Earth & life science reporting .pptx.g11gas

Earth and Life Science G11-Gas

1. T h e i mportance of rocks

2. What i s r o c k s ? – C o m p o s e d o f o n e o r m a n y d i f f erent minerals . – N a turally occur i n g s o l i d a g g r e g a te of o n e o r m o r e m i n erals o r m i n e r a l i o d s .

3. W h a t i s t h e simple d e f i n i tion of rock ? A relatively hard, naturally occurring mineral material. Rock can consist of a single mineral or of several minerals that are either tightly compacted or held together by a cementlike mineral matrix. The three main types of rock are igneous, sedimentary, and metamorphic.

4. W h a t a r e c a l l e d rock? There are three kinds of rock: i gneous , sedimentary, and metamorphic. Igneous rocks form when molten rock (magma or lava) cools and solidifies. Sedimentary rocks originate when particles settle out of water or air, or by precipitation of minerals from water. They accumulate in layers.

5. Classification of Igneous Rocks Crystalline rocks - are made of interlocking crystals. - form from cooling and solidification - texture is grain or crystal size

6. R OCKS – Is a naturally occurring solid aggregate of one or more minerals or mineraloids. – For example, the common rock granite is a combination of the quartz, feldspar and biotite minerals.

7. Granite is the predominant igneous rocks in continents. Basalt and Gabbro predominate in rocks underlying the oceans. Andesite usually found along the continental margins and is the building material of most young volcanic mountains.

8. Granite - usually light colored with large crystals, able to reflect light falling on its surface, and has medium weight for its size.

9. Basalt -- dark in color, composed of very fine crystals, dull, unable to reflect light, heavy for its size.

10. Classification of Igneous Rocks Glassy rocks- composed primarily of glass and contains few crystals. - formed when magma, under high pressure, releases the pressure suddenly, causing the gases to come out of solution. Obsidian -- dark in color, composed of small crystals, glassy and of medium weight.

11. – In more viscous lava, were gas can not escape easily, the lava is churned into a “froth”. When cooled quickly, it forms pumice, a frothy glass that floats in water. Pumice -- may be light or dark in color, dull, spongelike in appearance, and very light in weight

12. Classification of Igneous Rocks Fragmental rocks – composed of fragments when trapped gases are released during an eruption. - Pyroclasts are pieces of lava blasted out of a vent.

13. Taal Volcano is part of a chain of volcanoes along the island of Luzon, which were formed by two tectonic plates colliding over 500,000 years ago. Since the formation of this large caldera (Taal Lake), subsequent eruptions created another volcanic island, within Taal Lake, known as Volcano Island.

14. W h a t a r e e x a m p le s o f i g n e ous rock ? I gneous rocks can be divided into four categories based on their chemical composition:  felsic , intermediate, mafic, and ultramafic. There are two basic types: 1) intrusive igneous rocks such as diorite, gabbro, granite and pegmatite that solidify below the Earth's surface; and 2) extrusive igneous rocks such as andesite, basalt, obsidian, pumice, rhyolite and scoria that solidify on or above the Earth's surface.

15. Chemical composition of Igneous Rocks ( based on silicate content ) Mafic rocks - silica poor (45-55%) - gabbro, basalt Felsic rock s - silica rich (65% or more SiO2) - rhyolite, granite Intermediate rocks - contain significant amount (30-50%) of dark ferromagnesian minerals like pyroxene and amphibole. - diorite, andesite Ultramafic rocks - contain less than 45% silica and is rich in Fe, Mg, Ca. - olivine, pyroxene

16. METAMORPHIC ROCKS A rock buried deep in the interior of the Earth melts, assuming the temperature is high enough, to form magma. But when temperature is not high enough for the rocks to melt, metamorphosis occurs. Solid state, fluids, like water plays a significant role in metamorphic processes

17. T y p e s Thermal Metamorphism (contact) - takes place not too far below the surface, so the dominant factor is temperature. Dynamothermal metamorphism (regional) - are almost always foliated, indicating differential stress during re-crystallization.

