Doc Brown's Chemistry - Earth Science & Geology Revision Notes
for KS4 Science, GCSE, IGCSE & O Level Courses
Science Revision worksheet on ATMOSPHERIC and GEOLOGICAL CHANGES on EARTH
A set of cue structured questions with all the tasksheet answers provided!
QUESTIONS on 1. The Evolution of the Earth's atmosphere and Carbon Cycle ... 2. The Rock Cycle (details evolve through sections 3. to 9.) ... 3. Weathering of Rocks ... 4. Igneous Rocks ... 5. Sedimentary Rocks ... 6. Metamorphic Rocks ... 7. The structure of the Earth ... 8. Plates and their movement ... 9. Plate Tectonics ... 10. The Moon and Planets
GCSE/IGCSE/O Level KS4 Earth Science-Geology ANSWER-REVISION-NOTES 1. Evolution of the Earth's atmosphere and Carbon Cycle ... 2. The Rock Cycle and types of rock ... 3. Weathering of Rocks ... 4. Igneous Rocks ... 5. Sedimentary Rocks ... 6. Metamorphic Rocks ... 7. The Structure of the Earth ... 8. Tectonic Plates , Wegener's theory, evidence for continental drift ... 9. More on Plate Tectonics, effects of plate movement, volcanoes, earthquakes etc. ... 10. A few geology and atmosphere notes on the Moon and Planets
1(a)(i) For 200 million years the Earth's atmosphere hasn't changed. Describe the composition of the present day atmosphere in terms of the major and minor gases present (you can mention pollutants without going into there sources and effects). (ii) Describe a simple experiment to determine the % of oxygen in air. (iii) How is carbon dioxide removed from the atmosphere? (iv) How is carbon dioxide returned to the atmosphere? (v) What is the connection between the Carbon-Cycle described in (iii) and (iv) and maintaining a constant amount of oxygen in the atmosphere? (vi) What is causing 'Global Warming'?
1(b) The composition of the early Earth atmosphere was very different from what it is today. Where did the gases come from to form this early atmosphere? What were the main gases present in this early atmosphere?
1(c)(i) How did the seas and oceans form? Would any of the gases dissolve in the seas and oceans? (ii) What sort of compounds might be formed? (iii) Why are seas/oceans full of salts? Why have the salt concentrations increased over time?
1(d) What sort of life-forms first evolved on Earth? What happened in terms of evolution, over 2000 million years ago, that significantly changed the composition of the Earth's atmosphere? What initial effect did this have on the composition of the atmosphere? (clue: initially one gas significantly increased and one gas significantly decreased). What two major effects did this atmospheric change have on the course of evolution?
1(e) What happened, and how, to (i) ammonia and (ii) methane present in the early atmosphere that you have quoted in 1(b)? What other new 'gas' (iii) was formed in the upper atmosphere as well as oxygen from photosynthesis? AND what is its significance to the well-being of present day 'life'!?
On a white sheet of A4 make as large copy as possible of the Rock Cycle from any suitable textbook or syllabus. Mark on it clearly where you would find the following ...weathering, erosion, transportation of weathered rock, igneous rock formation, sedimentary rock formation, metamorphic rock formation, rising magma, uplift, sedimentation, possible additions later? site of plate descending, site of new plate forming etc.?
What are the three 'groups' or main types of rocks called? What is the typical sort of chemical structure and bonding in rocks? What sort of typical physical properties do they have? Which rocks erode away the most easily and which are more 'weather resistant'?
3(a) Describe the different processes that contribute to the Weathering of Rocks. Short simple notes explaining how the process happens will do. Make sure you include physical weathering e.g. water freezing in rock cracks, chemical weathering eg acid rain water on limestone, biological weathering e.g. the action of plant roots.
3(b) Explain the meaning of the words erosion, transportation and deposition including how are the weathered rock fragments moved?, where too?, what happens to the 'bits' of rock in the end?, how do they change in shape and size in transportation?. What sort of major geological features do these processes create?
4(a) What is magma and lava? What do we mean by igneous rocks? What ways are they formed and what are they generally like physically?
4(b) Describe how and where the igneous rock granite* is formed. Describe its characteristics and why is it called an intrusive rock?
4(c) (i) Describe with a diagram what we mean by an igneous intrusion*. (ii) How and why, can an igneous intrusion, end up as a hill or mountain? (this is involves describe the possible sequence of geological changes). (iii) Explain why an igneous intrusion contains younger rock than the surrounding sedimentary rock.
4(d) Describe how and where** the igneous rock basalt* is formed. Describe its characteristics and why is it called an extrusive rock? (** there are at least two quite different locations where basalt is formed, even if its made from the same material!)
* Include in answers to 4(b)-(d) comments on the connection between crystal size and the rate of cooling of the molten magma and the appearance of granite and basalt.
5(a) Describe what we mean by a sedimentary rock. Describe in general how they are formed.
5(b) Give brief descriptions of mudstone/shale, limestone/chalk, sandstone and coal. What do they look like? what are they formed from? where and how were they formed?
5(c) What is the chemical composition of limestone? Describe a simple test that might suggest a given rock is limestone. What is formed on heating limestone? Briefly describe some uses of limestone.
