Mountains Essays - Plate Tectonics, Volcanology, Igneous Petrology

Mountains I. INTRODUCTION A mountain is an elevated land mass usually higher than its surroundings. Some are isolated, but they usually appear in ranges(MsBs95W32). "A group of ranges closely related in form, origin, and alignment is a mountain system; an elongated group of systems is a chain; and a complex of ranges, systems, and chains continental in extent is a cordillera, zone, or belt."(MsBs95W32). Some mountains are remains of plateaus, mesas, and buttes, through erosion(Summerfield). Others are cones of volcanoes formed with igneous rock. Fault-block mountains occur where blocks of the earth's surface are raised relative to other neighboring blocks. Most of the great mountains are either fold mountains or complex structures formed by many different natural activities. The ultimate cause of mountain building is only theoretical and abstract. Although, the plate tectonics is the first reasonable theory, stating that the crust of the earth breaks into several parts that eventually collide with another. Where they collide, stresses cause deformation and uplift of the land, which forms folded and/or faulted mountain chains. The highest point on earth, Mt. Everest, is also believed to have been formed by folding when the Australian-Indian plate collided with the Eurasian plate. II.TABLE OF CONTENTS IINTRODUCTION IITABLE OF CONTENTS III.TYPES OF MOUNTAINS 1. VOLCANOES 2. FOLDING & FAULTING 3. RESIDUAL MOUNTAINS IV.VOLCANO FORMATION 1. TYPES & NOMENCLATURE 2. PROCESS 3. EXAMPLE V.FOLDING AND FAULTING 1. PROCESS 2. EXAMPLE VI.PLATEAUS TO MOUNTAINS 1. TYPE 2. EXAMPLE VII.CONCLUSION VIII.BIBLIOGRAPHY III.TYPES OF MOUNTAINS M ountains can be created in many different ways. Two very well-known and quite common ones are volcanic mountains and folded mountains. Other important ones include residual mountain formation in which a plateau is eroded away into a mountain. 1. Volcanoes Volcanoes are formed when the magma reserves underground erupts. Also There are many different types of eruptions that the Geologists have classified into, according to their location, style, and other features. These variations contribute to the different and distinct shapes of each volcanoes. 2. Folding & Faulting According to the Microsoft Office Bookshelf 1995, the earth is changing its shape constantly every year by a few centimeters. This caused the earth to move from one huge continent called Pangea to what it looks like now in almost 200 million years(30 Boehm). When the giant pieces of landmasses move around, they tend to bump into each other some day. When they collide, they create a fold, and if the fold gets too much pressure, it breaks and becomes a fault. Fold and Fault mountains are ubiquitous throughout the world. 3. Residual Mountains Due to the weathering, parts of the world change frequently, but slowly. This can also happen to a plateau. If a small plateau's edges are washed away by rain and wind, it forms a new mountain-like structure, which we call residual mountain, meaning that it became a mountain from the remainders of many erosions. VI.VOLCANO FORMATION V olcanoes are one of the "fastest of all the processes making the Earth's relief features"(quoted from 2 Scarth). While some eruptions are quick and powerful, others can be very slow and continue for over hundreds of thousands of years.(2 Scarth). Two thirds of the volcanoes can be found in the Pacific ring of fire(14 Scarth). Most others are usually submerged undersea, or makes up an island with cooled igneous rocks; Hawaii rises 9000m above the sea floor. Magma, which is what igneous rocks were to begin with, is formed from molten parts of asthenosphere(150-650km under ground) which is a part of the upper mantle(60-650km u.g.)(p20-21 Scarth). A. Types & Nomenclature The volcanoes are classified by its eruptive style and by the type of magma it ejects(32 Scarth). There is almost an infinite number of kinds of volcanoes possible, but most geologists divide them into four main groups: Hawaiian, Vulcanian, Strombolian, and Pelean(33 Scarth). These names all come from famous volcanoes around the world, but not all other volcanoes always exactly fit in to one group, and there are other minor groups such as Flood basalt, Surtseyan, Plinian, Debris-avalanche(34 Scarth). Here is a table about some volcanoes and their features. B. Process Every volcano has a different style just as they have different names. They sometimes look similar, but most of the times, they are very distinct from the other. The usual process volcanoes go through are, although, quite similar. The lower part of the upper mantle and the transition zone between the two mantles, called