sedimentary facies.pdf
- 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
- 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