Get 2 days of unlimited access
Study Guides (350,000)
US (190,000)
UA (1,000)
GEO (1)
Study Guide

GEO 101 Study Guide - Summer 2018, Comprehensive Midterm Notes - List Of Rocks On Mars, Erosion, Weathering


Department
GEO
Course Code
GEO 101
Professor
Dr.Charles F.Andrus
Study Guide
Midterm

This preview shows pages 1-3. to view the full 64 pages of the document.
GEO 101
MIDTERM EXAM
STUDY GUIDE
Fall 2018

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

The Earth's Exterior
Various external forces affect the earth's surface, such as different climates and the
amount of rainfall. Freezing, thawing, and running water all contribute to weathering
and erosion, processes that break rock down into tiny particles. These particles are
then transported by water, ice, or wind as sediment. The processes of erosion reduce
mountains to hills, create canyons, valleys, and soils, and deposit huge amounts of
sediments that either become eroded again or are preserved and lithified into
sedimentary rock.
Geologic Time
Geoscientists have estimated the earth to be about 4.5 billion years old. As the crust
cooled, early geologic processes were largely volcanic, building up continental crust and
a primitive atmosphere. Bacterial forms of life have been found in rocks that are billions
of years old. Complex oceanic organisms such as trilobites began to appear only about
600 million years ago. From about 66 million to 245 million years ago, dinosaurs and
other reptiles flourished all over the world. In contrast, human beings have existed in
only about the last 3 million years, less than a thousandth of the age of Earth.
The Earth Today
Even though it is nearly 5 billion years old, the earth is still active, and landscapes are
constantly changing. The majority of continental rocks have been explored, studied, or
sampled. The principle of uniformitarianism—also known as “the present is the key to
the past”— is still applicable. Ancient rocks show textures that can be seen forming
today from processes such as volcanic eruptions, earthquakes, hot springs, wind,
weathering, river action, sedimentation, and erosion.
Technology now allows scientists to probe far deeper than Hutton or Lyell could
centuries ago. Underwater cameras, microscopes, geophysical equipment, analytical
techniques, sensing devices, and drilling advancements have allowed us to better
determine how rocks form. Scientists use uniformitarianism to apply this knowledge to
older rocks to better understand the complex history of the earth.
History of Physical Geology
Physical geology is the study of the earth's rocks, minerals, and soils and how they
have formed through time. Complex internal processes such as plate tectonics and
mountain building have formed these rocks and brought them to the earth's surface.
Earthquakes are the result of the sudden movement of crustal plates, releasing internal
energy that becomes destructive at the surface. Internal heat and energy are released
also through volcanic eruptions. External processes such as glaciation, running water,
weathering, and erosion have formed the landscapes we see today.
About 2300 years ago, the Greeks, led by the philosopher Aristotle, were among the
first to try to understand the earth. During the 1600s and 1700s, scientists believed the
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

earth had been produced by gigantic, sudden, catastrophic events that built mountains,
canyons, and oceans.
In the late 1700s, James Hutton, a Scottish doctor, proposed that the physical
processes that shape the world today also operated in the geologic past—a principle
known as uniformitarianism. Another early concept was the law of superposition—in an
undeformed sequence of sedimentary rocks, each layer is younger than the ones below
it and older than those above it. The law of faunal successionstates that fossils in these
rocks occur in the same kind of order, and changes in fossil content represent changes
in time. Thus, rocks from different parts of the world containing the same type of fossil
formed about the same time. English geologist Charles Lyell enlarged on these ideas
and modernized geology with his series of books in the mid to late 1800s.
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version