Day 1 Finals Flashcards
Zone of greatest Turbulence
Away from the zone of greatest velocity
It is the depressions may be rounded or
sharp, cusped in profile, and have crests lying
across the current path. Also related to separated
Erosional Marks
A process of erosion, ___________ refers to the strictly mechanical wear of bedrock by moving detrital and other materials during (a) their migration downslope under the influence of gravity, and (b) their further transportation by erosional agencies such as running water, moving ice, or wind.
Corrasion
The erosion of weak, cohesive rocks by the force of water in a river
Fluid Stressing
Largest particle size the stream can carry
Competence
Maximum volume of sediments a stream can carry of a given size
Capacity
Transportation of sediment occurs in three ways:
Suspension, Saltation, and
Rolling.
Force that pulls the water downslope
Force of Gravity
Resistance for downslope movement
Frictional Forces
Roughness is controlled by:
Amount of Vegetation
Size of Bed
Bank Material
Irregularity of adjacent channel cross sections
Discharge is expressed as _______________
Discharge is expressed as volume of water
over time where
Q= AV
Q = Discharge
A = Cross Sectional Area
V= Velocity of the flowing water
A graph where Flow volume of water plotted against time
Hydrograph
height of maximum height of the stream over time
Stage Hydrograph
discharge over time
Discharge hydrograph
How to calculate flood return period
𝑟𝑒𝑡𝑢𝑟𝑛𝑝𝑒𝑟𝑖𝑜𝑑= (𝑛𝑢𝑚𝑏𝑒𝑟𝑜𝑓𝑦𝑒𝑎𝑟𝑠+1) / (𝑟𝑎𝑛𝑘𝑜𝑓𝑡ℎ𝑒𝑖𝑛𝑑𝑖𝑣𝑖𝑑𝑢𝑎𝑙𝑓𝑙𝑜𝑜𝑑)
T or F. Bedload increases as flow velocity and discharge increases.
True. Bedload is reported to be
only 1% of the overall sediment
discharge of the river, however 70%
in alpine areas.
Zone where in streams swiftly flow down steep mountain slopes and cut deep, v-shaped valleys. Waterfalls and rapids occur in this zone
Zone 1 Headwaters
Zone where Lower elevation streams merge toflow down on gentle slopes. Valleys broaden as coalescing rivers start to meander
Zone 2 Transfer Zone
Zone at the lowest elevations, a river meanders across a broad, nearly flat valley and floodplain.
Zone 3. Depositional Zone
T or F. If a drainage basin and channel morphology are related to the geologic, climatic and hydrologic character of the basin, it is not necessary describe the features quantitatively in order to investigate these relationships.
F. If a drainage basin and channel morphology are related to the geologic, climatic and hydrologic character of the basin, then it is necessary to describe the features quantitatively in order to investigate these relationships.
What is the second largest river basin in the Philippines, and what is itss total land area
Mindanao River Basin, 21,503 Km^2
What are the 5 Provinces that covers the Mindanao River Basin
Bukidnon, Maguindanao, North Cotabato, South Cotabato, and Sultan Kudarat
what is the largest river in the philippines
Cagayan River
Formula for drainage density
𝐷𝑟𝑎𝑖𝑛𝑎𝑔𝑒𝐷𝑒𝑛𝑠𝑖𝑡𝑦= sum𝐿/𝐴Where:
L= Stream Length
A= Drainage Basin Area
What are the geometrical way to categorized stream order?
Strahler, Horton, Shreve, Hack
states that the number of streams of
different orders in a drainage basin tends closely to approximate an
inverse geometric series in which the first term is the number of
streams of order one.
Law of Stream number
states that the average lengths of the
streams of each of the different orders in a basin closely approximate
a direct geometric series in which the first term is the average length
of streams of the first order.
Law of Stream length
slopes states that slopes of streams of different
orders are related to the stream order by an inverse geometric series
Law of stream slopes
states that the main drainage basin
areas of streams of different orders tends to closely approximate a
direct geometric series in which the first term is the mean area of the
first order basins.
The law of drainage basin area
states that the drainage areas of
streams of each order and the total stream length contained within
and supported by these areas is direct logarithmic function.
The law of contributing areas
direct logarithmic function of the area
of the drainage basin of the stream above the point at which
discharge was measured.
The discharge of a stream is a direct logarithmic function of the area
is an index of the potential energy available in the drainage
basin. The higher the relief the higher the erosional forces acting on
the basin
Relief
Determines the erodibility of the surface
materials, and to some extent the permeability
Lithologic Variations
Gives secondary permeability for fluid flow, and
a primary control for the orientation and drainage pattern of a system
Geologic Structure
Development of stream
pattern on a pristine surface
Initiation
The growth of the channel
into the available area and blocking out
of the network
Elongation
Filling out the network
with lower order tributaries
Elaboration
When drainage
density is the greatest and the network
fills the open spaces
Maximum Extension
loss of identity of the small
order streams with progressive reduction
of drainage density through time
Integration
Most commonly formed on horizontally
bedded and uniform sediments or on
uniformly resistant crystalline rocks.
