DOCSLIB.ORG

Geologic Time, Concepts, and Principles

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geologic Time, Concepts, and Principles GEOLOGIC TIME, CONCEPTS, AND PRINCIPLES Sources: www.google.com en.wikipedia.org Thompson Higher Education 2007; Monroe, Wicander, and Hazlett, Physical orgs.usd.edu/esci/age/content/failed_scientific_clocks/ocean_salinity.html https://web.viu.ca/earle/geol305/Radiocarbon%20dating.pdf TCNJ PHY120 2013 GCHERMAN GEOLOGIC TIME, CONCEPTS, AND PRINCIPLES • Early estimates of the age of the Earth • James Hutton and the recognition of geologic time • Relative dating methods • Correlating rock units • Absolute dating methods • Development of the Geologic Time Scale • Geologic time and climate •Relative dating is accomplished by placing events in sequential order with the aid of the principles of historical geology . •Absolute dating provides chronometric dates expressed in years before present from using radioactive decay rates. TCNJ PHY120 2013 GCHERMAN TCNJ PHY120 2013 GCHERMAN Geologic time on Earth • A world-wide relative time scale of Earth's rock record was established by the work of many geologists, primarily during the 19 th century by applying the principles of historical geology and correlation to strata of all ages throughout the world. Covers 4.6 Ba to the present • Eon – billions to hundreds of millions • Era - hundreds to tens of millions • Period – tens of millions • Epoch – tens of millions to hundreds of thousands TCNJ PHY120 2013 GCHERMAN TCNJ PHY120 2013 GCHERMAN EARLY ESTIMATES OF EARTH’S AGE • Scientific attempts to estimate Earth's age were first made during the 18th and 19th centuries. These attempts all resulted in ages far younger than the actual age of Earth. 1778 ‘Iron balls’ Buffon 1710 – 1910 ‘salt clocks’ Georges-Louis Leclerc de Buffon • Biblical account (1600’S) 26 – 150 Ma for the oceans to become 74,832 years old and that as salty as they are from streams humans were relative newcomers. carrying low-concentrations of salt into an initially fresh-water ocean TCNJ PHY120 2013 GCHERMAN THE FOUNDERS OF MODERN GEOLOGY is considered to be the founder of modern geology. •Hutton first suggested that present day processes operating over long periods of time could explain all 1830 Principles of Geology geologic features. •Argued convincingly for Hutton's conclusions and established the •Hutton’s observations led to the principle of uniformitarianism as establishment of the principle of the guiding principle of geology . uniformitarianism . TCNJ PHY120 2013 GCHERMAN PRINCIPLES OF UNIFORMITARIANISM •This principle simply states that all investigations can assume that physical and chemical laws have operated through time, and the same processes which operate today (with allowance for varying rates), have also operated throughout Earth's history. TCNJ PHY120 2013 GCHERMAN PRINCIPLES OF UNIFORMITARIANISM Stephen Jay Gould (September 10, 1941 – May 20, 2002) was an American paleontologist, evolutionary biologist, and historian of science. He was also one of the most influential and widely read writers of popular science of his generation. He spent most of his career teaching at Harvard University and working at the American Museum of Natural History (NY). In the latter years of his life, Gould also taught biology and evolution at New York University. Gould's most significant contribution to evolutionary biology was the theory of punctuated equilibrium , which he developed with Niles Eldredge in 1972. Gould argued that Hutton's interpretation of uniformitarianism actually included a cyclical series of events in which all of Earth history was repeated with "repair" of the earlier age, much as many primal societies view time as a cyclical, rather than linear, phenomenon. Furthermore, the rates of geological processes were not required to be constant or gradual in either Hutton's or Lyell's concept of uniformitarianism. Similarly, catastrophism was not originally linked to a sequence of "special creations" or similar total recreation of the world geology and life. Instead, each sequence bounded by unconformities and containing a "new biosphere" was believed to be the result of a "revolution" which did not invoke any suspension of presently operating laws of nature. TCNJ PHY120 2013 GCHERMAN FUNDAMENTAL PRINCIPLES OF RELATIVE DATING •Relative dating is accomplished by placing events in sequential