Clastic material (pieces of other rocks or fragments of skeletons) may become cemented together and chemical precipitation and evaporation can form sedimentary rocks. All igneous rocks began as magma (molten rock) which cooled and crystallized into minerals. Geologists classify igneous rocks based on both their crystal size and composition. Igneous rocks may look different because they may have cooled at different rates and the "mother" magma (original melted rock) was of a different composition. Variations in these two factors have created many igneous rocks.
Similarly, volcanic degassing determines the state of the atmosphere and climate and influences the ways in which volcanoes erupt. Hence, throughout geological history, volcanic degassing has been crucial to planetary habitability as it evidently prevented the planet from freezing, despite lower atmospheric pressures, by generating an adequate greenhouse effect. However, volcanoes occasionally erupt cataclysmically, emitting great volumes of gas and ash into the upper layers of the atmosphere. As a result, the volcanic debris may block incoming sunlight, causing global cooling, and can thereby lead to widespread crop failure and famine. The habitable zone of the Earth is, therefore, dependant on the operation of plate tectonics, as it provides the necessary conditions for atmospheric evolution and life on
The central cores of major mountain ranges consist of intrusive igneous rocks, usually granite. When exposed by erosion, these cores (called batholiths) may occupy huge areas of the Earth's surface. Coarse grained intrusive igneous rocks which form at depth within the crust are termed as abyssal; intrusive igneous rocks which form near the surface are termed hypabyssal. Extrusive igneous rocks Extrusive igneous rocks are formed at the crust's surface as a result of the partial melting of rocks within the mantle and crust. Extrusive Igneous rocks cool and solidify quicker than intrusive igneous rocks.
Tsunamis happen when the plates on the crust of the earth move, therefore moving the entire plate so that the water rises and is pushed forward, therefore causing a tsunami (Drohan, 2009, p.21). These tectonic plates are everywhere, under everything from the biggest mountain to the smallest hill. Though it is infrequent, volcanoes have been known to cause tsunamis. It happens when to volcano begins to erupt, but instead of coming out from the top of the volcano a lateral blast shoots out from the side. Next, a quickly moving avalanche of lava pours into the water near it causing the wave to travel to distant coastlines (Springer, 2005).
When one volcano explodes, the other habitually follow. Fortunately, it just finishes in a giant lava flow, that can do much damage if it passes through town or forests, but otherwise, it just flows until it cools down, or until it dives in a sea or an ocean. There are lots of these volcanos in countries on the edges of different tectonic plates. For example the Iceland, which is on the limit between the European plate and the American one. This actually causes other problems like earthquakes and other seismic activities, but the volcanoes are one of the
Mid-ocean ridges are sub-surfaced mountain ranges located at the boundaries between the tectonic plates that make up the Earth’s crust (van Dover, 2000; Tivey, 2007; Martin et al., 2008). As the plates are pulled apart by tectonic forces, hot soft rock from the deep Earth emerges to fill the fissure. As the generated ocean crust laterally moves away from the spreading-axis, the age of the crust and the depth of the sediment cover increase systematically (van Dover, 2000). Therefore, different types of hydrothermal vents occur at different areas of the ultramafic sea floor. The simplest of these are the columnar sulfide chimneys at the East Pacific Rise (EPR).
The earth wasn’t always solid. Billions of years ago it was a blob of magma floating in space. Over time the surface cooled, but the centre remained molten rock. The pressure and heat broke the surface into plates that float on a sea of magma below. These plates are constantly moving, drifting apart creating divergence boundaries and crashing together creating convergence boundaries, colliding with the power to forge mountains, and splitting solid rock like it was paper.
The great heat from this localized hotspot melts the Pacific plate above the hotspot and the spreading seafloor along the plate boundary pushed over the rocky crust. Magma was produced from the melting rock of the Pacific plate. The magma rise through the mantle and the crust as a thin thermal plume because magma is less dense than the solid rock of the plate. It was erupting beneath the ocean to form an active seamount. With the countless eruptions under the sea, the height of seamount keep increase until it breaks the ocean surface and becomes an island volcano.
These creatures, over hundreds of thousands of years, are able to change their DNA to adapt to their environment, which is an incredible thought. However, on Earth, the land is always changing, and everything will soon evolve once more to be fit in their habitats. Two hundred million years ago, there was a large supercontinent called Pangea, a strange formation of all seven continents that exist today. Pangea was the largest landform ever to exist on this planet, but was pushed apart by plate tectonics. Earthquakes and waves pushed the supercontinent apart, showing how strong that tectonic plates can be.
theories and ideas presented thus, not generally accepted. In the 1960s, plate tectonics emerged that explained Earth’s features such as continents, oceans, volcanoes, earthquakes, valleys and mountains. This theory became widely accepted by virtually all Earth scientists. A plate is a solid rock that is large and rigid while the Greek word tectonics means ‘to build’. Plate tectonics is the study of how the surface of the Earth is formed, how the separate pieces of it moves and the effects of this movement (Cambridge Dictionaries, 2014) Understanding the dynamic planet upon which we live has been made and transformed significantly although the concept is fairly new.