Physical Sciences and Mathematics Commons^™

Geologic Time, John J. Renton, Thomas Repine

Readings and Notes

It is not surprising that humans have wondered how long Earth has existed. At one extreme, there were the Brahmans of India who believe that Earth never had a beginning and will never have an end. Others were of the opinion that Earth was old, but perhaps not eternally old. In 450 BC, for example, a Greek historian named Herodotus (484 - 425 BC) expressed the opinion that Earth was very old, basing his estimate on the results of his studies of the Nile Delta. He observed that the delta was growing layer by layer as a result of the …

A Geology Field Trip, John J. Renton, Thomas Repine

Readings and Notes

oduction to Field Trip I had several objectives in mind when I prepared this field trip. I want to develop in you an interest, an understanding, and an appreciation of geology of the region. I want to show you differences between three of the basic physiographic provinces within Appalachia, the Low Plateau, the High Plateau, and the Appalachian Mountain Section of the Valley and Ridge Province. I also want to show you the role that the kinds and structures of the underlying rocks plays in the formation of the topography of a region in order to have you better understand …

Oceans And Shorelines, John J. Renton, Thomas Repine

Readings and Notes

Until 1872 when H.M.S, Challenger, a British warship converted for research, made its historic voyage, relatively little was known about the oceans. The voyage, funded by the British government, was mandated to chart the depth of the ocean, measure the various ocean currents, amass data on the composition of the ocean's water and bottom sediments, and collect information on ocean life. At the time of the voyage, except for a few soundings, almost nothing was known about the ocean bottom. Most scientists of the day had considered the vast expanses of the deep ocean basins to be nothing more than …

The Ordovician Period, John J. Renton, Thomas Repine

Readings and Notes

The Ordovician Period extends in time from 505 million years ago until 438 million years ago. You will remember from our discussions of the Cambrian that the Ordovician Period of time and the Ordovician System ofrocks was suggested by Professor Lapworth as a means of solving the dilemma presented by Murchison and Sedgewick as to the "ownership" of a section of rock that both claimed when Murchison wanted to include the upper portion of Sedgewick's Cambrian System as the lower portion of his Silurian System. Sedgewick, you will remember, responded by demanding that the lower portion of his Silurina System …

The Cambrian Period, John J. Renton, Thomas Repine

Readings and Notes

The Cambrian Period extends from 570 million years ago to 505 million years ago. Notwithstanding the discovery of the Ediacara fauna, the Cambrian Period of the Paleozoic Era has historically been taken as the beginning of historical time based on the first appearance of abundant fossil remains. It is interesting to note, however, that where first described, the lower Cambrian was not very fossiliferous.

The Triassic Period And The Beginning Of The Mesozoic Era, John J. Renton, Thomas Repine

Readings and Notes

The Triassic Period is the first period of the Mesozoic Era, a span of time from 245 million years ago to 66 million years ago. Although the Mesozoic era commonly known as the "Age of the Dinosaurs,', it should be pointed out that there were other important evolutionary developments taking place such as the appearance of the first mammal birds and flowering plans. The onset of the Mesozoic Era, the Triassic Period, was also a time of profound tectonic activity affecting the entire North American craton. In the east, the primary event was the breakup of Pangea and the formation …

The Jurassic Period, John J. Renton, Thomas Repine

Readings and Notes

During the Jurassic Period, Europe was covered by a shallow sea in which a rich fauna was encapsulated in sequences of limestones and shales. These Jurassic rocks were the training ground for many of the early geologists as they began to formulate some of the basic precepts of geology. Foremost amongst these was William Smith (1769-1839) who was the first to discover how to use fossils to correlate between separated outcrops. He gained his knowledge and understanding of fossils in his profession of a surveyor and in the building of canals throughout southern England where the canals were cut into …

The Mississippian Period, John J. Renton, Thomas Repine

Readings and Notes

The first rocks to attract the attention of the early European were those containing the coals, primarily because of their importance in supplying the source of energy for the Industrial Revolution which began in the mid-1700s. As early as 1808, the coal-bearing rocks were referred to on the Continent as the "bituminous terraine' while the British geologists called them the "Coal Measures" The name Carboniferous was introduced in 1822 by Conybeare and Philips when they were attempting to make sense of the rocks of England and Wales. They proposed that all of the rocks from the Coal Measures down to …

