test 2 study guide Flashcards
Know the difference between weathering and erosion.
weathering is destructive processes change the rock physically and chemically. Erosion initial removal of weathered material.
Understand the difference between mechanical and chemical weathering and explain how mechanical weathering speeds chemical weathering.
mechanical is anything that breaks rock up into smaller pieces. Chemical is decomposition of a mineral into new chemical compounds. Mechanical can expose new area’s to atmosphere speeding up chemical weathering.
Understand the concept of equilibrium in chemical weathering.
if something is in equilibrium with surroundings it is considered stable. If not in equilibrium, not stable, will have reaction and change until equilibrium is reached.
Know how carbonic acid is formed and its role in solution and hydrolysis.
CO2 combines with water in atmosphere (raindrop), the Hydrogen looks to kick out the cation.
Name the 4 products of chemical weathering of the crust.
Iron Oxide, Ions, Clay, and Quartz.
Understand climatic effects on chemical weathering.
chemical weathering is slow in dry places and faster in humid wet places
What is the ecological significance of laterite soils?
some of the most nutrient poor soil with some of the most rich ecosystems in the world
. Understand compressive and shear stress and how they align minerals
Shear stress parallel, compressive stress perpendicular
Explain the differences between contact and regional metamorphism, including role of pressure, origin, and resulting texture.
contact: heat from magma body makes the rock, little pressure and results in non foliated texture
regional metamorphism: convergent plate boundaries sheering or squeezing lots of pressure and foliation
List in order the progressive metamorphic series, including parent rock.
Shale, Slate, Phyllite, Schist, Gneiss
Differentiate between detrital and chemical sediments and rocks.
detrital sediments are solid particles like sand gravel and silt. Chemical sediments are dissolved ions
Know detrital grain sizes and their resulting clastic rocks.
Size L to S: Gravel, Sand, Silt, Clay
Corresponding rocks: Breccia and conglomerate, sandstone, siltstone, and shale.
Understand how grain size (larger/smaller) and rounding change (increase/decrease) with transport.
The farther sediments have been transported the smaller and more round they become
In what type of tectonic environment are most metamorphic rocks formed? Which plate boundary?
Convergent boundaries
Know the metamorphic equivalents of certain parent rocks and vice versa.
Shale is parent to Hornfels
Basalt is parent to Hornfels
Sandstone is parent to Quartzite
Limestone is parent to Marble
Know the definition of crossbedding, mud cracks, and ripple marks.
cross bedding- thin layers of rock inclined at an angle to the more nearly horizontal bedding planes of larger rock
mud crack- crack formed in very fine grained sediment as it dries
ripple marks- small ridges formed on sediment surfaces exposed to wind or water are perpendicular to the motion.
Be able to list common environments of deposition for sandstone, shale, limestone, and conglomerate.
Sandstone- high energy, River, Alluvial Fan, and Beach
Shale- Low energy, lake, lagoon, deep sea, and low energy rivers
Limestone- Reef
Conglomerate- high energy, River, Alluvial Fan,
Be able to explain the effect on slope stability: Slope angle
stable on gentle slopes or horizontal surface, unstable on steep or vertical slope
Be able to explain the effect on slope stability: debris thickness
stable on slight thickness, unstable at great thickness.
Be able to explain the effect on slope stability: plane orientation
stable for planes at right angles to hillside slopes. Unstable for planes parallel to hillside slopes
Be able to explain the effect on slope stability: Vegetation
stable in heavy vegetation, unstable in light vegetation
Be able to explain the effect on slope stability: triggers
triggers are earthquakes, heavy rainfall, undercutting bottom of the slope, or weight added to upper part of a slope. These all cause the slope to become unstable.
Understand fully the role of water in mass wasting.
dry 33 degree has low strength and low stability
damp at 90+ degrees has high strength and high stability
Saturated at 0 very low strength and stability
List several ways in which mass wasting hazards can be lessened during and after construction.
Site selection, retaining walls, stitching, Quick-Veg, Terracing
Creep
Very slow, continuous downslope movement of soil or debris.
earthflow
Slow-to-rapid mass wasting in which fine-grained soil moves downslope as a very viscous fluid.
toecutting
removing the base of the slope, (bad)
beach
high energy produces quartz sandstone
mudflow/debris flow
A flowing mixture of debris and water, usually moving down a channel.
rockfall
Rock falling freely or bouncing down a cliff.
avalanche
large amounts of debris falling, most deadly
rockslide
Rapid sliding of a mass of bedrock along an inclined surface of weakness.
gneiss
A metamorphic rock composed of light and dark layers, made of feldspar hornblende, mica and quartz, parent rock is shale or granite.
hornfels
A fine-grained, unfoliated metamorphic rock.
schist
metamorphic rock composed of mica parent rock of either shale or basalt.
quartzite
metamorphic rock composed of quartz, parent rock is sandstone
phyllite
metamorphic rock composed of mica parent rock is either shale or basalt
marble
metamorphic rock composed of calcite parent rock is limestone
Slate
metamorphic rock composed of mica parent rock is either shale or basalt
Foliation
Parallel alignment of textural and structural features of a rock.
Sorting
Process of selection and separation of sediment grains according to their grain size (or grain shape or specific gravity)
Bedding
An arrangement of layers or beds of rock.
chert
A hard, compact, fine-grained sedimentary rock formed almost entirely of silica.
rounding
The grinding away of sharp edges and corners of rock fragments during transportation.
coal
made of carbon parent rock is coal
formation
A body of rock of considerable thickness that has a recognizable unity or similarity making it distinguishable from adjacent rock units. Usually composed of one bed or several beds of sedimentary rock, although the term is also applied to units of metamorphic and igneous rock. A convenient unit for mapping, describing, or interpreting the geology of a region.
shale
A fine-grained sedimentary rock (grains finer than 1/16 millimeter in diameter) formed by the cementation of silt and clay (mud). Shale has thin layers (laminations) and an ability to split (fissility) into small chips (weaker than slate)
limestone
A sedimentary rock composed mostly of calcite
Frost wedging
A type of frost action in which the expansion of freezing water pries a rock apart.
Hydrolysis
chemical weathering of feldspar
solution
Usually slow but effective process of weathering and erosion in which rocks are dissolved by water.
abrasion
The grinding away of rock by friction and impact during transportation.
laterite
tropical regions have laterite soils that are very low nutrient soil.
