In your post, you will introduce yourself, say why you are interested in this course, and your expectations. You will also examine your daily activities and think about how you use geology in your everyday life. Think about the materials you use, the places you travel and describe how you think geology is used or applied in your life.
For example, I use my mobile phone on a daily basis. There are several ore minerals that are used in the construction of phones. Most of the circuitry in phones is conducted through copper wires. The source of copper is chalcopyrite – an ore mineral. I could not imagine what my life would be like without my smartphone as I depend on it for travel, communication, work, etc.
Your initial post should be a minimum of 200 words, and you should respond to at least 2 of your classmates’ posts. You are expected to cite any sources that you use in your research of what geologic items are used in your daily life. Please be sure you cite your sources correctly using either APA or MLA style. For assistance in citing source correctly, please reference the Purdue OWL.
PART 2! LAB!
The Earth is very old and many of its features were formed before people came along to study them. Studying Earth’s past is much like detective work—using clues such as positions of rock layers to uncover distinct stories. The work of geologists and paleontologists is very much like the work of forensic scientists at a crime scene. The ability to put events in their proper order is the key to unraveling the hidden story of Earth’s history.
Relative dating is a geologic term that describes the set of principles and techniques used to sequence geologic events and determine the relative age of rock formations. You will find that most of these concepts are easy to understand.
Upon completing this lab, you should be able to:
Describe and interpret the 5 key relative age dating principles.
Describe and interpret the 3 different kinds of unconformities.
Draw and interpret the geologic history of a cross-section.
Watch the video below for instructions on the lab you will be completing in this unit. An example is also provided of what you will be expected to complete in this lab. Once you have completed your original assignment, please ensure you submit it to the Unit 1 Lab Assignment To Complete box.
In this presentation, you will find the instructions for your lab assignment. We will also walk you through an example of what you will need to construct on your own and submit to the assignment folder for your lab grade. The purpose of this lab is for you to take what you have learned about relative age dating principles in this unit and construct a cross section that shows this. Your cross-section must include the following. One, unconformity, five geologic layers, and at least two relative age dating principles. You should recall that unconformities can be described as being an angular unconformity, a disconformity, and non-conformity. >> Examples of geologic layers you can use include sandstone, mudstone, limestone, shale, chert, silt stone, and conglomerate. >> You are more than welcome to use other sedimentary layers that are not listed here. You will also recall that relative age dating principles are classified as rinciple of horizontality, principle of superposition, principle of lateral continuity, principle of cross-cutting relationships, principle of inclusions, and principal of fossil succession. We are now going to walk you through an example. For this example, I will show an angular unconformity. >> My five geologic layers will be sandstone, limestone, limestone, shale, and siltstone. >> I will also show the principle of original horizontality, principle of superposition, and principal of cross-cutting relationships. Step one, I chose three of the geologic layers and 50 00:01:58,250 –> 00:02:00,140 layered them on top of each other to show the principle of superposition. Here we can see that since sandstone is towards the bottom, it was deposited first, followed by siltstone, and lastly, shale. My second relative age dating principle I want to show is the principle of original horizontality. This principle states that layers of sediments are originally deposited horizontally under the action of gravity. You notice that I have tilted my three layers to deviate from original horizontal position. This age dating principle tells me that my sandstone, siltstone, and shale layers were not deposited at this angle. Some tectonic activity tilted them away from their original horizontal position. >> Now I want to show an angular unconformity here. >> My older tilted silt, stone and shale have been eroded a bit. >> This process allows for a younger group of sediments. >> In my example, these are limestone and mudstone to deposit on top of the new erosional surface. You see I have added these layers at the top of the image. The boundary between the siltstone, shale, and limestone is represented in my image as a dark blue line and represents my angular unconformity. My last relative age dating principle left to show is the principle of cross-cutting relationships. Here I have intruded an igneous feature called a dike, represented by the red vertical bar. The principle of cross-cutting relationship tells us that the igneous intrusion is always a younger than the layers of rocks it crosses. >> I have drawn my igneous intrusion over the sandstone, siltstone, shale, limestone, and mudstone, cross-cutting all five of my layers. >> This is my finished cross section. This is what your submission should look like. Here I have a complete cross section showing one unconformity, five geologic layers, and at least two relative age dating principles. You can draw a cross section that shows more than this, but these are your minimum requirements. On the left of our cross section, we see a geologic history of the cross section. The oldest deposition is the deposition of the sandstone, followed by the deposition of the siltstone, and then the shale. These three layers were then tilted. A period of erosion follows to form an angular unconformity. After the period of erosion, limestone gets deposited, followed by deposition of mudstone. Finally, we have the intrusion of the Igneous dike that cross-cuts all layers. 127 00:05:03,104 –> 00:05:05,830 Hopefully, the example shown here demonstrates to you what is expected in this lab. Please be creative and enjoy the process. Your task again is to construct your own cross-section that demonstrate your knowledge and understanding of relative age dating principles. You must submit a labeled cross-section along with the geologic history of your cross section from start to finish. Please be sure to sign and date your drawing. before you upload to the assignment folder, You can scan and attach your submission or you can take a picture with your phone and upload it. Here are a few suggestions. You will want to choose your geologic layers, which unconformity, and your two relative age dating principles you want to show before you begin drawing, Be sure to think about the ordering of your events. You may have several ssketches before you are happy with your final cross-section. >> And that’s okay. >> It is also best to draw your cross-section on paper first before using any type of software program, if you choose to do it this way. But a hand-drawn cross-sections is perfectly acceptable. Please begin your first assignment and have some fun showing us what you have learned.