Metamorphic P-T Phase Diagrams

Click on an image or the link in the caption, and a PDF file of the diagram will download to your computer. Some of the PDF files are animations -- they contain more than one page that can be shown in sequence to see changes as temperature or some other variable changes.

Unless otherwise noted, these figures were drafted by Dexter Perkins or John Brady.

1-Component Systems

PT diagram for the system SiO2 based on Swamy and Saxena (1994).

Download PDF (Acrobat (PDF) 17kB Mar31 07)
Aluminum Silicates PT diagram for the system Al2SiO5 based on Holdaway (1971).

Download PDF (Acrobat (PDF) 21kB Oct12 07)


MgO-Al2O3-SiO2

These phase diagrams are based on calculations made using Rob Berman's TWQ software and database.

MASPT PT diagram for the system MgO-Al2O3-SiO2

Download PDF (Acrobat (PDF) 19kB Jun6 07)
Phase relationships in the MAS system This pdf animation includes several different phase diagrams depicting phase relationships in the system MgO-Al2O3-SiO2. The first considers only four minerals. Additional minerals are added one-by-one. Most of the reactions on the first few diagrams are metastable because enstatite and corundum are not considered.

Download PDF (Acrobat (PDF) 43kB Jun6 07)


CaO-MgO-SiO2-H20 (ultramafic rocks)

These phase diagrams are based on calculations made using Rob Berman's TWQ software and database.

Reactions in the system CMSH Petrogenetic grid for the system CaO-MgO-SiO2-H2O.
Download PDF (Acrobat (PDF) 19kB May26 07)
CMSH petrogentic grid Petrogenetic grid for the system CaO-MgO-SiO2-H2O.
Download PDF (Acrobat (PDF) 19kB May26 07)


CMSH reactions Animated PDF showing changes in minerals assemblages during progressive metamorphism in the CaO-MgO-SiO2-H2O system.
Download PDF (Acrobat (PDF) 102kB May26 07)
CMSH assemblages on PT diagram P-T diagram showing compatibility diagrams in the system CaO-MgO-SiO2-H2O.
Download PDF (Acrobat (PDF) 32kB May26 07)


CMSH low T reactions Schematic P-T diagram showing several low temperature reactions in the system CaO-MgO-SiO2-H2O, with compatibility diagrams.
Download PDF (Acrobat (PDF) 20kB May26 07)
Example pseudosection CMSH #2 Schematic pseudosections for low temperature reactions in the system CaO-MgO-SiO2-H2O. Bulk composition (red dot in triangle) is near that of typical mantle peridotites.
Download PDF (Acrobat (PDF) 18kB May26 07)


Example pseudosection CMSH #3 Schematic pseudosections for low temperature reactions in the system CaO-MgO-SiO2-H2O. Bulk composition (red dot in triangle) is more SiO2-rich than most mantle peridotites.
Download PDF (Acrobat (PDF) 21kB May26 07)
CMSH pseudosection example #4 Schematic pseudosections for low temperature reactions in the system CaO-MgO-SiO2-H2O. Bulk composition (red dot in triangle) is more SiO2-rich than most mantle peridotites.
Download PDF (Acrobat (PDF) 17kB May26 07)


Pseudosection for CMSH from low T to high T Pseudosection (CaO-MgO-SiO2-H2O system) for a composition near to that of typical mantle peridotites.
Download PDF (Acrobat (PDF) 22kB May26 07)
CMSH triangle Important phases in the system CaO-MgO-SiO2-H2O.
Download PDF (Acrobat (PDF) 23kB May26 07)


Al2O3-SiO2-H20

These phase diagrams are based on calculations made using Rob Berman's TWQ software and database.

Phase diagram for the ASH system Petrogenetic grid for the system Al2O3-SiO2-H2O.
Download PDF (Acrobat (PDF) 19kB May26 07)
Phase diagram for the ASH system Petrogenetic grid for the system Al2O3-SiO2-H2O.
Download PDF (Acrobat (PDF) 19kB May27 07)


ASH reaction progress Animated PDF showing changes in minerals assemblages during progressive metamorphism in the system Al2O3-SiO2-H2O.
Download PDF (Acrobat (PDF) 73kB May27 07)


CaO-Al2O3-SiO2

These phase diagrams are based on calculations made using Rob Berman's TWQ software and database.

CAS system Petrogenetic grid for the system CaO-Al2O3-SiO2.
Download PDF (Acrobat (PDF) 16kB May27 07)
CAS system Petrogenetic grid for the system CaO-Al2O3-SiO2.
Download PDF (Acrobat (PDF) 26kB May27 07)


CAS system Petrogenetic grid for the system CaO-Al2O3-SiO2.
Download PDF (Acrobat (PDF) 26kB May27 07)
CAS pseudosection P-T pseudosction for the system CaO-Al2O3-SiO2.
Download PDF (Acrobat (PDF) 21kB May27 07)


CaO-Al2O3-SiO2-H20

These phase diagrams are based on calculations made using Rob Berman's TWQ software and database.

CASH system Petrogenetic grid for the system CaO-Al2O3-SiO2-H2O.
Download PDF (Acrobat (PDF) 21kB May27 07)
CASH system Petrogenetic grid for the system CaO-Al2O3-SiO2-H2O.
Download PDF (Acrobat (PDF) 21kB May27 07)