Minerals and Rocks 1
What are the 3 types of rocks?
Sedimentary, igneous, and metamorphic rock
Scientists have identified more than _______ kinds of minerals
3,000
What is softest mineral and what is the hardest?
talc; diamond
What are all the soil horizons?
A horizon (topsoil)
B horizon (subsoil)
C horizon (weathered bedrock)
Bedrock
Why is humus good for plants?
Has nutrients for new plants to grow
What are the properties of mineral? (5 properties)
Color, hardness, luster, streak, and texture
The older the relative age of a rock layer, the ________ it is found
lower
What scale do scientists use to measure hardness?
What is its range and what do they represent?
Mohs' hardess scale
(softest) 1-10 (hardest)
Which layer of soil do most living things make a home in? Why?
Topsoil; it is rich in humus and minerals
What do pore spaces hold?
Air and water
What is hardness?
A mineral's ability to scratch another mineral or be scratched by another mineral
What is streak?
When you scratch a mineral along a white tile, it leaves behind a powder called streak
What is obsidian?
What was it used for in Ancient North America?
Igneous rocks that hunters used to make spears
What happens to water if the soil permeability is high?
What grows in the subsoil?
The roots of strong plants
What are two ways igneous rocks can form?
1. When magma below Earth's crust cools and hardens
2. When lava from a volcanic eruption cools and hardens
How do metamorphic rocks form?
Any type of rock that chemically changes under heat and pressure to become a metamorphic rock
How do sedimentary rocks form and how long does it take for them to form?
Sediments are cemented or pressed together over millions of years
The properties and thicknesses of soils depend on...?
(5 answers)
Climate, ecosystem, bedrock, steepness of the land, and time
How can soil thicken?
Over time if it is left alone
What metamorphic rock is good when making tiles for roofs, billiard tables, and walkways? Why?
Slate because it is waterproof
What kind of change occur to their properties when rocks change into metamorphic rocks?
What do those changes depend on?
Chemical change
Amount of heat and pressure
What are the sediments in sedimentary rock made of?
(5 answers)
rocks, minerals, bits of plants, shells, or other hard materials
What do pore spaces do?
Act like a filter.
They remove certain substances from the water as it moves through. This keeps the water clean.
Why are soil profiles different from place to place?
The rock and humus that make up soil are not the same everywhere