Theories on the formation of dry valleys: Superposition theory Drainage system develops on less permeable rock overlying limestone Drainage system is superimposed on limestone terrane Subterranean drainage forms and valley becomes dry Base level change Drainage developed with groundwater table close to surface Uplift, lowering of sea level, or local base level by erosion results in lowering of gw table and subterranean migration of surface water Pocket valley: Valley headed by a large spring Poljes: Large valleys or depressions with broad valley floors which are oriented along a tectonic trend.
(Superposition theory Drainage system; develops; ) (Valley; headed; Large valleys or depressions with broad valley floors) Context(Valley headed,List([465, 478))):(Theories on the formation of dry valleys: Superposition theory Drainage system develops on less permeable rock overlying limestone Drainage system; is superimposed; ) (valley; becomes; dry Base level change Drainage) (broad valley floors; are oriented; L:along a tectonic trend) (dry Base level change Drainage; developed; )
Valley headed,List([465, 478))
Superposition theory Drainage system Valley Theories on the formation of dry valleys: Superposition theory Drainage system develops on less permeable rock overlying limestone Drainage system valley broad valley floors dry Base level change Drainage
develops headed is superimposed becomes are oriented developed
Large valleys or depressions with broad valley floors
dry Base level change Drainage
L:along a tectonic trend