Name: Professor name: Class Time: The Virtual Field trip is to be completed by your self. You should not work with a partner. This is not group work. Nor should you search for answers on the internet. These are not correct as the student who posted these did a poor job with the answers. If you look at the videos with closed captioning, the spelling for some geologic terms is incorrect. If you are unfamiliar with a word or geologic concept, look it up and get the correct spelling. By submitting this work, I attest that I have not violated the UH Academic Honesty code. I did this work by myself and did not copy any portion of my answers from a website, another student or any other source (your initials here) Questions for the Edwards formation Video Questions as you watch the video at Bee Cave road answer the questions below 1) Houston sits on sediments that dip shallowly toward the Gulf of Mexico. Do these sediments become older or younger as you head toward Austin (Central TX)? 2) The Edwards Plateau is the result of what type of faulting (reverse/thrust/normal/strike slip)? 3) The Edwards Limestone is not a pure limestone, what makes it dirty? 4) What is the depositional environment for the Edwards formation? 5) What is the dominant fossil found in the Edwards formation? 6) In what time period was the Edwards formation deposited? 7) What caused the Edwards formation to have a different color near the surface on the ends of the road cutout? 8) How does the Edwards aquifer get recharged with water? 9) What geologic structure on the fault plane allows for an understanding of fault displacement? 10) Is Austin, TX in the hanging wall or footwall of the fault system?
Gigapan Questions Answer the following questions using the gigapan image for the Edwards formation/bee cave road cut out For each of the following questions take a partial screenshot of the relevant portion of the gigapan image, 1) Trace three contacts between beds. 2) Circle an area where chemical weathering has taken place. 3) Using the contacts you drew, how thick are the individual limestone beds? (Hint: trees/shrubs are 5-10 ft. tall.) 4) Are all the beds in the Edwards formation the same thickness? 5) Does the thickness of individual beds remain constant across the outcrop? You may have to relook at the entire gigapan image to answer this question. Questions for Slaughter Gap Video Questions as you watch the video at Slaughter Gap answer the questions below 1) What rock type are the students standing on (igneous, metamorphic, or sedimentary)? 2) Are the mineral grains in the rock the students are standing on coarse or fine? 3) From this list of minerals, choose those that are present in the rock the students are standing on: quartz, cordierite, feldspar, olivine, pyroxene, amphibole, calcite, mica, pyrite, halite, gypsum 4) Based on this mineralogy, what type of rock is it? 5) What is the name of the formation on which the students are standing? 6) What is the numerical age of the rock students are standing on and in what Eon did it form? 7) What rock type is behind the students (igneous, metamorphic, or sedimentary)? 8) How large are the particles that make up the rock behind the students? 9) What is the name of the rock formation behind the students? 10) What is the numerical age for the rock behind the students and in what geologic Period did it form? What is the age difference between the two rock types at Slaughter Gap? 11) What type of contact is between the rock on which the students are standing and the rock that is behind the students? 12) How far does this contact, or a correlative contact, extend? Where else can you find it in the U.S?
