GLG 301 Lecture Notes - Lecture 19: Midcontinent Rift System, Graben, Transpression
Document Summary
Strike-slip faults: strike-slip faults have movement in the horizontal (strike or orientation of the fault) direction. Described by the motion of the fault block on the other side of the fault. Blind faults faults that do not break the surface (hazard for los angeles) so you don"t know they are there. Oblique faults faults with a combination of dip-slip and strike-slip motion transtensional (translation + tension) or transpressional (translation + compression) Faulting and the stress regime ( anderson s theory of faulting ) Strike-slip faults linear valleys due to fault gauge: shutter ridges , river offsets, springs (conduit for water) and oases, sag ponds (transtension) and pop-ups (transpression) Flower structures: transpressional (positive structures, palm tree structure) and transtensional (negative structures, tulip structures ) features, also due to closure at oblique angles. Normal faults: extensional settings typically thought of in the horst and graben situation (pure shear of symmetric system) Graben down dropped block between two normal faults.