SEDIMENTS CLASTIC

Some sediment is composed of clastic particles, although its components have undergone transport. Such sediment components dissolved in water and then transported as a solution of chemically precipitated. Formation of sediment deposition of minerals dissolved in water is called chemical sediment. And are generally formed in two ways:
- First, through biochemical reactions, as a result of the activity of plants and animals in the water. Examples are very small plants that live in the ocean could reduce the degree of acidity of the surrounding water and thus precipitated calcium carbonate.
- Second, through inorganic reactions in water. When the water at eye-hot water cools, it will precipitate opal and calcite. Another example is the evaporation of sea water or lake, causing the concentration of dissolved materials and start upsalt.as deposition of chemical sediments.
Based on the composition of sedimentary rocks are grouped into a siliceous non-clastic, siliceous, containing silica and a carbonate, cabonaceous, the main composition of calcium carbonate.

Another frequently encountered sediments is the main composition of the remaining animals rombakan generated directly from the physiological activities of organisms called biogenic sediments. The remains of the hard end up into fragments, or clastic. Sediment is the main component of these fragments are called sediment bioklastik.

The important biogenic sediments are composed of calcium carbonate, which is widespread in the oceans. Calcium carbonate can be precipitated by chemical precipitation from seawater, but most of the carbonate sediment is the result of biogenic activity; especially on a warm surface sea water. Here carbonates separated by organisms while making the rest of her hard and calcite or aragonite mengendaplah. When the calcium ions and bicarbonate in the water combine to form a solid calcium carbonate, according to the reaction:

                Ca2+             +     (HCO 3) 1-     ----->                   CaCO3      +                  H1+       

        Calcium ions                            bicarbonate ions                      Calcium carbonate            bicarbonate Hydrogen

Siliceous sediments (siliceous)
Many siliceous shaped colloidal precipitate; others are formed through chemical processes. Some of this sediment settles directly from the water, others are formed through the recrystallization process in the sediment during consolidation. Reference that is sure to distinguish the occurrence of these two deposits is minimal. A common form of nodules or concretion in limestone layers. Many of these nodules cored silikaan fossil material. This suggests that the occurrence of secondary processes.

Chert (chert or flint); issiliceous sedimentary rocks which are common, dense and hard. And is a form of quartz SiO2. The color ranges from white to dark gray. Same hardness, 7, shows the gloss (luster) such as glass (semi-vitreous). The nature of the outbreak is typical, flat and rounded parts (conchoidal fracture), very useful for early human tool-making.
Chert is found as layers or nodules in carbonate rocks or other sediments. Although it is an organic or inorganic deposits, some containing the remains of organisms silisious.

Siliceous sinter, is a chemical sediments that formed around the eyes, mineral water, geysers, also called geyserite. It is white or light-colored and porous.


Sediment carbonate (carbonaceous)

Non-clastic sediments consisting mainly of calcium carbonate minerals, calcite (CaCO3). carbonate sedimentary rocks are often found are limestone or limestone. Up to hundreds of meters thick and several square kilometers in extent. Most rocks are grouped in organic rock. In sea water contains many ions and carbonate kasium. In certain conditions of sea water saturated with these ions and sedimentation stone-limestone. These conditions include:
1. Warm water, where the ions are soluble in large quantities.
2. High evaporation, such as at the equator where the ions are concentrated near the surface when the amount of water is reduced.
3. Mixing water, triggering the occurrence of precipitation or precipitation.

In such conditions the occurrence of precipitation is possible, and if the water is formed mixing oolit , who grew up while the concentric layers of CaCO3 deposited thereon. In calm water, precipitated calcium carbonate with a needle-shaped crystals, lined with carbonate mud. This sediment after compaction crystallize back into a micro-crystalline limestone, with very fine crystals, which can only be viewed with a microscope with very high magnification. Limestones tend to have different physical properties, depending on its formation.