Dendritic
Usually develops on moderate to steep slopes,
but also where regional structure, such as
outcropping resistant rock bands, are elongated
and parallel. All forms of transition can occur this
type and dendritic and trellis pattern.
Parallel
Patterns most commonly on dipping or folded
sedimentary or weakly metamorphosed sedimentary
rocks; also areas of joints and faults which intersect with
right angles and old sand dunes with parallel alignment
Trellis
Usually have a more or less
perpendicular turns mainly caused by
crisscrossing fractures
Rectangular
Occurs around domes or cones, and
particularly common on volcanic areas
Radial
Patterns also develop around domes, where there exists
alternating resistant and weak beds, so that the major
channels cut through the strike and the low order streams
follow the dip of the rocks.
Annular
Can occur in a variety of conditions where local
hummocks and depressions inhibit a continuous
channel network. Irregular glacial deposits or
erosional hollows due to solution of underlying
lithology, irregular thawing permafrost. Coastal
dunes, delta plains, and wind eroded hollows
Multibasinal
Incised into rocks with complicated structural
patterns. Associated with crystalline metamorphic
rocks with a history of intense folding, jointing,
intrusions, alterations, and faulting.
Contorted
Fluvial sediments are laid down, and depositional landforms are
created at:
- Dominantly or partially subaerial conditions
- Topographic discontinuities
- Valleys and the margin of water bodies
What are the importance of fluvial deposits?
- Sources of groundwater
- Placer deposits
- Conduits for petroleum
- Coal deposits in paleo deltaic environments
All are general conditions of Alluvial fans except;
a. Arid to Semi Arid Environments, Occurs in Fault fronts, Tectonic Mountain Fronts or Sudden Topographic Discontinuities
b. General gradient: 3 6 , Marginal screes: ~30, Near the apex: ~10
c. Large Sediment Supply, Exhibits complex cross bedding, Flow Structures
d. None of the Above
D.
What are the arrangement of sediments (sediment mechanics) in alluvial fans?
Conglomerates/unsorted
sediments near the head, with
bettering sorting and finering
of sediments outwards
T or F. Geology influences the relation, in a drainage basin e.g underlain by sandstone have a smaller fan, compared to fans underlain by mudstone and shale
T
Fan surface is not dissected, Relatively smaller than fans of perennial streams
Dry Fans
Streams flows through incision, Coarser materials are rarely
carried downstream, River widens downstream,
braided , Progressively shifting channel
Wet Fans
Where alluvial fans are large enough, or sufficiently closely spaced, they may coalesce laterally to produce a depositional bed. To produce a piedmont zone
Bajada
Diverges/Converges around stable vegetated bars. Commonly formed by avulsions, flow diversions that cause the formation of new channels on the floodplain. When the new channels rejoin the parent channel downstream, islands are formed, which consist of isolated portions of the floodplain
A. Meandering
B. Anastomosing
C. Braided
D. Straight
B
High sediment supply, High Gradient changes, Low stability
A. Meandering
B. Anastomosing
C. Braided
D. Straight
C
Alluvial surface adjacent to a channel that is frequently inundated
Flood plain
Occasionally be formed by the incision of bedrock surfaces, but they are most likely the remnants of floodplains trenched by rivers
River Terraces
Formed when sediment-laden rivers flow
into standing bodies of water
Deltas
________ is strongly influenced by the relative densities of the inflowing and standing waters
Delta Morphology
A type of delta typically formed when rivers flow
into freshwater lakes
Homopycnal
Homopycnal deltas are devoid of ____________
tidal or wave forces
This type of delta carries large proportions of fine suspended load and usually occurs to the snout of tide water glacier
Hyperpycnal
This delta forms when rivers flow into saltwater (most common)
Hypopycnal
2 Classification of deltas
- High Destructive
- High Constructive
2 High destructive delta
Wave dominated
Tide dominated
2 High constructive delta
Lobate/Fan
Elongate/Bird’s foot
A high destructive delta that is flattened in a pan
Wave dominated
A high destructive delta that has funnel shaped distributaries
tide dominated
A high constructive delta whose distributaries change in position
similar to alluvial fans
Lobate (Fan)
A high constructive delta that delivers large quantity of fine sediment and is constantly shifting
Elongate (Bird’s foot)
Landforms composed of sandstones and siltstones
Arenaceous Landforms
An arenaceous landform that is most resistant, low drainage density, chemical weathering resistant, low infiltration, permeability through discontinuities
Silica-cemented
An arenaceous landform that has less resistant cement, locally high rates of infiltration-high permeability, rapid weathering, can be very weak mechanically and chemically, cliff forming
Iron-oxide cement
An arenaceous landform that is chemically and mechanically weak and also cliff forming
Calcium Carbonate cement
_________ landforms are composed of clay and shale, has low relief and support varies with the presence of water
Argillaceous
Argillaceous landforms typically divided into two groups:
- Under humid conditions/high moisture
- Under arid/semi-arid
T or F. Under humid conditions/high moisture has shallow water table and continuous vegetation cover
T
T or F. Under arid/semi-arid, moisture production is limited into the surface and sparse vegetation cover
F. * Under arid/semi-arid, moisture intake is limited into the surface and sparse vegetation cover
In humid argillaceous landform the most common drainage pattern is _____
dendritic
Argillaceous landforms has ______________ of layers
differing behavior of layers
_____ is the German form of the Slovene word “Kras” meaning craggy or stony ground
Karst
the process of dissolving limestones forming underground drainage
Karstification
The formation of karst requires the following:
- Humid weather
- “Hard” and thick limestone beds
- Thin or non-existent soil cover
- Well jointed limestones
The German word “______” and the French word “_____” refers to
small solutional sculpture
Karren; Lapies
T or F. Controls in Karrens is presence or absence of soil and vegetation cover
T.
