Homework Help is Here – Start Your Trial Now!
Science
Earth Science
fom the pluton. Examine the figure on the right and answer the following questions: 0. 4. (a) Chlorite and biotite are platy minerals. Do you think they are foliated in this contact aureole? Explain. Miles B (b) Where in the contact aureole would the highest temperatures have occurred? Explain your reasoning. B Metamorphic zones Hartland granite Andalusite Biotite Chlorite

fom the pluton. Examine the figure on the right and answer the following questions: 0. 4. (a) Chlorite and biotite are platy minerals. Do you think they are foliated in this contact aureole? Explain. Miles B (b) Where in the contact aureole would the highest temperatures have occurred? Explain your reasoning. B Metamorphic zones Hartland granite Andalusite Biotite Chlorite

Applications and Investigations in Earth Science (9th Edition)
Applications and Investigations in Earth Science (9th Edition)
9th Edition
ISBN:9780134746241
Author:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Chapter1: The Study Of Minerals
Section: Chapter Questions
Problem 1LR
See similar textbooks
icon
Related questions
Question
Parts a to c. That's what I need those.
3 Pg dn and T-P conditions are based on experimental work in which mate- can survive only under a specific range of temperature-pressure cise 7.5 will guide you through the reasoning used by those meta- - Metamorphic index minerals: Some metamorphic minerals index minerals form. Estimates of metamorphic conditions for regionally metamorphosed shales in northern Scotland are the change in mineralogy in wall rocks adjacent to plutons. Exer (T-P) conditions. They are called index minerals because their metamorphic grade, but we can't determine the precise inten- Index minerals were discovered when field geologists noted we know which of these minerals represents the highest rials with compositions similar to particular protoliths have Index minerals provide a relative intensity scale; that is, sity of the metamorphism experienced in terms of degrees Cel- sius or kilobars of pressure. Estimates of absolute (numerical) presence in a rock indicates what the T-P range was during meta- ctri enter ins FIGURE 7.13 Estimated temperature-pressure conditions in regionally metamorphosed shales from northern Scotland, superimposed on the aluminosilicate phase diagram. morphism. 10 - Kyanite these minerals represents the highest 30 7. 20 been heated and squeezed Sillimanite 10 to replicate conditions at which 2. Andalusite shown in FIGURE 7.13. 300 400 500 600 700 g08 Temperature ("C) Note that the garnet zone could be followed by either a kyanite or a sillimanite zone, depending on the precise T-P conditions will guide you through the reasoning used by those meta- morphic pioneers. EXERCISE 7.5 Index Minerals and Metamorphic Zones Name: Section: Course: Date: washt until the early 20th century that geologists recognized that contact metamorphic minerals were not randomly distributed throughout the contact aureole (the area around a pluton affected by contact metamorphism). The figure below shows the distribution of minerals in the contact aureole around the Hartland pluton, a small granite batholith in central Maine. The field mapper has noted that the minerals chlorite, biotite, and andalusite appeared in metamorphosed shales at different distances from the pluton. Examine the figure on the right and answer the following questions: 2 4 (a) Chlorite and biotite are platy minerals. Do you think they are foliated in this contact aureole? Explain. Miles B (b) Where in the contact aureole would the highest temperatures have occurred? Explain your reasoning. B Metamorphic zones O Hartland granite Andalusite Biotite Chlorite (continu
Transcribed Image Text:3 Pg dn and T-P conditions are based on experimental work in which mate- can survive only under a specific range of temperature-pressure cise 7.5 will guide you through the reasoning used by those meta- - Metamorphic index minerals: Some metamorphic minerals index minerals form. Estimates of metamorphic conditions for regionally metamorphosed shales in northern Scotland are the change in mineralogy in wall rocks adjacent to plutons. Exer (T-P) conditions. They are called index minerals because their metamorphic grade, but we can't determine the precise inten- Index minerals were discovered when field geologists noted we know which of these minerals represents the highest rials with compositions similar to particular protoliths have Index minerals provide a relative intensity scale; that is, sity of the metamorphism experienced in terms of degrees Cel- sius or kilobars of pressure. Estimates of absolute (numerical) presence in a rock indicates what the T-P range was during meta- ctri enter ins FIGURE 7.13 Estimated temperature-pressure conditions in regionally metamorphosed shales from northern Scotland, superimposed on the aluminosilicate phase diagram. morphism. 10 - Kyanite these minerals represents the highest 30 7. 20 been heated and squeezed Sillimanite 10 to replicate conditions at which 2. Andalusite shown in FIGURE 7.13. 300 400 500 600 700 g08 Temperature ("C) Note that the garnet zone could be followed by either a kyanite or a sillimanite zone, depending on the precise T-P conditions will guide you through the reasoning used by those meta- morphic pioneers. EXERCISE 7.5 Index Minerals and Metamorphic Zones Name: Section: Course: Date: washt until the early 20th century that geologists recognized that contact metamorphic minerals were not randomly distributed throughout the contact aureole (the area around a pluton affected by contact metamorphism). The figure below shows the distribution of minerals in the contact aureole around the Hartland pluton, a small granite batholith in central Maine. The field mapper has noted that the minerals chlorite, biotite, and andalusite appeared in metamorphosed shales at different distances from the pluton. Examine the figure on the right and answer the following questions: 2 4 (a) Chlorite and biotite are platy minerals. Do you think they are foliated in this contact aureole? Explain. Miles B (b) Where in the contact aureole would the highest temperatures have occurred? Explain your reasoning. B Metamorphic zones O Hartland granite Andalusite Biotite Chlorite (continu
