Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Rocks
James College Y8
| Question | Answer |
|---|---|
| What is the structure of the earths layers? | Crust>asthenosphere>mantle>outer core>inner core |
| What is the crust, how far down is it and what is it like? | The crust the outermost solid layer of the earth. It varies in thickness from about 7km under the ocean plates to 30-50km under the continental plates. This is also the layer that we mine our minerals from. |
| What is the mantle, how far down is it and what is it like? | It is much hotter than the crust and is chemically different from it. The deepest parts of the mantle are extremely hot and so the rocks move very slowly so slowly that they can be called rigid or semi-rigid. Mantle=300km -2900km from top to bottom. |
| What is the asthenosphere, how far down is it and what is it like? | Within the uppermost portion of the mantle is a layer called the asthenosphere. The rocks here behave plastically meaning the rocks in the asthenosphere can move slowly like plasticine. The asthenosphere is 300km deep. |
| What is the core, how far down is is and what is it like | The core of the earth is very dense, and scientists think that it is mostly composed of iron and nickel. The inner core is solid but the outer core is liquid. The outer core goes down to 5100km and the inner core goes down to 6370km. |
| What does weathering do to rocks? | Rocks broken down into smaller pieces physically, chemically or biologically. |
| What can physical weathering happen through? | Wind, temperature change, water and ice and crystallization of salt |
| How can wind be physical weathering? | Fine particles of rock can be carried and blasted against another rock |
| How can temperature change be physical weathering? | Quick temperature change can cause the rock particles to expand and contract too quickly |
| How can water and ice be physical weathering? | Water can enter cracks in rocks freeze and then expand making the crack bigger. Water can also wash over rocks wearing them down |
| How can crystallization of salt be physical weathering? | If crystals form in a rock which can grow and force to the rock to expand |
| What is an example of chemical weathering? | Water dissolving chemicals from the soil and air will react with rocks changing it or breaking it down. Example: oxygen and carbon dioxide=CO2 and CO2+H2O sometimes = carbonic acid |
| What is an example of biological weathering? | Living things and their products breaking down rocks. Example: Tree roots going through and growing in rocks, animals physically wearing and breaking down rocks. |
| What does erosion do to rocks? | Broken rock material being transported from one place to another |
| What is a native element | A native element is a metal found as a pure element (by itself) |
| What are igneous rocks? | Rocks that are form from hot melted rock solidifying into a solid form |
| What is the formation of igneous rocks? | When magma/lava cools and crystallizes. This can occur at the surface. Example: When a volcano spews lava across it's surroundings , underwater on the ocean floor or below the surface in little cracks or between layer of rock deep in the crust |
| What are extrusive igneous rocks? | Rocks formed at or near the surface are classified as extrusive igneous rocks. |
| How do cooling rates and crystal formation affect extrusive igneous rocks? | Magma that reaches the surface to become lava cools very rapidly (especially if the eruptions happen underwater). This fast cooling rates result in smaller crystals/no crystals. Because the crystals do not have enough time to grow due to fast cooling |
| What are intrusive igneous rocks? | Rocks formed from magma cooling below the surface are classified as intrusive igneous rocks |
| How do cooling rates and crystal formation affect intrusive igneous rocks? | Magma that does not reach the surface cools much slower. This slow cooling rate results in more time for the crystals on the rock to grow which forms bigger crystals. |
| What is some characteristics of igneous rocks? | They are made out of interlocking mineral crystals which can create hard rocks. Sometimes crystals are visible to the naked eye but sometimes a microscope is needed. Slicing the rock into think sections for examination is also sometimes done |
| How can igneous rocks be classified? | Igneous rocks can be classified by their texture and colour |
| What is colour in igneous rocks? | Linked to the rocks that the rock contain: Dark coloured (mafic) rocks are usually made out of minerals such as olivine or pyroxene. Light coloured (felsic) rocks contain high levels of silica rich materials such as quartz and feldspar. |
| How does the current position of an igneous rocks may not indicate where the formation location is and whether it is extrusive or intrusive? | Intrusive igneous rocks may be exposed at the surface due to folding, faulting and weathering. Extrusive igneous rocks may be exposed underground due to being buried by sediments. |
| What are some examples of extrusive igneous rocks? | The holes or spaces in some igneous rocks are caused by gas bubbles trapped during the quick cooling of lava resulting in a rough bubbly texture. 2 examples of extrusive igneous rocks with holes could be pumice and scoria |
| What are some examples of intrusive igneous rocks? | Granite and dolerite. It's easy to see the crystals in granite and is composed of quartz, feldspar and biotite. |
