MYTUTOR SUBJECT ANSWERS

2247 views

Describe how regional metamorphism of shale produces a sequence of rocks and minerals.

Metamorphism is a process by which preexisting rocks can be altered in composition or structure, to form a new rock. Regional metamorphism occurs in areas of above average pressures and temperatures, such as subduction zones. Shale is a sedimentary rock, which has a varied chemical composition, and it contains platy clay minerals that can align to pressure (associated with regional metamorphism).

 

Low-grade metamorphism (low pressure and temperature) of shale forms slate. Distinguishable by platy cleavage, where mica crystals align perpendicularly to pressure as well as the index mineral Biotite.

 

Medium-grade metamorphism (medium pressure and temperature) of shale forms schist. Schist is distinguishable by the index minerals Kyanite and/or Garnet, it may also show slight banding of dark/light minerals.

 

High-grade metamorphism (high pressure and temperature) of shale forms Gneiss. Gneiss shows very distinct banding between light and dark minerals, which have separated due to different compositions and has the index mineral Sillimanite.

 

It is important to point out that index minerals show the minimums pressure and temperatures the shale must have experienced. A metamorphosed shale may contain Biotite and Garnet (two minerals formed at different P+T), this shows that metamorphosed shale must have at least experienced medium grade metamorphism.

Josh S. A Level Geology tutor, GCSE Geology tutor, GCSE Geography tut...

2 years ago

Answered by Josh, an A Level Geology tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

4 SUBJECT SPECIALISTS

£22 /hr

Daniel V.

Degree: Earth Sciences (Bachelors) - Durham University

Subjects offered:Geology, Geography+ 2 more

Geology
Geography
Chemistry
-Personal Statements-

“Geology at Durham. Exams were very stressful. Run charity society. Footballer. Teach in different styles, recaps. Keywords stuck everywhere. ”

MyTutor guarantee

£20 /hr

Lucy A.

Degree: Geological Sciences (Bachelors) - Leeds University

Subjects offered:Geology

Geology

“I am a first year geology student and hope to help understand difficult topics as well as work on exam and revision techniques. ”

MyTutor guarantee

£20 /hr

Jennifer F.

Degree: MSci Geology with an International Year (Masters) - Birmingham University

Subjects offered:Geology, Geography

Geology
Geography

“Hi, I'm Jenny and I'm a first-year student at The University of Birmingham. I'm studying MSci Geology with an International Year. Being able to help people learn, whether that be academically or in other areas, has been a passion of m...”

About the author

Josh S.

Currently unavailable: for regular students

Degree: Earth Sciences (Masters) - Durham University

Subjects offered:Geology, Physics+ 2 more

Geology
Physics
Maths
Geography

“Who am I? Hello! I'm Josh and thank you for visiting my profile. I'm an undergraduate, currently in my second year, studying Earth Sciences (Geology) at Durham University. During my first year of A-level studies I was tutored for...”

You may also like...

Other A Level Geology questions

Explain why the Composition of the Plagioclase Feldspar may vary within an Intrusion.

Which fossil group will show 5-fold (Pentameral) symmetry, is composed of plates, a mouth and an anus on opposite surfaces?

Which tectonic settings experience earthquakes?

What is the difference between a baked and a chilled margin?

View A Level Geology tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok