6:21 PM
Instructions
Download Assignment4.pdf and the 8 image files named Rudite 1.png through Rudite 8.png. Complete as per instructions.
Important Note:the form that is included on page 6 Assignment 4 document for describing rudites in Part B of the assignment is NOT COMPLETE. A separate, complete form is provided in the attachments below. Please download it with the photos and submit Part B on this new form.
ADDITIONAL RUDITE PNG FILES ARE NEEDED THE REMAINING ARE RUDITE 4, 5 ,6, 7,8 but I am not able to attach more documents to in this attachment quote
Microsoft Word - Document6 Rudite 1 Rudite 2 Rudite 3 Rudite 4 Rudite 5 Rudite 6 Rudite 8 Photo Name Proper name for the Reasons for selecting the name rudite in photo (use back of page if needed) Answers to Assignment 4 Part B (i) Rudite 7 Microsoft Word - Assignment 4 .docx 1 ERSC 2P16 Clastic Sedimentology Fall 2021 Assignment 4. Classification of Terrigenous Sedimentary Clastic Rocks In this assignment you will determine the proper names for sandstones and rudites based on the classification schemes that are covered in the course notes. Part A. Classifying sandstones using Dott’s Classification To classify or determine the proper name of sandstones using Dott’s scheme you need to determine the relative proportions of various components of the rock in thin section by point counting (see notes for details). Because most students in this course have not yet taken optical petrology most are not in a position to actually collect such data. For this part of the assignment you are provided data collected by point counting four thin sections cut from sandstones (see the four tables on page 3 of this assignment). Use Dott's classification scheme to determine the proper name for the four samples for which point count data has been provided. Complete the necessary calculations to be able to use Dott’s classification (i.e., calculate the “normalized” proportions of quartz, feldspar and rock fragments expressed as a percentage of their total in each sample: see pages 49 to 52 of Chapter 3 of the course notes for details of calculating and plotting the data). Enter the values that you calculate in the appropriate fields in the table for data for each sample on page 3. Plot the proportions for each sample on the appropriate ternary diagram on pages 4 & 5 of this assignment and refer to figures 3-2 and 3-3 of Chapter 3 of the course notes to determine the specific name of the class of sandstone (e.g., quartz arenite). You must label each point that you plot with the sample number. Once you have determined the name of the class of a sample, write that name next to the sample number at the top line of the appropriate table on page 3. Finally, on a separate page briefly comment on the relative “maturity” of each of the four samples. Note that the examples provided in this assignment differ from those in the course notes in that they include proportions of “heavy minerals” and cement. When you “normalize” the data to 100% quartz, feldspar and rock fragments, the data on heavy minerals and cement are ignored. Part B. Rudites In this course the classification of rudites is described by defining a set of terms pertaining to rudites over pages 54 to 56 of the course notes with emphasis on Table 3-3 on page 55 (but don’t forget to see the figure on page 56). Refer to that section of the notes as you complete the following: 2 Within the folder for this assignment on the Sakai web site for ERSC 2P16 there is a folder containing a set of 8 photographs of rudites (Rudite 1 through Rudite 8) that represent several of the types listed in Table 3-3 of the notes. On the form that is on page 6 of this assignment write the most correct name for the rudite shown in the numbered photos. Don’t forget that the terms in table 3-3 can be combined to best describe the rudite. For example you could have an “oligomictic orthobreccia” - a clast-supported breccia made up of angular clasts of all the same lithology. In addition, briefly summarize the reason for the name that you chose in the space provided. Note that you may have more than one rudite of the same name among the photos. To hand in for Assignment 4: • Completed tables on page 3. • Ternary diagrams (pages 4 & 5) with points plotted and numbered for each of the four samples. • Comments on the relative maturity of the sandstones for which the composition data was provided. • Completed form on page 6 providing names and rationales for those names for each the 8 rudite photos. Grades: Part A: -Normalized composition data – up to 2 points for each specimen (Max. Total = 8points) -Proper name of the sandstone – up to 1 point for each specimen (Max Total = 4 points) -Plot of points on the appropriate ternary diagram – 1 point each (Max. Total 4 points). -Comments on the maturity of each sandstone – 1 point each (Max. Total 4 points) Maximum Total for Part A = 20 points Part B: -Name of each rudite – up to 2 marks each (Max. Total=16 points) -Reason for selecting the name – up to 1 mark each (Max. Total=8 points) Maximum Total for Part B = 24 points Maximum Total for Assignment 4 = 44 points 3 Sample 1 Sample 2 Component % Normalized % Component % Normalized % Quartz 11 Quartz 11 Feldspar 5 Feldspar 18 Rock Fragments 15 Rock Fragments 54 Matrix 58 Matrix 10 Heavy minerals 3 Heavy minerals 1 Cement 8 Cement 6 Sample 3 Sample 4 Component % Normalized % Component % Normalized % Quartz 73 Quartz 6 Feldspar 5 Feldspar 31 Rock Fragments 2 Rock Fragments 21 Matrix 5 Matrix 32 Heavy minerals 3 Heavy minerals 6 Cement 12 Cement 4 100Total 100Total 100Total 100Total Data collected by point counting sandstones in thin section under a microscope for Part A of Assignment 4. Calculate the relative proportions of quartz, feldspar and rock fragments, normalized to 100% for those three components (see course notes for details). Record the normalized percentages in the appropriate field in the tables and enter the proper name of the class of sandstone for each sample based on Dott’s scheme (e.g., quartz greywacke). Don’t forget to fill in the total for the column of normalized percentages. Values are not required for the shaded fields in the tables. Enter the class of sandstone, based on Dott’s scheme, on the above line. Enter the class of sandstone, based on Dott’s scheme, on the above line. Enter the class of sandstone, based on Dott’s scheme, on the above line. Enter the class of sandstone, based on Dott’s scheme, on the above line. 4 10 20 30 40 60 80 80 90 70 60 50 40 30 20 10 90 80 70 10 20 30 40 50 60 QUARTZ RO CK F RA GM EN TSFELDSPAR 90 50 70 Arenite 5 10 20 30 40 60 80 80 90 70 60 50 40 30 20 10 90 80 70 10 20 30 40 50 60 QUARTZ RO CK F RA GM EN TSFELDSPAR 90 50 70 Graywacke 6 Rudite 1 Rudite 2 Rudite 3 Rudite 4 Rudite 5 Rudite 6 Rudite 8 Photo Name Proper name for the Reasons for selecting the name rudite in photo (use back of page if needed) Answers to Assignment 4 Part B (i) Rudite