order with the aid of the principles of historical geology . •Six fundamental principles: 1) Superposition – undisturbed strata are younger on top and older on the bottom 2) Original horizontality – strata are deposited as flat, horizontal layers 3) Lateral continuity – strata are laterally continuous until they pinch out 4) Cross-cutting relationships – younger features cross-cut older features 5) Inclusions – fragments contained in rocks are older than the rock 6) Fossil succession - stratigraphic layers of the same age contain the same fossils TCNJ PHY120 2013 GCHERMAN 3 of 6 PRINCIPLES OF RELATIVE DATING ESTABLISHED BY NICOLAS STENO 1) Superposition – undisturbed strata are younger on top and older on the bottom 2) Original horizontality – strata are deposited as flat, horizontal layers 3) Lateral continuity – strata are laterally continuous until they pinch out •Observed the burial of organisms on flooplains by gravity-settled sediment. •Subsequent floods covered previous deposits. •Layers are laid-down essentially horizontal, and •Extend laterally until they either pinch out or terminate against the edge of the depositional basin boundary TCNJ PHY120 2013 GCHERMAN FUNDAMENTAL PRINCIPLES OF RELATIVE DATING (cont.) 4) Cross-cutting relationships – younger features cross-cut older features Basic dike cuts This principle is attributed to Fault cuts and offsets strata and country rock and is James Hutton who first realized the is therefore a relatively younger therefore a younger significance of unconformities at structure structure Siccar Point, Scotland TCNJ PHY120 2013 GCHERMAN FUNDAMENTAL PRINCIPLES OF RELATIVE DATING (cont.) 5) Inclusions – fragments contained in rocks are older than the rock • Sills have two baked margins and may have inclusions from the bounding beds • Lava flows on Earth’s surface and may have pieces ripped up and included in overlying detrital bed. •Only the bottom contact is baked. TCNJ PHY120 2013 GCHERMAN FUNDAMENTAL PRINCIPLES OF RELATIVE DATING 5) Inclusions – fragments contained in rocks are older than the rock Top - SS older than igneous activity basalt inclusion in a granite from Wisconsin Bottom - Granite older than SS TCNJ PHY120 2013 GCHERMAN FUNDAMENTAL PRINCIPLES OF RELATIVE DATING (cont.) 6) Fossil succession •An English civil engineer noticed while building a canal in England independently recognized the principle of superposition by reasoning that fossils seen in the excavation bottom were older than those in overlying, leading to the principle of faunal and flora succession. TCNJ PHY120 2013 GCHERMAN FUNDAMENTAL PRINCIPLES OF RELATIVE DATING 6) Fossil succession - Stratigraphic layers of the same age contain the same collection of fossils Section B contains the youngest rocks ‘key bed’ or ‘marker horizon’ Section C contains the oldest rocks TCNJ PHY120 2013 GCHERMAN SUMMARY OF PRINCIPLES OF HISTORICAL GEOLOGY •The principles of historical geology, in addition to uniformitarianism , are superposition, original horizontality, cross-cutting relationships, lateral continuity, inclusions, and fossil succession. •These principles are used to determine the sequence of geologic events and to interpret them. TCNJ PHY120 2013 GCHERMAN UNCONFORMITIES are surfaces of discontinuity in the rock deposition sequence which encompass significant periods of time . •Unconformities 1 Ma nondeposition may result from nondeposition and/or erosion . erosion 3 Ma 2 Ma TCNJ PHY120 2013 GCHERMAN UNCONFORMITIES 1) Disconformity – Surface separates parallel strata on either side 2) Angular unconformity – Surface separates strata tilted differently 3) Nonconformity – Surface cut into crystalline (igneous and/or metamorphic) rocks, then covered by sedimentary rocks TCNJ PHY120 2013 GCHERMAN UNCONFORMITIES Nonconformity Angular unconformity Disconformity TCNJ PHY120 2013 GCHERMAN RELATIVE DATING EXAMPLE TCNJ PHY120 2013 GCHERMAN RELATIVE DATING EXAMPLE solution TCNJ PHY120 2013 GCHERMAN STRATIGRAPHIC CORRELATION is the demonstration of equivalency of rock units from one area to another. Key beds are stratigraphic units such as coal beds or ash layers, that are sufficiently distinctive to allow identification of the same unit in different places or area. TCNJ PHY120 2013 GCHERMAN STRATIGRAPHIC CORRELATION An example of using key beds to correlate stratigraphic sections ~65 Ma from three National Parks Key bed 1: in the southwest USA