GEOMORPHOLOGY (STRUCTURAL) Flashcards
What are structural landforms?
Geomorphic features controlled by underlying geologic structure and the distribution of rocks with different resistances to erosion
Plutons with dome-shaped geometry
Batholiths, Laccoliths
Pluton with subhorizontal shape
Sills
Pluton with steep attitude
Dykes, volcanic necks
what are the mechanical weakness in igneous rocks?
fractures anda faults
What are the usual mechanical weakness in sed rocks?
Bedding planes, joints. faults
Flat topped hills with steep slopes in which an upper resistant caprock protects the underlying softer sediments and is relatively large residuals
Mesa
Steep sloped with flat top but hills with limited areal extent
Butte
These are sed successions with a constant dip.
Homoclinal structures “Homo”-one “Clinal”-inclined
An assymertric ridge (hindi pantay/wlang symmetry) build of dipping sed rocks of alternating resistance against weathering and erosion, elongated along the strike wherein the steep front slope is opposite to the dip while the gentler slope is parallel to the dip
Cuestas
A sharp crested rige of hard rock, with steeply dipping strata usually >20 deg and steep near-symmetrical slopes which is a result of slow differential eroiion overtime of alternating hard and rock strata
Hogback
Drainage flowing in the dip direction?
Consequent/dip drainage
Drainange flowing opposite to the dip?
obsequent/antidip drainage
drainage flowing parallel to the strike
subsequent/strike drianage
V-shaped features with apexes pointing upslope in the interfluves and downstream valleys formed by incision of evenly spaced transverse gullies into dipping and well-bedded strat sequence.
Chevron
individualized resistant beds forming steeply inclined fin-like facets due to differential erotion in the interfluves
Flatirons
evelops where horizontal or very gently tilted strat bend abruptly along a narrow zone forming a step-like fold
Monocline fold
a feature whose face corresponds to an abrupt dip slope associated with forward tolted middle limb
Monoclinal Scarp
a concordant topography consist of a series of ridges associated with anticleines
Anticlinal ridge
a valley along axial zone which is a result of differential erosion of a soft sedimented core of anticlines
combe
A water gap which perpendicularly breached an anticlinal ridge
Cluse
A discordant relief of a hanging syncline
Perched syncline
Monolith-like structural landform of conglomerates with vertical cliffs developed by differential weathering and eroision controlled by vertical fractures
Conglomerate Pinnacle
Curved cavities developed in rock cliffs
Alcoves
Surface forming domes-shaped extrusions of salt fromations where the rate of salt exceed surface lowering mainly related to dissolution
Salt domes
Salt tectonics or movement of salt and salt bodies
Halokinesis
Piercing of overlying brittle rock by a more mobile and ductilely deformable material
Diapirism
glacier like salt lobes that override the adjoining country rock as a viscous flow
Namakiers/Salt glcier
