possible test answers 3

1A - Metamorphic rock is created deep in the earth's crust. Weight from the kilometers of rock above it creates pressure and heat from the mantle also combine. Together the rock is heated and pressured into new metamorphic rock.

1B - Describe what weathering is and what it does.

Weathering is the breaking of rock into smaller pieces called sediment. There are 2 types of weathering- Mechanical Weathering where the rock is physically broken into smaller pieces. Chemical weathering is when the minerals that hold the rock sediments together are dissolved. Rust is a form of Chemical weathering where the iron in the rock is dissolved by oxidation, breaking the rock apart. Frost wedging is a form of mechanical or physical weathering. Water can get into cracks in rock. When water freezes it takes up almost 10% more volume (space). It then freezes and expands on cold nights and thaws out in the warm day. The water thaws and refreezes over and over, and the constant pressure in the crack will break the rock apart. This process is called FROST WEDGING.

WEATHER IS NOT THE SAME THING AS WEATHERING.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

1B- What is erosion and what does it do.. use 2 examples

Description:

Erosion is the process where sediments are moved by things like gravity, water, waves, wind or ice

from one location and deposited in another.

EXAMPLES

- A Landslide is a form of erosion.

HOW  Sediments (earth, sand, gravel rocks) on the side of a hill are

loosened (sometimes by rain water) and then, because of gravity, the land slides down the hill.

Water and Gravity work together to erode (move) the sediment on a hill.

OR - Waves can erode a beach.

HOW  During a storm, the giant waves push and pull the sand, taking it away

from one beach, and depositing it somewhere else. Sand dunes in the middle of a lake or river

can result.

OR - Ice in the form of a Glacier can move rock debris from higher up the mountain.

HOW  As the Glacier moves down the mountain and valley, it takes the sediments with it,

depositing it at the end of the glacier. This is also an example of mechanical Weathering at the same time as Glacier freezes to the rock, then slides, breaking off pieces of the mountain stuck in the ice.

OR Gravity: Rocks break up higher up and fall onto rocks lower down, Gravity is moving (eroding) the

rock from one place and depositing it at another.

This is also an example of mechanical Weathering at the same time as the falling

rocks can break apart other rocks into sediments.

1C- What happens after sediments deposit to actually create new rock?

Layers of sediment are eroded and deposited in layers. Over time these layers get very thick.

When deposited in a lake or ocean for thousands of years, and that lake or ocean evaporates, the

sediment solidifies. Minerals in the sediment act like a glue, cementing the sediment into new

type of sedimentary stone like sandstone.

2.

Intrusive Igneous rock is formed when magma cools and hardens within cracks in the

crust before it can escape to the surface. Intrusive igneous rocks crystallize (solidify)

below the Earth's surface. The slow cooling that occurs there allows rocks with large

crystals to form. “Veins” of metallic minerals like gold and silver are created this way.

Granite and quartz are intrusive igneous rocks.

Extrusive Igneous rocks occur when lava erupts onto the surface (volcano, ridge) where

they cool quickly to form igneous rocks with small crystals.

Basalt, obsidian, and pumice, are extrusive igneous rocks.

3.

Convection currents are currents of magma in the mantle that is heated at the core where its density decreases, rises to the underside of the crust and is either redirected under the crust (pushing/pulling the crust with it), or sometimes it breaks through the crust creating ridges or volcanoes. As the current of magma flows flows below the crust it cools and begins to descend back to the core because it is now more dense (cooler). At the core it is heated again and repeats the cycle over and over. There many individual pockets of convection currents under the crust we call convection cells.

3B- As the currents create convections cells that move in different directions beneath the crust in the mantle. As magma passes below the crust it can pull or push the crust that is above it as it goes. These convection cells- can cause the crust to move and the plates to collide, come apart or slide by each other, causing earthquakes.

4. Extrusive igneous rock to Metamorphic rock

If igneous or sedimentary rock undergoes pressure and/or heating deep in the earth’s

crust, it transforms into metamorphic rock. It could reform into sedimentary rock.

BUT HOW DOES THE EXTRUSIVE IGNEOUS FIND ITS WAY FROM THE SURFACE TO DEEP IN THE CRUST?????????