System Tract
A system tract is part of a sequence, identified on the basis of stratal stacking pattern, position in a sequence and in the sea level curve and type of its bounding surfaces..
Generally there are four system tracts in a sequence i.e.
High Stand System Tract (HST),
Falling Stage System Tract (FSST),
Lowstand Stand System Tract (LST),
Trangressive System Tract (TST),
This figure shows deposition of different system tracts with reference to sea level changes and hierarchy of straigraphic sequences.
