« previous next »

Author Question: How was the style of plate tectonics different in the Archean than it is today? When did the present ... (Read 28 times)

vinney12

  • Hero Member
  • *****
  • Posts: 586
on: Jul 15, 2018

How was the style of plate tectonics different in the Archean than it is today? When did the present
  style of plate tectonics begin? What will be an ideal response?



Question 2

What is the origin of greenstone belts? What will be an ideal response?


Jossy

  • Sr. Member
  • ****
  • Posts: 336
Reply #1 on: Jul 15, 2018
Answer to Question 1

Earth in the Archean was much hotter than it is today because Earth's radiogenic heat production was
much higher; in other words, many radiogenic isotopes have decayed to stable daughters and no longer
give off heat. With more heat available, seafloor spreading and plate movements took place more
rapidly. The current plate tectonics style began by the Paleoproterozoic.



Answer to Question 2

Greenstone belts developed in back-arc marginal basins that open and then close. When the basin
opens, volcanism and sedimentation take place, and then the basin closes during a period of
compression. During closure, the rocks are intruded by plutons and metamorphosed, and the
greenstone belt is folded into a syncline and also faulted.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

In inpatient settings, adverse drug events account for an estimated one in three of all hospital adverse events. They affect approximately 2 million hospital stays every year, and prolong hospital stays by between one and five days.

Did you know?

The toxic levels for lithium carbonate are close to the therapeutic levels. Signs of toxicity include fine hand tremor, polyuria, mild thirst, nausea, general discomfort, diarrhea, vomiting, drowsiness, muscular weakness, lack of coordination, ataxia, giddiness, tinnitus, and blurred vision.

Did you know?

Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.

Did you know?

Methicillin-resistant Staphylococcus aureus or MRSA was discovered in 1961 in the United Kingdom. It if often referred to as a superbug. MRSA infections cause more deaths in the United States every year than AIDS.

Methicilli ...
Did you know?

There are approximately 3 million unintended pregnancies in the United States each year.

The skeleton of a dwarf elephant from the island of Crete. Dwarf elephants were present on some Medi The skeleton of a dwarf elephant from the island of Crete. Dwarf elephants were present on some Medi
Lac Operon cAMP present Lac Operon cAMP present
The default position for the throttle plate is in slightly open position. The servomotor then is ... The default position for the throttle plate is in slightly open position. The servomotor then is ...
Human population growth, 1700 - present Human population growth, 1700 - present
Icant keep calm, today is my due date Icant keep calm, today is my due date
Theory of Plate Tectonics Theory of Plate Tectonics
Video: Passive Smoke Exposure

For a complete list of videos, visit our video library