Shale Compaction
Organic Sediments
Outline
Three sedimentary are important volumetrically. They are: MUDSTONE(shale), SANDSTONE, and LIMESTONE. These very common rocks contain a very limited set of 5 or 6 minerals:
| MINERAL | MUDSTONE % | SANDSTONE % | LIMESTONE % |
|---|---|---|---|
| Quartz | 32 | 70 | 4 |
| Feldspar | 18 | 8 | 2 |
| Clay Minerals | 34 | 9 | 1 |
| Calcite and Dolomite | 8 | 11 | 93 |
| Iron Oxides | 5 | 1 | - |
Calcite, silica and iron oxides are the main cements that bind sedimentary rocks. Iron oxides in very small quantities can be responsible for red, orange and green colouration in sedimentary rocks. Fine grained rocks such as shales and mudstones usually appear dark grey to black. Black shales may contain sigificant amounts of organic carbon.
Shale Compaction
Organic Sediments
Outline