Navajo Sandstone totaling over 400 Ma of rock succession > 1 Ba Key bed 2: ~550 Ma Kaibab Limestone TCNJ PHY120 2013 GCHERMAN GEOLOGIC TIME, CONCEPTS, AND PRINCIPLES • Good guide fossils have • Time equivalence is usually demonstrated rather short intervals of by the occurrence of similar fossils (guide existence fossils) in strata. Note the facies change but time equivalence TCNJ PHY120 2013 GCHERMAN TCNJ PHY120 2013 GCHERMAN TCNJ PHY120 2013 GCHERMAN THE K-T BOUNDARY MARKER HORIZON Cooling at this time is consistent with a global sea-level drop of ~40 m beginning in geomagnetic polarity chron 30n and ending in chron 28r, clearly spanning the K-T boundary. This event followed closely on a sharp sea-level drop and subsequent rise of ~30 m, coincident with the highest δ 18 O values recorded for the 30 My before or afterward, which occurred in the middle of chron 30n, ~1 My before the
Load more

Recommended publications
  • History of Geology
    FEBRUARY 2007 PRIMEFACT 563 (REPLACES MINFACT 60) History of geology Mineral Resources Early humans needed a knowledge of simple geology to enable them to select the most suitable rock types both for axe-heads and knives and for the ornamental stones they used in worship. In the Neolithic and Bronze Ages, about 5000 to 2500 BC, flint was mined in the areas which are now Belgium, Sweden, France, Portugal and Britain. While Stone Age cultures persisted in Britain until after 2000 BC, in the Middle East people began to mine useful minerals such as iron ore, tin, clay, gold and copper as early as 4000 BC. Smelting techniques were developed to make the manufacture of metal tools possible. Copper was probably the earliest metal to be smelted, that is, extracted from its ore by melting. Copper is obtained easily by reducing the green copper carbonate mineral malachite, itself regarded as a precious stone. From 4000 BC on, the use of clay for brick-making became widespread. The Reverend William Branwhite Clarke (1798-1878), smelting of iron ore for making of tools and the ‘father’ of geology in New South Wales weapons began in Asia Minor at about 1300 BC but did not become common in Western Europe until Aristotle believed volcanic eruptions and nearly 500 BC. earthquakes were caused by violent winds escaping from the interior of the earth. Since earlier writers had ascribed these phenomena to The classical period supernatural causes, Aristotle's belief was a By recognising important surface processes at marked step forward. Eratosthenes, a librarian at work, the Greek, Arabic and Roman civilisations Alexandria at about 200 BC, made surprisingly contributed to the growth of knowledge about the accurate measurements of the circumference of earth.
    [Show full text]
  • Geologic Time Two Ways to Date Geologic Events Steno's Laws
    Frank Press • Raymond Siever • John Grotzinger • Thomas H. Jordan Understanding Earth Fourth Edition Chapter 10: The Rock Record and the Geologic Time Scale Lecture Slides prepared by Peter Copeland • Bill Dupré Copyright © 2004 by W. H. Freeman & Company Geologic Time Two Ways to Date Geologic Events A major difference between geologists and most other 1) relative dating (fossils, structure, cross- scientists is their concept of time. cutting relationships): how old a rock is compared to surrounding rocks A "long" time may not be important unless it is greater than 1 million years 2) absolute dating (isotopic, tree rings, etc.): actual number of years since the rock was formed Steno's Laws Principle of Superposition Nicholas Steno (1669) In a sequence of undisturbed • Principle of Superposition layered rocks, the oldest rocks are • Principle of Original on the bottom. Horizontality These laws apply to both sedimentary and volcanic rocks. Principle of Original Horizontality Layered strata are deposited horizontal or nearly horizontal or nearly parallel to the Earth’s surface. Fig. 10.3 Paleontology • The study of life in the past based on the fossil of plants and animals. Fossil: evidence of past life • Fossils that are preserved in sedimentary rocks are used to determine: 1) relative age 2) the environment of deposition Fig. 10.5 Unconformity A buried surface of erosion Fig. 10.6 Cross-cutting Relationships • Geometry of rocks that allows geologists to place rock unit in relative chronological order. • Used for relative dating. Fig. 10.8 Fig. 10.9 Fig. 10.9 Fig. 10.9 Fig. Story 10.11 Fig.
