Marine Geology Phần 1 potx

[...]... halfbillion years ago Figure 11 Early Cambrian marine fauna 17 Marine Geology Figure 12 About 500 million years ago, the continents surrounded an ancient sea called the Iapetus EUROPE NORTH AMERICA Iapetus Sea GONDWANA Figure 13 The configuration of the southern continents that comprised Gondwana AFRICA SOUTH AMERICA INDIA ANTARCTICA AUSTRALIA 18 The Blue Planet Figure 14 Fossil trilobites of the Carrara... after Earth’s creation 1 Marine Geology TABLE 1 THE GEOLOGIC TIME SCALE Period Epoch Age (millions of years) Holocene Era First Life-forms Geology 0. 01 3 11 Humans Mastodons Ice age Cascades 26 37 Saber-toothed tigers Alps 54 65 Whales Horses, Alligators Rockies Quaternary Cenozoic Tertiary Pleistocene Pliocene Neogene Miocene Oligocene Paleogene Eocene Paleocene Cretaceous Jurassic 210 Triassic 250 Permian... major ice age 13 Marine Geology Figure 8 The late Precambrian Ediacaran fauna from Australia 14 About 2 billion years ago, after most of the dissolved iron was locked up in the sediments, the level of oxygen began to rise and replace carbon dioxide in the ocean and atmosphere Major plate tectonic cataclysms caused oxygen levels to surge between 2 .1 and 1. 7 million years ago and again between 1. 1 and 0.7... Andrews, courtesy USGS) 11 Marine Geology TABLE 3 EVOLUTION OF THE BIOSPHERE Billions of Years Ago Percent Oxygen Biologic Effects Event Results Full oxygen conditions 0.4 10 0 Appearance of shell-covered animals Metazoans appear 0.6 10 Fish, land plants, and animals Cambrian fauna Approach present biologic environs Burrowing habitats 0.7 7 Ediacaran fauna Eukaryotic cells appear 1. 4 >1 Blue-green algae... just before a rapid diversification of multicellular life, culminating in an explosion of new species (Fig 8) TABLE 4 THE MAJOR ICE AGES Number of years ago Event 10 ,000–present 15 ,000 10 ,000 20,000 18 ,000 10 0,000 1 million 3 million 4 million 15 million 30 million 65 million 250–65 million 250 million 700 million Present interglacial Melting of ice sheets Last glacial maximum Most recent glacial episode... large amounts of sediment result in a highly complex marine geology This revised and updated edition is a much expanded and more inclusive examination of the intriguing subject of marine geology Science enthusiasts will particularly enjoy this fascinating subject and gain a better understanding of how the forces of nature operate on Earth Students of geology and Earth science will also find this a valuable... changing environmental conditions associated with tectonic processes.The history of several different ocean basins over the past billion years is discussed in Marine Geology, as well as the changing life-forms in each successive ocean basin XI Marine Geology Erickson presents a fascinating history of ocean exploration He shows how early explorations were slowly able to reveal data about ocean currents and... continents rapidly drifted away from each other As the con- Figure 9 An outcrop of retrograde blueschist rocks in the Seward Peninsula region, Alaska (Photo by C L Sainsbury, courtesy USGS) 15 Marine Geology Figure 10 The supercontinent Rodinia, 700 million years ago SIBERIA EURASIA r a to qu e eq ua t LAURENTIA or ANTARCTICA BALTICA AMAZONIA CONGO AUSTRALIA tinents dispersed and subsided, seas flooded... fact began as undersea volcanoes that broke the surface of the sea However, the preponderance of marine volcanoes is not exposed at the surface but spread out on the ocean floor as isolated seamounts XIII Marine Geology Chasms that challenge the largest terrestrial canyons plunge to great depths Massive submarine slides gouge deep depressions into the seabed and deposit enormous heaps of sediment onto... springs northwest of Imperial Junction, California (Photo by W C Mendenhall, courtesy USGS) 9 Marine Geology TABLE 2 RADIATION AND EXTINCTION OF SPECIES Organism Radiation Extinction Mammals Reptiles Amphibians Insects Land plants Fish Crinoids Trilobites Ammonoids Nautiloids Brachiopods Graptolites Foraminiferans Marine invertebrates Paleocene Permian Pennsylvanian Upper Paleozoic Devonian Devonian Ordovician . 76 10 The World’s Ocean Trenches 10 7 11 Comparison of Types of Volcanism 11 5 12 Major Volcanic Disasters of the 20th Century 11 8 13 Classification of Volcanic Rocks 12 1 14 Major Tidal Bores 16 3 15 . bibliographical references and index. ISBN 0- 816 0-4874-6 (hardcover: alk. paper) 1. Submarine geology. 2. Marine biology. I.Title. QE39 E68 2003 5 51. 46’08—dc 21 20020 012 95 Facts On File books are available. information contact: Facts On File, Inc. 13 2 West 31st Street New York NY 10 0 01 Library of Congress Cataloging-in-Publication Data Erickson, Jon, 19 48– Marine geology: exploring the new frontiers