Franciscan Complex limestone deposited at 17^o south paleolatitude.

At Laytonville, California, 3 blocks of pelagic limestone, each a few tens of metres long, are incorporated in the Franciscan melange. Bedding is well defined, but top indicators are lacking. Study of foraminfera showed that the blocks are of Albian and Cenomanian age and were deposited during the Cretaceous Long Normal Polarity Interval. Details of the foraminiferal zonation show that both blocks are right side up. The observed inclinations imply deposition on the Farallon plate at 17^o +/- 7^o S paleolatitude at c.96 m.y. BP. Consideration of reasonable paleolongitudes and possible times of incorporation of the blocks in the melange indicates a Farallon-North America convergence rate significantly higher than any observed today.- from Authors