Terrestrial climates near the time of the end-Cretaceous mass extinction are poorly known, limiting understanding of environmentally driven changes in biodiversity that occurred before bolide impact. We estimate paleotemperatures for the last approximately 1.1 million years of the Cretaceous ( approximately 66.6-65.5 million years ago, Ma) by using fossil plants from North Dakota and employ pal...

The Weihe Basin is a crucial part of the Fenwei Graben System and typical example an extensional fault basin. Over time, region has been developed around 212 ground fissures, with majority them being associated heavy rainfall. These water-eroded fissures have caused serious damage to farmland, houses, roads, Liangjiacun Meiyuancun Dizhentai most known. To understand developmental characteristic...

We characterize the topographic evolution of Pacific Northwest, United States, during Cenozoic. New paleosol carbonate stable isotope (δ 18 O) results from central Oregon are presented, along with published proxy data, including fossil teeth, smectites, and concretions. interpret a polygenetic history Cascade Mountain uplift along-strike, characterized by: 1) Steady Washington Cascades through ...

Mixed-layer illite-smectite (I-S) from a new set of Pennsylvanian-aged Illinois Basin underclays, identified as paleosols, are investigated to assess the impact (1) regional diagenesis across basin and (2) extent which ancient environments promoted illitization during episodes soil formation. Interpretations Reichweite Ordering ?° 2? metrics applied X-ray diffraction patterns suggest that most ...

The d18O values of pedogenic calcites, phyllosilicates, and iron (oxyhydr)oxides from fossil soils throughout the southwestern United States show systematic paleolatitudinal and temporal trends that indicate a significant change in soil moisture conditions and atmospheric circulation patterns over southwestern Euramerica throughout latest Pennsylvanian and Early Permian time. A progressive depl...

Vertical changes in distribution, abundance, and ichnodiversity of ichnocoenoses in alluvial deposits of the Willwood Formation suggest significantly drier moisture regimes in the Bighorn Basin, Wyoming, during the Paleocene–Eocene Thermal Maximum (PETM), a transient period of global warming. The Willwood Formation at Polecat Bench contains an abundant assemblage of ichnofossils, including vari...

Late Cretaceous coastal plain deposits of the Prince Creek Formation (PCF) offer a rare glimpse into an ancient, high-latitude, arctic greenhouse ecosystem for which there is no modern analog. Here, we employ quantitative biofacies analysis to explore spatio-temporal variability in PCF palynomorph and microbiota assemblages from nine paleosol horizons exposed along Colville River, North Slope, ...