Clay
From Wikipedia, the free encyclopedia Jump to: navigation, search
For other uses, see Clay (disambiguation).
The Gay Head cliffs in Martha's Vineyard consist almost entirely of clay.
Clay is a naturally occurring aluminium silicate composed primarily of fine-grained minerals. Clay deposits are mostly
composed of clay minerals, a subtype of phyllosilicate minerals, which impart plasticity and harden when fired or dried; they also may contain variable amounts of water trapped in the mineral structure by polar attraction. Organic materials which do not impart plasticity may also be a part of clay deposits.[1]
Contents
[hide] 1 Formation 2 Definition 3 Grouping 4 Historical and modern uses o 4.1 Medical and agricultural
uses o 4.2 Clay as a building material 5 See also 6 Footnotes 7 References 8 External links Tanah liat
Dari Wikipedia, ensiklopedia bebas Langsung ke: navigasi, cari
Untuk kegunaan lain, lihat Clay (disambiguasi).
Gay Kepala tebing di Martha's Vineyard terdiri hampir seluruhnya dari tanah liat.
Clay adalah aluminium silikat alami terutama terdiri dari mineral halus. Deposito Clay sebagian besar terdiri dari mineral tanah liat, suatu subtipe mineral phyllosilicate, yang memberi plastisitas dan mengeras bila dipecat atau kering, mereka juga dapat mengandung jumlah variabel air terperangkap dalam struktur mineral dengan daya tarik kutub. Bahan organik yang tidak plastisitas memberi mungkin juga menjadi bagian dari endapan lempung. [1] Isi [hide] • 1 Formasi • 2 Definisi • 3 Pengelompokan
• 4 Sejarah dan modern menggunakan o 4.1 Medis dan menggunakan pertanian o 4.2 Clay sebagai bahan bangunan • 5 Lihat juga
• 6 Catatan kaki • 7 Referensi • 8 Pranala luar
[
edit
] Formation
Deforestation for clay extraction in Rio de Janeiro city - Brazil. The picture is of Morro da Covanca - Jacarepaguá. Clay minerals are typically formed over long periods of time by the gradual chemical weathering of rocks, usually silicate-bearing, by low concentrations of carbonic acid and other diluted solvents. These solvents, usually acidic, migrate through the weathering rock after leaching through upper weathered layers. In addition to the weathering process, some clay minerals are formed by hydrothermal activity. Clay deposits may be formed in place as residual deposits in soil, but thick deposits usually are formed as the result of a secondary sedimentary deposition
process after they have been eroded and transported from their original location of formation. Clay deposits are typically associated with very low energy
depositional environments such as large lakes and marine deposits.
Primary clays, also known as kaolins, are located at the site of formation. Secondary clay deposits have been moved by erosion and water from their primary location.[2]
Deforestasi untuk ekstraksi tanah liat di kota Rio de Janeiro - Brasil. Gambar adalah Morro da Covanca - Jacarepaguá.
Clay mineral biasanya terbentuk selama jangka waktu yang lama oleh kimia bertahap pelapukan batuan, biasanya silikat-bearing, dengan konsentrasi rendah dari asam karbonat dan pelarut diencerkan lainnya. Pelarut ini, biasanya asam, bermigrasi melalui pelapukan batuan setelah pencucian melalui lapisan lapuk atas. Selain proses pelapukan, beberapa mineral lempung yang terbentuk oleh aktivitas hidrotermal. Deposito Clay dapat dibentuk di tempat seperti deposito residu dalam tanah, tapi deposito tebal biasanya terbentuk sebagai hasil dari proses pengendapan sedimen sekunder setelah mereka telah terkikis dan diangkut dari lokasi asli formasi mereka. Clay deposito biasanya berhubungan dengan lingkungan
pengendapan energi yang sangat rendah seperti danau besar dan deposito laut. Tanah liat primer, juga dikenal sebagai kaolins, terletak di lokasi pembentukan. Endapan lempung sekunder telah dipindahkan oleh erosi dan air dari lokasi utama mereka. [2]
[
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] Definition
electron microscope photograph of smectite clay - magnification 23,500 Clays are distinguished from other fine-grained soils by differences in size and mineralogy. Silts, which are fine-grained soils that do not include clay minerals, tend to have larger particle sizes than clays, but there is some overlap in both particle size and other physical properties, and there are many naturally occurring deposits which include both silts and clays. The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 µm (clays being finer than silts), sedimentologists often use 4-5 μm, and colloidchemists use 1 μm.[1] Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg Limits. ISO 14688 grades clay particles as being smaller than 2 μm and silts larger.
Quaternary clay in Estonia.
Lempung dibedakan dari tanah halus lainnya oleh perbedaan dalam ukuran dan mineral. Silts, yang merupakan tanah berbutir halus yang tidak meliputi mineral lempung, cenderung memiliki ukuran yang lebih besar dari tanah liat, tapi ada beberapa tumpang tindih baik dalam ukuran partikel dan sifat fisik lainnya, dan ada banyak deposito alami yang mencakup baik silts dan lempung. Perbedaan antara lanau dan lempung bervariasi oleh disiplin. Ahli geologi dan ilmuwan tanah biasanya mempertimbangkan pemisahan terjadi pada ukuran partikel 2 pM (tanah liat halus yang dari silts),
sedimentologists sering menggunakan 4-5 pM, dan kimia koloid menggunakan 1 pM. [1] Geoteknik insinyur membedakan antara silts dan tanah liat berdasarkan sifat plastisitas tanah, yang diukur dengan Batas tanah 'Atterberg. ISO 14688 partikel tanah liat nilai sebagai lebih kecil dari 2 pM dan silts lebih besar.
[
edit
] Grouping
Depending on the academic source, there are three or four main groups of clays: kaolinite, montmorillonite-smectite, illite, and chlorite. Chlorites are not always considered a clay, sometimes being classified as a separate group within the phyllosilicates. There are approximately 30 different types of "pure" clays in these categories, but most "natural" clays are mixtures of these different types, along with other weathered minerals.
