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DefinitionMetamorfosisme process is a process that causes changes in mineral composition, texture and structure on the rocks because of heat and high pressure, as well as the active chemical solution. The end result of the process metamorfisme is metamorphic rock. So rocks are igneous rocks formed by processes metamorfisme on pre-existing rocks. Rock (which had existed previously) can be igneous, sedimentary and metamorphic.

Mineral composition    Compiler minerals metamorphic rocks can be divided into the minerals:

    From the appearance of three-dimensional, Fabrik can be divided into:

Texture    Based on mineral grain size, can be differentiated into:

Structure    Structures in metamorphic rocks known there are three:

In nature, the rocks which have only very rarely lineasi structure, and most other berlineasi foliasi also formed. Foliasi may be irregular, curved or folded when deformed.

Origin of Peat (Peat)The coal is generally derived from peat (peat) deposits in a swamp. Important factors in the formation of peat:

Evolution of Flora DevelopmentThe oldest coal-old from Michigan Central Hurorian derived from algae and fungi. While in the Lower and Upper Devonian era, mostly from coal Psilophites (spt: Taeniocrada decheniana (lower Devonian)). Most of the coal from this era had an average of a thin layer (3-4m) and have no economic value. In Carbon Up, plant start up high until it reaches an altitude of more than 30m but not seberagam now. In this era dominated by: Lepidodendron, Sigillaria, Leginopteris oldhamia, Calamitea. Age of the Upper Carboniferous period known as bituminous coal. Perm important layer of coal was found in the USSR, the dominant form of Gymnosperm cordaites. In the Mesozoic era mainly Jurassic and Lower Cretaceous, Gymnosperm (Ginkcophyta, Cycadophyta and Cornifers) is an important shaper of coal plants, especially in Siberia and Central Asia. In the old swamp and Upper Cretaceous Tertiary Angiosperm plants grow rapidly in N. America, Europe, Japan and Australia. When compared with the Carbon plant at the time, plants in the Mesozoic era, especially the Tertiary era more diverse and specific, and produces a thick peat deposits and diverse in type fasiesnya. The development and evolution will affect the diversity of flora and type of coal produced.


ClimateIn a warmer climate and wet plants grow faster and diverse. Layers of Carbon-old coal-rich Upper Cretaceous and Early Tertiary Top deposited in this climate. However, in the southern Hemisphere and Siberia there are also rich deposits of coal which diendapakan in moderate to cold climates, for example coal-post glacial inter PermoCarbon Gondwana (from Ganganopteris glossopteris) and Permian and Jurassic age coal of the Lower Angara konitnen. Coal layer is deposited in a warm and wet climate is usually lighter and thicker than that deposited in wet climates.

Tectonic and paleogeographic RequirementsLayer formation depends on the relationships and structures on the regional paleogeographic sedimentation. Formation of peat (peat) occur in the depressed area surface and surface water requires a relatively fixed throughout the year above or at least equal to the soil surface. This condition appears in many areas where a lot of flat coastal swamps associated with persisir beach. Besides the swamp also appeared on land (shore or Inland lakes). Depending on the original position of its geography, paralic coal deposit (sea coast) and limnic (Inland) is different.

Coal Paralic Swampy has few trees or no trees and formed outside the distal margin of the delta. Formation is the result of regression and transgression of sea water. Many large coastal Swampy growing under the protection of sand bars and pits that can produce thick deposits of coal.

Back samps natural levee formed behind the great river. At the back Swampy, peats (peat) is rich in mineral matter from flooding that often occurs. Peat deposits can only be preserved in the subsidence area. As a result, many coal-rich sediments associated with this area, as it often appears in the foredeep on a big mountain folds.

Sequence of thick sediment, where in it there is a thin layer of coal (<2m) with a large spread and the presence of marine intercalation is characteristic of the coal bed which was deposited in foredeeps of a large mountain folds. Cyclothem is looping between Inorganic sediment and peat with this sequence is often repeated.

In backdeeps part of a huge mountain folds, subsidence usually fewer and fewer number of layers of coal. When paralic coals deposited in foredeeps, most limnic coals deposited in a large continental basin. Limnic coals have character: formed in a continental graben, the number of layers slightly but each layer is very thick.

Throughout the world karst landscapes vary from rolling hills dotted with sinkholes, as found in portions of the central United States, to jagged hills and pinnacle karst found in the tropics. The development of all karst landforms requires the presence of rock which is capable of being dissolved by surface water or ground water. The term karst describes a distinctive topography that indicates dissolution (also called chemical solution) of underlying soluble rocks by surface water or ground water. Although commonly associated with carbonate rocks (limestone and dolomite) other highly soluble rocks such as evaporates (gypsum and rock salt) can be sculpted into karst terrain. Understanding caves and karst is important because ten percent of the Earth’s surface is occupied by karst landscape and as much as a quarter of the world’s population depends upon water supplied from karst areas. Though most abundant in humid regions where carbonate rock is present, karst terrain occurs in temperate, tropical, alpine and polar environments. Karst features range in scale from microscopic (chemical precipitates) to entire drainage systems and ecosystems which cover hundreds of square miles, and broad karst plateaus. Although karst processes sculpt beautiful landscapes, karst systems are very vulnerable to ground water pollution due to the relatively rapid rate of water flow and the lack of a natural filtration system. This puts local drinking water supplies at risk of being contaminated. In the mid 1980’s, flooding of caves in the highly populated area of Bowling Green, Kentucky, caused industrial waste to leak into the vast system of underground fissures polluting the ground water in local wells. Due to urban expansion millions of dollars is spent annually in the United States to repair damage to roads, buildings and other structures which are built on unstable karst surfaces.

