Geology

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Mineralogy As a discipline, mineralogy has had close historical ties with geology. Minerals as basic constituents of rocks and ore deposits are obviously an integral aspect of geology. The problems and techniques of mineralogy, however, are distinct in many respects from those of the rest of geology, with the result that mineralogy has grown to be a large, complex discipline in itself. Nepheline greasy light gray , sodalite blue , cancrinite yellow , feldspar white , and ferromagnesian minerals black in an alkalic syenite from Litchfield, Maine, U. About 3, distinct mineral species are recognized, but relatively few are important in the kinds of rocks that are abundant in the outer part of the Earth. Thus a few minerals such as the feldspars, quartz, and mica are the essential ingredients in granite and its near relatives. Limestones , which are widely distributed on all continents, consist largely of only two minerals, calcite and dolomite. Many rocks have a more complex mineralogy, and in some the mineral particles are so minute that they can be identified only through specialized techniques. It is possible to identify an individual mineral in a specimen by examining and testing its physical properties. Determining the hardness of a mineral is the most practical way of identifying it.

GEOLOGICAL TIME

Life Letters and Journals, published by John Murray The Geologic Column, accepted purely by faith, is the Bible for the Evolutionist. Lyell took away peoples belief that there was a biblical flood. Scientists theorize that sediments were deposited on the earth over millions and billions of years. There are many problems with this theory, some of which are described here: Unfortunately no such column exists.

Geologic time relative dating puzzles relative ve dating is used to arrange geological events, relative dating principles and the rocks they leave behind, in a method relative dating vs absolute dating geologic time relative dating puzzles of reading the order is.

Earthquake Mitigation Measures Minimizing or avoiding the risks from earthquakes involves three subject areas. First is the ability to predict their occurrence. While scientists cannot routinely predict earthquakes, this area is of growing interest and may be a key factor in reducing risks in the future. This information is used to address the third area of earthquake risk reduction-mitigation measures.

Following a discussion of prediction, assessment, and mitigation, the types and sources of earthquake information are presented. Earthquake Prediction A report on an erroneous prediction of an earthquake in Lima, Peru, states: Earthquake prediction is still in a research and experimental phase. Although a few successful predictions have been made, reliable and accurate predictions having a long lead time, and useful location and magnitude estimates, are many years in the future Gersony, Some progress is being made in regional, long-term prediction and forecasting.

Recent studies show that major earthquakes do not recur in the same place along faults until sufficient time has elapsed for stress to build up, usually a matter of several decades. In the main seismic regions, these “quiet” zones present the greatest danger of future earthquakes. Confirming the seismic gap theory, several gaps that had been identified near the coasts of Alaska, Mexico, and South America experienced large earthquakes during the past decade.

Moreover, the behavior of some faults appears to be surprisingly constant:

Geology Online Subchapter

These principles continue to provide the basic framework within which geologists read the record of Earth history and determine relative ages. The principle of uniformitarianism states that physical processes we observe operating today also operated in the past, at roughly comparable rates, so the present is the key to the past. The principle of original horizontality states that layers of sediment, when first deposited, are fairly horizontal because sediments accumulate on surfaces of low relief such as floodplains or the sea floor in a gravitational field.

If sediments were deposited on a steep slope, they would likely slide downslope before they could be buried and lithified.

¥principles of stratigraphy: ¥deposition, succession, continuity and correlation Relative Age Dating Depositional Succession ¥Sedimentary rocks ¥deposited as beds or ¥Principle applies to sedimentary rocks formed in an aqueous environment Law of Initial Horizontality.

Relative dating Cross-cutting relations can be used to determine the relative ages of rock strata and other geological structures. Methods for relative dating were developed when geology first emerged as a natural science. Geologists still use the following principles today as a means to provide information about geologic history and the timing of geologic events. The principle of uniformitarianism states that the geologic processes observed in operation that modify the Earth’s crust at present have worked in much the same way over geologic time.

In geology, when an igneous intrusion cuts across a formation of sedimentary rock , it can be determined that the igneous intrusion is younger than the sedimentary rock. Different types of intrusions include stocks, laccoliths , batholiths , sills and dikes. The principle of cross-cutting relationships pertains to the formation of faults and the age of the sequences through which they cut.

Faults are younger than the rocks they cut; accordingly, if a fault is found that penetrates some formations but not those on top of it, then the formations that were cut are older than the fault, and the ones that are not cut must be younger than the fault. Finding the key bed in these situations may help determine whether the fault is a normal fault or a thrust fault. For example, in sedimentary rocks, it is common for gravel from an older formation to be ripped up and included in a newer layer.

A similar situation with igneous rocks occurs when xenoliths are found.

Practice questions: Geologic Time

Geology[ edit ] The regular order of the occurrence of fossils in rock layers was discovered around by William Smith. While digging the Somerset Coal Canal in southwest England, he found that fossils were always in the same order in the rock layers. As he continued his job as a surveyor , he found the same patterns across England. He also found that certain animals were in only certain layers and that they were in the same layers all across England.

Due to that discovery, Smith was able to recognize the order that the rocks were formed.

