SEQUENCE STRATIGRAPHY - TRANSGRESSION, REGRESSION AND SYSTEM TRACTS
SEQUENCE STRATIGRAPHY TRANSGRESSION Shoreline shift landward Retrogradational pattern - fining upward Feature name - Estuaries Sea level rise Deepening upward (Deep facies found at the top whereas shallow facies found at the bottom) Transgressive system tract found - due to rapid increase in sea level REGRESSION Shoreline shifts seaward either due to sedimentation - Normal regression due to sea level fall - Forced regression Regression is of two types 1) NORMAL REGRESSION Shoreline shift seaward due to sedimentation Low stand system tract, High stand system tract 2) FORCED REGRESSION Shoreline shift seaward due to rapid fall in sea level Falling stage system tract - rapid decrease in sea level Coarsening upward - Progradational pattern SYSTEM TRACTS 1) FSST - Rapid fall in sea level : Forced regression 2) LST - Sea level just start rising (initial stage when sea level start rises) 3) TST - rapid rise in sea le ve l : Transgression (retrogradation pattern) 4) HST...