Lab 5 Weathering and sedimentary rocks Online Supplement (1)
docx
keyboard_arrow_up
School
University Of Georgia *
*We aren’t endorsed by this school
Course
1121L
Subject
Geology
Date
Apr 3, 2024
Type
docx
Pages
3
Uploaded by SuperHedgehogPerson445
Lab 5: Spring 2024
Lab 5: Weathering and Sedimentary Rocks
Student Name Nicole Maxey
(For TA Use) Raw score_____/39
Points______/100
To complete this lab, find supplied materials in eLC in the folder Assignment Lab 5: Weathering and Sedimentary rocks Word .doc file and a powerpoint.
Use a word processor to modify this file and type in your responses. Whatever word processor you use,
save your work as a PDF or Word Doc and upload it to eLC.
Write down questions that develop and ask your TA during meeting time of the lab or via email. Familiarize yourself with the slides in eLC
and watch any videos linked
. Linked videos are in your slideshows AND on this worksheet. Answer the questions below to receive credit. Items are not necessarily in order, so you will have to do some searching and remember where you have found things and go back to them.
Before a sedimentary rock can form, pieces of other rocks must be weathered out of position and then transported downhill and then downstream through some erosion process or processes. Interestingly, sedimentary rocks are possibly the most important rock type of the three major types of rocks we will cover (others are igneous and metamorphic rocks) because sedimentary rocks contain earths record of life, as fossils, and many of the main energy sources humans use for our society are derived from sedimentary rocks. Further, water resources people depend on are often contained within
sedimentary rocks. Let’s find out more.
1)
From the slide show presentation in eLC that your TA will help you cover, what are the two types of weathering that lead to rocks crumbling? (2 points)
Chemical and Physical weathering 2)
Sometimes people think of weathering and erosion happening hand-in-hand, and these processes often do occur simultaneously. However, these ideas are two different things. Weathering is purely the break-down of rock material, and erosion is: (2 points)
Erosion is the transportation of sediment through wind, rain, water, etc. 3)
Eventually all transported sediment stops, at least temporarily. These depositional areas are unique to the environment that brought in the sediment and caused it to stop moving. The compaction and sedimentation of sand grains yields a particular rock called: (1 point)
Sandstone
4)
The four different agents that move rock and transport it are: (4 points)
Wind, water, ice, gravity (Aeolian, Fluvial, Glacial, Colluvial)
5)
In detrital sedimentary rocks, what three minerals tend to survive longest because they are resistant to erosion processes? (3 points)
Quartz, feldspar, and clay
Lab 5: Spring 2024
6)
From the video with minerals at the Mica Mine from week 3 lab, the sedimentary rocks in the area are shown at the beginning of the video and discussed at the end. During the discussion of the mineral quartz, weathering processes are described. https://www.youtube.com/watch?
v=wa4_bC4tgc8
After a mineral like quartz breaks off of other rocks, what will happen to that mineral material during its journey downstream? Eventually this leads us to many of the sand grains found all over the world. (2 points).
The mineral material starts to form big/large components in sedimentary rocks and then it'll become smaller into sand/quartz grain. 7)
Layers of rock found throughout much of the Earth’s surface are sedimentary rocks. In Bangs Canyon of Colorado, what are the two rock layers’ names discussed there? (2 points)
Chinle & Wingate
8)
In what physical orientation are the two rock layers of Bangs Canyon? (1 point)
The two layers are horizontal
9)
The rock layers are said to be Jurassic and Triassic in age in the video, which means they might have dinosaur fossils in them. Watch this video to learn about fossils in sedimentary rocks and how you might identify them: Sedimentary rocks and dinosaurs - YouTube
. Rocks like these in the video are very close to the Mica Mine at a place called the Mygatt-Moore Quarry.
A. What two dinosaur names are given in the video? (2 points) The two dinos are Camarasaurus and Saurapod
B. What sedimentary rock type is best at preserving dinosaur bones out of the 3 discussed? (1 point)
Shale
C. Why might conglomerate cause damage to bones? (2 points)
Because of the fact flood streams move lots of sediment, meaning more power from the
stream water= more broken/damaged bones & fossils become.
The Morrison Formation rocks at Mygatt-Moore, and the Chinle and Wingate rocks of Bangs Canyon, are all terrestrial sedimentary rock layers. This means the sediments accumulated on land either in rivers and streams or, in the case of the Wingate, as large sand seas like the Sahara. 10) Rocks that are more likely to deposit offshore include chemical sedimentary rocks, where precipitated minerals like calcite form the rock called Limestone (1 point)
11) Deposition by evaporation of large quantities of water may leave behind sea salt, which is the minerals: Halite & Gypsum (2 points)
Lab 5: Spring 2024
12) One of the consequences of burying organic material, like peat or forests or jungles, is that the sediment may accumulate so much that water is squeezed out, the rocks become heated and density of the organic material increases. This process is the basic description of how what energy resource forms? Coal (2 points) 13) The matrix of a sedimentary rock contains small rock material between larger grains. Sometimes, that matrix isn’t there and there is simply empty space between grains. In some rocks underground, the empty spaces of rocks may contain water, or oil, or natural gas. As society continues to use these resources extracted from rock, the importance of understanding how many rocks layers have these resources and how much is there is critical to continuing to live the way we do. The holes in rocks are called: Pores (1 point)
14) What is the general trend of grain size if one is to move downstream in a river? It may be necessary to move tens to hundreds of miles to see these differences. (3 points) The more/further you go downstream grain is less coarse, is rounded, and weaker minerals=weathered out
15) Synthesis: Toward the end of the slide show there is a picture of the Grand Canyon. These sedimentary rocks have accumulated in rocks that are thousands of feet thick. Many of the rock layers contain sediments that were originally transported from rocks of the Appalachian Mountains, even though the Grand Canyon region is in Arizona. Use the information you have collected in your mind in working through the slides, videos and questions to explain the whole process of how Appalachian rocks got to Arizona as newer sedimentary rocks. Use the following key words by placing each one in a complete sentence in a logical order: smaller and more rounded, transport, weather or weathering, flowed from _______to ________, diagenesis, time,
deposition. (7 points)
The Appalachian rocks moved to Arizona through an old river system which flowed from the Appalachians westwards across most of North America. So over time, the sediment that was being transported in the river was being weathered and eroded at the same time. The further along it went, the more the sediment was being eroded and getting smaller/more rounded. As it continues on, the sediment deposited itself and went through the process of diagenesis, which is where the sediment turns to a sedimentary rock, this occurred as once it was deposited the sediment got buried and compacted, cementing all the sediment into what we know as a sedimentary rock.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help