05 Structural Geology

05 Structural Geology - is known as a fault Components of a...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
(E) Structural Geology Geologic structures are formed under the application of stress The type of structure produced depends on the nature of the stress and on the rock behaviour Brittle behaviour favours the formation of fractures Plastic (ductile) behaviour favours the formation of folds Folds Plastic deformation results from compression or shear stress Components of a fold — refer to handouts Types of folds — refer to handouts Folding due to compression produces a net horizontal shortening of the crust as well as some thickening Plate collision is a source of immense compressive stresses, hence major fold belts are associated with collisions at plate margins (with ductile rocks) Folded mountains Faults Brittle rock fractures in response to both compressive and tensile stresses as well as shear stresses Where there is relative movement between rocks on either side of the fracture, it
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: is known as a fault Components of a fault refer to handout Types of faults refer to handouts Tension may produce very steeply sloping faults, whereas compression (in brittle rocks) may produce shallowly sloping faults Block mountains and rift valleys Unconformities 1. Disconformity The most difficult kind of unconformity to recognize The sedimentary rock layers above and below it are parallel e.g. It can develop as sediment deposition is interrupted for a period of time (say, absent of water for a period of time) 2. Angular Unconformity Bedding planes in rock layers above and below the unconformity are not parallel The presence of an angular unconformity usually implies a significant period of erosion, as well as uplift 3. Non-conformity...
View Full Document

This note was uploaded on 09/26/2011 for the course CIVIL CIVL taught by Professor Wong during the Spring '11 term at HKU.

Ask a homework question - tutors are online