Concept of Stratigraphy
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Short-Lived Increase in Erosion During the African Humid Period: Evidence from the Northern Kenya Rift ∗ Yannick Garcin A, , Taylor F
Earth and Planetary Science Letters 459 (2017) 58–69 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Short-lived increase in erosion during the African Humid Period: Evidence from the northern Kenya Rift ∗ Yannick Garcin a, , Taylor F. Schildgen a,b, Verónica Torres Acosta a, Daniel Melnick a,c, Julien Guillemoteau a, Jane Willenbring b,d, Manfred R. Strecker a a Institut für Erd- und Umweltwissenschaften, Universität Potsdam, Germany b Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum GFZ, Telegrafenberg Potsdam, Germany c Instituto de Ciencias de la Tierra, Universidad Austral de Chile, Casilla 567, Valdivia, Chile d Scripps Institution of Oceanography – Earth Division, University of California, San Diego, La Jolla, USA a r t i c l e i n f o a b s t r a c t Article history: The African Humid Period (AHP) between ∼15 and 5.5 cal. kyr BP caused major environmental change Received 2 June 2016 in East Africa, including filling of the Suguta Valley in the northern Kenya Rift with an extensive Received in revised form 4 November 2016 (∼2150 km2), deep (∼300 m) lake. Interfingering fluvio-lacustrine deposits of the Baragoi paleo-delta Accepted 8 November 2016 provide insights into the lake-level history and how erosion rates changed during this time, as revealed Available online 30 November 2016 by delta-volume estimates and the concentration of cosmogenic 10Be in fluvial sand. Erosion rates derived Editor: A. Yin −1 10 from delta-volume estimates range from 0.019 to 0.03 mm yr . Be-derived paleo-erosion rates at −1 Keywords: ∼11.8 cal. -
Deformation Characteristics of the Shear Zone and Movement of Block Stones in Soil–Rock Mixtures Based on Large-Sized Shear Test
applied sciences Article Deformation Characteristics of the Shear Zone and Movement of Block Stones in Soil–Rock Mixtures Based on Large-Sized Shear Test Zhiqing Li 1,2,3,*, Feng Hu 1,2,3, Shengwen Qi 1,2,3, Ruilin Hu 1,2,3, Yingxin Zhou 4 and Yawei Bai 5 1 Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; [email protected] (F.H.); [email protected] (S.Q.); [email protected] (R.H.) 2 College of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing 100049, China 3 Innovation Academy of Earth Science, Chinese Academy of Sciences, Beijing 100029, China 4 Yunnan Chuyao Expressway Construction Headquarters, Chuxiong 675000, China; [email protected] 5 Henan Yaoluanxi Expressway Construction Co. LTD, Luanchuan 471521, China; [email protected] * Correspondence: [email protected] or [email protected]; Tel.: +86-13671264387 Received: 27 July 2020; Accepted: 15 September 2020; Published: 17 September 2020 Abstract: Soil–rock mixtures (SRM) have the characteristics of distinct heterogeneity and an obvious structural effect, which make their physical and mechanical properties very complex. This study aimed to investigate the deformation properties and failure mode of the shear zone as well as the movement of block stones in SRM experimentally, not only considering SRM shear strength. The particle composition and proportion of specimens were based on field samples from an SRM slope along national highway 318 in Xigaze, Tibet. Shear zone deformation tests were carried out using an SRM-1000 large-sized geotechnical apparatus controlled by a motor servo, considering the effects of different stone contents by mass (0, 30%, 50%, 70%), vertical pressures (50, 100, 200, 300, and 400 kPa), and block stone sizes (9.5–19.0, 19.0–31.5, and 31.5–53.0 mm). -
Lithostratigraphic Mapping Through Saprolitic Regolith Using Soil Geochemistry and High-Resolution Aeromagnetic Surveys
EGU2020-20242 https://doi.org/10.5194/egusphere-egu2020-20242 EGU General Assembly 2020 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Lithostratigraphic Mapping Through Saprolitic Regolith Using Soil Geochemistry and High-Resolution Aeromagnetic Surveys. Helen Twigg and Murray Hitzman iCRAG, School of Earth Sciences, University College Dublin, Belfield, Dublin, Ireland The Neoproterozoic Central African Copperbelt located in southern Democratic Republic of Congo (DRC) and the northwestern Zambia and contains 48% of the world’s cobalt reserves and significant resources of copper, zinc, nickel and gold. A good understanding of the geology is critical for successful mineral exploration. However, geological mapping is hindered by low topographic relief, limited outcrop, and a generally deep (10-100m) weathering profile developed since