Dynamic Planet B/C

[Unome]

Figured I might as well start this. For those who don't already know, this year's topic is Tectonics.

First question(s) (Click to Show Hidden Text)

1. What are the layers of the ophiolite suite?
2. If an ophiolite is found near a coastline, what tectonic processes is this indicative of?

[bhavjain]

Figured I might as well start this. For those who don't already know, this year's topic is Tectonics.

First question(s) (Click to Show Hidden Text)

1. What are the layers of the ophiolite suite?
2. If an ophiolite is found near a coastline, what tectonic processes is this indicative of?

Answer (Click to Show Hidden Text)

1. From least deep to most deep: sediments, pillow lava (basalt), sheeted dykes, gabbro, and peridotite.
2. Obduction at a convergent plate boundary.

[Unome]

Correct, your turn!

[bhavjain]

What is the smallest tectonic plate? Biggest? (Must be major or minor plates)

[chscioly]

Answer (Click to Show Hidden Text)

Smallest plate-Scotia Plate
Largest plate-Pacific Plate
I haven't been able to find a clear definition of major and minor plates. It seems like different sources are defining them based on different area requirements.

[Unome]

Answer (Click to Show Hidden Text)

Smallest plate-Scotia Plate
Largest plate-Pacific Plate
I haven't been able to find a clear definition of major and minor plates. It seems like different sources are defining them based on different area requirements.

I've found the same thing. Generally I rely on definitions provided on websites for college courses or in commonly-used textbooks, as that is what event supervisors tend to use.

[bhavjain]

Answer (Click to Show Hidden Text)

Smallest plate-Scotia Plate
Largest plate-Pacific Plate
I haven't been able to find a clear definition of major and minor plates. It seems like different sources are defining them based on different area requirements.

Correct. Wikipedia lists two more smaller minor plates, but all my other sources list Scotia as the smallest microplate.

[chscioly]

Question (Click to Show Hidden Text)

Give three pieces of evidence supporting continental drift.

[Unome]

Answers (Click to Show Hidden Text)

1. The presence of similarly layered/formed rock formations on many southern continents (iirc the Karoo supergroup is a major example).
2. Magnetic polarity changes in older rocks, especially those that have rotated due to continental drift, or those that have been reversed along seafloor spreading axes.
3. The abundance of similar fossil flora and fauna on many southern continents that presumably could not have crossed the oceans, implying that there once existed a land-based connection between the continents.

[chscioly]

Correct, your turn!