8.3 Sedimentary Flashcards
1
Q
Clastic sedimentary
A
-Rocks are weathered and trapped under ground forming a rock
-Has layers, broken rocks
-e.g sandstone and shale
2
Q
Chemical sedimentary
A
-Desolved minerals in ground water crystalises. The water evaporates leaving crystal behind
-crystals are present
- e.g lime stone, flint
3
Q
Biogenic sedimentary
A
- Formed by dead animals/ plant remains buried under ground
-many layers, no clear sediments, soft and brittle
-e.g coal
4
Q
Strata
A
-The laying or rock
5
Q
what are index fossils?
A
Fossils used to compare starta from different regions
6
Q
How are fossils made?
A
-Buried in low oxygenated areas and decay underground slowly
7
Q
why do only some organisms become fossils
A
They have to be buried while they are dying or straight after dying.
