Lacustrine Environments - Trace Fossils as Indicators of Sedimentary Environments - page 371

TABLE 1 A Lake Basin Zonation Scheme for the Interpretation of Lake-Basin Sedimentary Successions with Trace Fossils

Hierarchical
classification of
lake-basin zones

Lake-basin zonation
Basin margin to lake margin Lake margin to basin center

Terrestrial Lake margin Lacustrine

Permanently lacustrine

Margin Zone of lake-level rise-and-fall (including ephemeral lakes)

Supralittoral Eulittoral Littoral Sublittoral Profundal

Margin Terrestrial

Depositional environments

Wind/wave-
influenced
lacustrine
environments

Terrestrial Eolian Backshore

(lagoon, flats,
and/or
marsh)

Beach Swash zone

(shoals, spits)

Lower
shoreface or
bench slope

Offshore (below storm
wave base; below
chemocline/thermocline)

Upper shoreface or high-
energy bench platform
(above normal wave base)

Alluvial to fluvio-
lacustrine
environments

Alluvial
fans

Alluvial
floodplain

Upper delta-
plain

Delta-
plain

Lower delta-
plain

Proximal
delta-front

Distal
delta-front

Prodelta Profundal

(turbidites, underflow
deposits)

Low-energy
lacustrine
environments

Terrestrial Low-energy littoral or low-

energy bench platform
Emergent
vegetation

Sublittoral
slope or low-
energy bench
slope

Profundal
(suspension fall-out
deposition)

Wetlands and/or mud flats (palustrine)
(not applicable for high-gradient or coincident margins)

Submerged
vegetation

¬ Increasing duration of periods of subaerial exposure Occasionally subaerially

exposed

Not normally subaerially exposed

Controls affecting sedimentation, biogenic activity, and production and preservation of biogenic structures by lake - basin zone

Geological controls: Tectonic setting and activity; structural features, bedrock geology and sediment composition, subsidence rate,
basin shape and size, gradient, base level, preexisting geomorphologic features, autogenic gradient-related features (e.g., benches, deltas)
Climatic controls: Climatic setting, mean annual temperatures, seasonality; precipitation/evapotranspiration ratio, temperature and
humidity extremes, climatic cycles and climatic disturbances, paleoclimatic history

Basin-scale
controls