Chapter 13-3 Flashcards
What is compaction?
the process by which sediment is pressed together as more and more layers on top of each other. Water and air get squeezed out from between the particles.
What causes rocks to form cracks, and break in to smaller pieces and then become into sediment?
Sunlight, wind, water, ice, and changing temperatures.
What is cementation?
the process by which sediment particles are glued together to make a sedimentary rock.
What carries rock pieced down to lakes or seas?
Wind and water
Why does sediment move downhill?
Due to the force of gravity
What is the important motion for forming sedimentary rock?
Downhill motion of sediment
What is the most common rock on Earth’s surface? What percentage of the earth’s surface does it cover?
sedimentary rock; it covers 75% of the earth’s surface
How can we identify sedimentary rock?
By the suze of the praticles in it.
What is the difference between clay and silt?
Clay=smooth
Silt=gritty
What kind of sedimentary rock is formed by clay and silt?
mudstone
What do sand particles form?
“Sandstone”
What is a “conglomerate”?
a lumpy rock, made of rounded gravel
What is “low-grade metamorphism”?
occurs under conditions of low temperatire and pressure.
When is a metamorphic rock formed?
When an existing rock is heated an squeezed under pressure. There are three ways to form metamorphic rock: low-grade metamorphism, contact metamorphism, and high-grade metamorphism
What is the result of “low-grade metamorphism”?
New minerals form.
How does “contact metamorphism” work?
When heated but not squeezed by high pressure.
How does “high-grade metamorphism” work?
involves high-pressure and either low or high temperatures.
How do fossils form?
- Organism’s body is quickly covered in sediments from a mud slide or something like that.
- Some body parts decay fast (flesh) but others decay slowly (bone, teeth)
- after a long time, these harder body parts are preserved by other minerals. Fossils are the remains of prehistoric organisms
Summarize the rock cycle and draw a diagram
You must be able to re-produce the picture on 308.