Introduction to Geology: Chapter 2 – Basic Geologic Principles The science of geology is founded on basic principles that are useful for making observations about the world around us. This chapter presents a mix of information that is essential (fundamental) to all following chapters. relative dating.

Relative dating Cross-cutting relations can be used to determine the relative ages of rock strata and other geological structures. Methods for relative dating were developed when geology first emerged as a natural science. Geologists still use the following principles today as a means to provide information about geologic history and the timing of geologic events.

The principle of uniformitarianism states that the geologic processes observed in operation that modify the Earth’s crust at present have worked in much the same way over geologic time. In geology, when an igneous intrusion cuts across a formation of sedimentary rock , it can be determined that the igneous intrusion is younger than the sedimentary rock.

Different types of intrusions include stocks, laccoliths , batholiths , sills and dikes. The principle of cross-cutting relationships pertains to the formation of faults and the age of the sequences through which they cut. Faults are younger than the rocks they cut; accordingly, if a fault is found that penetrates some formations but not those on top of it, then the formations that were cut are older than the fault, and the ones that are not cut must be younger than the fault.

Finding the key bed in these situations may help determine whether the fault is a normal fault or a thrust fault. For example, in sedimentary rocks, it is common for gravel from an older formation to be ripped up and included in a newer layer. A similar situation with igneous rocks occurs when xenoliths are found.

These foreign bodies are picked up as magma or lava flows, and are incorporated, later to cool in the matrix. As a result, xenoliths are older than the rock which contains them. The Permian through Jurassic stratigraphy of the Colorado Plateau area of southeastern Utah is an example of both original horizontality and the law of superposition.

Relative dating

Thus we do not know the numeric age of any given layer. The civilizations that deposited the trash had a culture and industrial capabilities that evolved through time. The oldest inhabitants used primitive stone tools, later inhabitants used cups made of ceramics, even later inhabitants eventually used tin cans and then changed to Aluminum cans, and then they developed a technology that used computers.

This shows that society has evolved over the years. Similar cultures must have existed in both areas and lived at the same time.

Sep 11,  · The Geologic Time Scale. The timescale used by geologists as a framework for earth’s history, its sequence of rocks and fossils and the events they record, was largely established during the s using Steno’s principles of relative geologic age, Smith’s principle of faunal succession, and the theory of unconformities by Hutton and others.

The Adana Basin in Turkey. The Iskenderun Basin in Turkey. The Moesian Platform in Bulgaria. The Carpathian Basin in Poland. The Yeniseiy-Khatanga Basin in Russia. The Farah Basin in Afghanistan. The Helmand Basin in Afghanistan. The Manhai-Subei Basin in China.

Lab

The assumption that the geologic column is a base from which to calibrate the C dates is not wise. With a half-life of only years, carbon dating has nothing to do with dating the geological ages! Whether by sloppiness or gross ignorance, Dr. Hovind is confusing the carbon “clock” with other radiometric “clocks. Being ancient, the C content has long since decayed away and that makes it useful in “zeroing” laboratory instruments.

Years in time = T Where 1) (formula relationship: following the by expressed be can dating radiometric of principle The intrusions, igneous and faults as such features geologic that states, Introduction events geologic of dating absolute and Relative cut which.

Practice exam questions written by Timothy H. Heaton , Professor of Earth Sciences, University of South Dakota Click the circle by an answer with the mouse, then click on the Submit button to get a response. You will be told if your answer is correct or not and will be given some comments. What is relative dating? Going on a date with a sibling or cousin.

Establishing that something happened a very long time ago. Establishing a sequence of events. Placing a specific date on an event.

Homework and Assignment Help: Liberty University PHSC Week 3 Mastering Geology Assignment 6

March 28, This post is about elevation measurements for exposure-dating samples, and how accurate they need to be. Basically, the main thing that controls cosmogenic-nuclide production rates is site elevation, or, more precisely, atmospheric pressure — at higher elevation, there is less atmosphere between you and the extraterrestrial cosmic-ray flux, so the production rate is higher. Thus, to compute the cosmogenic-nuclide production rate at a sample site, the first thing we need to know is the elevation.

geologic time, concepts, and principles •Relative dating is accomplished by placing events in sequential order with the aid of the principles of historical geology.

Introduction to Geology Chapter 2 – Basic Geologic Principles The science of geology is founded on basic principles that are useful for making observations about the world around us. This chapter presents a mix of information that is essential fundamental to all following chapters. This chapter is an introduction to rocks and minerals, and the rock cycle. Basic chemistry is important to all sciences, especially geology! Everything around us is made of chemical compounds that have testable and identifying characteristics, allowing them to be classified, and their age determined.

This also applies to rocks, minerals, and derivative materials such as sediments and soil. The chemical composition of Earth’s crust has similarities with other stony planets, with silicate-rich rocks being dominant in most locations on the surface. In addition, basic geologic principles can be applied to resolving the order of events leading to the formation of rocks and landscape features. This section presents many basic concepts that are universal to all physical sciences.

Click on thumbnail images for a larger view. Layered rocks in a sea cliff in Encinitas, CA with an angular unconformity. What are “rocks” and “minerals” – explain the differences. Describe essential concepts of chemistry related to earth materials. What is the chemical and mineral composition of the Earth’s crust?

Law of Superposition


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