Crustal Deformation Economic Consequences of Geologic Structures Tracing
- Slides: 27
Crustal Deformation
Economic Consequences of Geologic Structures • Tracing Coal Seams, Aquifers, etc. • Ore Deposits are often localized along faults and folds • Petroleum Traps
Anticlines and Synclines
Monoclines and Homoclines
Axial Plane
How Fast Can Folds Form?
Which Way was Up? Sedimentary Structures are governed by: • Gravity • Exposure to the Surface They all have a “right way up”
Foliation is a sheetlike structure that forms when rocks are deformed.
Foliation a. Flattening b. Grain Rotation c. Solution d. New Minerals e. Partial Melting f. Shearing
Foliation In every case, the foliation is: • In the direction of least resistance • at right angles to the direction of greatest compression.
Folds and Foliation • On a small scale (microscopic to centimeters), foliation forms by a variety of mechanisms, but always at right angles to the direction of greatest compression • On a large scale (centimeters to kilometers), rocks fold. The axial plane of the fold is also at right angles to the direction of greatest compression
Folds and Foliation
The Importance of Minor Folds
How Geologists Use These Clues • Here's an outcrop that might be seen in the field.
How Geologists Use These Clues • Picture the axial plane of the fold as parallel to the foliation. • The other side of the fold is roughly a mirror image of the side we can see.
How Geologists Use These Clues • We can mentally fill out the sketch to get an idea of the shape of the fold. • Note that we still have no idea how big the fold is, only what kind it is.
What if we did it the other way?
Isostasy
The Airy Model
The Pratt Model
Both Ideas are Correct at Times
How Isostasy Works
Isostatic Rebound in Canada
Isostatic Rebound in Scandinavia
Domes and Basins
Domes and Basins
Domes and Basins
- Crustal deformation
- Crustal deformation
- Crustal deformation
- Compare geologic time with the geologic column.
- Elastic compliance
- The economic consequences of legal origins
- Diastrophism
- Crustal extension
- Earths major crustal plates
- Homologous structures examples
- Economic growth vs economic development
- Economic growth vs economic development
- Economic systems lesson 2 our economic choices
- California department of conservation
- Geologic time scale
- Geologic
- Geologic column definition
- What is the longest subdivision in geologic time
- How is the geologic time scale organized
- Geologic history of texas
- Geologic time scale animals
- Principle of original horizontality
- What is reletive age
- Geologic time
- Geologic time scale in a calendar year
- 4 zoic eras
- Geological time scale graphic organizer
- Geologic time