Varve (or varved clay) is clay with visible annual layers, formed by seasonal
differences in erosion and organic content. This type of deposit is common in former glacial lakes. When glacial lakes are formed there is very little movement of the water that makes the lake, and these eroded soils settle on the lake bed. This allows such an even distribution on the different layers of clay.[2]
Quick clay is a unique type of marine clay indigenous to the glaciated terrains of Norway, Canada, Northern Ireland, and Sweden. It is a highly sensitive clay, prone to liquefaction, which has been involved in several deadly landslides.
Tergantung pada sumber akademik, ada tiga atau empat kelompok utama dari tanah liat: kaolinit, montmorilonit-smektit, ilit, dan klorit. Klorit tidak selalu dianggap sebagai tanah liat, kadang-kadang dikelompokkan sebagai kelompok yang terpisah dalam phyllosilicates. Ada sekitar 30 jenis "murni" lempung dalam kategori, tapi yang paling "alami" tanah liat adalah campuran dari berbagai jenis, bersama dengan mineral lapuk lainnya.
Varve (atau tanah liat varved) adalah tanah liat dengan lapisan tahunan terlihat, dibentuk oleh perbedaan musiman di erosi dan
kandungan organik. Jenis deposito adalah umum di danau-danau glasial bekas. Ketika danau glacial terbentuk ada gerakan sangat sedikit air yang membuat danau, dan erosi tanah ini menetap di tempat tidur danau. Hal
ini memungkinkan seperti distribusi yang merata pada lapisan yang berbeda dari tanah liat. [2]
Cepat tanah liat adalah jenis tanah liat laut yang unik adat ke medan glaciated Norwegia, Kanada, Irlandia Utara, dan Swedia. Ini adalah tanah liat sangat sensitif, rentan terhadap likuifaksi, yang telah terlibat dalam beberapa mematikan longsor.
[
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] Historical and
modern uses
Clay layers in a construction site. Dry clay is normally much more stable than sand with regard to excavations.
Clays exhibit plasticity when mixed with water in certain proportions. When dry, clay becomes firm and when fired in a kiln, permanent physical and chemical changes occur. These reactions, among other changes, cause the clay to be
converted into a ceramic material. Because of these properties, clay is used for making pottery items, both utilitarian and
decorative. Different types of clay, when used with different minerals and firing conditions, are used to produce
earthenware, stoneware, and porcelain. Prehistoric humans discovered the useful properties of clay, and one of the earliest artifacts ever uncovered is a drinking vessel made of sun-dried clay.[citation needed] Depending on the content of the soil, clay can appear in various colors, from a dull gray to a deep orange-red.
Clay tablets were used as the first known writing medium, inscribed with cuneiform script through the use of a blunt reed called a stylus.
Clays sintered in fire were the first form of ceramic. Bricks, cooking pots, art objects, dishware, and even musical instruments such as the ocarina can all be shaped from clay before being fired. Clay is also used in many industrial processes, such as paper making, cement production, and chemical filtering. Clay is also often used in the manufacture of pipes for smoking tobacco. Until the late 20th century bentonite clay was widely used as a mold binder in the manufacture of sand castings.
Clay, being relatively impermeable to water, is also used where natural seals are needed, such as in the cores of dams, or as a barrier in landfills against toxic seepage (lining the landfill, preferably in
combination with geotextiles).[3] Recent[when?] studies have investigated clay's absorption capacities in various applications, such as the removal of heavy metals from waste water and air
purification.
Clay lapisan di lokasi konstruksi. Tanah liat kering biasanya jauh lebih stabil daripada pasir berkaitan dengan penggalian. Lempung plastisitas menunjukkan bila
dicampur dengan air dalam proporsi tertentu. Setelah kering, tanah liat menjadi tegas dan ketika dibakar dalam sebuah tungku,
perubahan fisik dan kimia tetap terjadi. Reaksi ini, antara perubahan lain, menyebabkan tanah liat untuk dikonversi menjadi bahan keramik. Karena sifat ini, tanah liat digunakan untuk membuat barang-barang tembikar, baik utilitarian dan dekoratif. Berbagai jenis tanah liat, bila digunakan dengan mineral yang berbeda dan kondisi pembakaran, digunakan untuk memproduksi gerabah, periuk, dan porselen. Prasejarah manusia menemukan
sifat yang berguna dari tanah liat, dan salah satu artefak paling awal yang pernah ditemukan adalah kapal minum terbuat dari tanah liat kering sinar matahari. [rujukan?] Tergantung pada isi tanah, tanah liat dapat muncul dalam berbagai warna, dari
membosankan abu-abu ke dalam oranye-merah.
Clay tablet digunakan sebagai media menulis pertama dikenal, ditulis dengan huruf paku script melalui penggunaan buluh tumpul disebut stylus.
Lempung sinter dalam api adalah bentuk pertama dari keramik. Batu bata, memasak pot, benda-benda seni, dishware, dan bahkan alat musik seperti Ocarina semua dapat dibentuk dari tanah liat sebelum dipecat. Clay juga digunakan dalam berbagai proses industri, seperti pembuatan kertas, produksi semen, dan kimia penyaringan. Clay juga sering digunakan dalam pembuatan pipa untuk merokok. Sampai tanah liat akhir abad ke-20 bentonit secara luas digunakan sebagai bahan pengikat cetakan dalam pembuatan coran pasir.
Clay, yang relatif kedap air, juga digunakan dimana seal alam dibutuhkan, seperti dalam inti bendungan, atau sebagai penghalang di landfill terhadap rembesan beracun (lapisan TPA, sebaiknya dalam kombinasi dengan geotekstil). [3]
Baru-baru ini [kapan?] studi telah menyelidiki kapasitas penyerapan tanah liat di berbagai aplikasi, seperti penghilangan logam berat dari air limbah dan pemurnian udara.
[
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] Medical and agricultural
uses
A traditional use of clay as medicine goes back to prehistoric times. An example is Armenian bole, which is used to soothe an upset stomach, similar to the way parrots (and later, humans) in South America originally used it.[4] Kaolin clay and
attapulgite have been used as anti-diarrheal medicines.