The Pennsylvanian Period, John J. Renton, Thomas Repine

Readings and Notes

In many respects, the mountain building of the Acadian Orogeny never really came to an end. Following the collision of Avalonia with the eastern margin of Laurasia with the subsequent creation of the Acadian Highlands, Gondwana and South America, now joined together into a single continent, were approaching from the east and south respectively. Even before the continent-continent collision that would occur at the close of Permian time, the highlands of Acadia along the eastern margin of Laurasia and Llanoria along the southern margin were being maintained as uplands in response to the compressional forces generated by the converging continents. …

The Cenozoic Era, John J. Renton, Thomas Repine

Readings and Notes

It has been said that the modem world unfolded during the Cenozoic Era. It is true that every feature of the modem landscape was formed during the Cenozoic Era. The Alps and the Himalaya have literally risen from the ocean floor. The Rocky mountains have been formed, worn away and re-uplifted to their present heights. The Appalachian Mountains that had formed at the close of the Paleozoic and worn away by the end of the Triassic, were uplifted and sculpted into their present form during the Cenozoic. All the other mountains of the world were also elevated and sculpted to …

The Cretaceous Period, John J. Renton, Thomas Repine

Readings and Notes

A global rise in sea level occurred during the Cretaceous; as a result, sea level stood as high during the Late Cretaceous than at any other time in the Phanerozoic history of Earth. Although Pangea had begun to breakup during the Early Mesozoic Era, the smaller continents remained tightly clustered at the beginning of Cretaceous time. The continued breakup of Pangea and the dispersion of the newly created continents were among the most important events that occurred during the global geography of the Cretaceous. Especially important was the breakup of Gondwana. Gondwana was still intact at the beginning of the …

The Permian Period, John J. Renton, Thomas Repine

Readings and Notes

The Permian Period was a time of great crisis in Earth's history. The Permian saw the final closure of the Iapetus Ocean that had formed following the breakup of the super­ continent of Rodinia in the late pre-Cambrian; the closure resulting in the formation of another super-continent, Pangea. It was during the Permian that two of Earth's major mountain chains, the Appalachians and the Urals, were created. The period was one of climatic extremes. By the end of the Permian, Earth had not only experienced its most widespread glaciation but also the formation of deserts the likes of which had …

The Silurian Period, John J. Renton, Thomas Repine

Readings and Notes

The Silurian Period is the shortest of all the periods of the Paleozoic Era, lasting only 30 million years from 438 million years ago until 408 million years ago. As the Silurian Period opens, the eastern margin ofLaurentia was dominated by the Taconic Highlands that had been created during the Taconic Orogeny at the close of the Ordovician. The rest of the craton was essentially flat-lying and covered by a shallow sea. Except for the northeastern margin which was involved in a major orogeny following the Taconic Orogeny, Laurentia was tectonically quiet throughout the Silurian. About 10 million years before …

Geologic History Of West Virginia, John J. Renton, Thomas Repine

Readings and Notes

The exposed rocks and those that underlie the surface of West Virginia record approximately 300M years of Earth history. This may sound like a very long period of time, but in reality, it only represents about 7% of the total age of Eai1h. Before we undertake a discussion of the geologic history of West Virginia, there are some basic topics we should review in order to fully appreciate what will follow. To that end, the following topics will be discussed: 1) The Origin of Earth, 2) The Response of Rocks to Stress, 3) Some Basic Characteristics of Sedimentary Rocks, 4) …

Earth's Place In Space, John J. Renton, Thomas Repine

Readings and Notes

I've always thought that a story should start at the beginning. Since this book is the story of Earth, we will start at the beginning. According to the astronomers, in the beginning, there was no need for geology because there were no minerals or rocks; there was no Earth; there was no Sun; there were no stars or planets. According to the astronomers, there was a time when even our present universe didn't exist. In the 1920s, the Belgian astronomer Georges Lemaitre hypothesized that everything presently contained within the entire Universe was once compressed into in a sphere he called …

Kinds Of Volcanoes, John J. Renton, Thomas Repine

Readings and Notes

By definition, a volcano is a conical structure that builds around a volcanic vent. A volcanic vent is an opening from which molten rock and gases erupt. According to the definition, there is no size requirement. There are volcanoes that you can span with your legs while on the other hand, there is Mt. Fiji.

