Lecture notes
Lecture Notes LEC 172 Lecture 9 Deformation
- Module
- Geology (LEC172)
- Institution
- Lancaster University (LU)
Lecture Notes for LEC 172 Geology - Lecture 9 - Deformation 1
[Show more]
Seller
Follow
Content preview
Friday 3rd December 2021 LEC 172Deformation -1
Deformation:
The time required for some geologic
events/processes. The scale is logarithmic,
i.e. it has equal divisions between powers
of 10.
Deformation takes place on a range of time
scales, e.g.
• s – min during seismic activity
• Ma for mountain building
Deformation has occurred in the past (we know this from field observations) and occurs today (seismic activity,
landslides etc).
Geologic structures resulting from deformation, provide a record of the forces which operated in the past.
e.g., Faults & Folds
Interpretation of structures:
1. Helps to understand the history of the Earth
2. Aids exploration of natural resources (e.g. natural gas, petroleum, coal, ore deposits)
3. Helps to select appropriate sites for dams, bridges, nuclear power plants, roads, housing estates etc
Sources of information on deformation processes:
1. Field observations (geologic maps)
2. Laboratory experiments
3. Computer simulations
4. Theoretical calculations
Stress & Strain:
Fractured and contorted minerals/rocks have been deformed, i.e., their original shapes/volumes have been
altered by stress.
Stress = force/area (SI unit = Pa = N m-2)
Pressure = force/area
Compression stress acts to shorten an object:
Tension stress acts to lengthen an object:
Normal stress acts perpendicular to a surface (either compression or tension)
Shear stress acts parallel to a surface
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ciarangreer. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £7.16. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53068 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now