Meteorite Impact

From Meteorite Impact to Constellation City is a historical geography of the City of Greater Sudbury. The story that began billions of years ago encompasses dramatic physical and human events. Among them are volcanic eruptions, two meteorite impacts, the ebb and flow of continental glaciers, Aboriginal occupancy, exploration and mapping by Europeans, exploitation by fur traders and Canadian lumbermen and American entrepreneurs, the rise of global mining giants, unionism, pollution and re-greening, and the creation of a unique constellation city of 160,000. The title posits the book’s two main themes, one physical in nature and the other human: the great meteorite impact of some 1.85 billion years ago and the development of Sudbury from its inception in 1883. Unlike other large centres in Canada that exhibit a metropolitan form of development with a core and surrounding suburbs, Sudbury developed in a pattern resembling a cluster of stars of differing sizes. Many of Sudbury’s most characteristic attributes are undergoing transformation. Its rocky terrain and the negative impact from mining companies are giving way to attractive neighbourhoods and the planting of millions of trees. Greater Sudbury’s blue-collar image as a union powerhouse in a one-industry town is also changing; recent advances in the fields of health, education, retailing, and the local and international mining supply and services sector have greatly diversified its employment base. This book shows how Sudbury evolved from a village to become the regional centre for northeastern Ontario and a global model for economic diversification and environmental rehabilitation.

PART I CHAPTER 1 T E — , , . . . . . . . . . 15 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Geological change — the answers within, and without. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Man on the Moon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Back to the beginning — from the Big Bang to early Earth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Impact — the ubiquitous process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 The oldest rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Time to cool — birth of the Kaapvaal continent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Old crust in the Vredefort Dome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Rifting, oceans, volcanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Mountains, fire and ice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 The unique Bushveld magmatic event. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 CHAPTER 2 C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Extinction or survival — our restless Earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Meteorite-impact catastrophes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Normal (background) versus mass extinctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 A brief look at the impact record in the Solar System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 What are the projectiles capable of causing an impact catastrophe?. . . . . . . . . . . . . . . . . . . . . . . 87 What is an impact crater? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 How can we identify impact structures? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Shock metamorphism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 CHAPTER 3 T A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Tswaing meteorite crater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Does Tswaing have a twin? (Kalkkop Crater, Eastern Cape Province) . . . . . . . . . . . . . . . . . . . . . . . 108 South Africa’ s other Giant Impact Morokweng impact structure, — North West Province . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Our southern African neighbours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Testimony of earliest impact catastrophe — Barberton and the Northern Cape Province . . 113 Traces of catastrophe in the Karoo?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 6 CHAPTER 4 V : T W . . . 117 The Vredefort Structure revealed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Getting to know the giant: By road through the Vredefort Structure . . . . . . . . . . . . . . . . . . . 120 Traversing the outer parts of the Vredefort Dome (Fochville to Parys) . . . . . . . . . . . . . . . . . . 12 5 The geology of the Vredefort Dome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Text and illustrations explore the theory that the collision of an asteroid with the Earth ended the Cretaceous Period and caused the extinction of the dinosaurs.

A Short History of Nearly Everything meets Astrophysics for People in a Hurry in this humorous, accessible exploration of how meteorites have helped not only build our planet but steered the evolution of life and human culture. The Solar System. Dinosaurs. Donkey Kong. What is the missing link? Surprisingly enough, it's meteorites. They explain our past, constructed our present, and could define our future. Impact argues that Earth would be a lifeless, inhospitable piece of rock without being fortuitously assaulted with meteorites throughout the history of the planet. These bombardments transformed Earth’s early atmosphere and delivered the complex organic molecules that allowed life to develop on our planet. While meteorites have provided the raw materials for life to thrive, they have radically devastated life as well, most famously killing off the dinosaurs and paving the way for humans to evolve to where we are today. As noted meteoriticist Greg Brennecka explains, meteorites did not just set us on the path to becoming human, they helped direct the development of human culture. Meteorites have influenced humanity since the start of civilization. Over the centuries, meteorite falls and other cosmic cinema have started (and stopped) wars, terrified millions, and inspired religions throughout the world. With humor and an infectious enthusiasm, Brennecka reveals previously untold but important stories sure to delight and inform readers about the most important rocks on Earth.

"This volume contains a sizable suite of contributions dealing with regional impact records (Australia, Sweden), impact craters and impactites, early Archean impacts and geophysical characteristics of impact structures, shock metamorphic investigations, post-impact hydrothermalism, and structural geology and morphometry of impact structures - on Earth and Mars"--

Disk contains: HAZARDS version 5.5, designed to predict asteroid or comet impacts with the Earth.

Although about 70 percent of known terrestrial meteorite impacts involve sedimentary rocks, the response of such rock to hyper- velocity impact is not well understand. Evans (Missouri State U., Springfield) introduces a dozen papers from a session on impact geology at the 2004 Geological Society of America Annual Meeting. Arranged by rocks' stratigraphic order (oldest to youngest) in proximal and distal settings, papers study topics including: characterization of impact sediments; a model for impact cratering processes; development of breccias (rock composed of sharp fragments embedded in a fine- grained matrix) in the Chesapeake Bay impact structure; and the method of impact stratigraphy applied to aging of the K-T boundary associated with mass extinction. The well-illustrated volume is not indexed.

Proceedings of the Fourth International Conference on Large Meteorite Impacts and Planetary Evolution held at the Vredefort Dome, South Africa, in Aug. 2008.

This volume is a compilation of the research presented at the International Asteroid Day workshop which was celebrated at Barcelona on June 30th, 2015. The proceedings discuss the beginning of a new era in the study and exploration of the solar system’s minor bodies. International Asteroid Day commemorates the Tunguska event of June 30th, 1908. The workshop’s goal was to promote the importance of dealing proactively with impact hazards from space. Multidisciplinary experts contributed to this discussion by describing the nature of comets and asteroids along with their offspring, meteoroids. New missions to return material samples of asteroids back to Earth such as Osiris-REx and Hayabusa 2, as well as projects like AIM and DART which will test impact deflection techniques for Potentially Hazardous Asteroids encounters were also covered. The proceedings include both an outreach level to popularize impact hazards and a scientific character which covers the latest knowledge on these topics, as well as offering proposals of promising new techniques that will help gain new insights of the properties of these challenging bodies by studying meteoroids and meteorites. Asteroids, comets, meteoroids and meteorites are introduced with descriptions of their nature, origin, and solar system pathways.