Paleosol caliche in the New Haven Arkose, Connecticut: Record of semiaridity in Late Triassic–Early Jurassic Time

Recently discovered caliche paleosol profiles are widely distributed in braided-stream sandstone and overbank mudstone in the 1,500- to 2,500-m sequence of red beds in the New Haven Arkose. During Late Triassic to Early Jurassic time, the tropical rift valley commonly was semiarid with an annual 100 to 500 mm of seasonal precipitation. The paleoclimate was much drier than is indicated by the view that these red beds are the classic example of accumulation in a tropical, wet regime with more than 1,250 mm of annual precipitation (Krynine, 1950).