Depositional Environments
Location Environment Agents of
Deposition Sediment Types Rock Types / Structures /
Fossils
1. Alluvial Fan Continental water, gravity poorly sorted rock and
mineral fragments any detrital rock type
including arkose
2. Desert Dunes Continental wind rounded, well-sorted sand-
sized quartz sandstone with cross
bedding
3. Lake / Playa Lake Continental water sand, mud; halite and gypsum
in dry climates sandstone, mudstone or
shale; evaporites
4. Glacial Continental ice, water poorly sorted deposits with
variable grain size any detrital, except arkose
5. River/Stream Continental water sand in channels, mud and
plant materials outside sandstones w/ ripple marks
& cross beds, mudrocks,
possible coal / plant fossils
6. Beach Transitional water quartz sand and shell
fragments quartz sandstones with
shell fragments
7. Delta Transitional water sand in channels; mud and
plant material sandstones, shale, possible
coal / plant fossils
8. Tidal Flat Transitional water mud, calcite-rich mud Mostly fossiliferous
mudrocks, limestone
9. Barrier Island Transitional water quartz sand and shell
fragments sandstones with shell
fragments
10. Shallow Marine Marine water sand to mud to calcite-rich
mud, shells sandstone, mudrocks,
limestone w/ marine fossils
11. Deep Marine Marine water clay-sized fragments,
microscopic calcite & silica
shells
claystone, chalk, chert
12. Organic Reef Marine water, corals calcite from abundant marine
life, esp. corals fossiliferous limestone
13. Submarine Fan Marine water, turbidity
currents graded beds, mud mudstone, sandstone
showing graded beds
14. Continental Shelf Marine water mud mudrocks
15. Lagoon Marine water fossils, mud and calcite-rich
mud fossiliferous shales and
limestones
