Geology-Reviewer-P PDF Lecture Notes

LECTURE 1: INTRODUCTION TO GEOLOGY Geology - study of earth - origin , history, composition, structures and physical properties - process that shape it - resources that could obtained Greek Meaning: - geo – earth - logos -- study Geology as a Discipline: 1. The relevance of time...

LECTURE 1: INTRODUCTION TO GEOLOGY Geology - study of earth - origin , history, composition, structures and physical properties - process that shape it - resources that could obtained Greek Meaning: - geo – earth - logos -- study Geology as a Discipline: 1. The relevance of time 2. The issue of scale 3. The complexity of replicating natural systems and phenomena in the laboratory Main Branches of Geology: 1. Physical Geology - deals with the materials that comprise the Earth and the processes that affect it a. Volcanology – study of volcanoes and volcanic activity b. Seismology – study of earthquakes and the mechanical properties of the earth c. Mineralogy – study of minerals and its properties d. Petrology – study of rocks and the conditions under which they are formed e. Geomorphology – study of landforms and the processes that shape them f. Geophysics – physics of the Earth and its environment in space g. Geochemistry – study of the chemical composition and processes of the Earth and other planets h. Planetary Geology – concerned with the geology of celestial bodies i. Environmental Geology – use of geologic information to manage our environment j. Engineering Geology – application of geologic information to engineering problems k. Mining Geology – Deals with the applications to mining l. Petroleum Geology – application of geology to the search of hydrocarbons 2. Historical Geology – study of the origin and evolution of the Earth through time a. Paleontology –study of prehistoric life as represented by fossils b. Stratigraphy – study of rock layers and layering (stratification) c. Geochronology – deals with the determination of the age of the Earth and its materials Basic Concepts in the history of Geology: 1. Catastrophism - Baron Georges Cuvier - worldwide catastrophes are the agents of change that alter the physical features of the Earth over time - widely accepted by theologians in the early 1800s due to similarity with Biblical events such as Noah’s Flood 2. Uniformitarianism - James Hutton - “The present is the key to the past.”  - “The present is the key to the future.” - advocates the idea that the Earth is continuously modified by geologic processes that have always operated throughout time Geohazards – earth processes that cause life and property loss 1. Flooding 2. Earthquake 3. Volcanic Activity 4. Landslide 5. Mudflows Geologists at Work: 1. Relevance to daily life 2. Mineral Deposits 3. Resource Exploration LECTURE 2: THE PLANET EARTH Formation of the Universe: Big Bang Theory Formation of the Solar System: Nebular Hypothesis The Universe: Origin: Big Bang Theory - states that about 13.7 billion yrs. ago, all of the energy and matter compressed into an incomprehensibly hot and dense state - began to expand and cool hurling matter in all direction - proposed by the Belgian priest Georges Lemaître in the 1920s - Edwin Hubble justified Lemaître’s theory through observations that the Universe is continuously expanding; galaxies are moving away from each other The Solar System: Leftover from the Big Bang: sun, planets, satellites and rings, comets, and asteroids, meteoroids and dust COMPOSITION OF THE SOLAR SYSTEM BY MASS Object Percentage of Mass Sun 99.85% Jupiter 0.10% All other planets 0.04% Comets 0.01% Satellites and rings 0.00%  Asteroids 0.00% Meteoroids and dust 0.0000001% The Solar System: Origin: Nebular Hypothesis - proposed by Immanuel Kant and Pierre Simon de Laplace in the 18th century - Nebula – bodies of our solar system evolved from an enormous rotating cloud - starting 4.6 billion years ago, which contracted due to gravity - cloud of dust and dust (nebula) started to gravitationally collapse. - nebula contracted into a rotating disk due to gravity - repeated collisions caused the dust-size particles to coalesce into asteroid-size bodies - cooling caused rocky and metallic material to condense into tiny solid particles THE SOLAR SYSTEM Mercury, Venus, Earth, Mars - - inner or terrestrial planets (nearest the sun) - rocky composition: largely silicate rocks and metals (Si, Fe, O) Jupiter, Saturn, Uranus, Neptune - giant or Jovian planets (outer planets; far from the sun) - lack solid surfaces: in gaseous or liquid form - composition: light elements (H, He, Ar, C, O, Ni) Pluto - neither a terrestrial or Jovian planet - similar to the icy satellites of the Jovian planets Planets – scientists agreed that for a celestial body to qualify as a planet: a. it must be in orbit around the Sun b. it must be large enough that it takes on a nearly round shape; and c. it has cleared its orbit of other objects Earth – started as “dust ball” from the nebular gas and dust brought together by gravity (accretion) - heated (heating) and eventually segregated into layers (differentiation) as it cooled - when cooling set in, the denser elements (e.g., iron) sank while the lighter ones floated out into the surface, creating a differentiated Earth Layers of Earth: Discontinuities/Boundaries: 1. Mohorovicic – crust – mantle 2. Gutenberg – core – mantle 3. Lehmann – outer core – inner core Earth’s Vital Statistics: 1. Chemical Composition – 34.6% Iron, 29.5% Oxygen, 15.2% Silicon,12.7% Magnesium 2. Shape – flattened at the poles and bulging at the equator 3. Size – Earth’s circumference was first calculated by Eratosthenes Circumference = 360 degrees 800 km = 7 degrees 4. Equatorial Radius = 6378 km 5. Polar Radius = 6357 km 6. Equatorial Circumference = 40076 km 7. Polar Circumference = 40008 km Volume = 260,000,000,000 cu. miles 8. Density = 5.52 g/cm3 External Features of the Earth: Lithosphere – made up of moderately rigid plates (may consist of oceanic or continental lithosphere) – 7 major plates + several smaller plates Earth’s Large Scale Features: 1. Continents Continental Crust – Thick (30-60 km), old (250-4000 m.y.) and light - does not subduct - largest features: a. Mountain Belts – proposed by L. Kober as orogen in 1921 - Orogen – an extensive belt of rocks deformed by orogeny, associated in places with plutonic and metamorphic rocks - an episode of mountain building - such as the Andes, Alps, Himalaya, Urals, Appalachians, Caledonian, and NA Cordillera b. Cratons – kratos (greek) – strength - first proposed by L. Kober as kratogen in 1921 - old and stable interior part of the continent that has been relatively undisturbed - includes the shield which is free from sedimentary cover 2. Ocean Basins – thin - geologically young (