Travertine or tufa is limestone formed by the evaporation of the eye-water and rivers that contain calcium carbonate in solution. Sediment-water eyes or hot and cold water flow at the surface, resembling a sponge, porous, brittle-textured soil and sometimes branched, called tuff.

Caliche. limestone precipitate is formed in soils in semiarid regions berkomposisi carbonate rocks above. Capillarity draw ground water containing calcium carbonate in the solution above. On the surface of the water evaporates leaving the sediment as cement in the soil or as thin layers.

Dolomite or dolostone. The composition of calcium-magnesium carbonate (CaMg) CO3, rock solid texture such as sugar (sugary), gray and does not react with HCl acid. The formation of sedimentary dolomitecarbonate generally during recrystallization. The size of the calcium ions and is almost the same magnesium allowing calcium ions replace magnesium ions in the structure of calcite. Dolomitisasi fossils may be found, but no organism that form shells with dolomite.


Sediment organic
Sediment non-clastic other is formed from the remnants of micro-organisms whose life floating in the sea. After death, the remainder or the rigors of towing sink and accumulate to form sedimentary mud (Muddy sediment) are called deep-sea ooze. If it consists mainly of carbonate, called calcareous ooze.
Coral, algae and organime colonies growing on shallow seabed also precipitate kasium tropical coral reef or carbonate to form carbonate reef. Besides there are also siliceous calcareous ooze ooze, the main ingredient siliceous Remains.
Radiolarian ooze, derived from micro-protozoa, radioaria, groups of animals were single cells that form the shell of silica. His life was floating near the surface of the sea. After death his body sank to the seabed. And accumulate in large quantities and can form the majority of sediment deposition in areas of very slow pace, especially in the sea. Carbonate shell dissolved in cold water temperature and high hydrostatic pressure in the deep ocean, but silica remains stable; so that the shells of the radiolarians accumulated.

Diatomaceous, silisious plants that also are microscopic. Many forms, some are like the stem, rounded and circular. His life was floating on the surface of the sea, and concentrated in a number of extraordinary magnitude. Each plant contains a small drop of oil, which may be the main raw materials of petroleum. Rock the teridiri from the rest of this plant such as soil texture and appearance (earthy). Is loose, smooth, white powder, similar to chalk. Other organic sediment composition of carbonate in the form of primary fossilan limestone, lime (chalk) and marl.

Fossilan limestone. In general, limestone is formed by material derived from organic materials, including those consisting of shells of marine animals. The composition of the shell of the mineral calcite is taken from the sea water solution, where her life. After the animal dies, a number of shells accumulated on the sea or shallow sea, tersemen by calcite, silica or other materials and settles.

Limestone (chalk) is a limestone composed of shell fossilan protozoa (single cell animals had), especially those that form globular shell, rounded, its name Globigerina. Chalk white, light and soft, like chalk.

Marl (marl) consists of a mixture of shells and shell fragments with mud and sand. Is actually a limestone with impurities (impurity).

Salt deposits. In addition to limestone, found also salt and gypsum deposits, both of which are the result of evaporation. contains salts of mineral halite, NaCl composition, and Gypsum composition CaSO4.2H2O. Both exist as layers in a confined area.

ClLASSIFICATION OF SEDIMENTARY ROCK I

Classification of sedimentary rocks 

This secondary rocks deposited under conditions that vary greatly, resulting in genesis variety. Similarly, texture, composition and appearance of the resulting sedimentary rocks. So there is classification base manifold. 

The ideal classification of sedimentary rocks, based on grain size and shape, and composition of its constituent materials. 

Simple grouping in sedimentary rocks are the two major groups: 

1. Clastic sedimentary rocks, formed from rock fragments, or the remains of shells of marine or freshwater animals, either still intact or debris. 

