Science of structure, composition and structure of the Earth's crust (Earth = Ge), its physical properties and history of development as well as the processes that shape them. The term was first used in 1778 by the Swiss meteorologist Jean-André Deluc (1727-1817); before, geognosy was in use. The earth's crust consists of three different rock formations. These are crystalline or solidified rocks, sedimentary or stratified rocks and metamorphic or deformed rocks.
Crystalline or solidification rocks: These are caused by cooling and solidification. The plutonic rocks (plutonites) are formed when ascending magma slowly cools down long before it reaches the surface of the earth and is then mineralized in large crystals. The most common crystalline plutonic rocks are granite, mica schist and gneiss. As molten magma gets closer to the surface of the earth or in the vent of an extinct volcano, it increasingly crystallizes into fine and fine crystals due to the faster cooling processes, forming hard, dense solidification rocks such as basalt or obsidian. In the eruption rocks (volcanic rocks), liquid magma ignites eruptively as lava to the earth's surface to cool in the water or in the air. From the eruption ash precipitate arise gas-filled tuff rocks, while the porous solidified lava flows to fertile lava soils weather.
Sediment / stratified rocks: These rock materials were formed from washed-out weathering products such as sand, mud, clay, humus and other fine particles of suspended matter, which were transported with the rivers into the sea, together with dead ones seaweed and plankton sank to the bottom of the sea and deposited on the bottom of the sea. Sedimentary rocks are the only rocks that can contain fossils (testimony of bygone life). Due to the increasing pressure of the ever newly forming sediment layers as well as by chemical processes, these sediments were pressed into solid rock. Sandstone became sandstone, clay became slate, and deposits of plants and animals (such as shells, corals, snails) became chalk and limestone.
Metamorphic or Formed Rocks: These are pristine crystalline rocks or sedimentary rocks that have been converted to other types of rocks over millions of years by extremely high pressure and high temperatures deep in the Earth's crust. The best known of these are gneiss (from crystalline or sedimentary rock), marble (from limestone), shale (from slate or clay) and quartzite (from sandstone).
Rocks are exposed to physical and chemical weathering processes, and ultimately all the rock decomposes into dust. In dependence of climate and water balance developed in the course of millions of years, the different soil types. For the viticulture this has an important meaning, because starting rock and climate determines significantly over the soil type, The soil structure, the water Resources (such as. Water storage capacity and water discharge ) and especially the nutrient availability directly affect the vegetation type and thus the vitality and growth of the vine, The color of the soil also influences the microclimate due to its influence on the sunlight or heat absorption.
In interaction with climate, exposition (Direction of incidence of the sun's rays) and Tilt or. hillside The geological conditions of the location essentially determine the quality of the wine. And it is part of the craftsmanship of the winemaker, by choosing the appropriate vine and document, as well as by appropriate measures at the Weingarten Care on his terroir to create the best wines. The criteria for the suitability of an area for viticulture is called Weinbauwürdigkeit, See also below soil type,