SW Science 10 Unit 6 Relative Dating Worksheet Name: __________________________________ Student #: ____________ 6.2 Geologic Time 6.2.2 Relative Dating The Law of Superposition In any undisturbed sequence of strata, the oldest layer is at the bottom of the sequence, and the youngest layer is at the top of the sequence. The Cross-Cutting Law Any feature that cuts across a body of sediment or rock is younger than the body of sediment or rock that it cuts across. NOTE: • A fracture is a crack in rock. • A fault is a fracture along which movement has occurred. The Law of Inclusions If one rock body contains fragments of another rock body it must be younger than the fragments of rock it contains. OR…The inclusions are older than the rocks which contain them. Inclusions Inclusions of B are older than C. Page 2 Telling Relative Time Use the laws of superposition, inclusions and cross-cutting relationships to determine the relative ages of the following cross-sections. Determine the OLDEST bed FIRST. 1 2 3 SW SC10 UNIT 6 Earth Forces Relative Dating WS Page 3 H G F E C D B A 4 M 5 Outline the sequence of events in the cross sections below by numbering each rock unit or event in the order in which it occurred or was deposited. Youngest ________ ________ ________ ________ 6 Oldest ________ E SW SC10 UNIT 6 Earth Forces Relative Dating WS Page 4 C Refer to the cross-section on the left. For each of the following pairs of rock layers, identify the relative dating law that would be used to determine which bed was older and which was younger. Circle the letter of the OLDER bed. 7 A & B ________________________ C & D ________________________ D & E ________________________ J & K ________________________ 8 Refer to the cross-section above. for each of the following pairs of rock layers identify the relative dating law that you used to determine which bed was older and which was younger. Circle the letter of the YOUNGER bed. M & A ______________________________________________________ J & N ______________________________________________________ H & C ______________________________________________________ D & M ________________________________________________________ SW SC10 UNIT 6 Earth Forces Relative Dating WS .
Recommended publications Geologic Time Two Ways to Date Geologic Events Steno's LawsFrank 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.
Lab 7: Relative Dating and Geological TimeLAB 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.
Mechanical Stratigraphic Controls on Natural Fracture Spacing and PenetrationJournal of Structural Geology 95 (2017) 160e170 Contents lists available at ScienceDirect Journal of Structural Geology journal homepage: www.elsevier.com/locate/jsg Mechanical stratigraphic controls on natural fracture spacing and penetration * Ronald N. McGinnis a, , David A. Ferrill a, Alan P. Morris a, Kevin J. Smart a, Daniel Lehrmann b a Department of Earth, Material, and Planetary Sciences, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166, USA b Geoscience Department, Trinity University, One Trinity Place, San Antonio, TX 78212, USA article info abstract Article history: Fine-grained low permeability sedimentary rocks, such as shale and mudrock, have drawn attention as Received 20 July 2016 unconventional hydrocarbon reservoirs. Fracturing e both natural and induced e is extremely important Received in revised form for increasing permeability in otherwise low-permeability rock. We analyze natural extension fracture 21 December 2016 networks within a complete measured outcrop section of the Ernst Member of the Boquillas Formation Accepted 7 January 2017 in Big Bend National Park, west Texas. Results of bed-center, dip-parallel scanline surveys demonstrate Available online 8 January 2017 nearly identical fracture strikes and slight variation in dip between mudrock, chalk, and limestone beds. Fracture spacing tends to increase proportional to bed thickness in limestone and chalk beds; however, Keywords: Mechanical stratigraphy dramatic differences in fracture spacing are observed in mudrock. A direct relationship is observed be- Natural fractures tween fracture spacing/thickness ratio and rock competence. Vertical fracture penetrations measured Fracture spacing from the middle of chalk and limestone beds generally extend to and often beyond bed boundaries into Fracture penetration the vertically adjacent mudrock beds.
Scientific Dating of Pleistocene Sites: Guidelines for Best Practice ContentsConsultation 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
Personal Details: Relative Dating Methods Archaeology; PrinciplesComponent-I (A) – Personal details: Archaeology; Principles and Methods Relative Dating Methods Prof. P. Bhaskar Reddy Sri Venkateswara University, Tirupati. Prof. K.P. Rao University of Hyderabad, Hyderabad. Prof. K. Rajan Pondicherry University, Pondicherry. Prof. R. N. Singh Banaras Hindu University, Varanasi. 1 Component-I (B) – Description of module: Subject Name Indian Culture Paper Name Archaeology; Principles and Methods Module Name/Title Relative Dating Methods Module Id IC / APM / 17 Pre requisites Objectives Archaeology / Stratigraphy / Dating / Keywords Geochronology E-Text (Quadrant-I) : 1. Introduction In archaeology, the material unearthed in the excavations and archaeological remains surfaced and documented in the explorations are dated by following two methods namely, absolute dating method and relative dating method. In the former method, the artefacts are being preciously dated using various scientific techniques and in a few cases it is dated based on the hidden historical data available with historical documents such as inscriptions, copper plates, seals, coins, inscribed portrait sculptures and monuments. In the latter method, a tentative date is achieved based on archaeological stratigraphy, seriation, palaeography, linguistic style, context, art and architectural features. Though the absolute dates are the most desirable one, the significance of relative dates increases manifold when the absolute dates are not available. Till advent of the scientific techniques, most of the archaeological and historical objects were dated based on relative dating methods. Archaeologists are resorted to the use of relative dating techniques when the absolute dates are not possible or feasible. Estimation of the age was merely a guess work in the initial stage of archaeological investigation particularly in 18th-19th centuries.
