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38 Cards in this Set
- Front
- Back
igneous rocks |
formed by magma cooling asit moves upward toward the ground surface |
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describe intrusive igneous rocks |
1) below the ground surface; 2) slow coolingprocess; 3) coarse grained |
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decribe extrusive igneous rocks |
1) at the ground surface; 2) rapidcooling; 3) fine grained |
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name 3 intrusive igneous rocks |
1) granite 2) diorite 3) gabbro |
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name 3 extrusive igneous rocks |
1) rhyolite 2) andesite 3) basalt |
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sedimentary rocks |
formed by soildeposits that have transformed into rock through hardening process calledinduration or lithification |
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describe clastic sedimentary rocks
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formed by pressure from overlying strata andcementation through precipitation; layered/stratified |
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describe carbonate sedimentary rocks |
organic materials origin; generallyconsisting of CaCO3 (calcium carbonate) |
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name 3 clastic rocks |
1) Sandstone 2) Shale 3) Conglomerate |
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name 3 carbonate rocks |
1) limestone 2) chalk 3) dolomite |
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describe a sinkhole |
carbonate rocks are dissolved by long exposure to acidic water and cause underground caverns; the soil above caves into the caverns |
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metamorphic rocks |
formed by both igneous and sedimentary rocks subjected to intense heat and pressure |
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name 3 types of foliated metamorphic rocks |
1) slate 2) schist 3) gneiss |
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name 2 types of nonfoliated metamorphic rocks |
1) quartzite 2) marble |
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physical weathering |
disintegration of rocks into smallerparticles through physical or mechanical process |
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chemical Weathering |
disintegrationof rocks through chemical reactions between the minerals in the rock, water,and oxygen |
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residual soils |
soils that remain in place becauseof faster weathering process than the transporting process; common in tropicalregions |
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Transported Soils |
soils that formed by the deposition ofsediments that have been transported from their places of origin by various agents |
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GlacialSoils |
transportedby glaciers |
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Alluvial(or Fluvial) Soils |
transportedby rivers and streams:92768 |
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Lacustrineand Marine Soils |
transportedbeneath lakes and ocean,respectively |
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AeolianSoils |
transportedby wind |
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Colluvial Soils |
transported downslope by gravity suchas landslide |
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describe till glacial soils |
unsortedand unstratifiedglacial sediments directlydeposited by glaciers |
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describe outwash glacial soils (glaciofluvial soils): |
soils deposited by meltwaterstreams flowing beyond the margin of the glacier carry |
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characteristics of using a test pit |
- Continuousprofile - Shallowerdepths - Disturbedsample |
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characteristics of using drilling |
- Morecommon technique - Deeperdepths - Lessdisturbed sample |
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site exploration steps |
1) Reviewof background information 2) Fieldreconnaissance 3) Field exploration (drilling, sampling, in-situ testing) 4) Laboratory testing (Chapters 10 and 12) 5) Geotechnicalinterpretations/Analysis 6) Reporting |
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solid stem auger |
Suitable for firm and dense soils but may not be drilled further if hardbouldersare encountered |
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hollow stem auger |
hollow stem casing provideslateral support insidethe hole during drilling and hence reduces the possibility of caving; suitable for looser soils |
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mud rotary drilling
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Drillingfluid provides a hydrostatic pressure to preventcaving (suitable for loose sand below GWT) |
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rock coring |
Hole is advanced with a rotary diamonddrill bit (hollow cylinder), and nearly continuous undisturbed samples, rockcores,are obtained. |
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Shelbytube sampler |
- A thin wall tube islowered to the bottom of the boring, then smoothly pressed intothe soil. - Used for clayey soils toobtain “undisturbed” sample - Thelarger the tube diameter, the less the sample disturbance |
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split spoon sampler |
- A split spoon tube islowered to the bottom of the boring, then drivenintothe soil with a hammer - Typically used for sandy soils toobtain sample (samples obtained from split spoon sampler are moredisturbedthan those from Shelby tube) |
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StandardPenetration Test (SPT) |
- Drivethe split spoon sampler over 18 in (45cm) - Recordno. of blows per each 6 in (15 cm) penetration - Stopthe test if more than 50 blows are required for anyof the intervals (refusal). - Stopthe test if more than 100 totalblows are required (refusal) |
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ConePenetration Test (CPT) |
A hydraulic ram pushesthe cone assemblyinto the ground and instruments measure resistance topenetration. |
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CPT vs. SPT |
CPT Advantages: - Providesmuch more reliable datawith better resolution. - Providescontinuous profile CPT Disadvantages: - Doesnot give a sample - Needto mobilize a special rig to perform CPT - Cannotbe performed to deeper depths in very dense soils or gravelly soils |
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soil is... |
- a natural material - a particulate material - consists of all three phases of matter |