Allen Independent School District · Web viewSedimentary rock, Fossils, and Fossil Fuels Sediments...
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Sedimentary rock, Fossils, and Fossil Fuels Sediments (broken pieces of rock) are deposited in an area (oſten under water) and pile up over me. These small pieces of rock form sedimentary layers and more pressure is put on the lower (oldest) layers as the amount of sediment on top of them increases. This pile up of sediments compacts the lower layers of sediment forcing the water out from between the rocks. Cementaon happens as dissolved minerals become deposited in the spaces between the sediments. These minerals act as glue or cement to bind the sediments together. Fossils form when an organism dies and is covered quickly by sediment. An example would be a sand storm moving in quickly and covering the organism. Organisms that live in the sedimentary layer or on the sea floor become fossils more oſten. Once covered with sediment the organism is compacted along with the sediment and as sedimentary rock forms, it may leave an impression fossil on the rock. (mold fossil) The remains of the organism decay, but minerals may fill this space and create a 3-D fossil (cast fossil) Fossils provide evidence that can help us understand the condions of that specific locaon/ region at a given past me. For instance, we could find out that an area that is currently a desert was once covered by water. Fish fossils on a mountain tell us the mountain was once under water. Fossils will be found in sedimentary rocks only!!! Remember, the older fossils are in the lower rock layers and younger fossils are in the higher rock layers. Fossil Fuels being forming as sedimentary rock forms, but it takes HEAT, PRESSURE, and TIME (lots of me)! Because it takes so long to form, fossil fuels are considered nonrenewable resources. If dead plant maer or Peat is trapped in the sediment layers it will be compacted along with the sediment. As the layers are pushed down heat from the earth along with pressure from the sediments will harden it into COAL. If dead animal maer, mainly microscopic sea organisms, is trapped in the sediment layers it is compacted, and heated over me to form OIL. Natural Gas may also form in areas where oil is located.
Transcript of Allen Independent School District · Web viewSedimentary rock, Fossils, and Fossil Fuels Sediments...
Sedimentary rock, Fossils, and Fossil Fuels
Sediments (broken pieces of rock) are deposited in an area (often under water) and pile up over time.
These small pieces of rock form sedimentary layers and more pressure is put on the lower (oldest) layers as the amount of sediment on top of them increases.
This pile up of sediments compacts the lower layers of sediment forcing the water out from between the rocks.
Cementation happens as dissolved minerals become deposited in the spaces between the sediments. These minerals act as glue or cement to bind the sediments together.
Fossils form when an organism dies and is covered quickly by sediment.
An example would be a sand storm moving in quickly and covering the organism.
Organisms that live in the sedimentary layer or on the sea floor become fossils more often.
Once covered with sediment the organism is compacted along with the sediment and as sedimentary rock forms, it may leave an impression fossil on the rock. (mold fossil)
The remains of the organism decay, but minerals may fill this space and create a 3-D fossil (cast fossil)
Fossils provide evidence that can help us understand the conditions of that specific location/ region at a given past time.
For instance, we could find out that an area that is currently a desert was once covered by water.
Fish fossils on a mountain tell us the mountain was once under water.
Fossils will be found in sedimentary rocks only!!!
Remember, the older fossils are in the lower rock layers and younger fossils are in the higher rock layers.
Fossil Fuels being forming as sedimentary rock forms, but it takes HEAT, PRESSURE, and TIME (lots of time)!
Because it takes so long to form, fossil fuels are considered nonrenewable resources.
If dead plant matter or Peat is trapped in the sediment layers it will be compacted along with the sediment. As the layers are pushed down heat from the earth along with pressure from the sediments will harden it into COAL.
If dead animal matter, mainly microscopic sea organisms, is trapped in the sediment layers it is compacted, and heated over time to form OIL.
Natural Gas may also form in areas where oil is located.
Igneous Rock
Sediment
Sedimentary Rock
Metamorphic Rock
Magma
Weathering & Erosion
Weathering & Erosion
Weathering & ErosionCementing &
Compaction
Heat & Pressure
Heat & Pressure
Melting
MeltingCooling
There are two kinds of igneous rockIntrusive: Cools below the earth’s surface – contain large crystals from mineralsExtrusive: Cools above the earth’s surface – has holes in the rock from gasbubbles or can be glassy if lava cools very quickly before bubbles can formExamples of igneous rock:Basalt, Granite, Obsidian
Metamorphic Rock often contains ribbon-like layers, and has shinycrystals from minerals (sparkles).Examples: Gneiss, Marble, Slate
Sedimentary Rock is soft and breaks apart relatively easily (crumbly). You can often see pebbles and sand in these rocks.Examples: Conglomerate, Limestone, and Sandstone.
Fossils are formed in this type of rock!