The degree of development of karst landforms varies greatly from region to region. Large drainage systems in karst areas are likely to have both fluvial (surface) and karst (underground) drainage components. As stated in the introduction, the term karst describes a distinctive topography that indicates dissolution of underlying rocks by surface water or ground water. Water falls as rain or snow and soaks into the soil. 

The water becomes weakly acidic because it reacts chemically with carbon dioxide that occurs naturally in the atmosphere and the soil. This acid is named carbonic acid and is the same compound that makes carbonated beverages taste tangy. Rainwater seeps downward through the soil and through fractures in the rock responding to the force of gravity. The carbonic acid in the moving ground water dissolves the bedrock along the surfaces of joints, fractures and bedding planes, eventually forming cave passages and caverns.

Limestone is a sedimentary rock consisting primarily of calcium carbonate in the form of the mineral calcite. Rainwater dissolves the limestone by the following reaction: Calcite + Carbonic acid = Calcium ions dissolved in ground water + Bicarbonate ions dissolved in ground water. Cracks and joints that interconnect in the soil and bedrock allow the water to reach a zone below the surface of the land where all the fractures and void spaces are completely filled (also known as saturated) with water. This water-rich zone is called the saturated zone and its upper surface is called the water table. The volume of void space (space filled with air or water) in soil or bedrock is termed porosity. The larger the proportion of voids in a given volume of soil or rock the greater the porosity. When these voids are interconnected, water or air (or other fluids) can migrate from void to void. Thus the soil or bedrock is said to be permeable because fluids (air and water) can easily move through them. Permeable bedrock makes a good aquifer, a rock layer that holds and conducts water. If the ground water that flows through the underlying permeable bedrock is acidic and the bedrock is soluble, a distinctive type of topography, karst topography, can be created.

The first part of our animation shows evolution of karst landforms created by downward movement of water accompanied by dissolution of rock and mass transport of sediments in stream channels. In tropical areas with thick massive limestones, a remarkable and distinctive landscape of jagged hills and narrow gorges completely dominates the landscape. Movement of solution along fractures and joints etches the bedrock and leaves limestone blocks as isolated spires or pinnacles. Pinnacles range from small features a few inches tall to intermediate forms a few feet tall to large pinnacles hundreds of feet tall. Besides the etching of pinnacles and residual hills, sheets of flowing water move down sloping surfaces creating a variety of etched surface features. Our computer animation shows the dominant landforms, such as pinnacles, cones, and towers, commonly found in the tropical karst environment of northern Puerto Rico.

Our paper model represents another type of karst landscape, that of a rolling limestone plain such as is found in south-central Kentucky, northern Florida, and the Highland Rim of central Tennessee where doline karst is the dominate feature. Doline karst is the most widely distributed type of karst landscape. The landscape is dotted with sinkholes (dolines) which can vary widely in number and size. For the Sinkhole Plain in central Kentucky, there are approximately 5.4 sinkholes per square kilometer over a 153 square kilometer area. For north Florida there are almost 8 sinkholes per square kilometer over a 427 square kilometer area (White, 1988, table 4.1, page 100). Karst topography dominated by sinkholes or dolines usually has several distinct surface features. Our paper model shows features normally associated with karst topography.

Sinkholes (also known as dolines) are surface depressions formed by either: 1) the dissolution of bedrock forming a bowlshaped depression, or 2) the collapse of shallow caves that were formed by dissolution of the bedrock. These sinkholes or shallow basins may fill with water forming lakes or ponds. Springs are locations where ground water emerges at the surface of the earth. Disappearing streams are streams which terminate abruptly by flowing or seeping into the ground. Disappearing streams are evidence of disrupted surface drainage and thus indicate the presence of an underground drainage system. Cave entrances are natural openings in the earth large enough to allow a person to enter. Caves may reflect a complex underground drainage system.

Bowen found by experiment that the order in which minerals crystallize from a basaltic magma depends on temperature. As a basaltic magma is cooled Olivine and Ca-rich plagioclase crystallize first. Upon further cooling, Olivine reacts with the liquid to produce pyroxene and Ca-rich plagioclase react with the liquid to produce less Ca-rich plagioclase. But, if the olivine and Ca-rich plagioclase are removed from the liquid by crystal fractionation, then the remaining liquid will be more SiO2 rich. If the process continues, an original basaltic magma can change to first an andesite magma then a rhyolite magma with falling temperature.

Volcanic eruptions, especially explosive ones, are very dynamic phenomena. That is the behavior of the eruption is continually changing throughout the course of the eruption. This makes it very difficult to classify volcanic eruptions. Nevertheless they can be classified according to the principal types of behavior that they exhibit. An important point to remember, however, is that during a given eruption the type of eruption may change between several different types.

Non explosive eruptions are favored by low gas content and low viscosity magmas (basaltic to andesitic magmas).

Explosive EruptionsExplosive eruptions are favored by high gas content and high viscosity (andesitic to rhyolitic magmas).