The relationship between fracturing, asymmetric folding, and normal faulting in Lisburne Group carbonates: West Porcupine Lake Valley, Northeastern Brooks Range, Alaska

• Main Author: Shackleton, John Ryan
• Format: Thesis
• Language: English
• Published: 2003
• Subjects: Faults (Geology); Alaska; West Porcupine Lake Valley; Folds (Geology); Geology; Stratigraphic; Pennsylvanian; Mississippian; Brooks Range
• Online Access: http://hdl.handle.net/11122/14933

Thesis (M.S.) University of Alaska Fairbanks, 2003 The distribution of fold related fractures and other mesoscopic structures in asymmetrically folded Mississippian to Pennsylvanian Lisbume Group carbonates gives clues concerning the mechanism of folding. Since fracture sets pre-date and post-date folding, it is important, but sometimes difficult, to determine which fracture sets are related to folding. Higher density of fold related fractures and dissolution cleavage in the hinges than limbs of two folds in the study area is evidence for fixed hinge detachment folding. However, geometric modeling of box shaped folds in the study area suggests that some folds may have formed by either detachment folding or trishear fault propagation folding. Formulaic modeling of fracture density in a stratigraphic section using stratigraphic attributes such as lithology, bed thickness, and chert content predicts general trends in fracture density, but other factors such as slip along bed contacts may obscure the relationship between fracture density, lithology and bed thickness.