Geology 1100 Chapter 6
The structure that may form where a stream enters a lake is called Delta Till Alluvial fan Sedimentary basin
A delta
Evidence of transgressions and regressions is preserved in the rock record. Based on the distribution of the deposits in the image below, which answer BEST describes the history of this shoreline A transgression only A regression only A transgression then a regression A regression then a transgression
A transgression then a regression
The textures presented in rock outcrops can tell us specific details about the paleoenvironment in which they were deposited. Which arrow BEST represents the dominant wind direction during deposition A B C D
B
The roundness of individual grains can tell us much about a rocks depositional history. The image below shows relative levels of rounding that clasts can display. What is the primary difference between the depositional histories of the grain labeled A and the one labeled B A is more welled sorted than B B is more well sorted than A A was transported a longer distance than B B was transported a longer distance than A
B was transported a longer distance than A
Rocks formed dominantly from the calcium carbonate shells of marine organisms are classified as____ and called ____. Clastic, arkose Organic, coal Biochemical, limestone Chemical, travertine
Biochemical, limestone
Clastic sedimentary rocks form in different depositional environments the size and shape of the clasts are paramount to determining the type of rock that's formed upon lithification. What type of clastic sedimentary rock will form from the environment shown below Shale Breccia Conglomerate Siltstone
Breccia
Which of the following rock types doesn't contain the mineral calcite Chert Fossiliferous limestone Chalk micrite
Chert
Which if the following lists accurately describes grain size increasing from smallest to large Sand, silt, pebbles Clay, silt, sand Silt, clay, sand Sand, cobbles, pebbles
Clay, silt, sand
Clastic sedimentary rocks form in different depositional environments. The size and shape of the clasts are paramount to determining the type of rock that's formed upon lithification. What type of clastic sedimentary rock will form from the environment below Shale Breccia Conglomerate Siltstone
Conglomerate
Ripple marks, dunes, and cross bedding are useful indicators of Water depth Flow velocity Sediment source Current direction
Current direction
The following figure shows several different samples of sediments in optical microscope view. Which of the samples displays the BEST sorting A B C D
D
Sedimentary structures preserved in rock outcrops can give us insight into what the environment was like when the sediments were originally deposited. What type of environment created the bedding structure shown below Shallow ocean Desert with migrating dunes Down-cutting river system Swamp
Desert with migrating dunes
Which if the following is a general term used to describe all the physical, chemical, and biological processes that make a sedimentary rock from sediments? Diagenesis Diamictite Dolostone Detritus
Diagenisis
What is the most logical past environment to have produced a deposit consisting of layers of unsorted, unstratified sedimentary clasts, clay-sized to boulder-sized? Floodplain Sand dunes Shallow water carbonate area Glacial valley
Glacial valley
The following picture is an idealized sketch of a particular sedimentary structure. What is the name for this set of structures Ripple marks Graded beds Cross bedding Mud cracks
Graded beds
Which of the following is NOT one of the major classes of sedimentary rocks Clastic Biochemical Chemical Intrusive
Intrusive
Which if the following features is a bed-surface marker, meaning it appears on the surface of a bed due to events during or soon after sediment deposition Laminations Cross beds Graded bedding Mud cracks
Mud cracks
Which if the following sedimentary features is the surest indicator that the past environment was subaerial (under air), not marine (underwater) Turbidites Mud cracks Scour marks Fossil marine clam shell imprints
Mud cracks
The organic sedimentary rock that is composed of mud-sized particles and partially decayed organic matter (kerogen) derived from plankton and algae remains is Coal Fossiliferous limestone Chert Oil shale
Oil shale
Which if the following statements is TRUE Conglomerates consist of large, angular clasts Pieces of broken rock are collectively called clasts or detritus A well sorted clastic rock is made up of different sized particles All clastic sedimentary rocks are cemented (held together) by calcite
Pieces of broken rock are collectively called coasts or detritus
Which of the following processes is associated with the formation of travertine Deposition Lithification Compaction Precipitation
Precipitation
The section below shows a series of graded beds superimposed on one another. What series of events could have produced this set of structures Migrating sand dunes Repetitious evaporation from a saline lake Repeated turbidite currents Oscillating ocean waves
Repeated turbidite currents
A sedimentary basin that forms when continental lithosphere is stretched, causing down dropped crustal blocks bordered by elongate mountain ranges, is called a Rift basin Passive margin basin Intracontinental basin Foreland basin
Rift basin
Which of the following sedimentary structures indicates that the sediments were deposited in a moving fluid Mud cracks Fossil footprints Ripple marks Laminations
Ripple marks
This diagram shown is a profile of Ripple marks from water flowing from A to B Ripple marks from water flowing from B to A Sand dunes from wind blowing A to B Sand dunes from wing blowing B to A
Ripple marks created by water flowing from A to B
According to the diagram below, which sediment sample has traveled the shortest distance and why? Sample 3, it contains small quartz grains Sample 2, its very well sorted and contains feldspar Sample 3, its properly sorted but well rounded Sample 1, it contains both resistant and nonresistant minerals
Sample one, because it contains both resistant and non resistant minerals.
If you find quartz sandstone in the place it formed, you know you are looking at an ancient Avalanche on a submarine slope Sand dune Swamp Alluvial fan
Sand dune
What is the most logical ancient environment to have produced a deposit consisting of layers of well-sorted sandstone with cross beds several meters high? Alluvial fan along a mountain front Sand dunes Shallow valley carbonate area Glacial valley
Sand dunes
Formation of a clastic sedimentary rock involves five stages. Which of the following describes erosion? Disintegration of bedrock into separate particles Compaction and cementation of loose particles to form solid rock Separation of rock or regolith from its substrate Process by which particles settle out of transport medium
Separation of rock or regolith from its substrate
A clastic sedimentary rock with clay and silt sized grains that breaks in thin sheets is called Mudstone Shale Siltstone Wacke
Shale
As sediment is transported downstream, away from its point of origin, the particles become Smaller More angular Poorly sorted Dominantly feldspar
Smaller
Sedimentary rocks can form by each of the following processes EXCEPT By precipitation of minerals from water solution Cementing together of loose grains of pre-existing rocks Shell fragments or carbon rich relicts of plants Solidification from a melt
Solidification from a melt
The distribution of sedimentary rocks reflects the relative historical position of different depositional environments. The following two images show a change in the relative position of marine and terrestrial depositional environments. What is the name for this shift shown from time 1 to time 2 Transgression Aggradation Regression Suppression
Transgression
When sea level rises (as shown in the image), the shoreline migrates inland, flooding the land and depositing coastal sediments over pre-existing terrestrial sediments. This process is called Rifting Uplifting Transgression Regression
Transgression
A clastic sedimentary rock composed of angular pebble-sized fragments surrounded by matrix is A) breccia B) conglomerate C) Shale D) Arkose
breccia