18. Classification Non-foliated rocks are named on the basis of its composition. -marble (calcite), quartzite (quartz), hornfels Foliated rocks – foliation - phyllite, schist, slate

19. Metamorphic rocks present in the Himalayas include schist, migmatite, phyllite, gneiss and amphibolite.

20. W h a t a r e t h e e x a m p les of m e t a m o r phic r o c k s ? Common metamorphic rocks include phyllite, schist, gneiss, quartzite and marble.

21. W h a t a r e s e d i m e n tary rocks ? Sedimentary rocks are formed from deposits of pre-existing rocks or pieces of once-living organism that accumulate on the Earth's surface.

22. W h a t a r e t h e e x a mples of s e d i mentary rocks ? Common sedimentary rocks include sandstone, limestone, and shale. These rocks often start as sediments carried in rivers and deposited in lakes and oceans. When buried, the sediments lose water and become cemented to form rock. Tuffaceous sandstones contain volcanic ash.

23. 3 t ypes of s e d i mentary rock s Sedimentary Rocks Sedimentary rocks are formed from pieces of other existing rock or organic material. There are three different types of sedimentary rocks: clastic, organic (biological), and chemical. Clastic sedimentary rocks, like sandstone, form from clasts, or pieces of other rock. Organic sedimentary rocks, like coal, form from hard, biological materials like plants, shells, and bones that are compressed into rock.

24. The formation of clastic and organic rocks begins with the weathering, or breaking down, of the exposed rock into small fragments. Through the process of erosion, these fragments are removed from their source and transported by wind, water, ice, or biological activity to a new location. Once the sediment settles somewhere, and enough of it collects, the lowest layers become compacted so tightly that they form solid rock.

25. Chemical sedimentary rocks, like limestone, halite, and flint, form from chemical precipitation. A chemical precipitate is a chemical compound—for instance, calcium carbonate, salt, and silica—that forms when the solution it is dissolved in, usually water, evaporates and leaves the compound behind. This occurs as water travels through Earth’s crust, weathering the rock and dissolving some of its minerals, transporting it elsewhere. These dissolved minerals are precipitated when the water evaporates.

26. W h a t i s e x o g enic processes ? Exogenic process? Exogenic processes include GEOLOGICAL PHENOMENA AND PROCESSES THAT ORIGINATE EXTERNALLY TO THE EARTH'S SURFACE. They are genetically related to the atmosphere, hydrosphere and biosphere, and therefore to processes of weathering, erosion, transportation, deposition, denudation etc.

27. Features of exogenic processes? WEATHERING, MASS WASTING, EROSION, AND DEPOSITION are the main exogenic processes. All the exogenic processes are covered under a general term- denudation, which means strip off or uncovers. The elements of nature capable of doing these exogenic processes are termed geomorphic agents (or exogenic geomorphic agents).

28. What do you mean by exogenic processes? THE PROCESSES THAT TAKE PLACE AT OR NEAR THE EARTH'S SURFACE are called Exogenic Processes. These processes are a part of denudation process which involves wearing away of Earth's surface.

29. Why is it called exogenic processes? All the forces that act outside the earth's surface and cause changes in the earth's surface are called exogenic forces. And ALL THESE FORCES THAT ARE CONSTANTLY ACTING ON THE SURFACE OF THE CRUST (erosion, transport, and storage) AND ARE CAUSING THE EVOLUTION OF LANDFORMS are called exogenic processes

30. What are the 4 exogenic processes? WEATHERING, MASS WASTING, EROSION, AND DEPOSITION are the main exogenic processes.

31. W h a t i s t h e i m p o rtance of r o c k s ? Economic significance of rocks Rocks are of great resource value, some directly and some as constituents of minerals. Soils are derived from weathering of rocks. Almost all types of building materials used for paving roads, floors or building walls of houses come from rocks.