2. Non-clastic sedimentary rocks, or organic chemistry and is formed by chemical processes or biological processes. 

Clastic sedimentary rocks 

Loose fragments or dust destruction or rombakan results mechanically from pre-existing rocks are called detritus (from the Latin word became obsolete). Sedimentary detritus also called clastic sediments (derived from the Greek meaning klastos rupture). Clastic sediments transported in various ways, can be rolled down the slope due to gravity, or carried away gletsyer, by wind or by water flow. 

When transportation stops, mechanically deposited sediment with a typical system in accordance with the mechanism of transport. Precipitation occurs because the energy carrier down. 

Sediment sliding, rolling or flowing down the slopes either by gravity or gletsyer in general is a mixture of random particles of various sizes. While the sediment particles carried by wind or water deposited when wind speed or water flow is reduced. Deposited particle size relates to the speed of the carrier. The greater the speed the greater-borne particles. The big difference between the fine grain and the rough is very extreme. 

Because it takes a great reference point, and was created by Wentworth, known as the Wentworth classification or scale, Table 1.1. 

Nama                                 Ukuran

Boulder                            ³256 mm

Cobble                        64 - 256 mm

Pebble                            4 - 64 mm

Granule                            2 - 4 mm

Sand                           1/16 - 2 mm

Silt                        1/256 - 1/16 mm

Clay                             £ 1/256 mm

	Table 1.1 Scale Wentwoth; boulder and Cobble can be interpreted as a lump, pebble with gravel, granule size of gravel, sand with sand, while silt and clay with silt is clay.

Clastic sedimentary rocks or sedimentary rocks also called detritus, consists of fragments of various sizes. Large granules called fragments and "bound" by the mass of the grains are more subtle, which is called the matrix. And grouped according to grain size material components, becomes: 

Rudaceous 

Sedimentary rocks consisting of coarse grained fragments or fragments of rock. Rocks including conglomerates and breccias are. 

Conglomerates is the result of a mixture of gravel lithification, sand, silt and mud fragment size from pebbles to boulders of rock which is a fraction of existing (old), 

and rounded shape (rounded). While the matrix which are among the fragments are generally composed of mineral fragments. 

Breccia is similar to conglomerate but fragments form an angle (angular not rounded) (Figure 1.1 A and B). 

Similar breccia generated by a volcanic eruption activity called volcanic breccia.

  

FIGURE 1.1. Conglomerate, rounded fragments of (A) and Breccia, fragmen angled (B).

Conglomerates or breccias are fragment consisting of a wide range of materials called conglomerate or breccia polimik. While consisting of only one kind of framen just called conglomerate or breccia monomik. For example, only fragments of andesite. 

Arenaseous (arenaceous) 

Rocks are dominated by sand-sized material, consisting of sandstone, arkose and graywacke. 

Sand-stone consists of material which is mainly sand-sized grains (1 / 16 to 2 mm), although there are particles larger or smaller (eg sandstone or sandstone gravel silt). Distinction of different types of sandstones are usually based on the composition. The most resistant mineral quartz, is a common mineral in sandstones. When the grains are mainly quartz, quartz sandstone called. 

Arkose sandstone or arkose. Arenaceous rocks generally consist of a mixture of sand quartz and feldspar fragments. May also contain rock fragments and small-grained minerals and angled. 

Arkose appearance similar to granite, so that there are interpreting as a result of decomposition of granite. Arkose often colored red or pink caused by a mineral containing iron oxide. 

Greywacke term is generally used for the sandstone composition of quartz, feldspar and large amounts of rock fragments (frozen, sedimentary and metamorphic) are smooth (lithic particles). A common association is volcanic ash and dust with quartz and feldspar fragments. Generally gray to black due to the matrix that resembles slate. The composition of the matrix is ​​composed of a mixture of mica, and quartz chlorit. Graywacke interesting because its existence is widespread in the active pathway (tectonic) in the entire world. Percentage of total volume of sediment. 

Argillaceous 

Entirely composed of clay or the percentage of high clay content. Argillaceous The term is also used as an adjective to name rocks containing clay. Examples are shale. 