A more recent[when?] and limited use is as a specially formulated spray applied to fruits, vegetables, and other vegetation to repel or deter codling moth damage, and at least for apples, to prevent sun scald. A 2007 article in The Journal of
Antimicrobial Chemotherapy found that
certain iron-rich clay was effective in killing bacteria.[5]
[
edit
] Clay as a building material
Clay is one of the oldest building materials on Earth, among other ancient, naturally-occurring geologic materials such as stone and organic materials like wood. Between one-half and two-thirds of the world's population, in traditional societies as well as developed countries, still lives or works in a building made with clay as anessential part of its load-bearing structure. Also a primary ingredient in many natural building techniques, clay is used to create adobe, cob, cordwood, and rammed earth structures.
[sunting] Kedokteran dan menggunakan pertanian
Sebuah penggunaan tradisional dari tanah liat sebagai obat kembali ke zaman prasejarah. Contohnya adalah batang Armenia, yang digunakan untuk menenangkan sakit perut, mirip dengan burung-burung beo cara (dan kemudian, manusia) di Amerika Selatan awalnya menggunakannya. [4] Kaolin tanah liat dan attapulgite telah digunakan sebagai obat anti-diare.
Seorang yang lebih baru [kapan?] dan
penggunaan terbatas, semprot diformulasikan secara khusus diterapkan pada buah-buahan, sayuran, dan vegetasi lain untuk mengusir atau mencegah kerusakan Codling ngengat, dan setidaknya untuk apel, untuk mencegah kudis matahari.
Sebuah artikel 2007 di The Journal of
Antimicrobial Kemoterapi menemukan bahwa tanah liat besi kaya tertentu yang efektif dalam membunuh bakteri. [5]
[sunting] Clay sebagai bahan bangunan Clay adalah salah satu bahan bangunan tertua di Bumi, antara lain kuno, bahan geologi yang terjadi secara alamiah seperti batu dan bahan organik seperti kayu. Antara satu setengah dan dua-pertiga dari penduduk dunia, dalam masyarakat tradisional maupun negara-negara maju, masih tinggal atau bekerja di sebuah bangunan dibuat dengan tanah liat sebagai bagian penting dari struktur load-bearing. Juga merupakan bahan utama dalam banyak teknik bangunan alam, tanah liat digunakan untuk membuat adobe, tongkol, kayu bakar, dan menabrak struktur bumi.
HOW TO MAKE A
CLAY BRICK
http://www.brighthub.com/engineering/c ivil/articles/45788.aspx
Red clay bricks have been in use for quite some time now. You will usually find this procedure is mainly for building adobe. Bricks cover up the major portions of the building walls. Continue reading to discover the six steps involved in clay brickmaking:
Soil testing: You need to test the soil from which you plan to prepare the brick. The proportion of sand to clay in the soil should not be more than 50% (minimum 30%). But how to test that? A simple method is to mix 10 teaspoons of the soil to a glass of clean water, stir it completely, and keep it overnight. You will see two clear layers of clay and sand. From
the size of each layer you can find out the proportion.
Prepare the mold: Wooden (ideally beech wood) planks and nails are used to prepare brick molds. The standard size of a brick is 14” x 10” x 4”. You can make molds for single brick as well as multiple bricks.
Prepare the clay: Dig the required amount of soil and ship it to the brickmaking site. Test if the soils need to be mixed with some additional amount of sand. Remember the sand plays an important role for removing the brick from the mold. Mix a sufficient amount of water to the soil to make it clay. The clay should be solid enough to hold its shape, but at the same time it should be liquid enough to fill in the mold.
Make the raw brick: Pour the prepared clay into the mold and let it set for half an hour. After that it should easily come out from the mold as raw brick.
Sun drying: The raw brick should be kept on dry sand in the sun for drying by solar energy. This is an important step for making adobe brick. Leave the brick until all the exposed edges become white. After that turn them on their edges. This whole process may take at least three weeks. The final moisture content of the adobe clay brick will be around 10-15%. At this point, the adobe bricks will be ready to use.
Fire Drying: In case you want to make fired red clay bricks, you need to cure the brick in a oven (kiln) under 1800 degrees
Fahrenheit temperature for seven more days.
batu bata merah telah digunakan untuk beberapa waktu sekarang. Anda biasanya akan menemukan prosedur ini terutama untuk membangun adobe. Bricks menutupi bagian utama dari dinding bangunan.
Lanjutkan membaca untuk menemukan enam langkah yang terlibat dalam brickmaking liat: • pengujian Tanah: Anda perlu menguji tanah dari mana Anda berencana untuk menyiapkan bata. Proporsi pasir untuk liat dalam tanah tidak boleh lebih dari 50% (minimal 30%). Tapi bagaimana untuk menguji itu? Sebuah
metode sederhana adalah mencampur 10 sendok teh tanah untuk segelas air bersih, aduk sepenuhnya, dan tetap semalam. Anda akan melihat dua lapisan yang jelas dari tanah liat dan pasir. Dari ukuran setiap lapisan Anda dapat mengetahui proporsi.
• Siapkan cetakan: Kayu (idealnya kayu beech) papan dan paku yang digunakan untuk
membuat cetakan batu bata. Ukuran standar batu bata adalah 14 "x 10" x 4 ". Anda dapat membuat cetakan untuk bata tunggal maupun beberapa batu bata.
• Siapkan tanah liat: Gali jumlah yang diperlukan tanah dan kirimkan ke situs brickmaking. Uji apakah tanah perlu dicampur dengan beberapa jumlah tambahan pasir. Ingat pasir memainkan peranan penting untuk menghilangkan batu bata dari cetakan. Mix yang cukup air untuk tanah untuk membuat tanah liat. tanah liat harus cukup solid untuk menahan bentuknya, tapi pada saat yang sama harus cair yang cukup untuk mengisi cetakan.
• Membuat bata baku: tanah liat disusun Tuang ke dalam cetakan dan biarkan ditetapkan untuk setengah jam. Setelah itu mudah harus keluar dari cetakan seperti batu bata mentah.
