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Geology 104--Earth Science

Exam No. 2 Study Guide

What defining characteristics do all minerals possess? Understand the difference between silicate and non-silicate minerals.  Know the basic chemical building block of the silicate minerals and how to draw this structure.  Understand the difference between ferromagnesian and non-ferromagnesian silicate minerals. 

How are igneous rocks classified?  What textural feature distinguishes intrusive from extrusive igneous rocks?  Be able to describe the following common igneous rocks in terms of texture and composition: granite, rhyolite, diorite, andesite, gabbro, basalt, obsidian, pumice, volcanic breccia.  In which plate tectonic settings are most igneous rocks found? 

How are sedimentary rocks classified?  Be able to describe the common detrital, inorganic, and organic (biochemical) sedimentary rocks in terms of grain size/shape (for detrital rocks) and composition (for chemical rocks).   

How are metamorphic rocks classified? Be able to distinguish foliated and non-foliated metamorphic rocks and be able to describe several examples of each.  In which plate tectonic settings do most metamorphic rocks form?   

Be able to draw out the rock cycle.  

Know the difference between an earthquake focus and epicenter.  Be able to describe the various types of seismic wave and the elastic deformation they cause.  Given a seismogram, be able to distinguish between P waves, S waves, and Surface waves.  Understand the difference between seismic wave amplitude (wave height) and period (time between successive wave crests).  What is the minimum number of seismogram records (each from a different location) needed to locate the source of an earthquake? For each increase of 1 on the Richter scale, approximately how much more energy is released? 

What lines of indirect evidence give us information about Earth’s interior?  How do we know that the Earth’s interior is layered?  How do we know that the outer core is liquid?  How do we know that the mantle is solid?  Where does Earth’s magnetic field originate? Has Earth’s magnetic field always been oriented toward the present-day North Pole?  Explain. 

How old is the Earth? What is the difference between relative and absolute dating?  Be able to apply the principles of relative dating to reconstruct the sequence of geologic events in a region. 

Know the time boundaries between the Cenozoic, Mesozoic, and Paleozoic Eras and between the Paleozoic Era and Precambrian time.  What types of fossils are dominant within each Era? 

Be able to summarize and draw the hydrologic cycle, and be able to explain the related processes that are associated with global water transport. 

Be able to analyze various surficial landforms in terms of mass transfer (i.e., sediment input vs output) and energy flow.

Important Vocabulary (not exhaustive)