CHAPTER 6 – 7 Soil Mineral Rocks Water Geology
In this lesson we discuss Soil Mineral Rocks Water Geology.
Which term best describes all the processes that move weathered rock materials and soils downslope?
Mass Wasting
What process created finely divided red, brown, and yellow minerals in soils?
Precipitation of iron oxides during the chemical weathering process
Why is the humus layer typically thicker in a cool, temperate forest soil then in a tropical rainforest soil?
Less humus is produced in the cool, temperate forest but the rate of decay and oxidation is slower than in a tropical rainforest
Which of the following best describes sets of fractures in relatively fresh bedrock, such as granite, that are roughly parallel to the land surface?
Sheeting fractures
From the land surface downward to the unweathered bedrock, which of the following is the correct order of the different soil horizons
O, A, E, B, C, bedrock
Which one of the following statements concerning soil erosion is NOT true?
Sheet erosion, rills, and arroyos or gullies develop mainly during prolonged droughts
Which term describes a soil formed by weathering of the underlying bedrock?
Residual
Which regolith material results from frost wedging?
Talus slopes
Which of the following best describes the process of mineral subtraction of eluviation?
Mineral subtraction of eluviation is the removal of very fine-sized silt and play particles from the A and E soil horizons
Which of the following statements concerning humus is NOT true?
Humus is readily leached from the B horizon in weakly acidic soil solutions
During the 1930s, the United States suffered its greatest natural catastrophe. What great natural disaster affected both the farmers and the urbanites and led to the creation of the Soil Conservation Service?
The Dust Bowl
What portion of an angular, fracture-bounded granitic block shows the highest rate of weathering?
The corners
Which one of the following statements concerning mechanical weathering is NOT true?
Mechanical weathering involves a major change in the mineral composition of the weathered material
Which one of the following is an important mechanical weathering process for enlarging fractures and extending them deeper into large boulders and bedrock in temperate and arctic environments?
Frost Wedging
What two factors speed up rates of chemical reaction and weathering in rocks and soils?
Warm temperatures; abundant moisture
Which of the following materials are most susceptible to chemical weathering my dissolution?
Calcite
Assume that water filling a crack in a rock undergoes cycles of freezing and melting. Which one of the statements is true?
Water expands as it freezes, causing the crack wall to be pushed apart
Which one of the following statements best describes erosion?
Erosion is the process by which weathered rock and mineral particles are removed from one are and transported elsewhere
What is probably the single most important, original, depositional feature in sedimentary rocks?
Bedding or stratification
In what type of depositional environment is oolitic limestone most likely to form?
Shallow, clear marine waters with vigorous current activity and lots of corals
Which one of the following is not a chemical sedimentary rock or evaporite?
Shale
What type of sandstone contains abundant feldspar?
Arkose
What characteristic is used to classify detrital sedimentary rocks?
Grain size of the detrital particles
What percentage of the continental areas of Earth’s surface is covered by sediments and sedimentary rocks?
75%
Which of the following sedimentary rocks would you expect to have originally been deposited by fast-moving streams?
Conglomerate
Which of the following best describes bedded gypsum and halite?
Chemically derived sedimentary rocks
Which of the following descriptions best matches a “greywacke”?
A sandstone with sand grains embedded in a clay-rich matrix
What mineral is the building block of microcrystalline flint, chert, and jasper?
Quartz (SiO2)
A cherty limestone would most likely contain which major constituents?
Silica and calcite
In which of the following sedimentary rocks are nonclastic textures common?
Limestones
What is the chemical formula for dolomite, the major mineral in dolostones?
CaMg(CO3)2
Of the following list, which common mineral found in igneous rocks is the most abundant mineral in detrital sedimentary rocks?
Quartz
Which of the following is a form of calcium carbonate?
Travertine
What is the main difference between a conglomerate and a sedimentary breccia?
Breccia clasts are angular; conglomerate clasts are rounded.
Which of the following sedimentary features would typically be found in shales but not in sandstones?
Mud cracks
What is the most common type of sedimentary rock?
Limestone
Which of the following applies to the basic constituents of halite, gypsum, and sylvite?
All are transported as dissolved ions and then deposited by evaporation.
What cement produces bright-red and yellow colors in some sandstones?
Iron oxide
Which of the following minerals is not a common cementing agent for sandstones?
Fluorite
Which of the following is not a type of limestone?
Arkose
For which of the following sediments does compaction play an important role?
Mud
Where do coal beds originate?
In freshwater coastal swamps and bogs