10.5 Organic Matter Preservation in Marine Sediments
MARINE DELTA
WITH SWAMPS
(PEAT)
SLOPE BASIN
(:,: HYPER·SALINE
STAGNANT WATER)
SLOPE APRON
WITH C-RICH
INERTINITE
MUD TURBIDITES
SILLED DEEP BASIN
OPEN OCEAN
SUBOXIC
t
LAYER
EQUATORIAL
__ - -- -UPWELLING
.--'-...-=. .. ,-,.""
-EXPANDED
OXYGEN MINIMUM
DURING TIMES OF
SHAl.LOW LAKE
(PEAT)
ANOXIC
477
FRESH-WATER LAKE
OXIC SURFACE WATER
SUBOXIC
LAYER
CORE OF
LlPTINITE-EXINITE-VITRINITE
COASTAL UPWELLING
EXINITE-LiPTINITE
SllJGGISH OCEANIC CIRCULATION
OCEANIC BLACK SHALE EVENTS
HIGHER SAUNE
SHELF WATER (?)
RESTRICTED BASIN
IESTUARINE CIRCULATION)
Fig. 10.11. Various depositional environments for
the aeeumulation of organie-rieh sediments with their
dominant types of kerogen. (After Brooks et al.
1987). Basins with stagnant bottom waters develop
comparatively stable suboxie or eompletely anoxie
zones, whereas zones of eoastal and equatorial
upwelling are eharaeterized by spatial and temporal
variations in their degrees of oxygen defieieney