5(d) What ultimately happens to rocks like limestone which are not eroded away?
5(e) Describe how fossils are formed in sedimentary rocks. What important facts can fossils tells us about sedimentary rocks and the environment in which they were formed? In what other ways is the fossil record importance to science?
5(f) Why would you not expect to find fossils in igneous rocks? Can you find fossils in metamorphic rocks?
5(g) Other than the details mentioned in (a)-(f) describe some other features found in sedimentary rock formations which allow scientists to work out facts about their origin and what has happened to them over long time periods of geological time.
6(a) What do we mean by a metamorphic rock? where and how are they formed?
6(b) Describe, with the help of a diagram, a link between metamorphic rocks and igneous intrusions.
6(c) What is slate formed from? how and where is it formed?
6(d) What is marble formed from? how and where is it formed
6(e) How is the rocks gneiss and schist formed? In what way is their origin different from slate and marble?
6(f) How does the chemical composition of a metamorphic rock compare with the original pre-existing rock from which it was formed. Clue - compare what you know about limestone and marble.
7(a) With the help of a diagram, show how the Earth is a three layered structure and label each layer.
7(b) Give a brief description of each layer, e.g. what does it consist of? how thick is it? is it solid, liquid, semi-solid?
7(c) How can we find out the age of rock formations in the crust? Is there more than one method? How accurate are they? How old is the planet Earth? Why is carbon-14 dating, used by archaeologists, no good for dating rock formations?
8. Plates and their movement (introducing the basic ideas and evidence)
8(a) The Earth's lithosphere is the crust and the upper part of the mantle. The Earth’s crust is divided into plates. What do we mean by this? What do they ‘float on’?
8(b) Describe, with a diagram how the plates are caused to move by convection currents from deep in the mantle. In your answer, also mention the following ... (i) what the heat source is that drives the convection system, (ii) how this convection system eventually produces new crust.
8(c) Where the plates of the Earth meet is called a plate boundary. Briefly describe some of the evidence which is used to ‘map out’ where the plate boundaries are.
8(d) Why was Wegener's theory of continental drift not accepted at the time? Briefly describe some of the evidence for ‘continental drift’ i.e. plate movement on a large scale over millions of years.
9. Plate Tectonics (using the basic ideas to explain all the effects)
9(a) Describe the basic mechanism of how new crust is formed i.e. plate expansion.
9(b) Describe the basic processes by which crust is returned to the mantle.
9(c) Describe how plate collision leads to the formation of fold mountains of both sedimentary and metamorphic rock, and therefore explain why it possible for the very cold summit of Mt Everest to be made of limestone, formed at the bottom of a warm shallow sea rich in plant and animal life! What sort of 'timescale' are we talking about?
9(d) Describe how plate movement can cause earthquakes. Can we predict these potential hazards? What scale is used to express the power and effects of earthquakes?
9(e) What is a volcano? Describe how, why and where volcanoes are most frequently formed.
9(f) Draw a diagram of rock layers containing folding, tilting and a fault line and describe how these two geological features are formed (and how they may be interpreted?).
9(g) What is a rift valley and how is it formed? a simple diagram will help.
9(h) In your answer to 8(b) it should be evident that the crust sections or plates are getting bigger on either side of an ocean ridge, so why isn’t the Earth expanding i.e. the net surface area steadily increasing?
9(i) Finally, and where we started! explain how plate tectonics and weathering explain the recycling of all rock formations i.e. The Rock Cycle.
10. The Moon and Planets Rocks (just a little extension!)
10(a) What do the atmosphere's of the planets Mars and Venus have in common with the Earth's early atmosphere? What do the atmosphere's of planets like Jupiter have in common with the Earth's early atmosphere?
10(b) What photographic evidence is there to suggest that water once flowed on Mars?
10(c) Does the moon have an atmosphere? Explain. Are there any sedimentary rocks on the moon? Explain. Are there likely to be any metamorphic rocks on the moon? Explain.
10(d)(i) Why is the surface of Venus much hotter than on Earth? (ii) Why is the surface of Mars much colder than on Earth.
GCSE/IGCSE/O Level KS4 Earth Science-Geology ANSWER-REVISION-NOTES 1. Evolution of the Earth's atmosphere, Gases in Air, Carbon Cycle, Origin of Life ... 2. Rock Cycle, Types of rock ... 3. Weathering of Rocks ... 4. Igneous Rocks ... 5. Sedimentary Rocks ... 6. Metamorphic Rocks ... 7. The Layered Structure of the Earth ... 8. Tectonic plate theory, Wegener's theory, evidence for continental drift ... 9. More on Plate Tectonics, effects of plate movement, volcanoes, earthquakes, faults etc. ... 10. A few geology and atmosphere notes on the Moon and Planets
Studying Revision for KS4 Earth Science GCSE/IGCSE/O level Chemistry Information Study Notes for revising for AQA GCSE Earth Science, Edexcel GCSE Science/IGCSE Chemistry & OCR 21stC Science, OCR Gateway Science WJEC gcse science chemistry CCEA/CEA gcse science chemistry (revise courses equal to US grade 8, grade 9 grade 10)
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