This topic contains a solution. Click here to go to the answer

Author Question: How do columnar joints form? What will be an ideal response?[br][br][b][color=#FBB117]Question ... (Read 73 times)

FButt

  • Hero Member
  • *****
  • Posts: 519
How do columnar joints form? What will be an ideal response?

Question 2

How is the behavior of gases different in a quiet and an explosive eruption? 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

at

  • Sr. Member
  • ****
  • Posts: 359
Answer to Question 1

In a lava flow, especially a mafic one, a distinctive pattern of columns bounded by fractures may form.
This occurs when the lava flow stops moving, contracts as it cools, and produces forces that cause
fractures to open. The fractures, called joints, appear as polygonal cracks that extend downward,
forming parallel columns with their long axes perpendicular to the cooling surface.



Answer to Question 2

When mafic magma rises toward the surface, the gases within it expand and are able to escape. Mafic
magmas usually erupt quietly. When felsic magma rises to the surface, the gases are unable to expand,
and the gas pressure increases. If the pressure becomes great enough, an explosion occurs and
pyroclastic materials are blown into the air





FButt

  • Member
  • Posts: 519
Reply 2 on: Jul 15, 2018
Thanks for the timely response, appreciate it


Animal_Goddess

  • Member
  • Posts: 339
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

 

Did you know?

Patients who have been on total parenteral nutrition for more than a few days may need to have foods gradually reintroduced to give the digestive tract time to start working again.

Did you know?

Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.

Did you know?

The Centers for Disease Control and Prevention has released reports detailing the deaths of infants (younger than 1 year of age) who died after being given cold and cough medications. This underscores the importance of educating parents that children younger than 2 years of age should never be given over-the-counter cold and cough medications without consulting their physicians.

Did you know?

About 80% of major fungal systemic infections are due to Candida albicans. Another form, Candida peritonitis, occurs most often in postoperative patients. A rare disease, Candida meningitis, may follow leukemia, kidney transplant, other immunosuppressed factors, or when suffering from Candida septicemia.

Did you know?

All adults should have their cholesterol levels checked once every 5 years. During 2009–2010, 69.4% of Americans age 20 and older reported having their cholesterol checked within the last five years.

For a complete list of videos, visit our video library