GEOL 462: Principles of Sedimentology and Stratigraphy

Lecture 03: Tuesday, January 20, 2009

Topics
1. Carbonate sediments and rocks
2. Carbonate cements and diagenesis
3. Carbonate classification
4. Carbonate petrography: examples
5. Dolomitization and the dolomite problem
6. Evaporites
7. Volcanic and volcaniclastic rocks
8. Other types of sedimentary rocks: cherts, phosphates, ironstone, and organic-rich deposits

Carbonate sediments and rocks
a. Understand the basic types of carbonate grains and their origin
b. Understand the origin of carbonate mud
c. Understand the mineral compositions of carbonates and their changes during lithification and diagenesis

Carbonate cements and diagenesis
Understand the basic diagenetic processes of carbonate and their products

Carbonate classification
• Understand the compositional classification of carbonates
• Require to remember the Dunham textural classification
• Are grainstone and packstone grain-supported? What percentage of mud does a grainstone contain ?
• What percentage of mud does a wackestone contain ?
• What environmental information you can infer from a lime mudstone or micrite ?

Carbonate petrography: examples
• Requires to be able to identify the following carbonate rocks:
    Grainstone, packstone; oolitic grainstone; bioclastic wackestone; intraclastic packstone;
    lime mudstone, peloidal packstone, crystalline dolomite.

Dolomitization and the dolomite problem
• Why is there a dolomite problem ?
• Read the reading assignment, especially the introduction to understand more about the dolomite problem

Evaporites
• Understand the common types of evaporites like anhydrite, gypsum, and halite
• Should be able to identify these evaporites in microscopes

Volcanic and volcaniclastic rocks
• Read the text and understand the common types of volcaniclastic rocks [Table 3.3 and Fig. 3.4, p. 31]

Other types of sedimentary rocks
• At least you need to know the names of other types of sedimentary rocks
• The two types of cherts