• Sun pengeringan: The bata mentah harus disimpan di pasir kering di bawah sinar matahari untuk pengeringan oleh energi surya. Ini merupakan langkah penting untuk membuat batu bata adobe. Biarkan bata sampai semua sisi terkena menjadi putih. Setelah itu menghidupkan mereka di tepi
mereka. Keseluruhan proses ini mungkin memakan waktu sedikitnya tiga minggu. Kandungan air akhir dari bata tanah liat adobe akan sekitar 10-15%. Pada titik ini, adobe bata akan siap digunakan.
• Api Pengeringan: Jika anda ingin membuat dipecat batu bata tanah liat merah, Anda perlu untuk menyembuhkan batu bata dalam oven (kiln) dengan suhu 1800 derajat
Fahrenheit selama tujuh hari lagi.
Conclusion
Brickmaking is an ancient art. If you want to make your own homemade clay bricks, then it is better that you use sun-dried adobe technique. This is simpler because a special oven (kiln) is required to make fired red clay bricks.
Brickmaking adalah seni kuno. Jika Anda ingin membuat batu bata tanah liat buatan Anda sendiri, maka lebih baik yang Anda gunakan dijemur teknik adobe. Hal ini sederhana karena oven khusus (kiln) diperlukan untuk membuat batu bata tanah liat merah dipecat.
Read more:
http://www.brighthub.com/engineering/civ il/articles/45788.aspx#ixzz1LvLXhWM8
Limestone
From Wikipedia, the free encyclopedia Jump to: navigation, search
For other uses, see Limestone (disambiguation).
This article's lead section may not adequately summarize its
contents. Please consider expanding the lead to provide an accessible overview of the article's key points. (September 2009)
Limestone
— Sedimentary Rock —
Limestone in Waitomo District, New Zealand Composition
Calcium carbonate: inorganic crystalline calcite and/or organic calcareous material
Limestone is a sedimentary rock
composed largely of the mineralscalcite and/or aragonite, which are different crystal forms of calcium carbonate (CaCO3).
Like most other sedimentary rocks, limestones are composed of grains; however, most grains in limestone are skeletal fragments of marine organisms such as coral 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.
The solubility of limestone in water and weak acid solutions leads to karst
landscapes. Regions overlying limestone bedrock tend to have fewer visible
as surface water easily drains downward through joints in the limestone. While draining, water and organic acid from the soil slowly (over thousands or millions of years) enlarges these cracks, dissolving the calcium carbonate and carrying it away in solution. Most cave systems are through limestone bedrock.
Batugamping di Kecamatan Waitomo, Selandia Baru
Komposisi
Kalsium karbonat: kristal kalsit anorganik dan / atau bahan berkapur organik
Kapur adalah batuan sedimen sebagian besar terdiri dari mineral kalsit dan / atau aragonit, yang berbeda bentuk kristal kalsium karbonat (CaCO3).
Seperti kebanyakan batuan sedimen lain, batugamping terdiri dari biji-bijian, namun kebanyakan butiran batu kapur adalah fragmen tulang organisme laut seperti karang atau foraminifera. Butir karbonat lainnya terdiri dari batugamping ooids, peloids, intraclasts, dan extraclasts. Beberapa
batugamping tidak terdiri dari biji-bijian sama sekali, dan dibentuk sepenuhnya oleh
presipitasi kimia kalsit atau aragonit, travertine yaitu.
Kelarutan batu kapur dalam larutan asam air dan lemah mengarah ke lanskap karst. Kawasan atasnya batuan dasar kapur
cenderung memiliki sumber air tanah terlihat lebih sedikit (kolam dan sungai), sebagai air permukaan mudah mengalir ke bawah melalui sendi di batu kapur. Sedangkan pengeringan, air dan asam organik dari tanah lambat (lebih dari ribuan atau jutaan tahun) membesar ini retakan, melarutkan kalsium karbonat dan membawanya pergi dalam larutan.
Kebanyakan sistem gua melalui landasan batu gamping.
Contents
1 Description 2 Classification o 2.1 Folk classification o 2.2 Dunham classification 3 Types 4 Limestone landscape 5 Uses 6 Gallery 7 References 8 Further reading 9 See also[
edit
] Description
Limestone quarry at Cedar Creek, Virginia, USA
La Zaplaz formations in Piatra Craiului Mountains
Limestone often contains variable amounts of silica in the form of chert (chalcedony, flint, jasper, etc.) or siliceous skeletal fragment (sponge spicules, diatoms, radiolarians), and varying amounts of clay,
silt and sand (terrestrialdetritus) 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 organisms die. 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 conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters (see lysocline). Secondary calcite may also be deposited by supersaturatedmeteoric waters (groundwater that precipitates the material in caves). This produces
speleothems, such as stalagmites and stalactites. Another form taken by calcite oolitic limestone, which can be recognized by its granular (oolite) appearance.
Limestone makes up about 10% of the total volume of all sedimentary rocks.[1][2] Limestones may also form in both lacustrine and evaporitedepositional environments.[3][4]
Calcite can be either dissolved 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. Karsttopography and caves develop in carbonate rocks due to their solubility in dilute acidicgroundwater. Cooling groundwater or mixing of different groundwaters will also create conditions suitable for cave formation.
Coastal limestones are often eroded by organisms which bore into the rock by various means. This process is known as bioerosion. It is most common in the tropics, and it is known throughout the fossil record (see Taylor and Wilson, 2003).
Because of impurities, such as clay, sand, organic remains, iron oxide and other materials, many limestones exhibit different colors, especially on weathered surfaces. Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock.
Travertine is a banded, compact variety of limestone formed along streams,
particularly where there are waterfalls, and around hot or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution
supersaturated with the chemical
constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls. Coquina is a poorly
consolidated limestone composed of pieces of coral or shells.
During regional metamorphism that occurs during the mountain building process (orogeny), limestone recrystallizes into marble.
Limestone is a parent material of Mollisol soil group.
La Zaplaz formasi di Pegunungan Piatra Craiului
Kapur sering mengandung sejumlah variabel silika dalam bentuk certa (kalsedon, batu api, jasper, dll) atau fragmen tulang silikous (spons spikula, diatom, radiolarians), dan jumlah bervariasi dari tanah liat, lanau dan pasir (detritus terestrial) dibawa dalam oleh sungai. Sumber utama dalam batu kapur kalsit adalah organisme yang paling sering laut. Organisme ini mengeluarkan cangkang yang terbuat dari
aragonit atau kalsit, dan meninggalkan kerang ini belakang setelah organisme mati.
