The following questions are smart questions raised by smart students. The questions are not covered in geography classes or in the textbook. Let's search for related information and learn from each other :)
All students can answer the following questions. A gold medal will be given to the best answer :)
1. Leung Ho Yee: is burying & compressing dead vegetation in swamp the ony way to form coal?
2. Lo Vanessa Hiu tung: How do people find crystals?
3. Lam Lok Ting: What forms minerals?
4. Lam Chu Hin: I'm not very sure about the definition of "minerals"
5. Ho Ka Ki: Why is water a kind of mineral?
6. Wong Win Queen: How to define some minerals as crystals? Are all crystrals formed from metals? Which methods are suitable for taking them out?
7. To Tsz Ching: Why are rocks and minerals important for us?
8. Choi Tsz Kiu: What is the imprtanc eof rocks & minerals to geography?
9. Chung Yuen Shan: Which minerals form limestone?
10. Lai Yin Sum: What is the factor affecting the color of rocks?
11. So Kam Kei: What is talc and talcum powder?
12. Tsang Suet Ying: I don't understand why hematite becomes red when it contacts with air and water.
13. Lo Hiu Tung: I don't know the formation of diamonds.
14. Ho Wing Man: How can wind affect the formation of sedimentary rocks?
15. Cheung Wing Sum: How do the geologists know how the Earth is formed and what the Earth is made up of?
16. Wong Hing Yin: Why do marbles have many colors?
17. Wong Nok Shun: How do geologists define some minerals as metal?
訂閱：
張貼留言 (Atom)
9. Chung Yuen Shan: Which minerals form limestone?
回覆刪除Limestone is a sedimentary rock composed of a largr amout of calcite. Calcite is calcium carbonate mineral and the most stable one. In addition, calaium carbonate is a chemical compound that common substance found in rock in all part of the world and the main composition are shells, pearls, ect..
4B Lo Hiu Tung
16. Wong Hing Yin: Why do marbles have many colors?
回覆刪除Ans: Marble is a metamorphic limestone. When limestone is heated and has pressure put on it, its calcite is melted. Larger crystals are formed and this is marble. Whatever is mixed in with the limestone decides the final color of the marble. If limestone is pure, you get a white marble. If it has hematite or clay in it, you will get a reddish color marble. Most marble is large grained and comes in many colors and patterns
There are some types of the marble colours.
1. White for marble Colors
There are a huge variety of shades for white marble. These shades depend on the country of origin. For example, a predominantly white marble with white and gray flecks, sometimes called Big White Flower is from China whereas a Bianco white marble leans toward ivory in color and is mined in Brazil and Italy.
2. Brown for marbles Colors
Brown and beige marbles are two of the most popular colors of marble countertops. Brown marble is widely available. Similar to beige, brown marble creates a traditional style and ambiance in a kitchen or bath. Coupling with a light finished wood can complete the look.
3. Blue for marble Colors
Blue marble countertops are quickly becoming a stylish choice for designers today and are prized for the beauty in their patterns. Blue marbles are mined mostly in coastal Africa and Brazil. Secondary colors are commonly whites, grays, blacks, and other shades of blue. Of the blue marbles, Azul marbles are the most sought after for their beauty and rarity.
4. Gold for marble Colors
The metallic colors in Gold and Copper marble are found worldwide, with the highest concentration of quarries in Brazil and South America. Gold and Copper marble will usually have secondary colors of white, black, and gray. Countertops of gold or copper marble will create a sense of luxury and richness in your kitchen or bath, especially paired with a darker colored cabinet.
Below is the web link of the answer,pls refer to the following pictures
http://www.granite-export.com/China_marble_colors.html
Queenie, Wong Win Queen
4C (27)
2. Lo Vanessa Hiu tung: How do people find crystals?
回覆刪除Ans:
How to find crystals
Step 1: Determine the type of crystals you wish to find to ensure that you're looking in the appropriate geographic location. Quartz crystals are quite common to many locations and are the easiest to find whereas amethyst or rare forms of crystals will be difficult to locate. Look at a map with detailed information on local minerals and natural resources for the area that you're searching in.
Step 2: Look for crystal or quartz veins on a mining map of the area that you're searching to narrow down your search field. These maps are available at mining facilities. Many mines allow digging for a small fee and this is the best way to find quality crystals.
Step 3: Sift through the tailings and clay lumps from the mining pit. Tailings are waste from the mines and usually have smaller crystals embedded within them.
Step 4: Look for shimmering sparkles on the ground near mining areas. This may be a piece of a larger crystal embedded in the ground and is usually a telltale sign of a good vein of quartz below.
Step 5: Look along the walls of mining shafts for the shimmer crystal or quartz deposits. These crystals will shimmer when shined with a flashlight.
Step 6: Use a 3 tinged garden scratcher or a small hoe to sift through rock and sediment near a quartz deposit. Larger crystal structures are usually secured tightly embedded in clay and will stay in place when bumped with a gardening tool if they happen to be protruding from the ground.
Here is the web link
http://www.ehow.com/how_5640076_crystals.html
Queenie, Wong Win Queen
4C (27)
11. So Kam Kei: What is talc and talcum powder?
回覆刪除Ans:
1.Talc (n.)
A fine-grained white, greenish, or gray mineral, Mg3Si4O10(OH)2, having a soft soapy feel and used in talcum and face powder, as a paper coating, and as a filler for paint and plastics.
(http://www.answers.com/topic/talcum-powder)
Talc is a mineral, produced by the mining of talc rocks and then processed by crushing, drying and milling. Processing eliminates a number of trace minerals from the talc, but does not separate minute fibers which are very similar to asbestos.
(http://www.preventcancer.com/consumers/cosmetics/talc.htm)
Talc is toxic. Talc particles cause tumors in human ovaries and lungs.Talc particles are able to move through the reproductive system and become imbedded in the lining of the ovary.
Talc poses a health risk when exposed to the lungs. Talc miners have shown higher rates of lung cancer and other respiratory illnesses from exposure to industrial grade talc, which contains dangerous silica and asbestos. The common household hazard posed by talc is inhalation of baby powder by infants.
(http://www.preventcancer.com/consumers/cosmetics/talc.htm)
2.