    [Show full text]
  • GE OS 1234-101 Historical Geology Lecture Syllabus Instructor
    G E OS 1234-101 Historical Geology Lecture Syllabus Instructor: Dr. Jesse Carlucci ([email protected]), (940) 397-4448 Class: MWF, 10am -10:50am, BO 100 Office hours: Bolin Hall 131, MWF, 11am ± 2pm, Tuesday, noon - 2pm. You can arrange to meet with me at any time, by appointment. Textbook: Earth System History by Steven M. Stanley, 3rd edition. I will occasionally post articles and other readings on blackboard. I will also upload Power Point presentations to blackboard before each class, if possible. Course Objectives: Historical Geology provides the student with a comprehensive survey of the history of life, and major events in the physical development of Earth. Most importantly, this class addresses how processes like plate tectonics and climate interact with life, forming an integrated system. The first half of the class focuses on concepts, and the second on a chronologic overview of major biological and physical events in different geologic periods. L E C T UR E SC H E DU L E Aug 27-31: Overview of course; what is science? The Earth as a planet Stanley (pg. 244-247) Sep 5-7: Earth materials, rocks and minerals Stanley (pg. 13-17; 25-34) Sep 10-14: Rocks & minerals continued; plate tectonics. Stanley (pg. 3-12; 35-46; 128-141; 175-186) Sep 17-21: Geological time and dating of the rock record; chemical systems, the climate system through time. Quiz 1 (Sep 19; 5%). Stanley (pg. 187-194; 196-207; 215-223; 232-238) Sep 24-28: Sedimentary environments and life; paleoecology. Stanley (pg. 76-80; 84-96; 99-123) Oct 1-5: Biological evolution and the fossil record.
    [Show full text]
  • Lab 7: Relative Dating and Geological Time
    LAB 7: RELATIVE DATING AND GEOLOGICAL TIME Lab Structure Synchronous lab work Yes – virtual office hours available Asynchronous lab work Yes Lab group meeting No Quiz None – Test 2 this week Recommended additional work None Required materials Pencil Learning Objectives After carefully reading this chapter, completing the exercises within it, and answering the questions at the end, you should be able to: • Apply basic geological principles to the determination of the relative ages of rocks. • Explain the difference between relative and absolute age-dating techniques. • Summarize the history of the geological time scale and the relationships between eons, eras, periods, and epochs. • Understand the importance and significance of unconformities. • Explain why an understanding of geological time is critical to both geologists and the general public. Key Terms • Eon • Original horizontality • Era • Cross-cutting • Period • Inclusions • Relative dating • Faunal succession • Absolute dating • Unconformity • Isotopic dating • Angular unconformity • Stratigraphy • Disconformity • Strata • Nonconformity • Superposition • Paraconformity Time is the dimension that sets geology apart from most other sciences. Geological time is vast, and Earth has changed enough over that time that some of the rock types that formed in the past could not form Lab 7: Relative Dating and Geological Time | 181 today. Furthermore, as we’ve discussed, even though most geological processes are very, very slow, the vast amount of time that has passed has allowed for the formation of extraordinary geological features, as shown in Figure 7.0.1. Figure 7.0.1: Arizona’s Grand Canyon is an icon for geological time; 1,450 million years are represented by this photo.