the Late Miocene. Multielement soil geochemistry provides a means for conducting geological mapping. Areas with outcrop or containing drill holes and/or trenches were utilized to relate known geological lithologies with soil geochemical results using major element and trace element ratios. The lithostratigraphy within a study area along the DRC-Zambia border can be geochemically sub- divided into three units. Mixed carbonate and siliciclastic lithologies of the lower portion of the local stratigraphy are typically characterised by elevated V, Ti, and Nb. Mudstones and siltstones are dominated by elevated Al, Fe and Ba. The upper portion of the local stratigraphy is geochemically neutral with regards to trace elements. Lithological discrimination through analysis of soil geochemical data is limited in some areas by intense weathering. A A-CNK-FM diagram exhibits how complete weathering of carbonate rocks and carbonate-rich breccias (after evaporites) results in the somewhat counter intuitive outcome that residual soils above carbonate rocks are amongst the most aluminum rich in the study area with >80% Al2O3 (mol%) or >80% combined Al2O3 (mol%) and FeO + MgO (mol%). -
Weathering, Erosion, and Susceptibility to Weathering Henri Robert George Kenneth Hack
Weathering, erosion, and susceptibility to weathering Henri Robert George Kenneth Hack To cite this version: Henri Robert George Kenneth Hack. Weathering, erosion, and susceptibility to weathering. Kanji, Milton; He, Manchao; Ribeira e Sousa, Luis. Soft Rock Mechanics and Engineering, Springer Inter- national Publishing, pp.291-333, 2020, 9783030294779. 10.1007/978-3-030-29477-9. hal-03096505 HAL Id: hal-03096505 https://hal.archives-ouvertes.fr/hal-03096505 Submitted on 5 Jan 2021 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. Published in: Hack, H.R.G.K., 2020. Weathering, erosion and susceptibility to weathering. 1 In: Kanji, M., He, M., Ribeira E Sousa, L. (Eds), Soft Rock Mechanics and Engineering, 1 ed, Ch. 11. Springer Nature Switzerland AG, Cham, Switzerland. ISBN: 9783030294779. DOI: 10.1007/978303029477-9_11. pp. 291-333. Weathering, erosion, and susceptibility to weathering H. Robert G.K. Hack Engineering Geology, ESA, Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente Enschede, The Netherlands e-mail: [email protected] phone: +31624505442 Abstract: Soft grounds are often the result of weathering. Weathering is the chemical and physical change in time of ground under influence of atmosphere, hydrosphere, cryosphere, biosphere, and nuclear radiation (temperature, rain, circulating groundwater, vegetation, etc.). -
Correlating Foreland Basin Subsidence with Eclogite Metamorphism
ATI..ANTic GEOLOGY 79 Loading the Laurentian margin: correlating foreland basin subsidence with eclogite metamorphism 2 3 4 John WF. Waldron•, R.A. Jamieson , G.S. Stockmal and L.A. Quinn 1Geology Department, Saint Mary '.S' University, Halifax, Nova Scotia B3H 3C3, Canada 'Department ofEarth Sciences, Dalhousie University, Halifax, Nova Scotia B3H 3J5, Canada 1Geological Survey of Canada (Calgary), 3303-33rd Street Northwest, Calgary, Alberta T2L 2A 7, Canada 'Department ofGeology, Brandon University, Brandon, Manitoba R7A 6A9, Canada Paleozoic loading of the former Laurentian continental de Lys Supergroup) are exposed in the Baie Verte Peninsula margin is recorded both in the subsidence history of the Ap and elsewhere. These units record Barrovian metamorphism palachian foreland basin and in metamorphic rocks now ex with peak temperatures around 700 to 750°C at 7 to 9 kbar; humed in internal parts of the Newfoundland Humber zone. isotopic data indicate that peak temperatures were reached in The Cambrian-Ordovician passive margin ofLaurentia Early Silurian time ('Salinian orogeny'), followed by rapid ex underwent a transition to a foreland basin setting beginning humation. Amphibolite facies metamorphism overprints an in Early Ordovician time. Middle Ordovician ('Taconian ') foreland earlier eclogite facies assemblage, for which minimum pres basin sediments (Table Head and Goose Tickle groups), in sures of 1.2 GPa at 500°C require burial of the Laurentian part derived from the Humber Arm Allochthon, are relatively margin beneath at least 40 km of overburden, which may have thin (ca. 250 m in offshore industry seismic data, thinning to included thrust sheets of continental margin rocks and the west). -
The Paleontology Synthesis Project and Establishing a Framework for Managing National Park Service Paleontological Resource Archives and Data
