GLG 301 Lecture Notes - Lecture 17: Structural Geology, Transtension, Fault Gouge
Document Summary
Transform (conservative) boundaries: plates slide by each other. No significant convergence or divergence faults with earthquakes. Often fault valley due to fault gouge. : oceanic transform faults. Offset ridge (mainly) segments (proposed by j. tuzo wilson) Movement occurs only between the ridge segments and is parallel to the fault (strike-slip fault). Fracture zones, extension of transform faults no motion, no earthquakes: continental transform faults, e. g. , san andreas (us), altyn tagh (china), The san andreas is not straight (same with other examples listed above) This creates pull apart basins where the boundary is in transtension (transform + extension) and restraining bends or. Pop-ups when the boundary is in transpression (transform + compression) Hawaii: chain of volcanic islands and guyots (flat-topped underwater seamounts = old volcanoes) whose age increases to the northwest, the only active volcanism occurs at one end of the chain. Bend(s) in the chain of islands correspond to changes in plate motion.
