Berkeley, Wednesday Feb 23. Worked most of the day with B. Clark on my Paleographic maps. His corrections relate many to Cal., from Cretaceous time to the close of the Cenozoic. My Pliocene map must be changed to three maps of this time to bring out the changes. Better have him send me three maps of California alone, that I will publish in my book. Best Crust geology probably can enter the Pal., and certainly since the Jurassic must be interpreted in the light of Block fault structures, and what all in the light of Fold nts like the Appalachians. Probably that type of Nts only form there more for the Pacific coast N. and S. America, and layed on the entire Pacific ocean. It will be many years yet before the Cal. structures are fully understood and can be described in simple language. Bruce Clark is hardly the man to ever describe them in simple and good English, but he may be the man that can do most of the field work to elucidate them.