Mechanism for
sapropel formation |
Predicted signature
in sapropels |
Existing evidence for
and against this mechanism |
---|---|---|
Influx of terrigenous organic material |
Negative ![]() ![]() ![]() ![]() |
+Plant debris, terrestrial biomarkers, & high C/N found in selected Eastern Mediterranean cores and sapropels (Deroo et al., 1978; Sigl et al., 1978). |
|
Unchanged ![]() |
+Negative ![]() ![]() |
|
Negative ![]() ![]() ![]() ![]() |
- ![]() ![]() ![]() |
|
Increased C/N ratio |
- No positive ![]() |
Influx of terrigenous nutrients and DIC, resulting in enhanced surface productivity |
Negative ![]() ![]() |
+Negative ![]() ![]() ![]() |
|
Negative ![]() |
+Oxygen isotope and other evidence for freshwater flooding during sapropel formation. |
|
No elevated C/N ratio |
+Light ![]() |
Upwelling-supplied increase in surface nutrients and DIC, resulting in enhanced surface productivity |
Heavier ![]() |
+Negative ![]() ![]() |
|
Lighter ![]() |
+Freshwater flooding likely triggered estuarine circulation and E. Med. upwelling. |
|
Lighter ![]() |
+Light ![]() |
|
Diatom bloom (upwelled waters are Si-rich) | ±Localized high diatom and silicoflagellate abundance in E. Med. sapropels (Sutherland et al., 1984). |
Deep-water anoxia and enhanced preservation |
Heavier ![]() |
+![]() ![]() ![]() ![]() |
|
Lighter ![]() |
+Freshwater flooding likely triggered estuarine circulation and Eastern Mediterranean anoxia. |
|
Possibly unchanged ![]() |
|