Talcum powder (n.)
A fine, often perfumed powder made from purified talc for use on the skin.
(http://www.answers.com/topic/talcum-powder)
4. Lam Chu Hin: I'm not very sure about the definition of "minerals"
回覆刪除Ans:
The minerals (inorganic nutrients) that are relevant to human nutrition include water, sodium, potassium, chloride, calcium, phosphate, sulfate, magnesium, iron, copper, zinc, manganese, iodine, selenium, and molybdenum.
They are required for life means that their continued supply in the diet is needed for growth, maintenance of body weight in adulthood, and for reproduction. The amount of each mineral that is needed to support growth during infancy and childhood, to maintain body weight and health, and to facilitate pregnancy and lactation,are listed in a table called the Recommended Dietary Allowances (RDA) 推薦飲食量
是40多年前(1948)由美國食物與營養委員會評估制定的，一直被用來當作預防各種維他命缺乏症的營養攝取標準‧.
1.http://www.answers.com/topic/mineral
2.http://hk.knowledge.yahoo.com/question/question?qid=7006112101323
Queenie, Wong Win Queen
4C(27)
13. Lo Hiu Tung: I don't know the formation of diamonds.
回覆刪除Ans: Diamonds crystallize at very high pressures. In nature this means that diamonds are created by geologic processes at great depth within Earth, generally more than 150 kilometers down, in a region beneath the crust known as the mantle. Other processes, explored later in this exhibition, bring diamonds to where people can find them.
This diagram shows the interior structure of Earth. The three concentric layers -- the core, mantle, and crust -- formed within a few hundred million years of Earth's coalescence 4.5 billion years ago. The core is primarily an iron-nickel alloy and makes up a large fraction of the mass of Earth. The vast mantle is sandwiched between the core and the thin crust and is composed predominantly of magnesium and iron silicate minerals. Our planet's crust is a thin, rocky skin. Diamonds can form in most of Earth's interior but not near its surface, where graphite is the stable form of carbon. Indeed, diamonds only survive at Earth's surface because great heat is required to break down the diamond structure.
http://www.amnh.org/exhibitions/diamonds/formation.html
You may also read the textbook 1B of your Chemistry, it tells you the detail of the structure of diamond.
Queenie, Wong Win queen
4C (27)
14. Ho Wing Man: How can wind affect the formation of sedimentary rocks?
回覆刪除Ans:
1.Sediments
Despite our impression that rock is a very hard substance, it's subjected to the extreme forces of nature. An integral part of the rock cycle occurs in the sediment phase where igneous, sedimentary and metamorphic rock break down into smaller fragments. These fragments face weathering, erosion and the extreme forces of compression to form new rocks and land features.
2.Sedimentary rocks
Sedimentary rocks form from the millions of fragments of rock sediment that pile at the base of rivers and streams over time. Layers form with repeated additions of all types of rocks, including metamorphic and igneous rocks. As wind and water carry these particles, erosion occurs to the rock itself. Deposition at a final resting-place results in layered rocks such as those seen on the cliff faces of river gorges. Sedimentary rocks aren't always smooth and can contain a variety of shapes and sizes of fragments embedded in the stone. According to the University Corporation of Atmospheric Research, 75 percent of the rocks at the Earth's surface are sedimentary rocks. Sedimentary rocks can change into igneous or metamorphic rock.
Metamorphic Rocks
3.Geology
Most fossils are found in sedimentary rock. Sedimentary rock is made of bits of sediment: sand, silt and mud along with minerals that accumulate and harden over time. Geologic forces that reveal fossils over time are erosion (the wearing away of the surface of the rock by the action of water and wind) and uplifting, which occurs when two of the plates of the earth's crust collide. Mountains, deserts, cliffs and eroded hillsides are all good places to search for fossils.
Hope this may help!
Queenie, 4C Wong Win Queen
Refer to the question no.14, here are the web link
回覆刪除1.http://www.ehow.com/about_5396986_fossils.html
2.http://www.ehow.com/about_5375559_types-rocks-rock-cycle.html
May I post help Suet Ying to post her answer to Hiu Tung's questions. She emailed it to me (Ms Leung)
回覆刪除Lo Hiu Tung: I don't know the formation of diamonds.
4C (21) Tsang Suet Ying's ans: Diamonds are formed when heat reaches a certain temperature in combination with a certain pressure being reached which only occurs at 75 to 120 miles below the earth's surface. It was commonly believed by many that diamonds were formed as a metamorphism of coal. The belief now is that temperature changes in the upper mantle of the earth causes carbon atoms to go deeper where they melt. It is believed that they shot out towards the earth's surface during volcanic activity and then settled in the pipes that were created by the force. These pipes are called Kimberley pipes and these are primary deposits. This is where miners look for diamond deposits. The diamonds that made it to river beds over time and perhaps with the help of erosion are known as alluvial deposits.
It is believed that the first delivery of these diamond deposits occurred 2.5 billion years ago. The most recent delivery was 45 million years ago. They take thousands of years to form. Their intrigue is further enhanced with the knowledge that they might be 45 million years old at least.
(MORE INFORMATION: http://www.articlesbase.com/advice-articles/the-formation-of-diamonds-164818.html)
10. Lai Yin Sum: What is the factor affecting the color of rocks?
回覆刪除ANS: Rocks may be various colors, depending on what they are composed of (Their mineral content) and whether they were formed under oxidizing conditions.
•Iron minerals in rocks deposited in deep water, such as in the ocean or deep lakes, are less oxidized, and these rocks tend to be black or gray.
•If rocks are deposited in shallow water, they may be more greenish or brown.
•Rocks deposited on land instead of under water are more oxidized, especially if they were deposited in wet environments, and so tend to be reddish or tan.
•White rocks can be formed in sand dunes, beaches, lakes, and shallow sea.
•Rocks formed at high temperatures, such as from the solidification of molten rock, or at great depths tend not to be red because the iron minerals cannot oxidize under these conditions.
•If rocks sit at the surface under wet conditions, the iron minerals can be oxidized, turning the rock red.
http://reynolds.asu.edu/azvt/mv_color_rocks.htm
Wong Nok Shun 4E(24)
3. Lam Lok Ting: What forms minerals?
回覆刪除ANS: There are four ways that minerals can be formed. From molten rock, from solution, within living cells and by recrystallization. Below are the explanation about the four ways
When as substances is in liquid or gaseous form the atoms are randomly arranged with no internal structure. What is happening internally when the substance changes phase from liquid or gas to solid is the atoms are becoming more and more organized and structured. This phase change can be precipitated by changes in the surrounding environment. The easiest way to form a crystal is by evaporation of water. There is a limit to the number of atoms that can be contained by a volume of water. As the volume decreases, the atoms are forced closer and closer together finally bonding together to form solid crystals when enough of the water has been removed. The size of the resultant crystal is dependent on the rate of evaporation over time. Slow evaporation yields few large crystals while quick evaporation yields many smaller crystals. Crystals can also form if the solution or vapor is cooled or subjected to a decrease in pressure. In general, hot solutions are able to accommodate more atoms per unit of solution. As the solution cools, the atoms have less and less room to move and when the solution has cooled sufficiently, the atoms link together precipitating the mineral. This is the same for changes in pressure. High pressures allow more atoms per unit volume. If the pressure is lowered, the atoms bond together forming the solid mineral.
http://wiki.answers.com/Q/How_are_minerals_formed
http://wiki.answers.com/Q/How_do_minerals_form
Wong Nok Shun 4E(24)
7. To Tsz Ching: Why are rocks and minerals important for us?
回覆刪除ANS: Here are some examples and uses of rocks and minerals in daily life. After reading it, you may understand more about the importance of rock and minerals.
Asbestos:
Asbestos is used in fireproof fabrics, yarn, cloth, paper, paint filler,
gaskets, roofing composition, as a reinforcing agent in rubber and
plastics, brake linings, tiles, electrical and heat insulation, cement, and
chemical filters.
Bauxite:
The main source of aluminum. Aluminum is used in the United States
in packaging, transportation, and building.
Stibnite:
Antimony metal is extracted from stibnite and other minerals.
Antimony is used as a hardening alloy for lead, especially storage
batteries and cable sheaths, also used in bearing metal, type metal,
solder, collapsible tubes and foil, sheet and pipes, and semiconductor
technology. Stibnite is used for metal fireworks. Antimony salts are
used in the rubber and textile industries, in medicine, and glassmaking.
Barium:
Used as a heavy additive in oil-well-drilling mud, in the paper and
rubber industries, as a filler or extender in cloth, ink, and plastics
products, in radiography, as alloys in vacuum tubes, deoxidizer for
copper, lubricant in X-ray tubes, spark-plug alloys. Also used to make
an expensive white pigment.
Beryllium:
Beryllium alloys are used mostly in applications in aerospace,
automobiles, computers, oil and gas drilling equipment, and
telecommunications. Beryllium salts are used in fluorescent lamps, in
X-ray tubes, and as a deoxidizer in bronze metallurgy. Beryl is the
source of the gemstones emerald and aquamarine.
Coal:
One of the world’s major sources of energy. More than half of all the
electrical energy that is generated and used in the United States comes
from coal.
Cobalt:
Used in super alloys for jet engines, chemical paint driers, pigments,
rechargeable batteries, magnets, and cemented carbides for cutting tools.
Copper:
Used in electric cables and wires, switches, plumbing, heating, roofing
and building construction, chemical and pharmaceutical machinery,
electroplated protective coatings and cooking utensils.
Feldspar:
A rock-forming mineral, industrially important in glass and ceramic
industries, pottery and enamelware, soaps, abrasives, bond for abrasive
wheels, cements and concretes, insulating compositions, fertilizer,
poultry grit, tarred roofing materials, and in textiles and paper
production.
Fluorite:
Used in production of hydrofluoric acid, which is used in the
electroplating, stainless steel, refrigerant, and plastics industries, in
production of aluminum fluoride, which is used in aluminum smelting,
as a flux in ceramics and glass, in steel furnaces, and in emery wheels,
optics, and welding rods. Used in drinking water and toothpaste.
Gold:
Used in dentistry and medicine, in jewelry and arts, in medallions and
coins, in ingots as a store of value, for scientific and electronic
instruments, as an electrolyte in the electro-plating industry.
Rock / Mineral Uses Resource Pages
Gypsum Processed and used as prefabricated wallboard or as industrial or
building plaster, used in cement manufacture, and agriculture.
Halite (Salt):
Used in human and animal diet, food seasoning and food preservation,
used to prepare sodium hydroxide, soda ash, caustic soda, hydrochloric
acid, chlorine, metallic sodium, used in ceramic glazes, metallurgy,
curing of hides, mineral waters, soap manufacture, home water
softeners, highway de-icing, photography, herbicide, fire extinguishing,
nuclear reactors, mouthwash, medicine, in scientific equipment for
optical parts. Single crystals used for spectroscopy, ultraviolet and
infrared transmission.
(Continuing Q7)
回覆刪除Lead:
Used in lead batteries, gasoline tanks and solders, seals or bearings, used
in electrical and electronic applications, TV tubes, TV glass,
construction, communications, protective coatings, in ballast or weights,
ceramics or crystal glass, tubes or containers, type metal, foil or wire, Xray
and gamma radiation shielding, soundproofing material in the
construction industry, and ammunition.
Limestone:
Limestone is used in the construction industry and is the main ingredient
from which aggregate, cement, lime, and building stone are made. As a
source for lime, it is used to make paper, plastics, glass, paint, steel,
cement, and carpets. Used in water treatment and purification plants,
and in the processing of various foods and household items (including
medicines).
Lithium:
Lithium compounds are used in ceramics and glass, in primary
aluminum production, in the manufacture of lubricants and greases,
rocket propellants, vitamin A synthesis, silver solders, underwater
buoyancy devices, and batteries.
Mica:
Mica is used in electronic insulators, ground in paint, as joint cement, as
a dusting agent, in well-drilling muds, and in plastics, roofing, rubber,
and welding rods.
Platinum:
Platinum is used principally as a catalyst for the control of automobile
and industrial plant emissions, and as a catalyst to produce acids,
organic chemicals, and pharmaceuticals. Also used in bushings for
making glass fibers used in fiber-reinforced plastic and other advanced
materials, in electrical contacts, in capacitors, in conductive and resistive
films used in electronic circuits, in dental alloys used for making crowns
and bridges, and in jewelry.
Potash:
Used as a fertilizer, in medicine, in the chemical industry, and to
produce decorative color effects on brass, bronze, and nickel. Is an
essential mineral for vegetable and animal life.
Quartz:
As a crystal, quartz is used as a semiprecious gemstone (agate, jasper,
onyx, amethyst, citrine, rose quartz, smoky quartz, etc.) Because of its
properties quartz is used for pressure gauges, oscillators, resonators, and
wave stabilizers; heat-ray lamps; and in prism and spectrographic lenses.
Used in the manufacture of glass, paints, abrasives, refractories, and
precision instruments.
Silver:
Used in photography, jewelry, and electronics. Used as currency, in
lining vats and other equipment for chemical reaction vessels, water
distillation, mirrors, electric conductors, batteries, silver plating, table
cutlery, dental, medical, and scientific equipment, electrical contacts,
and bearing metal.
Sodium carbonate:
Used in glass container manufacture, in fiberglass and specialty glass.
Also used in production of flat glass, in powdered detergents, in
medicine, as a food additive, photography, cleaning and boiler
compounds, and for pH control of water.
Sulfur:
Used in the manufacture of sulfuric acid, fertilizers, chemicals,
explosives, dyestuffs, petroleum refining, vulcanization of rubber,
fungicides.
Tantalum:
Used mostly in the production of electronic components. Alloyed with
other metals, it is also used in making carbide tools for metalworking
equipment, and in the production of super alloys for jet engine
components.
Titanium:
Titanium is a strong, lightweight metal often used in airplanes, and as a
brilliant white pigment used in paint, paper, and plastics.
Tungsten:
Used in metalworking, construction and electrical machinery and
equipment, in transportation equipment, as filament in light bulbs, as a
carbide in drilling equipment, in heat and radiation shielding, textile
dyes, enamels, paints, and for coloring glass.
Zeolites:
Used in aquaculture (fish hatcheries for removing ammonia from the
water), water softener, in catalysts, cat litter, odor control, and for
removing radioactive ions from nuclear plant waste.
(Continuing Q7)
回覆刪除Zinc:
Used as a protective coating on steel, with copper to make brass, and as
chemical compounds in rubber and paints, used as a sheet zinc and for
galvanizing iron, electroplating, metal spraying, automotive parts,
electrical fuses, anodes, dry cell batteries, fungicides, nutrition (essential
growth element), chemicals, roof gutter, engravers’ plates, cable
wrappings, organ pipes, in pennies, primers, paints, to protect ship hulls,
in lubricating oils and greases. Zinc oxide is used in medicine, paints, as
an electrostatic and photoconductive agent in photocopying.
Clay:
Used to coat the pages of newspaper, magazines, stationery, brochures,
and boxes so that the ink used in printing on them will be bright and will
not run. Also used as a brightener and abrasive in toothpaste, and in
medicines to provide a smooth coating for the stomach.
Chromite:
Used in making steel, “chromed” parts for automobiles and appliances
and in the manufacture of chromic acid which is used to tan much of the
leather used in making shoes, belts, purses, jackets, gloves, etc.
Hematite:
Hematite is processed to produce iron, which is used to make steel.
Steel, in turn, is used in everything from automobiles to flatware to the
machinery used in most manufacturing. Steel is used in the manufacture
of such things as kitchen appliances, furniture, tools, bridges, buildings,
construction equipment, highway construction, shipbuilding, and trains
and railroads. Powdered iron is used in magnets, high-frequency cores,
auto parts, and as a catalyst. Radioactive iron is used in medicine and as
a tracer element in biochemical and metallurgical research. Iron blue is
used in paints, printing inks, plastics, cosmetics, and paper dyeing.
Black iron oxide is used as a pigment and in polishing compounds,
medicines, and magnetic inks.
Gilsonite:
Gilsonite is used in the manufacture of wire insulation, paints and
varnishes, construction materials, asphalt, printing ink, oil well drilling,
and in foundry casting.
Kaolinite:
Kaolinite is a very fine white clay used as a filler in many products, for
coating pages in magazines and newspapers to prevent ink from
running, and as a whitener and abrasive in toothpaste.
Magnetite:
Magnetite is processed to produce iron which is used in making steel.
Steel is used to make nails, kitchen appliances, furniture, tools, bridges,
buildings, automobiles, construction equipment, manufacturing
machinery, and in highway construction, shipbuilding, trains, and
railroads. Powdered iron is used in magnets, high-frequency cores, auto
parts, and as a catalyst. Radioactive iron is used in medicine and as a
tracer element in biochemical and metallurgical research. Iron blue is
used in paints, printing inks, plastics, cosmetics, and paper dyeing.
Black iron oxide is used as a pigment and in polishing compounds,
medicines, and magnetic inks.
http://www.learnnc.org/lp/media/uploads/2008/01/4mineral_teacher_pages.pdf
(For more information, please go to http://library.thinkquest.org/J002289/uses.html
)
Wong Nok Shun 4E (24)
1. Leung Ho Yee: is burying & compressing dead vegetation in swamp the only way to form coal?
回覆刪除ANS: the answer is YES. Burying & compressing dead vegetation in swamp is the only way to form coal. However, dead vegatation cannot form coal by itself. Only when the environment is suitable, can dead vegatation change and form coal. Here are some additional information about the formation of coal.
Coal comes from the massive accumulation of dead land-based plant life, mainly trees. This organic matter was deposited in sedimentary basins on land (of continental origin), where the water was shallow. These basins were either close to the sea, often in the form of large lagoons, or inland, in the form of lakes or marshes. As a result of climatic variations, for example an increasingly heavy annual rainfall, it is thought that enormous forests sank below water, and their debris accumulated in sedimentary basins where it was rapidly covered by large quantities of mud and sand.
This sudden and premature burial sheltered the debris from the air, thus preventing it from rotting quickly. In the maritime areas, a sudden subsiding of the basin resulted in an inflow of seawater, decimating the forest. After these catastrophic episodes, the forest grew again until a new disaster happened, and so on. This repetitive cycle of events explains why, in the substratum, layers of coal alternate with layers of clay or sandstone (compacted sand). Subsequently the sedimentary basin sinks gradually under the weight of the sediments and the layers of dead plant matter are slowly transformed under conditions of increasing temperature and pressure. The cellulose in the wood is first of all changed into humic acids (products of incomplete decomposition, which give the earth its brown colour), then into bitumens and finally into elementary carbon. The process is extremely long: the oldest coal has the highest carbon content (90 to 95%) The most favourable period for the creation of coal was the Carboniferous Period (carboniferous means “coal-bearing”), between 360 and 290 million years ago. However, smaller quantities of coal continued to be formed in certain regionsduring all the subsequent epochs: the Permian Period (290 to 250 million years ago), and the Secondary Period (Mesozoic Era, 250 to 65 million years ago). The vegetal masses buried in the Tertiary Period (Cenozoic Era), less than 65 million years ago, are generally less evolved: they are often lignite deposits which still contain a lot of volatile matter (bitumens and residual lignite), but whose carbon content is lower. Coals of excellent quality can be found dating from the Tertiary Period, brought into early maturity by the heating effects of colliding tectonic plates: Palaeocene coal (65 to 55 million years ago) from Colombia and Venezuela, or Miocene coal (20 million years ago) from Indonesia. Finally, recent deposits (from 10,000 years ago until the present time) are very rich in fibrous debris. These consist of peat and they do not contain any elementary carbon – they were not sufficiently buried for that. Peat is found in peat marshes, boggy ground where it was plant matter such as mosses (sphagnum or peat moss) and grasses rather than the tree remains of forests that formed the deposits.
Besides the formation of coal, there are some detail ( uses , the coal production and consumption countries , coal uses in the future ) in the website
http://www.planete-energies.com/content/coal/formation.html
Also, I find one more useful website about the formation of coal with many photos and diagrams.
http://www.athro.com/geo/trp/gub/coal.html
Yeung King Fung 4F(35)
5. Ho Ka Ki: Why is water a kind of mineral?
回覆刪除Actually, water can be classified in many types. In our world, there are liquid water, bottled water, drinking water, you name it! Beside them, there is another kind of water --- mineral water. In fact, water is not a mineral itself. However, as water sits in contact with minerals , it can absorb some of the mineral content over time and become one kind of the minerals finally.
Here are some additional information about mineral water.
Mineral water is water containing minerals or other dissolved substances that alter its taste or give it therapeutic治療 value, generally obtained from a naturally occurring mineral spring or source. Dissolved substances in the water may include various salts and sulfur compounds. Mineral water can be sparkling (with effervescence泡騰), or still (without effervescence不沸騰).
Minerals
Mineral Waters contain - as suggest the name - various minerals and trace elements. They are usually measured as the residues (what remains) when a liter of water is evaporated at 180 degrees C. These minerals have various effects on the health of a person.
The mineralisation of a water changes slightly over time.
Acidity (pH)
Total Dissolved Solids (TDS)
Aluminum (Al)
Arsenic (As)
Borondioxyde (BO2-)
Bromine (Br-)
Calcium (Ca++)
Chloride (Cl-)
Cobalt (Co)
Carbondioxyde (CO2)
Chromium (Cr-)
Copper (Cu++)
Fluoride (F-)
Germanium (Ge)
Hardness
Hydrogencarbonate (HCO3-)
Iodine (I)
Iron (Fe++)
Lithium (Li+)
Magnesium (Mg++)
Manganese (Mn+)
Nitrate (NO3-)
Potassium (K+)
Rubidium (Rb)
Silica (SiO2)
Sodium (Na+)
Strontium (Sr++)
Sulphate (SO4--)
Zinc (Zn++)
For other information about mineral water, here is the website
http://www.wisegeek.com/what-is-mineral-water.htm
there are so many links related to mineral water. Also, beside “mineral water” , there is “mineral oil” in Earth. You can search it in this website.
Yeung King Fung 4F(35)
9. Chung Yuen Shan: Which minerals form limestone?
回覆刪除Limestone is a very common sedimentary rock of biochemical origin. It is composed mostly of the mineral calcite. Sometimes it is almost pure calcite, but most limestones are filled with lots of other minerals and sand and they are called dirty limestones. The calcite is derived mostly from the remains of organisms such as clams, brachiopods, bryozoa, crinoids and corals. These animals live on the bottom of the sea and when they die their shells accumulate into piles of shelly debris. This debris can then form beds of limestone. Some limestones may have been derived from non-biogenic calcite formation. Although some limestones can be nearly pure calcite, there is often a large amount or sand or silt that is included in the shelly debris.
Limestone often contains variable amounts of silica in the form of chert (aka chalcedony, flint, jasper, etc) or siliceous skeletal fragment (sponge spicules, diatoms, radiolarians), as well as varying amounts of clay, silt and sand sized terrestrial detritus carried in by rivers. The primary source of the calcite in limestone is most commonly marine organisms. These organisms secrete shells made of aragonite or calcite and leave these shells behind after the organism dies. Some of these organisms can construct mounds of rock known as reefs, building upon past generations.Below about 3,000 meters, water pressure and temperature causes the dissolution of calcite to increase non-linearly so that limestone typically does not form in deeper waters (see lysocline). Secondary calcite may also be deposited by supersaturated meteoric waters (groundwater that precipitates the material in caves). This produces speleothems such as stalagmites and stalactites. Another form taken by calcite is that of oolites (oolitic limestone) which can be recognized by its granular appearance.
As the aforementioned content told us that limestone is composed mostly of the mineral calcite. So let’s talk more about calcite.
Calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases.
When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures.
For additional information, here is the website talking about
1. Limestone (mineral)
2. COMPOSITION AND ORIGIN
3. DIAGENESIS OF LIMESTONE
4. WEATHERING AND METAMORPHISM
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http://www.webcitation.org/query?id=1257008095152489
Yeung King Fung 4F(35)
15. Cheung Wing Sum: How do the geologists know how the Earth is formed and what the Earth is made up of?
回覆刪除Ans: The Earth, at the beginning, was very different from what it is now. It did not have any atmosphere or water bodies. The common belief of scientists is that our planet earth was formed some 4.5 billion years ago. The sun, the planets and their satellites in our solar system were all formed due to the contraction of solar nebula. Solar nebula, from which our solar system is said to have formed, was a huge mass of spiral cloud made up of dust particles and various types of hot gases. The constituent elements of the solar nebula were mainly hydrogen and helium and some other heavier elements. Solar nebula began its contraction about 4.6 billion years ago. During the contraction process, its temperature came down and it began to rotate very fast. As a result of cooling, shrinking and rapid rotation, the outer part of the cloud got detached from the main body in the form of rings.
How was the physical structure of the Earth formed?
Each of the detached rings cooled and shrank further. Then, gradually the separated rings clustered together to form a globe. This globe or ball of hot gases was by now, cooled so much that all the gases in it were condensed to liquid form or lava. Over a period of time, with further decrease in temperature, the lava solidified to form the crust of the Earth. During the process of solidification, the heavy metals like iron, in their liquid form, descended to the center due to high density, forming the core. The remaining separated lava formed the mantle, which lies just below the crust. In this way, the layered structure of Earth was formed.
How were the oceans of the Earth formed?
Due to the cooling of earth, large amounts of steam escaped from its crust. As a result of the eruptions of volcanoes, substantial amounts of steam and various types of gases were also released. Geologists believe that a good amount of water was imported to the Earth during its collisions with several comets that contained ice. When the temperature on the Earth was very high, all the water remained in vaporous form above the atmosphere. Then, as the temperature on Earth decreased, all the steam condensed to form clouds. The resulted rainwater got accumulated in the craters formed on the surface by the impact of smashing of comets. This led to the formation of the oceans.
How was the atmosphere of the Earth formed?
The impact of collisions with comets enriched the Earth with water as well as many other essential gases like carbon dioxide, methane, nitrogen ammonia, etc. The gases discharged from volcanic eruptions and collisions with comets led to the formation of the new atmosphere over the Earth. Free oxygen was not available in the new atmosphere; it was either bound by hydrogen or some other elements. The ozone layer was absent in the newly formed atmosphere. As a result of which, the Earth's surface was exposed to ultraviolet radiation.
How were the continents of the Earth formed?
According to theories of geology, the present-day continents were formed due to fragmentation of a huge, single mass of land. The broken pieces of land masses then drifted away from each other. The Earth's crust comprises a number of large plates of solid rock floating on the liquid mantle. The molten rock of the mantle is in constant motion due to convection of heat that occurs deep inside it. Due to this internal motion, some of the plates are constantly sliding at the edges (more commonly) in relation to others. This kind of movement detached one plate from another and caused the drifting of the continents. It is believed that the mountains were formed when one plate of the crust pushed the other, and the resultant pressure thrust a part of the land upwards.
web link: http://www.buzzle.com/articles/how-was-the-earth-formed.html
Wong Win Queen
4C (27)
3. Lam Lok Ting: What forms minerals?
回覆刪除Minerals are formed by naturally occurred definite chemical composition/ chemical compounds and some of them have specific crystalline structures. They may also formed as a result of geological processes.
4F Ho Wing Man (8)
5. Ho Ka Ki: Why is water a kind of mineral?
回覆刪除According to the definition of minerals by the International Mineralogical Association ,a mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes’. Water’s molecule contains one oxygen and two hydrogen atoms connected by covalent bonds with the chemical formula H2O which means it is formed by a group of naturally occurred chemical compound. So water is a mineral.
4F Ho Wing Man (8)
7. To Tsz Ching: Why are rocks and minerals important for us?
回覆刪除Rocks are important because the use of rocks have a huge impact on the cultural and technological development of the human race. For example, igneous rocks, such as granite is the best material for construction.
Rock is a naturally occurring solid aggregate of minerals. No minerals then no rock. Also, minerals have many uses too. For example, water is a mineral and is essential for all living things.
Also,Rocks and minerals provides information for us to know more about the earth. For example, The study of the sequence of sedimentary rock strata is the main source for scientific knowledge about the Earth's history, including palaeogeography, paleoclimatology and the history of life.
4F Ho Wing Man (8)
14. Ho Wing Man: How can wind affect the formation of sedimentary rocks?
回覆刪除Sediments are formed during weathering, some of the particles are transported by the action of wind. When the water slows down it will deposit its load. Wind can be strong enough to act as a natural “sand blast” to slowly chip away at soft rocks. The size of the
particles is related to how fast the wind was moving when the particles were
deposited. Parallel layers of different grain sizes or compositions indicate successive depositional surfaces possibly indicating changes in depositional processes such as wind strength .In stream deposits, larger grain sizes suggest stronger currents.
So when the wind is strong that means faster currents, it can move larger sediments. And formed detrital sedimentary rocks include breccia, conglomerate, sandstone and shale. Cross bedding consists of bedded materials which are inclined at angles also due to deposition by wind.
Also, sediments deposited by wind do not have a distincly different depositional pattern than do sediments deposited by waves.
4F Ho Wing Man (8)
3. Lo Hiu Tung: I don't know the formation of diamonds.
回覆刪除Most natural diamonds are formed at high-pressure high-temperature conditions existing at depths of 140 to 190 kilometers (87 to 120 mi) in the Earth mantle. Carbon-containing minerals provide the carbon source, and the growth occurs over periods from 1 billion to 3.3 billion years (25% to 75% of the age of the Earth). Diamonds are brought close to the Earth surface through deep volcanic eruptions by a magma, which cools into igneous rocks known as kimberlites and lamproites. Diamonds can also be produced synthetically in a high-pressure high-temperature process which approximately simulates the conditions in the Earth mantle. An alternative, and completely different growth technique is chemical vapor deposition (CVD). Several non-diamond materials, which include cubic zirconia and silicon carbide and are often called diamond simulants, resemble diamond in appearance and many properties.
The formation of natural diamond requires very specific conditions—exposure of carbon-bearing materials to high pressure but at a comparatively low temperature range between approximately 900–1300 °C. These conditions are met in two places on Earth; in the lithospheric mantle below relatively stable continental plates, and at the site of a meteorite strike.
4F Ho Wing Man (8)
9. Chung Yuen Shan: Which minerals form limestone?
回覆刪除Limestone is composed largely of the mineral calcite (calcium carbonate: CaCO3). Limestones often contain variable amounts of silica in the form of chert or flint, a clay, silt and sand as disseminations, nodules, or layers within the rock. Secondary calcite may also be deposited by supersaturated meteoric waters (groundwater that precipitates the material in caves). This produces speleothems such as stalagmites and stalactites. Another form taken by calcite is that of oolites (oolitic limestone) which can be recognised by its granular appearance.
4F Ho Wing Man (8)
17. Wong Nok Shun: How do geologists define some minerals as metal?
回覆刪除Probably, minerals are defined as metals by chemists. After the chemists did experiments on an element and found that the element characterized by high electrical conductivity, described as an arrangement of positive ions surrounded by a cloud of delocalized electrons which are the most specific characteristic of metal, it would be defined as a metal.
4F Ho Wing Man (8)
15. Cheung Wing Sum: How do the geologists know how the Earth is formed and what the Earth is made up of?
回覆刪除The geologists know how the Earth is formed is not the kind of things that geologists and all of us find visible in rocks. They know because of patient evidence-collecting from meteorites and the geology of the other planets, analyses of very large bodies of geochemical data, and generations of serious argument among many different sets of specialists. For example, the study of the sequence of sedimentary rock strata is the main source for scientific knowledge about the Earth's history, including palaeogeography, paleoclimatology and the history of life.
The earth is made up of 3 layers, including the crust, the mantle and the core.
Crust: The vast majority of the continental crust is composed of granitic rock, high in oxygen, silicon, and aluminum.
While oceanic crust is generally composed of dark-colored rocks called basalt and gabbro.
Mantle: After studying rock samples, scientists have determined that the mantle is made mostly of the elements silicon, oxygen, iron, and magnesium.
Core: The Earth's outer core is most likely made up of an iron-nickel alloy while the inner core mostly iron and a bit of nickel and cobalt. This is due to inferences that iron, cobalt and nickel are denser than other materials found at different levels in the structure of Earth, such as magnesium in the mantle.
The Earth's inner core is roughly the same in composition, but in solid form.
4F Ho Wing Man (8)
16. Wong Hing Yin: Why do marbles have many colors?
回覆刪除It is because Marble is a metamorphic rock and composed of different recrystallized carbonate minerals, most commonly calcite or dolomite. Different minerals give different colours. So the marbles have many colours.
For example, carrara marble 卡啦啦大理石is white, Rouge de Rance (a limestone) is red and Phrygian marble弗里吉亞大理石is purple.
4F Ho Wing Man (8)
11. So Kam Kei: What is talc and talcum powder?
回覆刪除Talc is a fine-grained white, greenish, or gray mineral, Mg3Si4O10(OH)2, having a soft soapy feel. Talc is valued for its extreme softness, smoothness, hrdrophobicity, high lubricating and hiding power and for its ability to absorb oil and grease. Its resistance to heat, electricity and acids make it an ideal surface for lab counter tops and electrical switchboards. It is also an important filler material for paints, rubber and insecticides.
Talcum powder is a fine, often perfumed powder made from purified talc for use on the skin.
4F Ho Wing Man (8)
8. Choi Tsz Kiu: What is the imprtanc eof rocks & minerals to geography?
回覆刪除Rocks and minerals provides information for us to know more about the earth. For example, The study of the sequence of sedimentary rock strata is the main source for scientific knowledge about the Earth's history, including palaeogeography, paleoclimatology and the history of life.
If there is no rocks, we can not know any about geography or even there is no subject and study called geography!
4F Ho Wing Man (8)
4. Lam Chu Hin: I'm not very sure about the definition of "minerals"
回覆刪除According to the definition of minerals by the International Mineralogical Association ,a mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes’.
4F Ho Wing Man (8)
10. Lai Yin Sum: What is the factor affecting the color of rocks?
回覆刪除The minerals formed the rocks and the process of the formation of rocks are also factors affecting the colour of rocks. For example, marble is a metamorphic rock and composed of different recrystallized carbonate minerals, most commonly calcite or dolomite. Different minerals give different colours. So the marbles have many colours.For example, carrara marble 卡啦啦大理石is white, Rouge de Rance (a limestone) is red and Phrygian marble弗里吉亞大理石is purple.
4F Ho Wing Man (8)
13. Lo Hiu Tung: I don't know the formation of diamonds.
回覆刪除Most natural diamonds are formed at high-pressure high-temperature conditions existing at depths of 140 to 190 kilometers (87 to 120 mi) in the Earth mantle. Carbon-containing minerals provide the carbon source, and the growth occurs over periods from 1 billion to 3.3 billion years (25% to 75% of the age of the Earth). Diamonds are brought close to the Earth surface through deep volcanic eruptions by a magma, which cools into igneous rocks known as kimberlites and lamproites. Diamonds can also be produced synthetically in a high-pressure high-temperature process which approximately simulates the conditions in the Earth mantle. An alternative, and completely different growth technique is chemical vapor deposition (CVD). Several non-diamond materials, which include cubic zirconia and silicon carbide and are often called diamond simulants, resemble diamond in appearance and many properties.
The formation of natural diamond requires very specific conditions—exposure of carbon-bearing materials to high pressure but at a comparatively low temperature range between approximately 900–1300 °C. These conditions are met in two places on Earth; in the lithospheric mantle below relatively stable continental plates, and at the site of a meteorite strike.
4F Ho Wing Man (8)
11. So Kam Kei: What is talc and talcum powder?
回覆刪除The Talcum powder main ingredients are Talc.
Talc is generally white, slightly blue or green. The ingredients of Mg3 [Si4O10] (OH) 2 structure of the layered silicate minerals. Crystal belongs to triclinic system, leave the six-party single-crystal flake rare, massive dense, leaf-like, fibrous or radial aggregates.
Ground into powder with talcum powder called.
English name: Talcum powder or Talc powder
This product is for family-like magnesium silicate talc mineral salts, mainly composed of water-bearing magnesium silicate, by crushing after treatment with hydrochloric acid, washing, drying from.