| What are some common uses for igneous rocks | Igneous rocks are hard and strong which is good for building because it lasts long. Basalt-floor tiles, dolerite-road surfaces, granite-kitchen benchtops, scoria-landscaping, obsidian-jewellery |
| What are metamorphic rocks? | Rocks underground that have been changed through heat from the earths core and pressure from tectonic plates that are massive plates that make up the earths crust which move around colliding, pulling, pushing and scraping. |
| How does both melting and crystallization form a metamorphic rock? | If the rock is only partially melted and recrystallized then metamorphic rocks are form. New materials may form which often retains some traces of the original rock structure. Example: some fossil rich limestone partially recrystalize and make marble |
| What are the types of metamorphism? | Regional metamorphism: Rocks altered by both heat/pressure Contact metamorphism: Rocks altered by mostly heat Dynamic metamorphism: Rocks altered by mostly pressure |
| What is foliation? | Texture can be changed by metamorphism. When a rock becomes foliated the minerals move into layers or bands. Pressure can squash and crumble layers/bands making them wavy. |
| What is felsic rock? | Light coloured igneous rocks (felsic rocks) contain high levels of silica rich materials such as quartz and feldspar |
| What are sedimentary rocks? | Rocks that are formed from sediments compacting and cementing |
| What are clastic sedimentary rocks? | Formed when sediments are laid down by wind, water, gravity etc and then compact and cement. Often contain broken pieces of other rocks, have layers, have no interlocking grains (weaker). |
| What are chemical sedimentary rocks? | Form when minerals dissolve in ground water, crystallise within the sediments or evaporate leaving crystals. They are mostly soft |
| What are biogenic sedimentary rocks? | Form when dead plants/animals remains accumulate and cement. They are mostly soft except for chert and flint |
| What is geology? | The study of the earth and its rocks |
| What are plates? | Tectonic plates are massive plates that make up the earths crust which move around: colliding, pulling, pushing and scraping. The folding, sliding or sideways movement of the plate is known as shearing. |
| What is strata? | The layers of sedimentary rock horizontally. The younger layers fall on the top so the older layers are deeper. This provides us with which rock is older or younger but this doesn't provide us with the actual age |
| What is the formation of fossils? | Fossils are the preserved evidence of organisms. Fossils could be the whole body or only part of it. For the fossil to form it can't be in contact with oxygen so it needs to buried. When fossilisation occurs the soft organs decay leaving the bones |
| What are Tailings? | Waste materials(left overs) from a mine or mineral processing plants. Often toxic containing acids/poisonous chemicals. E.g tailings from gold mines usually contain the poison cyanide. They are often dumped into ponds or surrounded by earth walls. |
| What are mafic rocks? | Dark coloured igneous rocks (mafic rocks): usually made out of olivine or pyroxene. |
| How is crushing a process of rock processing? | Crushing is usually used over several stages to produce rocks of similar size. It also increases the surface area of the rock, making it easier to treat further. |
| How is magnets a process of rock processing? | Minerals that are magnetic can be removed by magnets, while very dense materials allow to drop out from the rest of the ore. The remainder of the ore continues processing. |
| How is enrichment a process of rock processing? | The minerals are enriched to concentrate them and improve quality: one enrichment process is forth floatation in which the desired ore is carried away on a frothy emulsion of oil and water. The unwanted remainder of the crushed rock called gauge is left. |
| How is extraction a process of rock processing? | Process of separating metals from the compound in which they occur. E.g iron, zinc and lead are extracted by heating in a blast furnace by themselves or with limestone/carbon. Intense heating=smelting. Aluminium is extracted by electrolysis (electricity) |
| What does deposition do to rocks? | Broken rock material settling, forming sediments which is why it is also called sedimentation (layers of the rock material). |
| Explain deposition in rivers? | Deposition is very common in rivers because broken rock is usually being transported by water in rivers which slows down around corners and rocks in the water wear down the sides of the river as well as more broken rocks depositing on the bottom . |
| Explain deposition when the river connects with the sea? | When a river meets the sea the water slows down which causes more broken rocks to deposit into sediments. Most of the material is deposited which can result in deltas (a river divides into several smaller rivers before flowing into the sea) |
| What are hydrothermal fluids? | Water superheated by magma, this means that the water is above its boiling point which dissolves the surrounding copper minerals (forming a solution). It carries it into spaces in surrounding rock which crystallise forming a rich copper mineral layer. |
Created by:
136867
Popular Earth Science sets