Beberapa organisme dapat membuat
gundukan batu yang dikenal sebagai terumbu, dengan membangun generasi masa lalu. Berikut sekitar 3.000 meter, tekanan air dan kondisi suhu menyebabkan pembubaran kalsit untuk meningkatkan nonlinearly, jadi
batugamping biasanya tidak terbentuk di perairan yang lebih dalam (lihat lysocline). kalsit sekunder juga dapat disimpan oleh air meteorik jenuh (air tanah yang presipitasi material di gua). Ini menghasilkan
speleothems, seperti stalagmit dan stalaktit. Bentuk lain yang diambil oleh oolitic kapur kalsit, yang dapat diakui oleh penampilan granular (oolite).
Kapur membuat sampai sekitar 10% dari total volume seluruh batuan sedimen [1] [2] batugamping juga dapat terbentuk di danau baik dan evaporite lingkungan pengendapan.. [3] [4]
Kalsit dapat berupa dibubarkan atau endapan oleh air tanah, tergantung pada beberapa faktor, termasuk suhu air, pH, dan konsentrasi ion terlarut. Kalsit menunjukkan karakteristik yang tidak biasa disebut retrograde kelarutan, di mana ia menjadi kurang larut dalam air dengan naiknya suhu.
Ketika kondisi yang tepat untuk curah hujan, kalsit bentuk lapisan mineral yang semen butir batu yang ada bersama-sama, atau dapat mengisi patah tulang.
topografi Karst dan gua-gua berkembang di batuan karbonat karena kelarutannya dalam asam encer air tanah. Pendinginan air tanah atau pencampuran air tanah yang berbeda juga akan menciptakan kondisi yang cocok untuk pembentukan gua.
batugamping Pesisir sering terkikis oleh organisme yang membosankan ke dalam batuan dengan berbagai cara. Proses ini dikenal sebagai bioerosion. Hal ini paling umum di daerah tropis, dan dikenal di seluruh catatan fosil (lihat Taylor dan Wilson, 2003). Karena kotoran, seperti tanah liat, pasir, sisa-sisa organik, oksida besi dan bahan lainnya, banyak batugamping menunjukkan warna yang berbeda, terutama pada permukaan lapuk. Batu kapur mungkin kristal, klastik, granular, atau besar, tergantung pada metode
pembentukan. Kristal kalsit, dolomit kuarsa, atau mungkin barit baris rongga kecil di batu. Travertine merupakan varietas, banded kompak batu kapur terbentuk sepanjang aliran, terutama di mana terdapat air terjun, dan sekitar mata air panas atau dingin. Kalsium karbonat diendapkan di mana penguapan air daun solusi jenuh dengan kandungan kimia dari kalsit. Tufa, berbagai berpori atau seluler travertine, ditemukan air terjun dekat. Coquina adalah kapur buruk konsolidasi terdiri dari potongan karang atau dinding.
Selama metamorfosis daerah yang terjadi selama proses bangunan gunung (orogeny), batu gamping recrystallizes ke marmer. Kapur merupakan bahan induk dari kelompok tanah Mollisol.
[
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] Classification
Two major classification schemes, the Folk and the Dunham, are used for
identifying limestone and carbonate rocks.
[
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] Folk classification
Main article: Folk classification
Robert L. Folk developed a classification system that places primary emphasis on the detailed composition of grains and interstitial material in carbonate rocks. Based on composition, there are three main components: allochems (grains), matrix (mostly micrite), and cement (sparite). The Folk system uses two-part names; the first refers to the grains and the second is the root. It is helpful to have a petrographic microscope when using the Folk scheme, because it is easier to determine the components present in each sample.[5]
[
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] Dunham classification
Main article: Dunham classification The Dunham scheme focuses onupon the texture of the grains that make up the limestone. Robert J. Dunham published his system for limestone in 1962; it
focuses on the depositional fabric of carbonate rocks. Dunham divides the rocks into four main groups based on relative proportions of coarser clastic particles. Dunham names are essentially for rock families. His efforts deal with the question of whether or not the grains were
originally in mutual contact, and therefore self-supporting, or whether the rock is characterized by the presence of frame builders and algal mats. Unlike the Folk scheme, Dunham deals with the original porosity of the rock. The Dunham scheme is more useful for hand samples because it is based on texture, not the grains in the sample.[6]
[sunting] Klasifikasi
Dua skema klasifikasi utama, Folk dan Dunham, digunakan untuk mengidentifikasi batu gamping dan batuan karbonat.
[sunting] Klasifikasi Folk
Artikel utama: klasifikasi Rakyat
Folk robert L. mengembangkan sebuah sistem klasifikasi yang menempatkan penekanan utama pada komposisi rinci biji-bijian dan bahan interstisial di batuan karbonat. Berdasarkan komposisi, ada tiga komponen utama: allochems (butir), semen matriks (kebanyakan micrite), dan (sparite). Sistem Folk menggunakan nama dua bagian, yang pertama mengacu pada biji-bijian dan yang kedua adalah akar. Hal ini membantu untuk memiliki mikroskop petrografi saat
menggunakan skema Folk, karena lebih mudah untuk menentukan komponen hadir dalam setiap sampel. [5]
[sunting] Klasifikasi Dunham Artikel utama: klasifikasi Dunham Skema Dunham berfokus pada tekstur pengendapan. Setiap nama didasarkan pada tekstur butir yang membentuk batu kapur. Robert J. Dunham diterbitkan sistemnya untuk batu kapur pada tahun 1962, tetapi berfokus pada kain pengendapan batuan karbonat. Dunham membagi batuan menjadi empat kelompok utama berdasarkan proporsi relatif dari partikel klastik kasar. Nama Dunham pada
dasarnya untuk keluarga rock. Upaya menangani Nya dengan pertanyaan apakah atau tidak butiran awalnya saling
berhubungan, dan karena itu mandiri, atau apakah batu dicirikan dengan adanya pembangun frame dan tikar alga. Berbeda dengan skema Folk, berkaitan Dunham dengan porositas asli dari batu. Skema Dunham lebih berguna untuk sampel tangan karena didasarkan pada tekstur, bukan biji-bijian dalam sampel. [6]
[
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] Types
Main article: List of types of limestone
[
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] Limestone landscape
Main article: Karst topography
The Cudgel of Hercules, a tall limestone rock (Pieskowa Skała Castle in the background)
Limestone is partially soluble, especially in acid, and therefore forms many
erosional landforms. These include limestone pavements, pot holes, cenotes, caves and gorges. Such erosion landscapes are known as karsts. Limestone is less resistant than most igneous rocks, but more resistant than most other sedimentary rocks. It is therefore usually associated with hills and downland, and occurs in regions with other sedimentary rocks, typically clays.
