Metamorphic Facies

Question 1

Describe the transition from zeolite to prehnite/pumpellyite

Answer 1

The presence of chlorite

Question 2

Describe the transition between the prehnite/pumpellyite facies to the Greenschist facies

Answer 2

Prehnite breaks down and slowly gives to actinolite and with an increase in T, pumpellyite disappears and gives away to epidote and actinolite

Question 3

Describe the transition from Greenschist facies to Amphibolite facies

Answer 3

Plagioclase increases in Ca content towards oligoclase, actinolite starts to break down with increase in T and actinolite,epidote and chlorite give off Al and provide it to hornblende

Question 4

Describe the transition between amphibolite facies and granulite facies

Answer 4

A transition from hydrous minerals to anhydrous minerals, water is expelled out of pore spaces so there isn’t enough H2O to form the hydrous minerals, hornblende breaks down into Cpx and Opx

Question 5

Decided the transition from zeolite and prehnite/pumpellyite facies to blueschist facies

Answer 5

Albitr breaks down by increase in pressure into jadeite and quartz

Question 6

Describe the transition from blueschist facies to eclogite facies

Answer 6

Reaction between galucophane and paragonite that creates garnet and omphacite, high pressures make it unstable for plagioclase to form