lab 8

Stream terrace

Step-like landform found above a stream and its flood plain.

Oxbow lake

a U-shaped body of water that forms when a wide meander from the main stem of a river is cut off, creating a free-standing body of water

radial drainage

a drainage pattern in which consequent streams radiate or diverge outward, like the spokes of a wheel, from a high central area; it is best developed on the slopes of a young, unbreached domal structure or of a volcanic cone.

annular drainage

a drainage pattern in which streams follow a roughly circular or concentric path along a belt of weak rock, resembling in plan a ringlike pattern.

rectangular drainage

a drainage pattern in which the main streams and their tributaries display many right-angle bends and exhibit sections of approx. the same length

Alluvial fan

a fan-shaped mass of alluvium deposited as the flow of a river decreases in velocity

Meander scar

a geological feature formed by the remnants of a meandering water channel

Stream piracy

a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighboring stream.

Competence (of a stream)

a measure of the maximum size of the particles that the stream can transport

Peneplain

a more or less level land surface produced by erosion over a long period, undisturbed by crustal movement

braided stream

a stream consisting of multiple small, shallow channels that divide and recombine numerous times forming a pattern resembling the strands of a braid.

meandering stream

a stream following a sinuous flow consisting of successive meanders.

Antecedent (or superimposed) stream

a stream that maintains its original course and pattern despite the changes in underlying rock topography.

geologic map

a two-dimensional map representing the rock formations exposed at Earth's surface

What type of feature is illustrated in the figure below?

alluvial fan

Point bar

an alluvial deposit that forms by accretion on the inner side of an expanding loop of a river

Floodplain

an area of low-lying ground adjacent to a river, formed mainly of river sediments and subject to flooding

Drainage divide

an elevated boundary that separates neighboring drainage basins

Study the Sundance, Wyoming (around Green Mountain) map and determine the drainage pattern.

annular drainage pattern

Study the Madison River on the Ennis, Montana map and determine whether the stream type is braided or meandering.

braided stream

What type of stream is illustrated in the figure below?

braided stream

old age stage erosion

broad, open valleys with widely meandering streams, indistinct divides, erosion remnants of resistance lithologies, surface near erosional base level.

What type drainage pattern is illustrated in the figure below?

dendritic

Classify the drainage pattern for Plate 41 (Red Wash, New Mexico; on the plateau).

dendritic drainage pattern

Study the Crowder, Mississippi map and determine the drainage pattern.

dendritic drainage pattern

Give the stage of regional erosion for the Kaaterskill, New York

mature

Study the Plate 40 (Bear Creek, South Dakota) and determine the stream type is braided or meandering.

meandering stream

Study the Tallahatchie River on the Crowder, Mississippi map and determine the stream type is braided or meandering

meandering stream

what type of stream is illustrated in the figure below

meandering stream

dendritic drainage

occurs when the tributary systems subdivide headway like the limbs of a tree.

trellis drainage

occurs where subparallel streams erode a valley along the strike of less resistant formations.

Give the stage of regional erosion for the Crowder, Mississippi

old age

What type of feature is Horseshoe Lake in the figure below from the Crowder, Mississippi map?

oxbow lake

What type drainage pattern is illustrated in the figure below?

radial

Drainage basin

the area drained by a river and all its tributaries

Gradient (or slope)

the grade measured by the ratio of drop in elevation of a stream per unit horizontal distance

Base level

the lowest point to which it can flow, often referred to as the 'mouth of the river'

Cut bank

the outside bank of a water channel (stream), which is continually undergoing erosion

Capacity (of a stream)

the total amount of sediment a stream is able to transport

mature stage erosion

well-drained terrain, all in slopes except floodplains; some tributaries streams meander; maximum relief.

Give the stage of regional erosion for the figure below?

youthful

youthful stage erosion

V-shaped valleys with few or no floodplains; many falls and rapids plus some lakes and swamps.