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Geologic Systems © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Geologic Systems © Jones & Bartlett2 Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OREarth DISTRIBUTION is a dynamic planet because the materialsNOT of its various FOR SALElayers are OR in motion. DISTRIBUTION The effects of both the hydrologic and the tectonic systems are dramatically expressed in this space photograph of eastern North America. The most obvious motion is that of the surface fluids: air and water. The complex cycle by which water moves from the oceans into the atmosphere, to the land, and back to the oceans again is the fundamental movement within the hydrologic system. The energy source that drives© Jones this system & Bartlett is the Sun. Learning, Its energy evaporates LLC water from the oceans© andJones causes & Bartlett Learning, LLC the atmosphereNOT to circulate,FOR SALE as shown OR above DISTRIBUTION by the swirling clouds of hurricane Dennis.NOT Water FOR SALE OR DISTRIBUTION vapor is carried by the circulating atmosphere and eventually condenses to fall as rain or snow, which gravity pulls back to Earth’s surface. Still acted on by the force of gravity, the water then flows back to the oceans in several subsystems (rivers, groundwater, and glaciers). In every case, © Jonesgravity & causes Bartlett the water Learning, to flow from LLC higher to lower levels. © Jones & Bartlett Learning, LLC Earth’s lithosphere may appear to be permanent and stationary, but like the hydrosphere, it NOTis FOR in constant SALE motion, OR DISTRIBUTIONalbeit much, much slower. There is now overwhelmingNOT FOR evidence SALE thatOR the DISTRIBUTION entire lithosphere moves, and as it does, continents split and the fragments drift thousands of kilometers across Earth’s surface perchance to collide with one another. The great Appalachian Mountain chain, visible here as a series of parallel ridges and valleys, formed when two conti- © Jones & Bartlettnents Learning, collided hundreds LLC of millions of years ago.© The Jones folded & and Bartlett crumpled Learning, rock layers formed LLC a NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 30 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. 9781449659011_CH02.indd 30 12/30/2013 3:09:53 PM © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALECourtesy of SeaWiFSOR Project, DISTRIBUTION NASA/Goddard Space Flight Center and ORBIMAGE © Jones & Bartlett Learning, LLC © Jones & BartlettBahamas Learning, LLC NOT FOR SALE OR DISTRIBUTION AppalachianNOT Mountains FOR SALE OR DISTRIBUTION Canadian Florida Shield Great Lakes © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION high mountain belt that was slowly eroded away by streams. Subsequently, the margin of North America formed as it rifted away from Africa. In fact, all of the structural features of our planet are the result of a simple system of moving lithospheric plates. Movement in this plate tectonic © Jonessystem & Bartlett is driven Learning, by the loss of LLCinternal heat energy. © Jones & Bartlett Learning, LLC The concept of a natural system, as developed for the study of geology, provides a framework NOT FORfor understandingSALE OR DISTRIBUTION how each part of Earth works and why it isNOT constantly FOR changing. SALE ORGeologic DISTRIBUTION systems are governed by natural laws that provide the keys to understanding Earth and all of its varied landscapes and processes. In this chapter, we consider the fundamentals of natural systems. We also explore the basics © Jones & Bartlett Learning,of the hydrologic LLC system and the tectonic system© Jones as the &ultimate Bartlett causes Learning, of geologic change. LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 31 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. 9781449659011_CH02.indd 31 12/30/2013 3:09:54 PM 32 2 Geologic Systems © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION Major ConceptsNOT FOR SALE OR DISTRIBUTION 1. A natural system is a group of interdependent components that interact to form a unified whole and are under the influence of related forces. The materi- als in a system change in an effort to reach and maintain equilibrium. © Jones & Bartlett2. Earth’s Learning, system of moving LLC water, the hydrologic system,© Jones involves & Bartlettthe move- Learning, LLC NOT FOR SALEment OR of DISTRIBUTION water—in rivers, as groundwater, in glaciers,NOT in oceans,FOR SALE and as waterOR DISTRIBUTION vapor in the atmosphere. As water moves, it erodes, transports, and deposits sediment, creating distinctive landforms and rock bodies. 3. Radiation from the Sun is the source of energy for Earth’s hydrologic system. © Jones & Bartlett Learning,4. A systLLCem of moving lithospheric© plates—the Jones & plate Bartlett tectonic Learning, system—explains LLC Earth’s major structural features. It operates from Earth’s internal heat. NOT FOR SALE OR DISTRIBUTION5. Where plates move apart, hot materialNOT FORfrom the SALE mantle OR wells DISTRIBUTION up to fill the void and creates new lithosphere. The major features formed where plates spread apart are continental rifts, oceanic ridges, and new ocean basins. 6. Where plates converge, one slides beneath the other and plunges down into © Jones & Bartlett Learning, LLC the mantle. The© major Jones features & Bartlett formed at Learning, convergent plateLLC margins are folded mountain belts, volcanic arcs, and deep-sea trenches. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 7. Where plates slip horizontally past one another, transform plate boundaries develop on long, straight faults. Shallow earthquakes are common. 8. Far from plate margins, plumes of less-dense mantle material rise to shallow levels, feeding within-plate volcanoes and producing minor flexures of the © Jones & Bartlettlithosphere. Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE9. Ear ORth’s crustDISTRIBUTION floats on the denser mantle beneath.NOT The crustFOR rises SALE and sinks OR in DISTRIBUTION attempts to maintain isostatic equilibrium. © Jones & Bartlett Learning,Geologic LLC Systems © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONA system is a group of interdependentNOT materials FOR that SALE interact OR with DISTRIBUTION energy to form a unified whole. Most geologic systems are open; that is, they can exchange matter and energy across their boundaries. The world is a unified whole. Nothing in or on it exists as an isolated entity. Everything © Jones & Bartlett Learning, LLC is interconnected. We© may Jones know myriad& Bartlett details Learning,about the many LLC separate items found NOT FOR SALE OR DISTRIBUTION on or inside Earth, butNOT most FOR of us do SALE not understand OR DISTRIBUTION how the pieces are interrelated and fit together. Without some concept of how the world functions as a whole, we easily miss important relationships between seemingly isolated phenomena, such as the criti- cal connections among rainfall, temperature, and landslides. To understand Earth and how it functions, we need a model or framework, a plan or map that shows how things © Jones & areBartlett interrelated Learning, and how things LLC operate. Such a framework© is Jones provided & by Bartlett the concept Learning, LLC NOT FOR SALEof the system OR DISTRIBUTION. NOT FOR SALE OR DISTRIBUTION What is a geologic system? There are many different kinds of systems. You are undoubtedly familiar with many natural and artificial systems. An engineer may think of a system as a group of interacting devices that work together to accomplish a specific task. In your home, there is an electrical system, a plumbing system, and a heating system. Each functions © Jones & Bartlett Learning,as an independent LLC unit in some way. Each© Jones transfers & material Bartlett or energy Learning, from one LLC place NOT FOR SALE OR DISTRIBUTIONto another, and each has a driving forceNOT that makesFOR theSALE system OR operate. DISTRIBUTION In another example, a biologist conceives of a similar kind of system, but it is one composed of separate organs made of living tissues that work
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