Shale, silt, mudstone and marl, including the rock group claystone (argilaceous rock) and is also called pelitik rocks. Relatively uniform large egg, smaller than sand (1 / 16 to 1 / 256 mm), including mudstone, consisting of fragments of minerals, especially quartz and feldspar, precipitated in water, fresh, brackish or marine. Shale when weathered broken into squares or small blocks. While the silt fractions of fragments forming thin sheets (eg cleavage). 

Stone clay (claystone) very fine grained, less than 1 / 16 mm. In general can not be used to examine an ordinary microscope, but it must be with an electron microscope that mempunuai very high magnification power. Although the grains are not visible, but is included in the clastic sediments 

SEDIMENTARY ROCK PART II

Lithification and Diagenesis

Lithification (lithification of the verb to lithify, which means a stone) is a process by which new dust sediments (unconsolidated) is slowly transformed into sedimentary rocks. During litifikasi changes occur. Overall the changes, in chemistry, physics and biology that affect sediment deposited since, during and after litifikasi called diagenesis. Diagenesis major changes and simple is compacting and cementing.

Compacting. The burden of accumulated sediment or other material causing grain relationships become more sticky and water contained in pore spaces between grains get out. Thus the volume of sedimentary rocks are formed into smaller, yet very compact.

Cementation. With the release of water from pore spaces, materials dissolved in it settles and glue (cement) the grains of sediment. Materials can cement a carbonate (CaCO3), silica (SiO2), oxides (iron) or clay minerals. These processes result in sediment porosity becomes smaller than the original material.

Recrystallization. When sediment accumulates, the minerals are less stable crystallized back or recrystallization, becomes stable. This process generally occurs in the porous coral limestone. Mineral aragonite (coral skeleton structure of living material), over time recrystallization be polimorfnya form, calcite.

Chemical alteration greatly affect the formation of sediments. The presence of oxygen, oxidizing environment, making turns organic waste into carbon dioxide and water, so that no organic remains. And absence of oxygen, reduction of environmental, organic remains are not entirely corrupted or modified. Even slowly turns into a solid carbon. After the physical properties of sedimentary rocks changed from the original dust, soft, becomes compact and hard

SEDIMENTARY ROCK PART I

The results of weathering and erosion of the earth's surface is the main ingredient sediments. The word comes from Latin sediments, sedimentum, which means the deposition. Sedimentary rocks exposed on land than most other rocks, igneous and metamorphic rocks, by 75 percent of land area, although only an estimated 5 percent of the volume of the outer portion of the earth. While it seems small, but the sedimentary rocks is very important in geology, because in it the history of recorded events geological past.

Sedimentary rocks are included in the secondary rocks because its constituent materials is the result of chemical activity and mechanical denudation of the rocks that already exists. Which precipitated from solution or suspension in water or air at normal temperature and pressure. Sediment is the result debris and crushed rock crust, composed of rock fragments, minerals and various other materials, transported by wind or water and deposited in indentations on land or at sea.

Material carried in suspension to settle for medium-speed transport detained or his physical condition changed. And the material deposited in solution due to changes in physical or chemical properties of the medium, or indirectly by the activities of animals and plants.
Sediment not only from inland sources, but can also accumulate on the edge of the basin-edge, which come down due to gravity.

Although theoretically not occurred below the water surface erosion, but there is still energy, water, waves and currents below the surface, which erode the coral reefs in the sea.
Results of scraping deposited around it, in the form of destruction.

Sedimentary material can be:
1. Fragments of an existing rock and minerals. For example in the river gravel, sand on the beach and mud in the sea or lake.
2. Organic material, such as coral reefs in the sea, the remains of shells of aquatic organisms and vegetation in the swamp.
3. The results of evaporation and chemical processes, brackish and salt didanau kasium in shallow marine carbonate.

