summary of sedimentary facies

1. SANA’A UNIVERSITY
FACULTY OF PETROLEUM &
NATURAL RESOURCES
PREPAREDBY:
ENG.MAGED SALEH AL-GHODHAIFI
SUPERVISOREDBY:
PROF.ABDULKAREEM AL-SUBBARI
SEDIMENTARY FACIES

2. Facies is a body of rock
characterized by a particular
combination that bestow an
aspect hat different from the
bodies of rock above, below
and laterally adjacent.
What
is the Facies?
01.

3. The Facies concept refers to the sum of
characteristics of a sedimentary unit, commonly
at a fairly small (cm-m) scale including:
What
is the Facies?
01.
♦ Lithology (e.g. sandstone, wackestone)
♦ Colour (e.g. red or green mudrocks)
♦ Texture (e.g. grain size, sorting, fabric)
♦ Sedimentary structures (e.g. crossbeds,
post-depositional)
♦ Mineralogical composition (e.g.
dolomitic, quartzose)
♦ Fossil content (e.g. micro- and
macrofossils, trace fossils)
♦ Bed geometry.

4. Facies is both a concept and a thing something.
we observe and describe using all the geological
tools available, and a concept in the sense that we
use these attributes to interpret ancient
environments.
What
is the Facies?
01.

5. Facies can be part of a bed, a whole bed, or several
beds.
What
is the Facies?
01.

6. A Sedimentary Facies is a body of sediment with distinctive
physical, chemical and biological attributes deposited in a
specific depositional environment.
What
is the Sedimentary Facies?
02.

7. Utilization
Of Sedimentary Facies?
03.
• original environment of deposition
can be determined.
• used to describe vertical and lateral variations in
strata.

8. 04.
♦ Sedimentary & geological history (small-large scale)
♦ Economic importance -e.g. hydrocarbons, water
♦ Economic importance -minerals and metals (e.g. gold-
diamonds-gypsum-aggregates)
♦ Prediction/management of contemporary environments
Importance
Of Sedimentary Facies?

9. 05.
Every depositional
environment puts its own
distinctive imprint on the
sediment, making a
particular facies. Thus, a
facies is a distinct kind of
rock for that area or
environment.
Sedimentary Environments
& Sedimentary Facies

10. 05.
Sedimentary Environments
& Sedimentary Facies
Sandstone facies (beach/shallow marine environment)
Shale facies (offshore marine environment)
Limestone facies (far from sources of terrigenous
input/ deep sea)

11. 05.
♦ Presence of cross bedded sandstone can form
during deposition in deserts, rivers, deltas, lakes,
beaches and shallow marine.
♦ In contrast, present of hermatypic corals
indicate that the sediments were deposited in
shallow clear and warm seawater.
Sedimentary Environments
& Sedimentary Facies

12. 05.
♦ Ripples marks developed on
surface of a sand body. This
texture can be diagnostic of
depositional environment. These
ripples are diagnostic of near-
shore tidal environment, but
ripples also develop in fluvial
(river) and aeolian (air,
sandstorm) environments.
Sedimentary Environments
& Sedimentary Facies

13. 06.
Associated
Terms
♦ Facies associations/assemblage:
constitute several facies that occur in combination, related to
one another, and typically represent one depositional
environment
♦ Facies successions:
a progressive change in certain facies properties in a specific
direction (vertically or laterally).

14. 06.
♦ Facies analysis:
facies analysis is the interpretation of strata in terms of
depositional environments (or depositional systems),
commonly based on a wide variety of observations
♦ Facies Model:
Facies Model is a general summary of a particular
depositional system, involving many individual examples from
recent sediments and ancient rocks
Associated
Terms

15. 07.
Generally, facies are distinguished by what aspect of the
rock or sediment is being studied.
♦ Lithofacies: Facies based on petrological characters such as grain
size and mineralogy
♦ Biofacies: Facies based on fossil content (flora & fauna)
♦ Ichnology: Facies based on trace fossil
types of
Sedimentary Facies

16. 07.
(core log sample)
types of
Sedimentary Facies
Lithofacies

17. 07.
Biofacies
types of
Sedimentary Facies

18. 07.
Ichnology
types of
Sedimentary Facies

19. 07.
types of
Sedimentary Facies

20. 08.
Walther’s
Law
Walther’s Law: ‘Facies adjacent to one another in a
continuous vertical sequence also accumulated adjacent
to one another laterally’.
Means that two different facies found superimposed on
one another and not separated by an unconformity, must
have been deposited adjacent to each
other at a given point in time

21. T H A N K Y O U S O M U C H
M A G E D S A L E H H A D I