Preface Af ter man y year s of bor rowing owning and renting offces in New Y ork and then westw ard in Boulder Colorado the Geological S ociety of America fnally mo ved into its own headquar ter s building in the autumn of 1 972 Its street ad dress 330 0 P enrose Place w as no accident the staf f ar ranged with the city to name the street in honor of the S ociety s benefactor Ric hard AF P enrose Jr Thanks to a generous endowment from P enrose carefully tended by succes si ve in vestment commit tees to an able and cooperati ve arc hitect and builder and to the vision of man y people on the GS A Council and staf f the headquar ter s build ing is not only functional but pleasing to the eye P enrose s memory is k ept ali ve both through the building itself and through the man y pieces of his per sonal memorabiliahis roc king c hair his magnifcent globe and par t of his outstand ing library whic h is ric h in books on early explorationshoused in the building Though it w as built more than for ty year s ago the headquar ter s building buc ks tradition with its unusual and spacious design and exhibits the grace and symme try of Ear th s materials The man y people associated with its planning were highly concerned with the view the landscaping and the ease and comfor t of the staf f W e hope the roc ks minerals and color s that decorate our building will remind staf f member s and visitor s how ric h in color form and texture are the natural features of our Ear th s crust v