#Fold mountains
20-Mar-95 22:56:10
Sb: #174872-#Fold mountains
Fm: Doug Mitchell 70621,702
To: Kamron Kirkconnell 73740,2246
Hi, Kamron–
I do not easily buy the Cook Islands Manihiki Plateau as something carved of
S. America by the E. Pacific spreading ridge, because I prefer to guess S.
America has been chasing that ridge since Pangaea. With subduction creating
the Andes, that ridge could have moved away from S. America only by spreading
faster than the subduction. It is the fastest spreading ridge we know, but
that is presumably because the subduction is fast also. Note that N. America
has apparently been catching up with and "eating" the northern continuation of
that ridge, though S. America is the faster moving continent.
Do the Cook Islands have continental rock? If none has been found, I will
simply assume that plateau is a basaltic eruption from the mid-Cretaceous
superplume episode or some such.
–Doug
–Doug