Impact melt rocks formed during hypervelocity impact events are ideal for studying structures. Here, we describe rock samples collected proximal to the 31 km wide 58 Ma Hiawatha structure, northwest Greenland, which is completely covered by Greenland Ice Sheet. The contain diagnostic shock indicators (e.g., planar deformation features [PDF] in quartz and shocked zircon) form three groups based ...

A large collection of dentigerous jaws quarried from the Gao Mine locality, late Paleocene, Paskapoo Formation, central Alberta, Canada, documents a new species early Paleogene phenacodontid “condylarth” Ectocion Cope, 1882. The species, stockeyae, smallest genus, occurs well before abrupt global warming at Paleocene–Eocene Thermal Maximum, an event purportedly causing rapid evolution “dwarfed”...

New coleoid cephalopods, assignable to the order Sepiida, are recorded from the Selandian/Thanetian boundary interval (Middle to Upper Paleocene transition, c. 59.2 Ma) along the southeastern margin (Toshka Lakes) of the Western Desert in Egypt. The two genera recognised, Aegyptosaepia n. gen. and ?Anomalosaepia Weaver and Ciampaglio, are placed in the families Belosaepiidae and ?Anomalosaepiid...

Metamorphic core complexes in the western North American Cordillera are commonly interpreted as result of a single phase large-magnitude extension during middle to late Cenozoic. We present evidence that mylonitic shear zones Harcuvar and Buckskin-Rawhide west-central Arizona also accommodated an earlier Late Cretaceous early Paleocene. Microstructural data indicate substantial top-NE mylonitiz...

New low-temperature thermochronology data from clastic sedimentary rocks in the northern Richardson Mountains, Canada, indicate significant exhumational cooling during late Eocene–early Oligocene time. Apatite (U-Th-Sm)/He (AHe) were collected 19 Proterozoic–Paleocene across a 115 km transect. Eighty-eight single-grain AHe dates range 16–300 Ma and are generally younger than stratigraphic ages,...

Mountain building in the Andes, longest continental mountain range on Earth, started Late Cretaceous but was highly diachronous. Reconstructing timing of surface uplift for each different Andean regions is crucial importance our understanding continental-scale moisture transport and atmospheric circulation, origin evolution Amazon River Rainforest, ultimately, species world most biodiverse cont...

[1] The late Paleocene to the early Eocene ( 58–52 Ma) was marked by significant changes in global climate and carbon cycling. The evidence for these changes includes stable isotope records that reveal prominent decreases in ı18O and ı13C, suggesting a rise in Earth’s surface temperature ( 4ıC) and a drop in net carbon output from the ocean and atmosphere. Concurrently, deep-sea carbonate recor...

Previous workers identified a magnetically anomalous clay layer deposited on the northern United States Atlantic Coastal Plain during the Paleocene-Eocene Thermal Maximum (PETM). The finding inspired the highly controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR), isothermal and anhysteretic remanent magnetization, first order reversa...