OPHIOLITE SEQUENCES

(Press & Siever)

 

 

OCEANIC CRUST IS SOMETIMES EXPOSED ON LAND AS A RESULT OF CONTINENTAL COLLISION

THESE ROCK SEQUENCES (OPHIOLITES) WERE RECOGNIZED BUT NOT UNDERSTOOD BEFORE THE DISCOVERY OF PLATE TECTONICS

GIVES ANOTHER WAY OF STUDYING OCEANIC SPREADING PROCESS

 

 

2 BILLION YEAR OLD OPHIOLITE IN QUEBEC, CANADA, SHOWING BASALT PILLOW LAVAS

INDICATES THAT PLATE TECTONICS HAS GONE ON FOR A LONG TIME