Facies
a. all of the physical, chemical, and biological aspects of the
environment in which sediments are deposited
b. scale dependent on the objectives of the study
Facies Associations or Belts
groups of facies genetically related that provide environmental
information
Stratal Architecture (Architectural Elements)
three-dimensional geometry of the facies associations
Process and Response Model (Fig. 8.1, p. 258)
In general, particular sets of environmental conditions will produce
unique sets of sedimentary deposits, allowing environments to
be reconstructed
Facies Successions
facies properties consistently changing in a specific direction
(vertical and lateral) important because individual
facies (i.e. crossbedding) can form in several different environments
NOTE: The vertical and lateral facies successions are what enable you to distinguish the type of depositional system. LEARN THE SUCCESSIONS!!!!!!!
Facies Model
general summary of facies used to identify specific depositional
environments
Uses of Facies Models
a. provide a comparative standard
b. establish a framework for future analyses
c. predictive model for new geological settings
d. basis for integrated interpretations
Define Transgression and Regression
Define Progradation and Aggradation
Categories of Depositional Environments (Tab. 8.2, p. 263)
Continental Fluvial: Alluvial Fans
General Recognition of Fluvial Deposits
a. few fossils with no marine fossils
b. poor to moderate sorting
c. red color due to hematite
d. unidirectional paleocurrents
e. strong downstream decrease in particle size
Fans
a. alluvial fans - terrestrial
b. fan deltas - subaqueous
Environmental Conditions example Death Valley
a. high relief
b. arid to semiarid climate
c. abundant supply of sediment
d. grade laterally into evaporitic lakes, playas, and dune fields
Geometry (Fig. 9.1, p. 269)
a. cone shaped to lobate in plan view
b. anastomosing channels
c. radial cross-section = concave up, cross-fan section = convex
upward
d. sorting from proximal to distal