164
d
DELTA f.RONT
=- ...... _- SHOREFACE
PRODELTA
DEEPER SHALLOWER
LOWER DELTA
PLAIN
- - - - - - - - - - ----- -b-~_:")
UNCONFORMITY
C SEA LEVEL RISE
b SEA LEVEL FALL
Chapter 3 Coastal and Shallow Sea Sediments
ALLUVIAL
PLAIN, LAKES
LOWER DELTA
,... ... ~PLAIN
DELTA FRONT
...--.,...,.._ (MOUTH BAR,
TIDAL RIDGES ,
ETC.)
SHOREFACE
HIGHSTAND
DEPOSITS OF
DELTA PLAIN
AND ALLUVIAL
PLAIN
INCISED VALLEYS
PEDOGENESIS
AND SUBAERIAL
EROSION
ALLUVIAL
PLAIN
PROGRADING "DEEP·WATER" DELTA
(LOWSTAND DEP.)
a RAPID SEA LEVEL RISE
(TRANSGRESSION)
-MARSH, LAKE DEP.
LAGOONAL, INTERTIDAL,
MARSH SEDIMENTS
TRANSGRESSIVE AND HIGHSTAND DEPOSITS
Fig. 3.36. Effects of sea-level changes on the
depositional environments of a classical, lobate delta.
a and c Rapid sea-level rise causes coastal retreat,
followed by a slowly prograding coastline during
highstand (shallow-water delta overriding former
delta plain). b Prograding shallow and subsequent
deep-water delta during sea-level fall and lowstand.
Sections d-f demonstrate mainly interdistributary
facies successions. See text for further explanation