Section 1 – Origin and characteristics of rocks and minerals Flashcards
Soil Variability
Soils are the result of UCTEAEPIAL
Prairie soils are relatively new <
The original material is a result of two geological processes:
Soils are the result of unique conditions that exist at each place in a landscape
Prairie soils are relatively new <10,000years old
The original material is a result of two geological process:
- Bedrock formation
- Glaciation
Western Canada had been under water for immense periods of time in the past. Over how long of a time frame ?
500 million years
Sediment in these water bodies -that were under water for 500 million years in Western Canada - settled to the bottom and was compressed into ___ ____ up to 3,000 meters thick
rock layers
Variations in the ?___\_ _ _ ?, of W. Canada, over 500 million years, led to different kinds of bedrock layers at different times.
water bodies
Formation of Sedimentary Bedrock
Western Canada has been under water for
Sediment in these water bodies settled to the
Variations in the water bodies led to different kinds of ? layers at different times
Formation of Sedimentary Bedrock
immense periods of time in the past 500 million years
bottom and was compressed into rock layers up to 3,000 meters thick
Variations in the water bodies led to different kinds of bedrock layers at different times
How old is the earth estimated to be?
(Sedimentary Layers south of Edmonton)
4.5 billion years
The unique characteristics of bedrock layers influences the ? that develop out of them
soils
The unique characteristics of bedrock layers influences the soils that develop out of them
– For example, soils developing out of saline bedrock tend to produce _______ soils while non-saline bedrock tends to produce more productive __________ soils.
Reality check
- – What does this mean in terms of reclamation?
saline
non-saline
- Soil salinity is the worst hindrance to crop-growing
- reclamation requires regular leaching which is
- irrigation and drainage
- Leaching is most often accomplished by ponding fresh water on the soil surface and allowing it to infiltrate. Leaching is effective when the salty drainage water is discharged through subsurface drains that carry the leached salts out of the area under reclamation.
- reclamation requires regular leaching which is
Anthropogenic vs. naturally occurring salts etc.?
The two major anthropogenic sources of salts are from irrigation water and fertilization.
Salts often originate from the earth’s crust. They also can result from weathering, in which small amounts of rock and other deposits are dissolved over time and carried away by water. This slow weathering may cause salts to accumulate in both surface and underground waters. The surface runoff of these dissolved salts is what gives the salt content to our oceans and lakes.
The relationship between bedrock and soil may be quite distant except for the help of ________, erosion, weathering etc.
glaciation
Glaciation and Deglaciation
Canada has been covered with ?km of ice several times over the past _____ years. This huge mass of ice moved by its own ______ grinding the rock below it and ______ it across the continent. It is estimated that the last continental glacier melted back from the prairies ? years ago
3
2 million
weight
redistributing
10-12,000
Bedrock and Soil Formation
Glaciation and Deglaciation produced four kinds of deposits:
- Glacial Till (from moving ? )
- Fluvial (from moving ?)
- Lacustrine (from calm water ?)
- Eolian (from ?)
- ice
- water
- lakes
- Wind
Glaciation and Deglaciation produced four kinds of deposits:
- ? (from moving ice)
- ? (from moving water)
- ? (from calm water lakes)
- ? (from Wind)
- Glacial Till
- Fluvial
- Lacustrine
- Eolian
Glaciation and Deglaciation produced four kinds of deposits:
- Glacial Till (from moving ice)
- Fluvial (from moving water)
3.
4.
- Lacustrine (from calm water lakes)
- Eolian (from Wind)
Glaciation and Deglaciation produced four kinds of deposits:
1.
2.
- Lacustrine (from calm water lakes)
- Eolian (from Wind)
- Glacial Till (from moving ice)
- Fluvial (from moving water)
Glacial Till
The material ____ ____ _____ _______ was broken into an unsorted mixture of boulders, stones, sand, silt, and clay. – This mixture is also called:
? material
boulder ?
crushed under moving ice
morainal
clay
Glacial Till
The material crushed under moving ice was broken into an unsorted mixture of ____, ____, _____, _____, and _____.
– This mixture is also called:
morainal _\__?__\_
_____ clay
boulders, stones, sand, silt, and clay.
material
boulder
Glacial Till –
- Well sorted or poorly sorted? Why?
- Well stratified or poorly stratified? Why?
- Stone and boulders are rounded or angular? Why?
- Sediments deposited directly from glacial ice generally are poorly sorted and
-
unstratified \
- meltwater streams or lakes are sorted and stratified.
- More transport = more sorted
- The rock fragments are usually angular and sharp rather than rounded, because they are deposited from the ice and have undergone little water transport.
Deglaciation and Soil Parent Material
– Melting back of the ice sheets involved ________of years of water dafrallf In addition to glacial till deposits:
Fluvial deposits remain where rivers once flowed (?)
Lacustrine deposits were left from ancient lakes (?)
Eolian deposits were formed by ? action (sand and silt; sand dunes and loess)
thousands
draining away through rivers and lakes long forgotten
(sand and gravel)
(silt and clay)
wind
Deglaciation and Soil Parent Material
Melting back of the ice sheets involved thousands of years of water draining away through rivers and lakes long forgotten.
In addition to glacial till deposits:
- ? deposits remain where rivers once flowed (sand and gravel)
- ? deposits were left from ancient lakes (silt and clay)
- Eolian deposits were formed by wind action (?)
Fluvial
Lacustrine
sand and silt; sand dunes and loess
Deglaciation and Soil Parent Material –
MB of the IS involved ? of ? of water draining away through rivers and lakes long forgotten. – In addition to glacial till deposits:
Fluvial deposits remain where rivers once flowed (? and gravel)
Lacustrine deposits were left from ancient lakes (? and clay)
Eolian deposits were formed by wind action (sand and silt; sand ? and loess)
Melting back of the ice sheets
thousands of years
sand
silt
dunes
The degree of sorting depends upon how much TtheShU.
Glacial till, containing a mixture of coarse ______ rock fragments, sand, silt, and ?, was deposited by the slow p_________ a_________ of an ice sheet, and is a good example of an angular, p-s sediment.
transport the sediment has undergone
angular
clay
plowing action
poorly-sorted
Very poorly sorted indicates that the sediment sizes are…
whereas well sorted indicates that the sediment sizes are similar (low variance). …
What would cause sediments to be poorly sorted?
Glaciers can transport almost ___ ____ sediment easily, and when ice flow slows down or stops, the sediment __ ____ _____, due to the density of the ___.
mixed (large variance)
any size
is not deposited
ice
most rocks on earth are
- ignerous, however most we see are sedimentary
- 95% rocks on earth=igneous (but only 25% on surface are igneous)
- 5% on earth = sedimentary (but 75% on surface are sedimentary)
any rock that is dark means that
it has a lot of organic content
T or F
lakes have coarser grained sediments
TRUE
the process of turning into rock
lithification
difference between mud and shale
any mud with laminated facility planes is shale but mud that doesnt is just mud
Porosity
Porosity consists of the tiny spaces in the rock that hold the oil or gas.
Porosity of a rock is a measure of its ability to hold a fluid.
permeability
Permeability is a characteristic that allows the oil and gas to flow through the rock.
The permeability of a rock is a measure of the resistance to the flow of a fluid through a rock. If it takes a lot of pressure to squeeze fluid through a rock, that rock has “low permeability” or “low perm.” If fluid passes through the rock easily, it has “high permeability,” or “high perm.”
well sorted rocks vs. poorly sorted have
porosity vs. low porosity
Well sorted rocks are porous
while
poorly sorted have low porosity
most well sorted=wind (desert)