How Do Sedimentary Beds Form? – and Why Can We See Them? Demonstrating How the Beds in Sedimentary Rocks Are Deposited
Earthlearningidea – https://www.earthlearningidea.com How do sedimentary beds form? – and why can we see them? Demonstrating how the beds in sedimentary rocks are deposited Sedimentary rock layers are called beds, if they are more than 1 cm thick*. Each bed was laid down by a single sedimentary event, so the beds in the photo below were laid down by many, many separate events of sand deposition. The junction between beds is called a bedding plane and is normally a flat horizontal surface. Bedding in a measuring cylinder, with sands of different colour on the left and sands of one colour (but added in several sedimentary episodes or spoonfuls) on the right. (Chris King). So, later when the sands have been compacted and cemented to form sandstones, the slight Bedding in 140 million year old sedimentary rocks, Morro differences between the top of one bed and the Solar, Lima, Peru. This series of beds has been tilted by bottom of another remain. These are later tectonic forces. attacked by weathering and erosion so that the Image licensed by Miguel Vera León under the Creative bedding plane and the beds can be seen. Commons Attribution 2.0 Generic license. Bedding planes are even clearer if there was an You can make your own beds by filling a 2 interval of time between the laying down of the measuring cylinder /3 full of water and adding upper and lower beds. In that time interval, the spoonfuls of sand. Each spoonful you add is a lower bed may have become more compacted, or single sedimentary episode and the junction partially eroded or sedimentary structures like between each layer is a bedding plane.
Earth Science Power StandardsMacomb Intermediate School District High School Science Power Standards Document Earth Science The Michigan High School Science Content Expectations establish what every student is expected to know and be able to do by the end of high school. They also outline the parameters for receiving high school credit as dictated by state law. To aid teachers and administrators in meeting these expectations the Macomb ISD has undertaken the task of identifying those content expectations which can be considered power standards. The critical characteristics1 for selecting a power standard are: • Endurance – knowledge and skills of value beyond a single test date. • Leverage - knowledge and skills that will be of value in multiple disciplines. • Readiness - knowledge and skills necessary for the next level of learning. The selection of power standards is not intended to relieve teachers of the responsibility for teaching all content expectations. Rather, it gives the school district a common focus and acts as a safety net of standards that all students must learn prior to leaving their current level. The following document utilizes the unit design including the big ideas and real world contexts, as developed in the science companion documents for the Michigan High School Science Content Expectations. 1 Dr. Douglas Reeves, Center for Performance Assessment Unit 1: Organizing Principles of Earth Science Big Idea Processes, events and features on Earth result from energy transfer and movement of matter through interconnected Earth systems. Contextual Understandings Earth science is an umbrella term for the scientific disciplines of geology, meteorology, climatology, hydrology, oceanography, and astronomy. Earth systems science has given an improved, interdisciplinary perspective to researchers in fields concerned with global change, such as climate change and geologic history.
Stage 1А–Аdesired Resultswww.nextgenscience.org STAGE 1 – DESIRED RESULTS Unit Title: Earth’s Place in the Universe Grade Level: 6 Length/Timing of Unit: Teacher(s)/Designer(s): Pascack Valley Regional Science Committee Science State standards addressed (verbatim): MSESS11 . Develop and use a model of the Earthsunmoon system to describe the cyclic patterns of lunar phases, eclipses of the sun and moon, and seasons. [Clarification Statement: Examples of models can be physical, graphical, or conceptual.] MSESS12. Develop and use a model to describe the role of gravity in the motions within galaxies and the solar system. [Clarification Statement: Emphasis for the model is on gravity as the force that holds together the solar system and Milky Way galaxy and controls orbital motions within them. Examples of models can be physical (such as the analogy of distance along a football field or computer visualizations of elliptical orbits) or conceptual (such as mathematical proportions relative to the size of familiar objects such as students’ school or state).] [Assessment Boundary: Assessment does not include Kepler’s Laws of orbital motion or the apparent retrograde motion of the planets as viewed from Earth.] MSESS13. Analyze and interpret data to determine scale properties of objects in the solar system. [Clarification Statement: Emphasis is on the analysis of data from Earthbased instruments, spacebased telescopes, and spacecraft to determine similarities and differences among solar system objects. Examples of scale properties include the sizes of an object’s layers (such as crust and atmosphere), surface features (such as volcanoes), and orbital radius.