Bands of limestone emerge from the Earth's surface in often spectacular rocky outcrops and islands. Examples include the Burren in Co. Clare, Ireland; the Verdon Gorge in France; Malham Cove in North Yorkshire and the Isle of Wight,[7]
England; on Fårö near the Swedish island of Gotland, the Niagara Escarpment in Canada/United States, Notch Peak in Utah, the Ha Long Bay National Park in
Vietnam and the hills around the Lijiang River and Guilin city in China.
The Florida Keys, islands off the south coast of Florida, are composed mainly of oolitic limestone (the Lower Keys) and the carbonate skeletons of coral reefs (the Upper Keys), which thrived in the area during interglacial periods when sea level was higher than at present.
Unique habitats are found on alvars,
extremely level expanses of limestone with thin soil mantles. The largest such expanse in Europe is the Stora Alvaret on the island of Öland, Sweden. Another area with large quantities of limestone is the island of Gotland, Sweden. Huge quarries in northwestern Europe, such as those of Mount Saint Peter (Belgium/Netherlands), extend for more than a hundred kilometers. The world's largest limestone quarry is at Michigan Limestone and Chemical Company in Rogers City, Michigan.[8] Kapur sebagian larut, terutama dalam asam, dan karena itu banyak bentuk bentuklahan erosi. Ini termasuk perkerasan batu kapur, lubang pot, cenote, gua dan jurang. Lanskap erosi tersebut dikenal sebagai karsts. Kapur kurang tahan dari batuan beku sebagian besar, tapi lebih tahan daripada kebanyakan batuan sedimen lainnya. Oleh karena itu biasanya berhubungan dengan bukit dan downland, dan terjadi di daerah dengan batuan sedimen lain, biasanya tanah liat. Band batu kapur muncul dari permukaan bumi di singkapan berbatu sering spektakuler dan pulau-pulau. Contoh termasuk Burren di
Co Clare, Irlandia; Gorge Verdon di Perancis; Malham Cove di North Yorkshire dan Isle of Wight, [7] Inggris; di Faro dekat pulau Swedia Gotland, yang gawir Niagara di Kanada Amerika Serikat / , Notch Peak di Utah, Ha Long Bay Taman Nasional di Vietnam dan perbukitan di sekitar Sungai Lijiang dan kota Guilin di Cina.
The Florida Keys, pulau-pulau lepas pantai selatan Florida, adalah terutama terdiri dari batugamping oolitic (Lower Keys) dan kerangka karbonat terumbu karang (Kunci Upper), yang berkembang di daerah tersebut selama periode interglasial ketika permukaan laut lebih tinggi dari saat ini.
Habitat unik ditemukan di alvars, sangat tingkat hamparan batu kapur dengan tanah kaos tipis. Hamparan seperti terbesar di Eropa adalah Stora Alvaret di pulau Öland, Swedia. Bidang lain dengan jumlah besar batu kapur adalah pulau Gotland, Swedia. Tambang besar di Eropa barat laut, seperti Gunung Santo Petrus (Belgia / Belanda), memperpanjang selama lebih dari seratus kilometer.
Tambang batu kapur terbesar di dunia berada di Michigan batu kapur dan Chemical
Company di Rogers City, Michigan. [8]
[
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] Uses
Limestone is very common in architecture, especially in Europe and North America. Many landmarks across the world, including the Great Pyramid and its associated complex in Giza, Egypt, are made of limestone. So many buildings in Kingston, Canada were constructed from it that it is nicknamed the 'Limestone City'.[9] On the island of Malta, a variety of
limestone called Globigerina limestone was, for a long time, the only building material available, and is still very frequently used on all types of buildings and sculptures. Limestone is readily available and relatively easy to cut into blocks or more elaborate carving. It is also long-lasting and stands up well to
exposure. However, it is a very heavy material, making it impractical for tall
buildings, and relatively expensive as a building material.
[sunting] Penggunaan
Kapur sangat umum dalam arsitektur,
terutama di Eropa dan Amerika Utara. Banyak tengara di seluruh dunia, termasuk Piramida Besar dan kompleks yang terkait di Giza, Mesir, terbuat dari batu kapur. Begitu banyak bangunan di Kingston, Kanada yang dibangun dari itu bahwa ia dijuluki 'Kota Kapur' [9]. Di pulau Malta, berbagai batu gamping yang disebut Globigerina batu kapur itu, untuk waktu yang lama, bahan bangunan hanya tersedia, dan masih sangat sering digunakan pada semua jenis bangunan dan patung. Kapur sudah tersedia dan relatif mudah untuk dipotong menjadi balok atau lebih rumit ukiran. Hal ini juga tahan lama dan berdiri baik untuk eksposur. Namun, bahan yang sangat berat, sehingga tidak praktis untuk bangunan tinggi, dan relatif mahal sebagai bahan bangunan.
The Great Pyramid of Giza, one of the Seven Wonders of the Ancient World, is made entirely from limestone.
Courthouse built of limestone in Manhattan, Kansas
A limestone plate with a negative map of Moosburg in Bavaria is prepared for a lithography print.