The West Virginia's Valley And Ridge Physiographic Province: An Overly Simplistic Introduction, John J. Renton, Thomas Repine

Readings and Notes

Anyone who has driven across West Virginia has noticed major changes in the lay of the land. In the western portion of the State the landscape belongs to the Appalachian Plateaus Physiographic Province. But what constitutes a plateau? According to the Glossary of Geology, a plateau is a dissected (stream carved) upland underlain by horizontal strata. In the case of the Appalachian Plateau, it is a relatively flat to gently rolling surface with an average elevation of about 900 feet underlain by gently folded to flat-lying sedimentary rocks. But what is a physiographic province? Again, according to the Glossary of …

The Devonian Period, John J. Renton, Thomas Repine

Readings and Notes

Until the 19th century, the rocks exposed throughout the provinces of Devonshire and Cornwall in southwestern England had long been considered to be Carboniferous in age because of their content of fossil plants. Closer investigation by Murchison and Sedgwick in 1836, however, showed that only the uppermost portion of these rocks contained fossil plants. Because the lower portion of the rock sequence was devoid of plant fossils, was highly deformed, and resembled the rocks of northwest Wales which they had recently studied, Murchison and Sedgwick assigned the rocks to the Cambrian System. However, local fossil collectors had submitted fossil corals …

Quantifying A Mining Investability Quotient To Mitigate Junior Mining Investment Risk, Jonathan Mickey Merguerian

Open Access Theses & Dissertations

Uncertainty and risk are inherent features of investing in mineral exploration ventures. Investors rely on qualitative and quantitative analysis to evaluate risk of capital. The distinction between risk and uncertainty pertaining to mineral exploration is that risk is an opportunity for loss and uncertainty can be described as the range of probabilities that some condition may occur (Rose, 1987). Stakeholders rely on a combination of investment conferences, risk analysis equations, press releases, financial reports, and investment research to determine if an investment potential. J. M. Cozzolini developed a formula for Risk Adjusted Value (RAV) of an exploration venture. The study …

Neuro-Fuzzy Classification Of Felsic Lava Geomorphology At Alarcon Rise, Mexico, Christina Hefron Maschmeyer

Theses and Dissertations

The Alarcon Rise is the only submarine oceanic spreading ridge setting where rhyolitic lavas have been found. This intermediate-rate spreading ridge provides a unique natural laboratory for studying the geomorphology of felsic submarine lava flows at oceanic spreading ridges. Seafloor observations of felsic lava indicate the flow morphology differs from typical submarine basaltic lava at the few other oceanic spreading ridges where differentiated compositions have been recorded. Morphologic variation between mafic and felsic lava flows, especially rhyolites, was also observed at Alarcon Rise.

The Monterey Bay Aquarium Research Institute conducted mapping surveys with autonomous underwater vehicle D Allan B. in …

Evolution Of A Flood Basalt Crustal Magmatic System: In Situ Mineral Data And Computational Modeling Of The Steens Basalt, Megan Graubard

All Master's Theses

Flood basalts are gigantic basaltic eruptions that modify the mass of the crust via intrusion of mantle-derived magma, and change its composition through interaction between magma and crust. The Steens Basalt, located in southeast Oregon, erupted approximately 16.8 million years ago, and is the oldest member of the Columbia River Basalt Group, the youngest and best-exposed flood basalt province on Earth. The Steens Basalt has an eruption volume of approximately 31,800 km³ and the duration of eruption is estimated to be between ~50,000 and 300,000 years. Major- and trace element whole rock data from 111 stratigraphically controlled samples from …