Lucas, S.G. and Sullivan, R.M., eds., 2018, Fossil Record 6. New Mexico Museum of Natural History and Science Bulletin 79. 589 THE PALEONTOLOGY SYNTHESIS PROJECT AND ESTABLISHING A FRAMEWORK FOR MANAGING NATIONAL PARK SERVICE PALEONTOLOGICAL RESOURCE ARCHIVES AND DATA VINCENT L. SANTUCCI1, JUSTIN S. TWEET2 and TIMOTHY B. CONNORS3 1National Park Service, Geologic Resources Division, 1849 “C” Street, NW, Washington, D.C. 20240, [email protected]; 2National Park Service, 9149 79th Street S., Cottage Grove, MN 55016, [email protected]; 3National Park Service, Geologic Resources Division, 12795 W. Alameda Parkway, Lakewood, CO 80225, [email protected] Abstract—The National Park Service Paleontology Program maintains an extensive collection of digital and hard copy documents, publications, photographs and other archives associated with the paleontological resources documented in 268 parks. The organization and preservation of the NPS paleontology archives has been the focus of intensive data management activities by a small and dedicated team of NPS staff. The data preservation strategy complemented the NPS servicewide inventories for paleontological resources. The first phase of the data management, referred to as the NPS Paleontology Synthesis Project, compiled servicewide paleontological resource data pertaining to geologic time, taxonomy, museum repositories, holotype fossil specimens, and numerous other topics. In 2015, the second phase of data management was implemented with the creation and organization of a multi-faceted digital data system known as the NPS Paleontology Archives and NPS Paleontology Library. Two components of the NPS Paleontology Archives were designed for the preservation of both park specific and servicewide paleontological resource archives and data. A third component, the NPS Paleontology Library, is a repository for electronic copies of geology and paleontology publications, reports, and other media. -
Historical Development and Problems Within the Pennsylvanian Nomenclature of Ohio.1
Historical Development and Problems Within the Pennsylvanian Nomenclature of Ohio.1 GLENN E. LARSEN, OHIO Department of Natural Resources, Division of Geological Survey, Fountain Sq., Bldg. B, Columbus, OH 43224 ABSTRACT. An analysis of the historical development of the Pennsylvanian stratigraphic nomenclature, as used in Ohio, has helped define and clarify problems inherent in Ohio's stratigraphic nomenclature. Resolution of such problems facilitates further development of a useful stratigraphy and philosophy for mapping. Investigations of Pennsylvanian-age rocks in Ohio began as early as 1819- From 1858 to 1893, investigations by Newberry, I. C. White, and Orton established the stratigraphic framework upon which the present-day nomenclature is based. During the 1950s, the cyclothem concept was used to classify and correlate Pennsylvanian lithologic units. This classification led to a proliferation of stratigraphic terms, as almost every lithologic type was named and designated as a member of a cyclothem. By the early 1960s, cyclothems were considered invalid as a lithostratigraphic classification. Currently, Pennsylvanian nomenclature of Ohio, as used by the Ohio Division of Geological Survey, consists of four groups containing 123 named beds, with no formal formations or members. In accordance with the 1983 North American Stratigraphic code, the Ohio Division of Geological Survey considers all nomenclature below group rank as informal. OHIO J. SCI. 91 (1): 69-76, 1991 INTRODUCTION DISCUSSION Understanding the historical development of Pennsyl- The Early 1800s vanian stratigraphy in Ohio is important to the Ohio The earliest known references to Pennsylvanian-age Division of Geological Survey (OGS). Such an under- rocks in Ohio are found in Atwater's (1819) report on standing of Pennsylvanian stratigraphy helps define Belmont County, and an article by Granger (1821) on plant stratigraphic nomenclatural problems in order to make fossils collected near Zanesville, Muskingum County. -
Facies and Mafic