Talc is the main component of water-bearing silicate talc magnesium.
Usually into a dense block, leaf-like, radial, fibrous aggregates. Colorless, transparent or white, but with a small amount of impurities and a light green, light yellow, Light brown or light red; cleavage was pearl gloss surface.
Hardness 1, the proportion of 2.7 to 2.8.
In the paper and used as a filler in rubber industry. Refractories for the metallurgical industry. Made use of talc-like ceramic with good dielectric and mechanical strength, is a high-frequency and ultra-high-frequency electric ceramic insulating material.
Hydrothermal alteration minerals are talc. Usually by the magnesium-rich rocks from hydrothermal alteration. Serpentinized peridotite intrusion in the late hot acidic aqueous solution and the role of CO2 can also be the formation of talc.
http://www.talcumpowder.cn/en/what_is_talc.html
4C So Kam Kei(19)
13. Lo Hiu Tung: I don't know the formation of diamonds.
回覆刪除A diamond is a transparent gem made of carbon, one of
the earth's most common elements. The formation of
diamonds began very early in the planet Earth's
history, when the condensation of solid matter into a
sphere caused the centre of the planet to become
subjected to incredible extremes of temperatures and
pressure.
Experiments and the high density of diamonds tell us
that they crystallize at very high pressures. In
nature this means that diamonds are created by
geologic processes at great depth within Earth,
generally more than 150 kilometers down, in a region
beneath the crust known as the mantle.
In the beginning of Earth formation
deposits of carbon element begin to crystallise deep
as diamonds. As the Earth's surface cooled, volcanic
activity forced streams of magna (liquid rock) to the
surface, carrying with it the diamond crystals. Later,
the diamond-bearing rock hardened, encasing the
diamonds in vertical volcanic "pipes".
But not all diamonds are found where they first came
to the surface. Subsequent erosion of the topsoils
over millions of years washed some of the diamonds
into streams and rivers, and sometimes as far away as
the sea. It is highly probable that they were first
discovered in areas such as these, far away from their
original location.
http://www.newton.dep.anl.gov/askasci/env99/env99366.htm
4C So Kam Kei(19)
1.Leung Ho Yee: is burying & compressing dead vegetation in swamp the only way to form coal?
回覆刪除4C (21) Tsang Suet Ying's ans:
More information can be found in website[1]
Yes, coal can only be formed by burying & compressing dead vegetation in swamp. Decomposition of the death of plant debris about 100 million years to 44 million years ago, so often referred to as fossil fuels. The formation of coal plants could grow in swamps or river deltas. When they die, bacteria decompose the wreckage through the decomposition of changes, gradually formed a thick layer of marsh material. In these years, these substances become harder into peat. The passage of time, peat deposition period and with the movement of the earth, making mud buried deeper underground coal, and minerals together and heat through to the role and biochemical reactions, some into sandstone or shale, increasing weight and the page level Other cover began to peat into various grades of coal, sandstone and other sediments forming the rock called sedimentary rock. The process in coal rank, the content of hydrogen, oxygen decreases while the content of carbon increases.
Reference[1]:http://hk.knowledge.yahoo.com/question/question?qid=7006072102872
2. Lo Vanessa Hiu tung: How do people find crystals?
4C (21) Tsang Suet Ying's ans:
More information can be found in website[1]
When People connect the current to the crystal, the crystal will be bulging. When we stop the current, the crystal will draw back as it is. When pass the current to the crystal again, the crystal can be a very fast, very stable to expand and contract. When the crystal is carefully cut to a certain size, length and width, thickness, the frequency of such oscillations can also be very accurate under control. So that people can find crystals
Reference[1]:http://hk.knowledge.yahoo.com/question/question?qid=7007082604534
3. Lam Lok Ting: What forms minerals?
4C (21) Tsang Suet Ying's ans:
A mineral is a naturally occurring solid chemical substance that is formed
through geological processes and that has a characteristic chemical
composition,
a highly ordered atomic structure, and specific physical
properties. By
comparison, a rock is an aggregate of minerals and/or
mineraloids and does not
have a specific chemical composition. Minerals
range in composition from pure
elements and simple salts to very complex
silicates with thousands of known
forms.
http://en.wikipedia.org/wiki/Mineral#Mineral_composition_of_rocks
7. To Tsz Ching: Why are rocks and minerals important for us?
4C (21) Tsang Suet Ying's ans:
Minerals can make cosmetic, such as base. Moreover, minerals can make many different kinds of jewelry. For example, Agate. Chinese people think that wear Agates not only for decoration, they can make our mind clear and improve efficiency. So Agate is one of the most popular products in China. Also, many Feng Shui products are made by minerals. Rock is important too because it can make furniture, e.g. chairs in parks.
9. Chung Yuen Shan: Which minerals form limestone?
回覆刪除4C (21) Tsang Suet Ying's ans:
Limestone is a sedimentary rock composed largely of the mineral calcite (calcium
carbonate: CaCO3). Like most other sedimentary rocks, limestones are composed of
grains; however, most grains in limestone grains are skeletal fragments of
marine organisms such ascoral or foraminifera. Other carbonate grains comprising
limestones are ooids, peloids, intraclasts, and extraclasts. Some limestones do
not consist of grains at all and are formed completely by the chemical
precipitation of calcite or aragonite. i.e. travertine.
http://en.wikipedia.org/wiki/Limestone
10. Lai Yin Sum: What is the factor affecting the color of rocks?
4C (21) Tsang Suet Ying's ans:
The color of rocks id affected by the minerals the rocks contained.
14. Ho Wing Man: How can wind affect the formation of sedimentary rocks?
4C (21) Tsang Suet Ying's ans:
More information can be found in website[1]
Weathering breaks the rocks into debris, or other biological remains. Then through erosion, sedimentation, and petrochemical, and other effects caused by the rock. Old age rocks were first deposited in the lower part; the more the level of those, then the more new age, which is called the overlay layer of rules. When sedimentary rocks often contain organisms when buried also, after a long life time can be preserved to become fossils; in igneous rocks there are more non-fossil.
Reference[1]:http://hk.knowledge.yahoo.com/question/question?qid=7007061701711