Limestone was most popular in the late 19th and early 20th centuries. Train stations, banks and other structures from that era are normally made of limestone. It is used as a facade on some skyscrapers, but only in thin plates for covering, rather than solid blocks. In the United States, Indiana, most notably the Bloomington area, has long been a source of high quality quarried limestone, called Indiana limestone. Many famous buildings in London are built from Portland limestone. Limestone was also a very popular
building block in the Middle Ages in the areas where it occurred, since it is hard, durable, and commonly occurs in easily
accessible surface exposures. Many medieval churches and castles in Europe are made of limestone. Beer stone was a popular kind of limestone for medieval buildings in southern England.
Limestone and (to a lesser extent) marble are reactive to acid solutions, making acid rain a significant problem to the
preservation of artifacts made from this stone. Many limestone statues and building surfaces have suffered severe damage due to acid rain. Acid-based cleaning chemicals can also etch
limestone, which should only be cleaned with a neutral or mild alkaline-based cleaner.
Other uses include:
It is the raw material for the
manufacture of quicklime (calcium oxide), slaked lime (calcium hydroxide), cement and mortar. Pulverized limestone is used as a
soil conditioner to neutralize acidic soils.
It is crushed for use as aggregate— the solid base for many roads. Geological formations of limestone
are among the best petroleum reservoirs;
As a reagent in flue gas
desulfurization, it reacts with sulfur dioxide for air pollution control. Glass making, in some
circumstances, uses limestone. It is added to toothpaste, paper,
plastics, paint, tiles, and other materials as both white pigment and a cheap filler.
It can suppress methane explosions in underground coal mines.
Purified, it is added to bread and cereals as a source of calcium. Calcium levels in livestock feed are
supplemented with it, such as for poultry (when ground up).[10] It can be used for remineralizing
and increasing the alkalinity of
purified water to prevent pipe corrosion and to restore essential nutrient levels.[11]
Used in blast furnaces, limestone extracts iron from its ore.
It is often found in medicines and cosmetics.
It is used in sculptures because of its suitability for carving.
Moosburg di Bavaria dipersiapkan untuk cetak litografi.
Kapur yang paling populer di akhir abad ke-20 ke-19 dan awal. Stasiun Kereta, bank dan struktur lain dari era yang biasanya terbuat dari batu kapur. Hal ini digunakan sebagai fasad pada beberapa gedung pencakar langit, tetapi hanya dalam pelat tipis untuk menutupi, daripada blok padat. Di wilayah
Amerika Serikat, Indiana, terutama Bloomington, telah lama menjadi sumber digali batu kapur berkualitas tinggi, yang disebut batu kapur Indiana. Banyak bangunan terkenal di London dibangun dari batu kapur Portland. Kapur juga blok bangunan yang sangat populer pada Abad Pertengahan di daerah mana itu terjadi, karena keras, tahan lama, dan biasanya terjadi pada permukaan eksposur mudah diakses. Banyak gereja abad pertengahan dan istana di Eropa terbuat dari batu kapur. Bir batu semacam populer kapur untuk bangunan abad pertengahan di Inggris selatan.
Kapur dan (sampai batas tertentu) marmer yang reaktif terhadap larutan asam, membuat hujan asam masalah signifikan terhadap pelestarian artefak yang terbuat dari batu ini. Banyak patung batu kapur dan permukaan bangunan telah mengalami kerusakan parah akibat hujan asam. bahan kimia pembersih Asam-based juga bisa etch kapur, yang hanya harus dibersihkan dengan pembersih alkali berbasis netral atau ringan.
Kegunaan lain meliputi: • Ini adalah bahan baku untuk pembuatan kapur (kalsium oksida),
kapur mati (kalsium hidroksida), semen dan mortar.
• Bubuk batu kapur digunakan sebagai kondisioner tanah untuk menetralkan tanah asam.
• Hal ini dihancurkan untuk digunakan sebagai agregat dasar-zat padat untuk banyak jalan.
• Geologi formasi batu kapur adalah salah satu reservoir minyak terbaik; • Sebagai reagen dalam desulfurisasi gas buang, bereaksi dengan belerang dioksida pengendalian pencemaran udara.
• Kaca keputusan, dalam beberapa kondisi, menggunakan batu gamping. • Hal ini ditambahkan ke pasta gigi, kertas, plastik, cat, keramik, dan bahan lainnya baik sebagai pigmen putih dan pengisi murah.
• Hal ini dapat menekan ledakan metana di tambang batu bara bawah tanah. • Purified, itu akan ditambahkan ke roti dan sereal sebagai sumber kalsium. • Kalsium tingkat di pakan ternak yang dilengkapi dengan itu, seperti untuk unggas (ketika bawah ke atas) [10]. • Hal ini dapat digunakan untuk remineralizing dan meningkatkan alkalinitas air dimurnikan untuk mencegah korosi dan pipa untuk mengembalikan tingkat gizi yang penting. [11]
• Digunakan dalam tanur tiup, kapur ekstrak besi dari bijih.
• Hal ini sering ditemukan dalam obat dan kosmetika.
• Hal ini digunakan dalam patung karena ada kesesuaian untuk ukiran.
Limestone
What Is Limestone
and How Is It Used?
What is Limestone?
Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters. It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal and fecal debris. It can also be a chemical sedimentary rock formed by the
precipitation of calcium carbonate from lake or ocean water.
Limestone-Forming Environment - Marine
Most limestones form in shallow, calm, warm marine waters. That type of environment is where organisms capable of forming calcium carbonate shells and skeletons can easily extract the needed ingredients from ocean water. When these animals die their shell and skeletal debris accumulate as a sediment that might be lithified into limestone. Their waste products can also contribute to the sediment mass. Limestones formed from this type of sediment are biological sedimentary rocks. Their biological origin is often revealed in the rock by the presence of fossils.
Some limestones can form by direct precipitation of calcium carbonate from marine or fresh water. Limestones formed this way are chemical sedimentary rocks. They are thought to be less abundant than biological limestones.
Today Earth has many limestone-forming environments. Most of them are found in shallow water areas between 30 degrees north latitude and 30 degrees south latitude. Limestone is forming in the Caribbean Sea, Indian Ocean, Persian Gulf, Gulf of Mexico, around Pacific Ocean islands and within the Indonesian archipelago.
