Environmental Engineering Reference
In-Depth Information
TABLE 6.5
Geologic Fold Structures and Characteristics
Structure
Characteristics
Monocline
Gentle warping, fold has only one limb
Syncline
Warping concave upward
Anticline
Warping concave downward (see
Figure 6.32)
Isocline
Tight folds with beds on opposite limbs having same dip
Overturned anticline
Warping stronger in one direction, causing overturning
Overthrust
Overturning continues until rupture occurs (see
Figure 6.52)
Recumbent folds
Strata overturned to cause axial plane to be nearly or actually horizontal (see
Figure 6.33)
Drag folds
Form in weak strata when strong strata slide past: reveal direction of movement of
stronger strata
Plunging folds
Folding in dipping beds (see Figure 6.31)
Overturned anticline
Isoclines
Overthrust
Monocline
Anticline
Syncline
FIGURE 6.30
Common geologic fold structures.
Syncline
Anticline
Axis
Strike
Trough
Pluge
Crest
Limb
Axial plane
Dip
FIGURE 6.31
Nomenclature of plunging folds.
