What are the minerals and textures observed in subduction-related

rocks?

Examples from Jenner Beach, CAFranciscan Complex

after Catlos and Sorensen, 2003

Late Jurassic-early Cretaceous agepeak P ~ 0.9-1.2 GPapeak T ~ 500-700°C

Case Study: Franciscan Complex

Jenner Beach – Mélange blocks eroded from the nearby hillsides

Geologists from around the world flock to Jenner Beach.

Image Courtesy of Sarah Penniston-Dorland

Blueschist

PPL

GAR

AMPH

PHE

PHE=Phengite, GAR=Garnet, AMPH=Amphibole

Image Courtesy of Sarah Penniston-Dorland

Blueschist

XPL

GAR

AMPH

PHE

Image Courtesy of Sarah Penniston-Dorland

Blueschist

PPL PHE=Phengite, GAR=Garnet, AMPH=Amphibole

GAR

AMPH

PHE

Image Courtesy of Sarah Penniston-Dorland

Blueschist

XPL

AMPH

PHE

GAR

Image Courtesy of Sarah Penniston-Dorland

Eclogite

PPL

GAR

AMPHPHE

CHL OMPH

CHL=Chlorite, OMPH=Omphacite

Image Courtesy of Sarah Penniston-Dorland

Eclogite

XPL CHL=Chlorite, OMPH=Omphacite

GAR

AMPHPHE

CHL OMPH

Image Courtesy of Sarah Penniston-Dorland

Eclogite

PPL TTN=Titanite, EPI=Epidote

TTN

EPI

Image Courtesy of Sarah Penniston-Dorland

Eclogite

XPL

TTN

EPI

TTN=Titanite, EPI=Epidote

Image Courtesy of Sarah Penniston-Dorland