    [Show full text]
  • GEOL 1104 Historical Geology
    Administrative Master Syllabus Course Information Course Title Historical Geology Laboratory Course Prefix, Num. and Title GEOL 1104 Division Life Sciences Department Geology Course Type Academic WCJC Core Course Course Catalog Description This laboratory-based course accompanies GEOL 1304, Historical Geography. Laboratory activities will introduce methods used by scientists to interpret the history of life and major events in the physical development of Earth from rocks and fossils. Pre-Requisites Credit for or concurrent enrollment in GEOL1304 Co-Requisites Enter Co-Requisites Here. Semester Credit Hours Total Semester Credit Hours (SCH): Lecture Hours: 1:0:2 Lab/Other Hours Equated Pay Hours 1.2 Lab/Other Hours Breakdown: Lab Hours 2 Lab/Other Hours Breakdown: Clinical Hours Enter Clinical Hours Here. Lab/Other Hours Breakdown: Practicum Hours Enter Practicum Hours Here. Other Hours Breakdown List Total Lab/Other Hours Here. Approval Signatures Title Signature Date Prepared by: Department Head: Division Chair: Dean/VPI: Approved by CIR: Rev. January 2020 Additional Course Information Topical Outline: Each offering of this course must include the following topics (be sure to include information regarding lab, practicum, and clinical or other non-lecture instruction). 1. The Sedimentary Environment 2. Geochronology Part I: Relative Dating of Strata 3. Geochronology Part II: Absolute or Radiometric Dating of Strata 4. Fossils, Taxonomy, and the Species Concept 5. The Sponges: Early Multi-celled Animals 6. The Corals and their Relatives 7. The Bryozoans: “Lacy Animals” 8. The Brachiopods: Bivalved Lophophorates 9. The Bivalves: Clams, Oysters, and Relatives 10. The Gastropods: Snails, Slugs, and Relativesacticum, and clinical or other non-lecture instruction).
    [Show full text]
  • The Importance of French Transformist Ideas for the Second Volume of Lyell’S Principles of Geology Pietro Corsi
    The importance of french transformist ideas for the second volume of lyell’s principles of geology Pietro Corsi To cite this version: Pietro Corsi. The importance of french transformist ideas for the second volume of lyell’s principles of geology. 2004. halshs-00002894 HAL Id: halshs-00002894 https://halshs.archives-ouvertes.fr/halshs-00002894 Preprint submitted on 20 Sep 2004 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THE BRITISH JOURNAL FOR THE HISTORY OF SCIENCE Vol. II t No. 39 (1978) < 221 > THE IMPORTANCE OF FRENCH TRANSFORMIST IDEAS FOR THE SECOND VOLUME OF LYELL'S PRINCIPLES OF GEOLOGY PIETRO CORSI* RECENTLY there has been considerable revaluation of the development of natural sciences in the early nineteenth century, dealing among other things with the works and ideas of Charles Lyell. The task of interpreting Lyell in balanced terms is extremely complex because his activities covered many fields of research, and because his views have been unwarrantably distorted in order to make him the precursor of various modern scientific positions. Martin Rudwick in particular has contributed several papers relating to Lyell's Principles of geology, and has repeatedly stressed the need for a comprehensive evaluation of Lyell's scientific proposals, and of his position in the culture of his time.