6. Relative and Absolute Dating Relative Dating Unit BGeologic Time Part I: Relative Dating Unit B Unit A James Hutton conceived of the Principle of Uniformitarianism at Sicar Point, Scotland in 1785. Think about how much time would pass to create the rock record shown above. What sequence of events would occur to produce the above record? Unit B Unit A 1. Deposition of sediment comprising Unit A (Sedimentation rates in the deep ocean range from .0005 - .001 mm per year). How long would it take to accumulate 200 meters of sediment?) 2. burial compaction & lithification of Unit A, 3. deformation (folding) of Unit A, 4. uplift and erosion of Unit A, 5. Deposition of sediment (Unit B), 6. burial compaction & lithification of Unit B, 7. deformation (folding) of Unit B, 8. uplift and erosion of Unit B. These geologic events require millions of years of time! Principle of Original Horizontality: Layered sedimentary rock is typically deposited horizontally, but can be deformed by tectonic processes. Can you think of a depositional environment where sedimentary layers are not deposited horizontally? Geologists use sedimentary structures to determine whether sedimentary layers or beds are right-side up, vertical or overturned. The Principle of Uniformitarianism states that the “present is the key to the past.” Those processes operating at the earth’s surface today are inferred to have operated in the past, such as the mudcracks forming in a playa lake today. Note the blowing sand in the background will fill in the cracks. The mudcracks shown above formed over 1.1 billion years ago in a dry lake basin are now found in Glacier National Park, Montana.
B-127 Lithostratigraphic Framework Of&A 'NlOO,G-3 &i flo, 12 7 g l F£i&f THE LITHOSTRATIGRAPHIC FRAMEWORK OF \;\ .-t "- THE UPPERMOST CRETACEOUS AND LOWER TERTIARY OF EASTERN BURKE COUNTY, GEORGIA Paul F. Huddlestun and Joseph H. Summerour Work Performed in Cooperation with United States Geological Survey (Cooperative Agreement Number 1434-92-A-0959) and U. S. Department of Energy (Cooperative Agreement Number DE-FG-09-92SR12868) GEORGIA DEPARTMENT OF NATURAL RESOURCES ENVIRONMENTAL PROTECTION DIVISION GEORGIA GEOLOGIC SURVEY Atlanta 1996 Bulletin 127 THE LITHOSTRATIGRAPHIC FRAMEWORK OF THE UPPERMOST CRETACEOUS AND LOWER TERTIARY OF EASTERN BURKE COUNTY, GEORGIA Paul F. Huddlestun and Joseph H. Summerour GEORGIA DEPARTMENT OF NATURAL RESOURCES Lonice C. Barrett, Commissioner ENVIRONMENTAL PROTECTION DIVISION Harold F. Reheis, Director GEORGIA GEOLOGIC SURVEY William H. McLemore, State Geologist Atlanta 1996 Bulletin 127 ABSTRACT One new formation, two new members, and a redefinition of an established lithostratigraphic unit are formally introduced here. The Oconee Group is formally recognized in the Savannah River area and four South Carolina Formations not previously used in Georgia by the Georgia Geologic Survey are recognized in eastern Burke County. The Still Branch Sand is a new formation and the two new members are the Bennock Millpond Sand Member of the Still Branch Sand and the Blue Bluff Member of the Lisbon Formation. The four South Carolina formations recognized in eastern Burke CountY include the Steel Creek Formation and Snapp Formation of the Oconee Group, the Black Mingo Formation (undifferentiated), and the Congaree Formation. The Congaree Formation and Still Branch Sand are considered to be lithostratigraphic components of the Claiborne Group.
Dating Techniques.PdfDating Techniques Dating techniques in the Quaternary time range fall into three broad categories: • Methods that provide age estimates. • Methods that establish age-equivalence. • Relative age methods. 1 Dating Techniques Age Estimates: Radiometric dating techniques Are methods based in the radioactive properties of certain unstable chemical elements, from which atomic particles are emitted in order to achieve a more stable atomic form. 2 Dating Techniques Age Estimates: Radiometric dating techniques Application of the principle of radioactivity to geological dating requires that certain fundamental conditions be met. If an event is associated with the incorporation of a radioactive nuclide, then providing: (a) that none of the daughter nuclides are present in the initial stages and, (b) that none of the daughter nuclides are added to or lost from the materials to be dated, then the estimates of the age of that event can be obtained if the ration between parent and daughter nuclides can be established, and if the decay rate is known. 3 Dating Techniques Age Estimates: Radiometric dating techniques - Uranium-series dating 238Uranium, 235Uranium and 232Thorium all decay to stable lead isotopes through complex decay series of intermediate nuclides with widely differing half- lives. 4 Dating Techniques Age Estimates: Radiometric dating techniques - Uranium-series dating • Bone • Speleothems • Lacustrine deposits • Peat • Coral 5 Dating Techniques Age Estimates: Radiometric dating techniques - Thermoluminescence (TL) Electrons can be freed by heating and emit a characteristic emission of light which is proportional to the number of electrons trapped within the crystal lattice. Termed thermoluminescence. 6 Dating Techniques Age Estimates: Radiometric dating techniques - Thermoluminescence (TL) Applications: • archeological sample, especially pottery.