13) List some of the characteristics of the rock behind the students? 14) What is the source of the detritus (sediment) in the rock behind the students and how far did it travel? Gigapan Questions Answer the following questions using the gigapan image Slaughter gap 1 for the first question and Slaughter gap 2 for the second question. For each of the following questions take a partial screenshot of the relevant portion of the gigapan image, The first image was taken at a location you can easily walk up to as shown by the red arrow on the topographic map of Slaughter Gap shown below. The second image is the view across a small stream and railroad track from first location as shown by the red line on the topographic map. The base of the gigapan image is parallel to the red line shown below. So, your contacts should be able to be traced across the valley with a similar geometry. Topographic Map of Slaughter Gap region provided by Dr. Leon Long, University of Texas at Austin 1) Draw a line approximately where the contact between the Precambrian basement and Hickory sandstone is. Hint: look for layered rock in contact with non-layered rock. You may have to zoom in and move around the image to look at the rock textures to identify this. Look down at the level where the students would have been standing. 2) Draw a line where the contact between the Precambrian basement and Hickory sandstone is and label the two rock formations with text. Hint: look for layered rock above the break in slope. Also look carefully at all rocks within the trees. Be careful as some of these have fallen down the cliff and others
are in place. You may have to zoom in to identify the rock type. Since this gigapan image was taken looking across a small creek to the west of the first image, the dip (angle) of the contact should be the same on both sides of the creek Questions for Inks Lake Video Questions as you watch the video of Inks Lake answer the questions below 1) What is the rock type the students are standing on (igneous, metamorphic, or sedimentary)? 2) Describe the rock texture (use terms such as granoblastic, foliated or layered). What name is this rock given? 3) What is the name of the rock formation the students are standing on? 4) Are the rocks the students are standing on older or younger than the rocks at Slaughter gap? 5) What geologic structure is present in the rocks on the other side of the river? 6) Do the igneous rocks cut the metamorphic rocks, and what does this tell you about which came first? 7) What type of igneous intrusions are there? 8) What is the protolith for the rock students are standing on? 9) What metamorphic index mineral is present at Inks Lake? (Hint: it is an aluminum silicate.) 10) What was the tectonic setting that created these rocks and what is its modern style equivalent? 11) What supercontinent was being built when this metamorphism and igneous activity was active in Texas? Gigapan Questions Answer the following questions using the gigapan image Inks Lake 1 for the first two questions and Inks Lake 2 for the third question. For each of the following questions take a partial screenshot of the relevant portion of the gigapan image, 1) Draw a polygon around a dike. 2) Draw a polygon around a sill. 3) In these two images, use a pen tool to highlight the foliation. 4) Draw a box around a fold. (Hint: look for the yellow notebook.) When describing metamorphic rocks, in which geologists cannot tell which layer is older or younger, they use the terms antiform and synform instead of anticline and syncline (look at figure 10.8 in your text). Is this an antiform or synform? Is it symmetrical, assymetric or overturned?
Geologic Map of granitic intrusives of the Llano Uplift adapted from Mosher (1996) Questions for Enchanted Rock Enchanted Rock State Natural Area has two exfoliation domes formed by mechanical erosion of Grenville age (1, 082 million year old) Town Mountain granite similar to what you heard about at Slaughter Gap. For an explanation of exfoliation domes, look at Smart Figure 6.5 in your text. Also, you may want to watch a movie of exfoliation at http://geotripper.blogspot.com/2014/09/ongoing-exfoliation-event-attwain.html The Town Mountain Granite intruded into the Packsaddle Schist (schist is not visible in the Gigapan image). The two granite domes are part of the second largest batholith in the Llano Uplift. The tallest dome is 425 above ground level. There are two gigapan images. One is taken from the parking lot at the entrance to the Enchanted Rock State Natural Area showing two granite domes. The second gigapan image was taken from the south dome looking north at the main dome that everyone hikes up. Gigapan Questions Answer the following questions using the gigapan image For each of the following questions take a partial screenshot of the relevant portion of the gigapan images,
1) For Enchanted Rock Gigapan 1 - draw a polygon around granite blocks on the dome to show the exfoliation process. Are the edges of the blocks are straight or curved. If they are straight, does this indicate that they formed by fracturing? 2) For Enchanted Rock Gigapan 1 - do you think the granite blocks will undergo either (1) further mechanical weathering, break into smaller pieces, slide down the side of the dome and be added to the granite rubble pile at the bottom of the dome or (2) be chemically eroded by rain? Explain your answer. 3) Enchanted Rock Gigapan 2 shows black stripes running down the slope of the dome. Using a pen tool (and not a line tool), trace one of these stripes down the dome from top to bottom. These stripes are caused by what type of weathering? Turn in two pdf files via email: 1) The questions, (This Document) with answers, saved as yourlastname_firstname_qa.pdf 2) Your geologic interpretation from the gigapans saved as yourlasname_firstname_vft.pdf Both files that you will turn in should be saved as a pdf and emailed to eas.uh.physical.geology@gmail.com