IGNEOUS ROCK PART II

Igneous outter

Magma that reaches the earth's surface, out through cracks or holes as the eruption of volcano lava, it cools rapidly and freezes into extrusive rocks. The exit of magma in the earth's surface through a linear fracture or fissure eruption called Eruption. In general, lowviscosity basaltic magma can flow around rekahannya, a stretch of basalt lava, calledbasalt plateau.

While coming out through a hole called the eruption of a volcano crater central. Magmacan flow through the slope, as lava flows or join up with the ejected gases as pyroclastic, orspice volcano. In the air immediately frozen while still incandescent.

Lava contained in various forms and types, depending on the composition magmanya and place or environment where pembekuannya happen.

When magma solidifies below the surface of the water formed pillow lavas, so named because frozen under the pressure of water above it looks like a pillow.The front of the rounded shape and accumulated flow overlapping, As well as in igneous, igneous outter is also present in several types, namely rhyolite anddacite, andesite, basalt and various pyroclastic rocks. In Classification of Frozen Rocks,including the rock group afanitik.

The fact that the rate of cooling of magma affect the grain size can be used as a simple way to distinguish igneous rocks frozen in from the outside. When igneous rocks showcoarse grains (coarse grains), the rocks are intrusive rocks. And conversely, if the fine-grained (fine grains) the extrusive rocks.

IGNEOUS ROCK PART I

Magma cools and solidifies can be below or above the earth's surface. When frozen below the earth's surface, forming the so-called igneous rocks or igneous intrusive in. And often also said to be a plutonic igneous rock. Meanwhile, when the magma can reach the earth's surface and then freezes, it forms igneous outside or extrusive igneous rock.

Igneous rock inner

Magma that solidifies below the earth's surface, cooling is very slow (can be up to millions of years), enabling the growth of large crystals and perfect shape, the body of intrusive igneous rock. Igneous body in shape and size has varied, depending on the conditions of magma and surrounding rocks. Magma can infiltrate the surrounding rocks, or break through the cracks, cracks in the rocks around it. In Figure 1.1. visible cross-section diagram of plutonic rock bodies. The forms are cut structure of the surrounding rocks, discordant, is batolit, stock, dyke (excavation) and levels of volcanic (volcanic neck).

While the shape is parallel to the structure of the surrounding rock, konkordan, is the sill, and lopolit lakolit.

Batolit, an igneous body in (plutons) greatest dimension. Irregular shape, cut the layers of rock that diterobosnya. Most batolit a mass gathering of a number of intrusive bodies that berkomposisi somewhat different. This difference reflects the variation of magma forming batolit. Some batolit reached more than 1000 km in length and 250 km wide. Of geophysical measurements and research on some batolit the exposed surface, the thickness is estimated between 20 to 30 km. Batolit not formed by magma that infiltrate the fracture, because there is no fracture of dimension batolit. And because of the large rocks batolit can drive on it. Although the rocks are intruded can be pressured upward by magma moving upwards slowly, surely there is another process that works. Magma that rises off the fragments of rock that covered it. This process is called stoping. The blocks of stoping denser than the magma that rises, so the precipitate. When the precipitate these fragments react and partially dissolved in the magma. But not all dissolved and precipitate at the bottom of the magma chamber (magma chamber). Every rock fragments that are in the body of magma that has been frozen named xenolith.

Stock, like batolit, irregular shape and dimensions smaller than batolit, not more than 10 km. Stock is accompanying an upper body batolit batolit or eroded.

Dike or excavation, also called the alley, is one of the intrusive rocks are compared with batolit, small dimension. The shape is tabular, as both sides parallel to the sheet, cutting structures (bedding) rocks, Figure 1.2.

Volcanic neck (level volcanics), is the pipe under the volcano crater, the magma to lava flows. Then, after covering the surrounding rock eroded, then the igneous rock that looks more or less cylindrical and protrude from the surrounding topography is called a volcanic level.

