RELATIONS BETWEEN RELATIVE CHANGES IN SEA-LEVEL AND CLIMATE SHIFTS - PENNSYLVANIAN-PERMIAN MIXED CARBONATE-SILICICLASTIC STRATA, WESTERN UNITED-STATES

Study of Pennsylvanian (Virgilian)-Permian (Wolfcampian) strata of the western United States (parts of Idaho, Utah, New Mexico, and Kansas) reveals complex relations between relative changes in sea level and sh ifts in climate, Relative falls in sea level are indicated by subaeria l exposure of subtidal sediments and fluvial incision through subtidal sediments, Changes in the character of pedogenesis and sediment trans port, deposition, and supply, and the variable distribution of climati cally sensitive lithofacies within cyclothems are interpreted to refle ct shifts in climate during deposition of each cyclothem. The majority of stratal relationships documented herein from a number of long-term climatic, sedimentologic, and shelf settings are consistent with a hy pothesis that relative highs in sea level are accompanied by more seas onal conditions, whereas relative lows are characteristically more ari d, Uncommon deviations are present, however, and may be due to (1) sho aling caused by sedimentation or tectonic uplift, independent of a eus tatic-climatic signal; (2) complex sedimentologic or geomorphic respon ses to climate change; (3) leads,lags, or thresholds in either glacial advance and retreat or the climatic response to such changes. This st udy shows that coupled climatic shifts and changes in sea level exert a pronounced, but varied, influence on stratigraphic architecture in d epositional settings across late Paleozoic ramps, The proposed climati cally enhanced cyclic and reciprocal sedimentation model predicts that during a single eustatic fall, updip areas have features indicating a more seasonal or humid climate that are overlain or overprinted by ch aracteristics suggesting more arid climate, In downdip areas that were not subaerially exposed until the late stages of a eustatic fall, onl y more arid climatic features are represented in the terrestrial or su baerial exposure features.