GEOL 106 Lecture Notes Mar 5.docx

2 Pages
Unlock Document

Geological Sciences and Geological Engineering
GEOL 106
David Alan Hanes

Volcanic Hazards Extrusive Rocks -Magma, when it comes out of the ground, will be in one of two forms 1. Lava (liquid) 2.Pyroclastic materials (hot particles) Magmas 1. Felsic: High viscosity (sticky), and high water content (more than 5%) 2. Mafic: Low viscosity (fluid), and low water content (less than 1%) REVIEW FROM GEOL 104 -Magma reaches the surface by coming through either fractures (fissures) or volcanic cones Volcanic Cones -Pipe-like conduit and vent bring magma to surface -Eruptions range from calm to violent; depends on magma composition -3 main types: 1. Cinder cone  Emits pyroclastic material About half a kilometer tall, 2 km wide at base Mafic or felsic composition Very steep slopes 2. Stratovolcano (composite cone) Felsic to intermediate composition Emits lava and pyroclastic material  4-5 km high, 15-20 km wide at base Very steep slopes 3. Shield Volcano Emits lava Composed of mafic materials (fluid) Not steep slopes Calm eruptions 5-10 km high, ~200 km across Formed from basalt layers Which are the most dangerous? Stratovolcanoes -Their magma is felsic or intermediate, therefore has high viscosity and high water content -This leads to high, steep-side
More Less

Related notes for GEOL 106

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.