32. W h a t h a p p en i f w e d o n 't have r o c k s ? Minerals make up most of what we use to build, manufacture and stand on — including rocks and soil — so if we really ran out of minerals, we'd all be scrambling for a spot on the planet's shrunken surface areas.

33. W h a t w i l l h a p p e n t o t h e earth without r o c k s ? Flexi Says: If the rock cycle stops, the processes such as weathering, erosion, transport, and deposition will also cease, and there will be no uplifting of rocks to form mountains, due to which eventually our planet may not be capable of supporting life.

34. W h e n w a s t h e first r o c k f o u nd ? In the outback of Australia, geologists have found sedimentary rocks that are sprinkled with immensely old zircons. Some of the zircons (but not the surrounding rock) date back as far as 4.4 billion years , making them the oldest traces of geologic history ever found.

35. W h e n d i d r o c k s c o m e t o E a r t h ? The 'light' rocks are on the Earth's surface Planet Earth is a rock too, but so much has happened since it was formed from dust and small rocks that smashed and stuck together 4.543 billion years ago. As the space dust hit each other to make the earth, it got super hot and melted.

36. W h e r e are t h e r o c k s f o u n d ? Chemical sedimentary rocks can be found in many places, from the ocean to deserts to caves. For instance, most limestone forms at the bottom of the ocean from the precipitation of calcium carbonate and the remains of marine animals with shells.

37. W h e r e are t h e m o s t r o c k s f o u n d ? In general, igneous rocks and metamorphic rocks form most abundantly at divergent and convergent plate boundaries. Sedimentary rocks can form anywhere on the Earth's surface, but the thickest accumulations are associated with convergent plate boundaries, where volcanoes and mountain ranges form.

38. W h e r e d o w e usually u s e r o c ks ? Rocks and minerals are all around us! They help us to develop new technologies and are used in our everyday lives. Our use of rocks and minerals includes as building material, cosmetics, cars, roads, and appliances . In order maintain a healthy lifestyle and strengthen the body, humans need to consume minerals daily.

39. W h y r o c k s are needed o n E a r th ? They help us to develop new technologies and are used in our everyday lives. Our use of rocks and minerals includes as building material, cosmetics, cars, roads, and appliances. In order maintain a healthy lifestyle and strengthen the body, humans need to consume minerals daily.

40. W h y i s r o c k i m p o rtant to l i v i n g t h i n gs ? Rocks, minerals, and soil are extremely important to all plants and animals, including humans. Plants and some animals live and grow in soil and depend upon minerals in the soil for growth and development. Many animals, including humans, eat plants that have grown in soil .

41. H o w i m p o rtan t r o c k s a r e ? Rocks are important in our daily life for many reasons. They are used in construction, manufacturing, and many other industries. Rocks are also important for scientific research and to help us better understand our planet.

42. H o w d o r o c k s a f f e c t o n e a r t h ? As rocks are uplifted into mountains, they start to erode and dissolve, sending sediments and nutrients into waterways and impacting the ecosystems for living things.

43. D o e s t h e earth n e e d r o c k s ? Rocks and minerals play a valuable role in natural systems such as providing habitat like the cliffs at Grand Canyon National Park where endangered condors nest, or provide soil nutrients in Redwood where the tallest trees in the world grow.

44. A r e r o c k s g o o d f o r t h e e a r th ? Rock Roles in the Environment On the surface, rocks seem entirely lifeless, but rocks play an important role in many ecosystems. For example, some rocks might provide the perfect home for a plant's root system. Others provide the solid, reliable surface necessary for moss or lichens to grow.

45. C o u l d w e s u r v ive w i t h out r o c k s ? Life as we know it would not exist without them. Everything that cannot be grown--that's neither plant nor animal--is a mineral or made from minerals. Agriculture, construction, manufacturing, transportation, electronics, art, science--almost every area of human activity depends in some way on minerals.

46. W o uld life on Earth be possible without the rocks? Rocks and soil are essential to sustaining animal life because they are the foundation of all habitats that provide safe shelter for animals. Without these materials, plant and animal life on Earth would not be possible.