Sill is the intrusion of igneous rock that konkordan or parallel to the bedding rock diterobosnya. Tabular-shaped with parallel sides.

In general there is a dike and sill the same time, is part of a system of intrusive rocks, drawing 1.2. Dike and sill can be very large. For example the Great Dike in Zimbabwe, Africa, is a gabbro mass of 500 km and 8 km wide, with walls walls are parallel and straight.

While there are examples of large sill near the city of New York, United States, on the cliff S. Hudson, its thickness is approximately 300 meters.

Lakolit intrusion similar to the sill is parallel to the bedding rock. Distinguished because the shape of the upper sill, rock diterobosnya or convex curved upwards, forming a gently sloping dome. While the bottom is similar to the sill. As a result of geological processes, either by force of endogenous, exogenous and style, in igneous rocks can be exposed or floating above the earth's surface. Although formed beneath the surface of the earth, lifted by tectonic forces,

Figure 1.1. Cross-sectional diagram of igneous rock in. Batolit-body of igneous rock which is very large, irregularly-shaped and basically unknown; stock-a small body and is equal to batolit; dyke-excavation or alley, which cut the plate-shaped structure surrounding rocks; sill-shaped together with the dyke, but parallel to the surrounding structures; lakolit together with the sill, the top convex upwards. Many igneous rocks in the volcano-related (Skinner, 2004).

Figure 1.2 Dike and sill is an intrusive rock bodies shaped flat (tabular). Dike cut the surrounding rock layers. Sill is injected between the layers of rock. (WK. Hamblin, 1989).

and eroded rock layers above it, so that the igneous rocks in the surface. Although today we see already above the earth's surface, they are still included in due to the formation of igneous rocks under the surface.

Lopolit shaped like the lakolit, only the top and bottom concave upwards.

Igneous rocks in addition to having various forms of intrusion of the body, there are also different types of rocks, based on the composition of its constituent minerals. Of the richest in minerals kuarsanya until at least the granite and granodiorite, diorite, gabbro and peridotite, as seen in the rock column in the table Faneritik Classification of Frozen Rocks.

ROCK

ROCK

Lithosfer nor crust consists of rocks. Rock has a broad meaning and differ with stones. 

Rock is the material that forms lithosfer or crust, composed of the minerals, are formed in nature and not live. Can be formed from only one set of various kinds of mineral or minerals. Both are compressed or not. For example clay, though not hard or mushy, but are formed in nature and consist of minerals (very fine grained), including rock. Instead of trees, hard and form in nature, but to live and not from the minerals, it does not include rock. While the stone, in the sense of the everyday is a hard lump. In geology a complementary word that gives a solid understanding and hard which is the result of a geological process. For example, sand dust, after experiencing the process of stone-sand litifikasi become dense and hard. Physical properties far different from the original material.

Studying rocks is a knowledge base for studying geology. By studying the rocks we can know the nature and history of our earth.

In the recorded rock geological processes that have occurred during the formation of rocks.

For example from the fossil in sedimentary rocks can be known environment where and when the rock was deposited and formed. And of magnetism that are stored in igneous rocks, which affected the Earth's magnetic field during freezing, can be studied polarization of the earth's magnetic field millions of years ago. And age can be determined by performing radioactive against these igneous rocks.

We have encountered a variety of rocks around us. Judging from their physical properties are very diverse, good color, hardness, cohesiveness, and its constituent materials. To make it easier to distinguish, made grouping or classification.

The simplest grouping is based on what happened or how the formation, or genesis into three main groups:

1. Igneous rock, formed from magma that cools and solidifies.

2. Sedimentary rock is rock formed from sediments deposited (on land or in water) and after experiencing geological processes into sedimentary rocks.

3. Metamorphic rocks or metamorphic rocks. Rocks, which have undergone changes in pressure and or high temperatures. Conversion into Metamorphic rocks, or metamorphic rocks without melting.