One of these areas is the Bahamas Platform, located in the Atlantic Ocean about 100 miles southeast of southern Florida (see satellite image at right). There abundant corals, shellfish, algae and other organisms produce vast amounts of
calcium carbonate skeletal debris that completely blankets the platform. This is producing an extensive limestone deposit.
Limestone-Forming Environment - Evaporative
A drop of water hangs and evaporates on the tip of a stalactite. National Park Service image.
Limestone can also form through evaporation. Stalactites, stalagmites and other cave formations (often called
"speleothems") are examples of limestone that formed through evaporation. In a cave, droplets of water seeping down from above enter the cave through fractures or other pore spaces in the cave ceiling. There they might evaporate before falling to the cave floor. When the water evaporates, any calcium carbonate that was dissolved in the water will be deposited on the cave ceiling. Over time this evaporative process can result in an accumulation of icicle-shaped calcium carbonate on the cave ceiling. These deposits are known as stalactites. If the droplet falls to the floor and evaporates there a stalagmite could grow upwards from the cave floor.
The limestone that makes up these cave formations is known as "travertine" and is a chemical sedimentary rock. A rock known as "tufa" is a limestone formed by evaporation at a hot spring, lake shore, or other area.
Composition of Limestone
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Limestone is by definition a rock that contains at least 50% calcium carbonate in the form of calcite by weight. All limestones contain at least a few percent other materials. These can be small particles of quartz, feldspar, clay minerals, pyrite, siderite and other minerals. It can also contain large nodules of chert, pyrite or siderite.
The calcium carbonate content of limestone gives it a property that is often used in rock identification - it effervesces in contact with a cold solution of 5% hydrochloric acid.
Varieties of Limestone
There are many different names used for limestone. These names are based upon how the rock formed, its appearance or its composition and other factors. Here are some of the more commonly used.
Chalk: A soft limestone with a very fine texture that is usually white or light gray in color. It is formed mainly from the calcareous shell remains of microscopic marine organisms such as foraminifers or the calcareous remains from numerous types of marine algae.
Coquina: A poorly-cemented limestone that is composed mainly of broken shell debris. It often forms on beaches where wave action segregates shell fragments of similar size.
Fossiliferous Limestone: A limestone that contains obvious and abundant fossils. These are normally shell and skeletal fossils of the organisms that produced the limestone.
Lithographic Limestone: A dense limestone with a very fine and very uniform grain size that occurs in thin beds that separate easily to form a very smooth surface. In the late 1700's a printing process (lithography) was developed to reproduce images by drawing them on the stone with an oil-based ink and then using that stone to press multiple copies of the image.
Oolitic Limestone: A limestone composed mainly of calcium carbonate "oolites", small spheres formed by the concentric precipitation of calcium carbonate on a sand grain or shell fragment.
Travertine: A limestone that forms by evaporative precipitation, often in a cave, to produce formations such as stalactites, stalagmites and flowstone.
Tufa: A limestone produced by precipitation of calcium-laden waters at a hot spring, lake shore or other location.
Uses of Limestone
Ordovician Mass Extinction San Andreas Fault Rare Earth Elements What is Geology?Limestone is a rock with an enormous diversity of uses. It could be the one rock that is used in more ways than any other. Most limestone is crushed and used as a construction material. It is used as a crushed stone for road base and railroad ballast. It is used as an aggregate in concrete. It is fired in a kiln with crushed shale to make cement.
Some varieties of limestone perform well in these uses because they are strong, dense rocks with few pore spaces. These properties enable them to stand up well to abrasion and freeze-thaw. Although limestone does not perform as well in these uses as some of the harder silicate rocks it is much easier to mine and does not exert the same level of wear on mining equipment, crushers, screens and the beds of the vehicles that transport it.
Some additional but also important uses of limestone include:
Dimension Stone: Limestone is often cut into blocks and slabs of specific dimensions for use in construction and in architecture. It is used for facing stone, floor tiles, stair treads, window sills and many other purposes.
Roofing Granules: Crushed to a fine particle size, crushed limestone is used as a weather and heat-resistant coating on asphalt impregnated shingles and roofing. It is also used as a top coat on built-up roofs.
Flux Stone: Crushed limestone is used in smelting and other metal refining processes. In the heat of smelting, limestone combines with impurities and can be removed from the process as a slag.
Portland Cement: Limestone is heated in a kiln with shale, sand and other materials and ground to a powder that will harden after being mixed with water.
AgLime: Calcium carbonate is one of the most cost-effective acid neutralizing agents. When crushed to sand-size or smaller particles limestone becomes an effective material for treating acidic soils. It is widely used on farms throughout the world.
Lime: If calcium carbonate (CaC03 is heated to high temperature in a kiln the products will be a release of carbon dioxide gas (CO2) and calcium oxide (CaO). The calcium oxide is a powerful acid neutralization agent. It is widely used as a soil treatment agent (faster acting than aglime) in agriculture and as an acid neutralization agent by the chemical industry.
Animal Feed Filler: Chickens need calcium carbonate to produce strong egg shells so calcium carbonate is often offered to them as a dietary supplement in the form of "chicken grits". It is also added to the feed of some dairy cattle who must replace large amounts of calcium lost when the animal is milked.
Mine Safety Dust: Also known as "rock dust". Pulverized limestone is a white powder that can be sprayed onto exposed coal surfaces in an underground mine. This coating improves illumination and reduces the amount of coal dust that activity stirs up and releases into the air. This improves the air for breathing and it also reduces the explosion hazard produced by suspended particles of flammable coal dust in the air.
Rock & Mineral Kits:
Get a rock, mineral or fossil kit to learn more about earth materials.
Limestone has many other uses. Powdered limestone is used as a filler in paper, paint, rubber and plastics. Crushed limestone is used as a filter stone in on-site sewage disposal systems. Powdered limestone is also used as a sorbent (a substance that absorbs pollutants) at many coal-burning facilities.
Limestone is not found everywhere. It only occurs in areas underlain by sedimentary rocks. Limestone is needed in other areas and is so important that buyers will pay five times the value of the stone in delivery charges so that limestone can be used in their project or process.