WE R SD F G Z X H. CVBN enter Index Minerals and Metamorphic Zones (continued) EXERCISE 7.5 Section: Name: Date: Course: (c) What does the distribution of minerals in the contact aureole suggest about the temperatures at which hese mapped minerals are stable? (d) Based on your answers above, list the three minerals mapped in this figure in order of increasing metamorphic 2. 3.. grade. 1. Temperatures in the area containing biotite, but not chlorite or andalusite, must have been appropriate to form biotite, but either too hot or too cool to form chlorite and andalusite, Biotite is therefore an index mineral for the T-P conditions in that part of the aureole, and this area is called the biotite zone. Similarly, the chlorite and andalu- site zones represent areas in which those minerals were stable. Chlorite, biotite, and andalusite are therefore index minerals for metamorphosed shales. If limestones and dolostones had also been present in the aureole, they would have produced different index minerals because they don't have the chemical composition needed to make these three minerals. Line B in the figure separates the biotite and chlorite zones, which means it separates the areas that were under conditions at which chlorite was stable from areas that were under conditions at which biotite was stable. This line is called the biotite isograd (iso = equal, grad = grade) because the metamorphic temperatures were exactly the same everywhere along it: just hot enough to make biotite. Similarly, dashed line A in the figure is the andalusite isograd. Metamorphic zones and isograds are also mapped in areas of regional metamorphism and may involve other meta- morphic index minerals. What Do You Think Geologists in Africa have found economically valuable concentrations of chromite (the principal ore of chromium) that formed by magmatic differentiation in thick mafic sills. In the same area, there are also mafic lava flows that look very much like the sills, but which contain none of the valu- able minerals. An investment firm is considering purchasing mineral rights for a mountain near the chromite deposits that has numerous tabular bodies of mafic igneous rock. You have been hired as a consultant to determine whether these bodies are intrusive sills, and therefore potential chromite sources worth the investment, or extrusive flows that would not be worth the money. What metamorphic evidence would you look for that
Transcribed Image Text:WE R SD F G Z X H. CVBN enter Index Minerals and Metamorphic Zones (continued) EXERCISE 7.5 Section: Name: Date: Course: (c) What does the distribution of minerals in the contact aureole suggest about the temperatures at which hese mapped minerals are stable? (d) Based on your answers above, list the three minerals mapped in this figure in order of increasing metamorphic 2. 3.. grade. 1. Temperatures in the area containing biotite, but not chlorite or andalusite, must have been appropriate to form biotite, but either too hot or too cool to form chlorite and andalusite, Biotite is therefore an index mineral for the T-P conditions in that part of the aureole, and this area is called the biotite zone. Similarly, the chlorite and andalu- site zones represent areas in which those minerals were stable. Chlorite, biotite, and andalusite are therefore index minerals for metamorphosed shales. If limestones and dolostones had also been present in the aureole, they would have produced different index minerals because they don't have the chemical composition needed to make these three minerals. Line B in the figure separates the biotite and chlorite zones, which means it separates the areas that were under conditions at which chlorite was stable from areas that were under conditions at which biotite was stable. This line is called the biotite isograd (iso = equal, grad = grade) because the metamorphic temperatures were exactly the same everywhere along it: just hot enough to make biotite. Similarly, dashed line A in the figure is the andalusite isograd. Metamorphic zones and isograds are also mapped in areas of regional metamorphism and may involve other meta- morphic index minerals. What Do You Think Geologists in Africa have found economically valuable concentrations of chromite (the principal ore of chromium) that formed by magmatic differentiation in thick mafic sills. In the same area, there are also mafic lava flows that look very much like the sills, but which contain none of the valu- able minerals. An investment firm is considering purchasing mineral rights for a mountain near the chromite deposits that has numerous tabular bodies of mafic igneous rock. You have been hired as a consultant to determine whether these bodies are intrusive sills, and therefore potential chromite sources worth the investment, or extrusive flows that would not be worth the money. What metamorphic evidence would you look for that
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Recommended textbooks for you
Applications and Investigations in Earth Science …
Applications and Investigations in Earth Science …
Earth Science
ISBN:
9780134746241
Author:
Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:
PEARSON
Exercises for Weather & Climate (9th Edition)
Exercises for Weather & Climate (9th Edition)
Earth Science
ISBN:
9780134041360
Author:
Greg Carbone
Publisher:
PEARSON
Environmental Science
Environmental Science
Earth Science
ISBN:
9781260153125
Author:
William P Cunningham Prof., Mary Ann Cunningham Professor
Publisher:
McGraw-Hill Education
Earth Science (15th Edition)
Earth Science (15th Edition)
Earth Science
ISBN:
9780134543536
Author:
Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:
PEARSON
Environmental Science (MindTap Course List)
Environmental Science (MindTap Course List)
Earth Science
ISBN:
9781337569613
Author:
G. Tyler Miller, Scott Spoolman
Publisher:
Cengage Learning
Physical Geology
Physical Geology
Earth Science
ISBN:
9781259916823
Author:
Plummer, Charles C., CARLSON, Diane H., Hammersley, Lisa
Publisher:
Mcgraw-hill Education,
SEE MORE TEXTBOOKS