded surface

 crest line: collection of crests along on a common folded surface

 inflection points: Location on a fold where curved limb segments of opposing convexity meet.

 hingeline: collection of hinge points along a singel folded surface

 axial surface: surface that passes through the hingelines of various folded layers in a sequence (axial trace is the intersectin of the axial surface with any other surface, e.g. outcrop)

 fold axis is a line that when moved parrallel t itself orchestrates afold

 cylindricalfolds are folds that possess fold axes; every part of the folded surface is oriented such that it contains a line whose orientation is identical to that of the hingeline

 dip isogons: lines joining points of equal dip on the outer and inner bounding surfaces of a bed.

READINGS

 Ch. 11 Folds

LECTURE
 
 

FOLD CLASSIFICATION

 TIGHTNESS: gentle, open, tight, isoclinal//based on interlimb abgles

 SIZE

 SYMMETRY: asymmetricalfolds have limbs of different lengths

 LAYER THICKNESS: concentric ore parallel folds: individual layers maintain a constant thickness similar folds display significant thickening in the hinge and significant thinning on the limbs CLASS 1B and class 2 folds
 
 

SLIDES