Metamorphic Facies and Metamorphosed Mafic Rocks l V.M. Goldschmidt (1911, 1912a), contact Metamorphic Facies and metamorphosed pelitic, calcareous, and Metamorphosed Mafic Rocks psammitic hornfelses in the Oslo region l Relatively simple mineral assemblages Reading: Winter Chapter 25. (< 6 major minerals) in the inner zones of the aureoles around granitoid intrusives l Equilibrium mineral assemblage related to Xbulk Metamorphic Facies Metamorphic Facies l Pentii Eskola (1914, 1915) Orijärvi, S. l Certain mineral pairs (e.g. anorthite + hypersthene) Finland were consistently present in rocks of appropriate l Rocks with K-feldspar + cordierite at Oslo composition, whereas the compositionally contained the compositionally equivalent pair equivalent pair (diopside + andalusite) was not biotite + muscovite at Orijärvi l If two alternative assemblages are X-equivalent, l Eskola: difference must reflect differing we must be able to relate them by a reaction physical conditions l In this case the reaction is simple: l Finnish rocks (more hydrous and lower MgSiO3 + CaAl2Si2O8 = CaMgSi2O6 + Al2SiO5 volume assemblage) equilibrated at lower En An Di Als temperatures and higher pressures than the Norwegian ones Metamorphic Facies Metamorphic Facies Oslo: Ksp + Cord l Eskola (1915) developed the concept of Orijärvi: Bi + Mu metamorphic facies: Reaction: “In any rock or metamorphic formation which has 2 KMg3AlSi 3O10(OH)2 + 6 KAl2AlSi 3O10(OH)2 + 15 SiO2 arrived at a chemical equilibrium through Bt Ms Qtz metamorphism at constant temperature and = -
Part 629 – Glossary of Landform and Geologic Terms
Title 430 – National Soil Survey Handbook Part 629 – Glossary of Landform and Geologic Terms Subpart A – General Information 629.0 Definition and Purpose This glossary provides the NCSS soil survey program, soil scientists, and natural resource specialists with landform, geologic, and related terms and their definitions to— (1) Improve soil landscape description with a standard, single source landform and geologic glossary. (2) Enhance geomorphic content and clarity of soil map unit descriptions by use of accurate, defined terms. (3) Establish consistent geomorphic term usage in soil science and the National Cooperative Soil Survey (NCSS). (4) Provide standard geomorphic definitions for databases and soil survey technical publications. (5) Train soil scientists and related professionals in soils as landscape and geomorphic entities. 629.1 Responsibilities This glossary serves as the official NCSS reference for landform, geologic, and related terms. The staff of the National Soil Survey Center, located in Lincoln, NE, is responsible for maintaining and updating this glossary. Soil Science Division staff and NCSS participants are encouraged to propose additions and changes to the glossary for use in pedon descriptions, soil map unit descriptions, and soil survey publications. The Glossary of Geology (GG, 2005) serves as a major source for many glossary terms. The American Geologic Institute (AGI) granted the USDA Natural Resources Conservation Service (formerly the Soil Conservation Service) permission (in letters dated September 11, 1985, and September 22, 1993) to use existing definitions. Sources of, and modifications to, original definitions are explained immediately below. 629.2 Definitions A. Reference Codes Sources from which definitions were taken, whole or in part, are identified by a code (e.g., GG) following each definition. -
Stratigraphical Framework for the Devonian (Old Red Sandstone) Rocks of Scotland South of a Line from Fort William to Aberdeen
Stratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen Research Report RR/01/04 NAVIGATION HOW TO NAVIGATE THIS DOCUMENT ❑ The general pagination is designed for hard copy use and does not correspond to PDF thumbnail pagination. ❑ The main elements of the table of contents are bookmarked enabling direct links to be followed to the principal section headings and sub-headings, figures, plates and tables irrespective of which part of the document the user is viewing. ❑ In addition, the report contains links: ✤ from the principal section and sub-section headings back to the contents page, ✤ from each reference to a figure, plate or table directly to the corresponding figure, plate or table, ✤ from each figure, plate or table caption to the first place that figure, plate or table is mentioned in the text and ✤ from each page number back to the contents page. Return to contents page NATURAL ENVIRONMENT RESEARCH COUNCIL BRITISH GEOLOGICAL SURVEY Research Report RR/01/04 Stratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen Michael A E Browne, Richard A Smith and Andrew M Aitken Contributors: Hugh F Barron, Steve Carroll and Mark T Dean Cover illustration Basal contact of the lowest lava flow of the Crawton Volcanic Formation overlying the Whitehouse Conglomerate Formation, Trollochy, Kincardineshire. BGS Photograph D2459. The National Grid and other Ordnance Survey data are used with the permission of the Controller of Her Majesty’s Stationery Office. Ordnance Survey licence number GD 272191/2002. -
Earth Science Power Standards
Macomb 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 Results
www.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.