    [Show full text]
  • Ice-Core Dating of the Pleistocene/Holocene
    [RADIOCARBON, VOL 28, No. 2A, 1986, P 284-291] ICE-CORE DATING OF THE PLEISTOCENE/HOLOCENE BOUNDARY APPLIED TO A CALIBRATION OF THE 14C TIME SCALE CLAUS U HAMMER, HENRIK B CLAUSEN Geophysical Isotope Laboratory, University of Copenhagen and HENRIK TAUBER National Museum, Copenhagen, Denmark ABSTRACT. Seasonal variations in 180 content, in acidity, and in dust content have been used to count annual layers in the Dye 3 deep ice core back to the Late Glacial. In this way the Pleistocene/Holocene boundary has been absolutely dated to 8770 BC with an estimated error limit of ± 150 years. If compared to the conventional 14C age of the same boundary a 0140 14C value of 4C = 53 ± 13%o is obtained. This value suggests that levels during the Late Glacial were not substantially higher than during the Postglacial. INTRODUCTION Ice-core dating is an independent method of absolute dating based on counting of individual annual layers in large ice sheets. The annual layers are marked by seasonal variations in 180, acid fallout, and dust (micro- particle) content (Hammer et al, 1978; Hammer, 1980). Other parameters also vary seasonally over the annual ice layers, but the large number of sam- ples needed for accurate dating limits the possible parameters to the three mentioned above. If accumulation rates on the central parts of polar ice sheets exceed 0.20m of ice per year, seasonal variations in 180 may be discerned back to ca 8000 BP. In deeper strata, ice layer thinning and diffusion of the isotopes tend to obliterate the seasonal 5 pattern.1 Seasonal variations in acid fallout and dust content can be traced further back in time as they are less affected by diffusion in ice.
    [Show full text]
  • The Geohistorical Time Arrow: from Steno's Stratigraphic Principles To
    JOURNAL OF GEOSCIENCE EDUCATION 62, 691–700 (2014) The Geohistorical Time Arrow: From Steno’s Stratigraphic Principles to Boltzmann’s Past Hypothesis Gadi Kravitz1,a ABSTRACT Geologists have always embraced the time arrow in order to reconstruct the past geology of Earth, thus turning geology into a historical science. The covert assumption regarding the direction of time from past to present appears in Nicolas Steno’s principles of stratigraphy. The intuitive–metaphysical nature of Steno’s assumption was based on a biblical narrative; therefore, he never attempted to justify it in any way. In this article, I intend to show that contrary to Steno’s principles, the theoretical status of modern geohistory is much better from a scientific point of view. The uniformity principle enables modern geohistory to establish the time arrow on the basis of the second law of thermodynamics, i.e., on a physical law, on the one hand, and on a historical law, on the other. In other words, we can say that modern actualism is based on the uniformity principle. This principle is essentially based on the principle of causality, which in turn obtains its justification from the second law of thermodynamics. I will argue that despite this advantage, the shadow that metaphysics has cast on geohistory has not disappeared completely, since the thermodynamic time arrow is based on a metaphysical assumption—Boltzmann’s past hypothesis. All professors engaged in geological education should know these philosophical–theoretical arguments and include them in the curriculum of studies dealing with the basic assumptions of geoscience in general and the uniformity principle and deep time in particular.
    [Show full text]
  • Full-Text PDF (Final Published Version)
    Pritchard, M. E., de Silva, S. L., Michelfelder, G., Zandt, G., McNutt, S. R., Gottsmann, J., West, M. E., Blundy, J., Christensen, D. H., Finnegan, N. J., Minaya, E., Sparks, R. S. J., Sunagua, M., Unsworth, M. J., Alvizuri, C., Comeau, M. J., del Potro, R., Díaz, D., Diez, M., ... Ward, K. M. (2018). Synthesis: PLUTONS: Investigating the relationship between pluton growth and volcanism in the Central Andes. Geosphere, 14(3), 954-982. https://doi.org/10.1130/GES01578.1 Publisher's PDF, also known as Version of record License (if available): CC BY-NC Link to published version (if available): 10.1130/GES01578.1 Link to publication record in Explore Bristol Research PDF-document This is the final published version of the article (version of record). It first appeared online via Geo Science World at https://doi.org/10.1130/GES01578.1 . Please refer to any applicable terms of use of the publisher. University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ Research Paper THEMED ISSUE: PLUTONS: Investigating the Relationship between Pluton Growth and Volcanism in the Central Andes GEOSPHERE Synthesis: PLUTONS: Investigating the relationship between pluton growth and volcanism in the Central Andes GEOSPHERE; v. 14, no. 3 M.E. Pritchard1,2, S.L. de Silva3, G. Michelfelder4, G. Zandt5, S.R. McNutt6, J. Gottsmann2, M.E. West7, J. Blundy2, D.H.