A surface karst landform with individual pits produced by rain drops
Rainpits
_______ are enclosed depressions
dolines
Large enclosed basins with flat floors of karst regions
Polje
A karst landform with tall and Narrow landforms standing above
a wide, flat valley
Tower and Pinnacle Karst
Karst in fluvial environment commonly develop _____
gorges
Underlain by crystalline rocks, generally metamorphosed lavas,
coarse-grained igneous rocks. Usually interpreted as remnants of volcanic arcs
Cratons
2 types of cratons
shields
platforms
zone of contacts in cratons are marked by ophiolite belts called ______-
sutures
a type of craton with exposed igneous and metamorphic rocks
shields
a type of craton with undeformed sedimentary rocks overlie the igneous/metamorphic basement
platforms
2 types of orogens
- Cordilleran
- Continental Collision
Landforms Controlled by faults
- Sharp boundaries of uplands and/or valleys
- Control/Strongly influence drainage patterns
- Juxtaposing rocks of different degrees of resistance to erosion
Landforms controlled by folds
- Cuesta
- Flat Iron
- Hogback
A fold-controlled landform that is steep on one side, gently sloping on the other
Cuesta
A fold-controlled landform that is steep on both sides
Flat iron
Drainage pattern on folds
Traverse stream
Longitudinal stream
Transverse- stream cuts ___________ the trend
across
Longitudinal- stream _____ the trend
follows
Defined on the basis of observable lithologic properties
Lithostratigtraphic Units
A lithostratigraphic unit with content that possess a certain degree of internal lithologic homogeneity or distinctive lithologic features and is mappable at a scale of 1:25,000
Formation
It a named entity within a formation having characteristics that
distinguish it from other parts of a formation.
Member
A geographically restricted unit that terminates on all sides laterally within a formation may be called a _____. A wedging unit may be called a ______.
lens and tongue
The smallest formal lithostratigraphic unit of sedimentary rocks
Bed
the smallest formal lithostratigraphic unit of volcanic flow rocks
Flow
______ are defined to express the natural relationships of associated formations. They are useful in regional mapping and stratigraphic analysis
Groups
T or F. The term “group” may be applied to litho-stratigraphic units that appear to be divisible into formations, but have not yet been so divided. In such cases, formations may be erected subsequently for one or all of the practical divisions of the group.
T
The formal name of a lithostratigraphic unit is compound and binary, consisting of a geographic name combined with a descriptive dominant lithologic term or the appropriate rank term.
Lithostratigraphic Nomenclature
is the original or subsequently designated type section of a named layered stratigraphic unit or of a stratigraphic boundary representing a specific interval or point in a specific sequence of rock strata, and constituting the standard for the definition and characterization of the stratigraphic unit or boundary.
Stratotype (type section)
the 5 stratotypes
Holostratotype
Parastratotype
Lectostratotype
Neostratotype
Hypostratotype
The original stratotype designated by the original
author
Holostratotype
A supplementary stratotype used in the original definition to illustrate the heterogeneity of the stratigraphic unit
Parastratotype
A stratotype for a previously described stratigraphic unit selected later in the absence of an adequately designated original stratotype.
Lectostratotype
A new stratotype selected to replace the older one which has been destroyed, covered, or otherwise made inaccessible.
Neostratotype
A stratotype proposed after the original designation of the holostratotype (and parastratotype) in order to extend knowledge of the unit or boundary to other geographic areas.
Hypostratotype (also called reference section)
2 description of stratotype
geographic
geologic
_____ are assemblages of rock bodies with distinct lithologic
characteristics and genetic associations. In a sense, they are a special class of complexes.
Ophiolites
case the assemblage does not represent a complete ophiolite sequence, the composite body may be called an __________________.
ophiolitic complex
A _________is a kind of complex consisting of a variety of
rocks in a fine-grained matrix
melange
Also known as “sedimentary melange”, consists of a chaotic mass of rock with large clasts older than the enclosing sedimentary sequence.
Olistostromes
