Fichas
Geological Structures Definitions
Fichas del conjunto (38)
- 1Define troughthe lowest point of a folded bed
- 2Define hanging wallthe side that lies above the fault plane
- 3Define footwallthe side that lies below the fault plane
- 4Define downthrowthe side of the fault that has moved down
- 5Define upthrowthe side of the fault that has moved up
- 6Define slickensidesthe polishing and striations found on a fault plane indicating the direction of relative movement
- 7Define fault brecciacomposed of fragments produced by rocks fracturing during faulting
- 8Define fold limbthe section of a fold between one hinge and the next, forming at the side of a fold
- 9Define hingethe line along which there is a change in amount and/or direction of dip, forming the most sharply curved part of the fold
- 10Define crestthe highest point of a folded bed
- 11Define fault dipthe angle between the fault plane and the horizontal
- 12Define axial planea plane that joins the hinges of all the beds. It bisects the fold
- 13Define axial plane tracethe outcrop of the axial plane at the Earth's surface
- 14Define plungethe angle of dip of the axial plane from the horizontal
- 15Define antiforman upward closing fold
- 16Define synforma downward closing fold
- 17Define cleavageplanes of weakness in a rock along which the rock will split
- 18Which rocks does cleavage form in?incompetent sedimentary rocks such as shale or clay made from clay minerals
- 19Where does cleavage form?perpendicular to the maximum pressure that forms a fold, so it at an angle to the bedding planes
- 20Define competentrocks are strong and brittles and tend to joint and fault
- 21Define bedding planemarks the break between beds. It represents a break in sedimentation, a change in composition or grain size, or a change in colour of sediments
- 22Define dipthe maximum inclination of a bed measured from the horizontal using a clinometer
- 23Define strikethe direction at right angles to the dip. There is zero dip in this direction. It is a bearing measured from north using a compass
- 24Define apparent dipis a dip that is measured to be less than the maximum inclination
- 25Define stressforce applied to rocks
- 26Define stress(change of length of line)/(the original length of line)
- 27Define tensionthe force trying to pull rocks apart - the Earth's crust will be lengthened
- 28Define compressionthe force trying to push rocks together - the Earth's crust will be shortened
- 29Define shear forcesforces which act along a plane in the rock and promote sliding along that plane
- 30Define beda unit of sedimentation, which can vary considerably in thickness
- 31Define incompetentrocks are weak and plastic and tend to fold and develop cleavage
- 32Define jointa fracture in competent rocks along which no observable movement has occurred
- 33Define tectonic jointsform as a result of folding and cause tension joints parallel to the axial plabne and cross joints on the limbs
- 34Define cooling jointsforms as a result of contraction on cooling of igneous rock
- 35Define unloading jointsoften horizontal as well as vertical and form as a result of lower pressure near to the surface
- 36Define faulta fracture in a rock along which there has been an observable amount of displacement
- 37Define fault planethe surface along which movement takes place
- 38Define throwthe amount of vertical displacement measured vertically between the top of the same bed seen on both sides of the fault
Información
- Descripción
- Undergraduate (Geological Structures) Geology - Part 1 Fichas sobre Geological Structures Definitions, creado por siobhan.quirk el 09/05/2013.
- Creado por
- siobhan.quirk
- Visitas
- 291
- Etiquetas
- Valoración