    [Show full text]
  • Geologic Timeline
    SCIENCE IN THE PARK: GEOLOGY GEOLOGIC TIME SCALE ANALOGY PURPOSE: To show students the order of events and time periods in geologic time and the order of events and ages of the physiographic provinces in Virginia. BACKGROUND: Exact dates for events change as scientists explore geologic time. Dates vary from resource to resource and may not be the same as the dates that appear in your text book. Analogies for geologic time: a 24 hour clock or a yearly calendar. Have students or groups of students come up with their own original analogy. Before you assign this activity, you may want to try it, depending on the age of the student, level of the class, or time constraints, you may want to leave out the events that have a date of less than 1 million years. ! Review conversions in the metric system before you begin this activity ! References L.S. Fichter, 1991 (1997) http://csmres.jmu.edu/geollab/vageol/vahist/images/Vahistry.PDF http://pubs.usgs.gov/gip/geotime/age.html Wicander, Reed. Historical Geology. Fourth Edition. Toronto, Ontario: Brooks/Cole, 2004. Print. VIRGINIA STANDARDS OF LEARNING ES.10 The student will investigate and understand that many aspects of the history and evolution of the Earth can be inferred by studying rocks and fossils. Key concepts include: relative and absolute dating; rocks and fossils from many different geologic periods and epochs are found in Virginia. Developed by C.P. Anderson Page 1 SCIENCE IN THE PARK: GEOLOGY Building a Geologic Time Scale Time: Materials Meter stick, 5 cm adding machine tape, pencil, colored pencils Procedure 1.
    [Show full text]
  • Scientific Dating of Pleistocene Sites: Guidelines for Best Practice Contents
    Consultation Draft Scientific Dating of Pleistocene Sites: Guidelines for Best Practice Contents Foreword............................................................................................................................. 3 PART 1 - OVERVIEW .............................................................................................................. 3 1. Introduction .............................................................................................................. 3 The Quaternary stratigraphical framework ........................................................................ 4 Palaeogeography ........................................................................................................... 6 Fitting the archaeological record into this dynamic landscape .............................................. 6 Shorter-timescale division of the Late Pleistocene .............................................................. 7 2. Scientific Dating methods for the Pleistocene ................................................................. 8 Radiometric methods ..................................................................................................... 8 Trapped Charge Methods................................................................................................ 9 Other scientific dating methods ......................................................................................10 Relative dating methods ................................................................................................10
    [Show full text]
  • Mineralogy and Origin of the Titanium
    MINERALOGY AND ORIGIN OF THE TITANIUM DEPOSIT AT PLUMA HIDALGO, OAXACA, MEXICO by EDWIN G. PAULSON S. B., Massachusetts Institute of Technology (1961) SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 18, 1962 Signature of At r . Depardnent of loggand Geophysics, May 18, 1962 Certified by Thesis Supervisor Ab Accepted by ...... Chairman, Departmental Committee on Graduate Students M Abstract Mineralogy and Origin of the Titanium Deposit at Pluma Hidalgo, Oaxaca, Mexico by Edwin G. Paulson "Submitted to the Department of Geology and Geophysics on May 18, 1962 in partial fulfillment of the requirements for the degree of Master of Science." The Pluma Hidalgo titanium deposits are located in the southern part of the State of Oaxaca, Mexico, in an area noted for its rugged terrain, dense vegetation and high rainfall. Little is known of the general and structural geology of the region. The country rocks in the area are a series of gneisses containing quartz, feldspar, and ferromagnesians as the dominant minerals. These gneisses bear some resemblance to granulites as described in the literature. Titanium minerals, ilmenite and rutile, occur as disseminated crystals in the country rock, which seems to grade into more massive and large replacement bodies, in places controlled by faulting and fracturing. Propylitization is the main type of alteration. The mineralogy of the area is considered in some detail. It is remarkably similar to that found at the Nelson County, Virginia, titanium deposits. The main minerals are oligoclase - andesine antiperthite, oligoclase- andesine, microcline, quartz, augite, amphibole, chlorite, sericite, clinozoi- site, ilmenite, rutile, and apatite.
    [Show full text]