Lecture 11: Sedimentary Rocks Flashcards
What type of rock is the majority of rocks on earth?
Igneous
What type of rock is the majority of rock on land?
Sedimentary
What is much of the ocean covered in?
Mud
What are Clastic sedimentary rocks formed from?
The products of mechanical weathering of pre-existing rocks
What are chemical sedimentary rocks?
Rocks that form from the precipitation of minerals from supersaturasolutions
What are biological sedimentary rocks composed of?
The shells of plankton
What conditions are well sorted sediments from?
Prolonged water or wind or action
What conditions are Poorly sorted sediments from?
They are not far removed from their source
What are the layers of sediment called individually?
Beds
What are the layers of sediment called collectively?
Strata
What is cross bedding?
When sediments are layered at an angle due to wind or water
What is wave ripple formation?
Very small dunes of sand or silt whose long dimensions are at right angles to the wave direction
What is Graded bedding?
When there are coarse grains at the base and fine grains at the top usually deposited by turbidity currents
What is Bioturbation?
When sediments are broken up by animals that often make cylindrical tubes or burrows
What are the two parts to Diagenesis?
Compaction and Cementation
What occurs in compactions?
Water is squeezed out
What occurs in Cementation?
Minerals precipitate out cements the rocks together`
What forms Shale in sedimentary rock?
Mud
At what temperature and pressure does Crude oil from?
100º and 3000m
At what temperature and pressure does Gas form?
150º and 4000m
What is Maturation?
When organic matter in sediments is converted to oil and gas
What type of Rock is the vast majority of sedimentary rock?
Siltstone
Mudstone
Shale
What sediment makes conglomerate?
Boulder
Cobble
Pebble
What sediment makes sandstone?
Sand
