Geology | Exam 1 Review Mineral and Energy Resources - “New Wealth is in the ground”o Timber baronso Silver barons o Oil baronso Salt barons - “Precious” minerals vs. “strategic” mineralso “strategic”: necessary for essential civilian, industrial, or military needso “precious”: ornamental or jewelry usage - Potential Energy Sourceso Solar radiationo Hydroelectric o Tidal o Nuclearo Windo Biomass crop- World Energy Use- What types of energy do we use?o 8%-renewable energy 1% solar 5% geothermal 6% waste 9% wind 20% biofuels 24% wood  35% hydroelectrico 9%-nuclear electric powero 21%-coalo 25%-natural gaso 37%-petroleum- Who uses the energy?o 19% commercialo 22% residentialo 28% transportationo 31% industrial- Quick Observationso 83% of our energy comes from non-renewable resources (coal, gas, oil)o No single usage sector dominateso Industrial sector has shown capacity to increase efficiency- More observations o “ending dependence on foreign oil” and “development of renewable energysources” seem unrelatedo Industrial sector has the most source diversity, followed by electric grido Transportation grid needs an attitude adjustment - Historical Energy Sources- Energy Self-Sufficiencyo The US was self-sufficient until the late 1950s when energy production began to outpace domestic productiono At the point, the nation began to import more energy to meet its needso In 2009, net imported energy accounted for 24 % of all energy consumed- Economic Sufficiencyo Our economy is twice as efficient over the last forty yearso After 1970, the amount of energy consumed to produce a dollar’s worth of the nation’s output of goods and services trended downo The decline resulted from efficiency improvements and structural changes in the economy o The level in 2009 was 54% below that of 1970- Energy Efficiency o We are about 20% more efficient per person in the last 30 years o Energy use per person stood at 214 million British thermal units in 1949o The rate generally increased until the oil price shocks of the mid-1970s and early 1980s when the trend reversed for a few yearso From 1988 on, the rate held fairly steady until the 2008-2009 economic downturno In 2009, 308 million Btu of energy wereconsumed per person, 44% above the 1949 rate- Fossil Fuelso Most energy consumed in the US comes from fossil fuelso Renewable energy resources supplied asmall but growing portiono In the late 1950s, nuclear fuel began to be used to generate electricityo From 1998 through 2009, nuclear electric power surpassed renewable energy- Electrical Grid o In the 1950s and 60s, coal, which had been important to residential and commercial consumers, was gradually replaced by other forms of energyo Petroleum consumption peaked in the early 1970so Natural gas consumption grew fast until the early 1970s, and then, with mild fluctuations, held fairly steady in the following yearso Meanwhile, electricity use (and related losses) expanded dramatically Fossil Fuels- Formation of fossil fuelso Originate as organic-rich sedimentary depositso Organic materials are the remains of plants and animalso Burial in sedimentary basins causes the organic material to be ‘cooked’ to different degrees, thereby producing different types of hydrocarbon materials- Conditions for Fossil Fuel Formationo Biologically productive environment producing large quantities of organic material – typically shallow water continental marginso Limited supply of oxygen to bottom waters in contact in sediment limits the biological activity that would act to decompose dead organic materialo Rapid burial of un-decomposed organic material provides for efficient capture of the organic material in sedimentary deposits- Subsidenceo The removal of rock from the mountains by weathering and erosion and the deposition of that material in the form of clastic sediment around the edges of the continents creates over times, a great shift in mass from the mountains to the continental edgeso The response to the loading of the edges of the continent with large accumulations of sediment is the slow sinking process known as subsidence, which because the lithosphere sinks/subsides under the great weight of sediment that accumulates over millions of years o Sediment from rivers gets deposited in alluvial fans- The Mississippi River Deltao Drains almost half of the continental USo One of the most important fossil fuel locations in the US (as well as Gulf of Mexico)o Lower Mississippi River has shifted over the past 6000 years creating large land areas and creating extremely thick accumulations of organic-rich and muddy sediment in different places at different timeso West of the Mississippi is low sulfur coal, so after the clean air act, most people got theircoal from the west- Coalo A black, brittle sedimentary rock that is composed primarily of organic materials which are primarily the remains of plants that were living at the time that the sedimentary rocks were depositedo Swamps are the primary sedimentary environments where thick accumulations ofplant material can result in the production of a major coal reserveo The subsidence of the land surfaces around the edges of continents means that the swampy environments that create thick accumulations of organic material eventually subside below sea level and are buried by younger sedimentary depositso A coal seam is a layer of coal beneath the sea floor o It forms a relationship to the modern swampy environment at the surface of the land, often developed in delta areas which are swampy and undergoes rapid subsidence and burial- Development of coalo The burial and heating of organic material creates a progressive change from the livingplants material to first peat, lignite, bituminous coal, and finally anthracite coalo Each of these steps involves progressive loss of nitrogen and water to create organic material with higher carbon and hydrogen contents and thus *higher energy contents*- Types of coalo Peat: commonly burned for fuel in boggy regions at high latitudes (Scotland, Ireland, etc)o Anthracite: highest grade of coal; because itis cooked at a relatively high temperature, ithas a relatively high energy content, and is also relatively free of pollution-causing impurities such as sulfuro Bituminous: used in power generation and industry; high energy contento Lignite: moderate energy level, not used formuch except being transformed into bituminous coal- US Coal Reserveso The