Earths Changes

Earths Changes

5th Grade SCIENCE

Sediments/Dirt

Image of sediments on a beach.

Sediments/Dirt

• Sediments are weathered down rock and dirt.

• Over the course of thousands of years these sediments can be "cemented" together through the rock cycle to become sedimentary rocks.

• As these sediments are deposited they form layers of rocks.

• You can dig just about anywhere in the world to see different layers of rocks.

• The oldest layer is the one furthest down.

Sedimentary Rocks

• Rocks made of sediments.

• Formation of sedimentary rocks ...

• Step 1 - rocks are weathered and eroded to form sediments (broken down pieces of rock)

• Step 2 - sediments are carried to the sea bed, river beds, or lake beds where they undergo pressure, compaction, and cementation.

• Step 3 - once the sediments are compacted and cemented together they are considered a sedimentary rock.

• Sedimentary rocks are made up of all other rocks. They can have layers or they can look like a bunch of pieces of rock glued together.

Multiple Choice

Rocks will break down into smaller pieces. What are those pieces called?

• Crust

• Fossils

• Plates

• Sediments

Multiple Choice

Which of the following directly lead to the formation of sedimentary rock?

• Heat and Pressure

• Chemical Change and Heat

• Compaction and Cementation

• Melting and Pressure

Multiple Choice

Which of the following statements describes the first step in the formation of sedimentary rocks?

• Overlying pressure from rocks and soil reduces the size or volume of sediments.

• Weathered material is moved by wind, water, or ice.

• Exposed rock and other surfaces are broken down by wind, water, ice, or other elements.

• Weathered and eroded material is deposited by wind, water, or ice.

Fossil Fuels

Image of a pumpjack with a beautiful West Texas sky.

Fossil Fuels

• Take millions of years and a lot of pressure to form. (COMPRESSION)

• Can be found in the form of coal, petroleum (oil), or natural gas.

• Are considered a non-renewable resource.

• Create greenhouse gasses when burned/used.

• Formed from prehistoric organisms including plants and animals that died and became buried under sediments.

Fossil Fuel Creation Stages

• Plants and animals die and begin to decay

• The dead plants and animals are deposited into the same area by water or other natural events

• The decaying plants and animals are buried by mud and debris where they are compacted together

• After millions of years and a lot of pressure the decaying matter becomes fossil fuels such as oil, natural gas, and coal.

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Multiple Choice

Which process is NOT a stage in the formation of fossil fuels?

• Compaction of fossils and layers of sediment

• Fossilization of dead plants and animals

• Deposition to create layers of sediment

• Eruption of liquids and gases for collection

Multiple Choice

Which list contains only processes that must occur in order for fossil fuels to form?

• Formation of faults, burial, glacier formation

• Organism growth, burial, volcanic eruptions

• Organism growth, burial, compaction

• Erosion, burial, earthquakes

Multiple Choice

Fossil fuels formed over long periods of time after particles in water settled to the sea floor and formed marine mud. What kinds of particles needed to be present in the marine mud in order for fossil fuels to form?

• Mostly sand and a few small bits of wood

• Mostly decaying organisms

• Mostly lava and a few sedimentary rocks

• Mostly metal minerals

Multiple Choice

Which prehistoric event led to the formation of oil?

• pressure from rock layers forming fossils

• melting and cooling of igneous rocks

• rapid growth of underground bacteria

• death and burial of microscopic sea life

Deltas

Picture shows a river delta leading to the ocean.

Deltas

• Formed near where rivers meet the ocean or other large bodies of water.

• Looks like "branches" from the river.

• Result of sediment buildup that blocks parts of the river, forcing the water to divert in difference directions.

• Size and shape of deltas can change for many reasons, including; the size and shape of sediments deposited in the delta and waves and tides of the nearby ocean.

Multiple Choice

What do you call the deposited sediment when a river meets an ocean or lake?

• delta

• levee

• sand dune

• basin

Multiple Choice

Which statement correctly describes how a landform is formed?

• A lake is formed when flowing water carves out the sides of a canyon.

• A mountain range is formed when glaciers slowly move across the landscape.

• A delta is formed at the mouth of a river when flowing water slows and deposits sediment.

• A U-shaped valley is formed when winds pick up and move sediment away from the landscape.

Multiple Choice

The size and shaped of a delta will change over time. Which of the following is not a likely reason the size and shape of a delta would change?

• the number and height of tides along the shore

• the amount and size of sediments carried by the river and streams

• the amount of hunting and fishing in the delta

• the number and size of waves from the ocean that reach the shore

Canyons

Artists rendering of a canyon formed by the cutting away of rock by a river.

Canyons

• Can be caused by a river cutting through the ground slowly.

• If caused by a river the canyon tends to be V shaped.

• Can be caused by a glacier making its way to the sea.

• If caused by a glacier the canyon tends to be U shaped.

Multiple Choice

A family traveled to the Grand Canyon for Spring Break. They observed that a section of the Grand Canyon is a wide, U-shaped valley.

What type of weathering most likely created this landform?

• A slow-moving, large, and heavy glacier many years ago

• High speed winds that whip through the canyon

• Rainwater washing away layers of the Earth’s crust

• Rainwater washing away layers of the Earth’s crust

Sand Dunes

Image of sand dunes with people walking across the top of them.

Sand Dunes

• Sand dunes are large hills, or mountains, of sand

• Sand dunes are easily moved by strong winds

• Sand dunes are usually found in dry places where there is a lot of sand

• Sand dunes in Texas can be found in Monahans, TX at the Monahands Sandhills State Park

• Fences are often constructed around sand dunes to help prevent the sand from blowing away and obstructing roads or local businesses and homes.

Multiple Choice

What is most likely the main reason a fence would be built around a sandhill near a road?

• To stop sand from sliding or blowing onto the road and covering it up

• To prevent a delta from forming at the bottom of the dune

• To keep water off the road

• To prevent marine animals from nesting on the dune

Multiple Choice

Monahans Sandhills State Park in Texas has almost 4,000 acres of sand dunes. Some of the dunes are as tall as a six-story building.

The dunes in the park are formed by —

• rainstorms

• tornadoes

• earthquakes

• strong winds