This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Compare and contrast confining pressure and compressional stress relating to metamorphic rocks. What ... (Read 107 times)

charchew

  • Hero Member
  • *****
  • Posts: 579
on: Jul 16, 2018
Compare and contrast confining pressure and compressional stress relating to metamorphic rocks. What will happen to the mineral crystals in each situation?
 
  Also, provide examples of geologic environments where such pressure would be the main agent of metamorphism.
  What will be an ideal response?

Question 2

What is gneissic banding, how does it form, and how does it compare to the color banding that is often found in marble?
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

onowka

  • Sr. Member
  • ****
  • Posts: 353
Reply #1 on: Jul 16, 2018
Answer to Question 1

Answer: Confining pressure on metamorphic rocks by applying pressure equally in all directions will collapse any open spaces between mineral grains to produce a more dense rock. An environmental example would be younger overlying materials burying sedimentary rocks and forcing them deeper into the interior. Compressional stress metamorphoses rocks by applying pressure that is greater in one direction and weaker in another. (For example, the horizontal pressure is greater than the vertical pressure.) This will cause the mineral crystals to elongate or reorient so that the crystal's long axis is perpendicular to the direction of highest pressure. An environment that would create such a scenario can include a convergent plate boundary.

Answer to Question 2

Answer: Gneissic banding is the highest degree of foliation that can form before the rock begins to melt. It forms in high-grade metamorphic conditions and when minerals segregate into separate layers, which often gives the appearance of alternating light and dark layers. This effect differs from color banding, which has alternating light and dark layers but little difference in mineral crystals between the layers.


charchew

  • Member
  • Posts: 579
Reply 2 on: Jul 16, 2018
Gracias!

essyface1

  • Member
  • Posts: 347
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

« previous next »
 

Did you know?

Chronic necrotizing aspergillosis has a slowly progressive process that, unlike invasive aspergillosis, does not spread to other organ systems or the blood vessels. It most often affects middle-aged and elderly individuals, spreading to surrounding tissue in the lungs. The disease often does not respond to conventionally successful treatments, and requires individualized therapies in order to keep it from becoming life-threatening.

Did you know?

Looking at the sun may not only cause headache and distort your vision temporarily, but it can also cause permanent eye damage. Any exposure to sunlight adds to the cumulative effects of ultraviolet (UV) radiation on your eyes. UV exposure has been linked to eye disorders such as macular degeneration, solar retinitis, and corneal dystrophies.

Did you know?

Hyperthyroidism leads to an increased rate of metabolism and affects about 1% of women but only 0.1% of men. For most people, this increased metabolic rate causes the thyroid gland to become enlarged (known as a goiter).

Did you know?

Certain chemicals, after ingestion, can be converted by the body into cyanide. Most of these chemicals have been removed from the market, but some old nail polish remover, solvents, and plastics manufacturing solutions can contain these substances.

Did you know?

Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.

Rocks are the most common geosphere materials, and can be fun, dangerous, beauti Rocks are the most common geosphere materials, and can be fun, dangerous, beauti
a) Using fingertip pressure b) Using hand-over-hand pressure a) Using fingertip pressure b) Using hand-over-hand pressure
The Distribution of Pressure The Distribution of Pressure
Apply direct pressure to points along the shoulders. Stand to one side and use your forearm to apply ... Apply direct pressure to points along the shoulders. Stand to one side and use your forearm to apply ...
Predators adapt to extreme water pressure and the absence of light Predators adapt to extreme water pressure and the absence of light
Red rocks due to oxidation of iron near the surface Red rocks due to oxidation of iron near the surface
Video: Structures that affect circulation - kidneys and blood volume and skeletal muscle pumping

For a complete list of videos, visit our video library