Discoveries of fossil remains of 50 million year old alligators on Ellesmere Island and 30}40 million year-old forests on Antarctica contrast sharply with our present vision of polar climates. These are not isolated discoveries or quirks of nature. An evergrowing body of faunal, Soral, and geochemical evidence shows that the Rrst half of the Cenozoic Era was much warmer than the present time. W...

The elevation of the intracontinental Atlas Mountains of Morocco and surrounding regions requires a mantle component of buoyancy, and there is consensus that this buoyancy results from an abnormally thin lithosphere. Lithospheric delamination under the Atlas Mountains and thermal erosion caused by upwelling mantle have each been suggested as thinning mechanisms. We use seismic tomography to ima...

It is proposed that many summit basins along the Aleutian Arc form from the clockwise rotation of blocks of the arc massif. Summit basins are arc-parallel grabens or half-grabens formed within the arc massif and are commonly located near or along the axis of late Cenozoic volcanism. Geomorphically, the Aleutian Arc appears to consist of contiguous rhombic blocks of varying size, tens to hundred...

Pelagic clay of the east-central Pacific province is shown to be a mixture of three primary detrital components, reflecting continental source areas in Asia, North America, and Central and South America. Relative contributions from each source area are a function of geography, and this distribution appears to have remained constant over the past five million years, despite changing flux rates. ...

Synthesis of regional plate movements reveals a major reorganization of global plate motion from Mesozoic to Cenozoic patterns that occurred primarily during the Eocene epoch (53.5 to 37.5 m.y.B.P.). The reorganization involved reorientation of relative plate motions with large N-S components into large E-W components, continuation of pre-existing E-W sea floor spreading, initiation of new E-W ...

The fossil record holds a wealth of ecological data, including data on biotic interactions. For example, holes in the skeletons of invertebrates produced by drilling activities of their enemies are widely used for exploring the intensity of such interactions through time because they are common and easily distinguished from non-biotic holes or holes produced by other types of interactions. Such...

Oceanic oxygen levels are projected to drop in certain areas due to warming climate, but the net effect to the overall ocean redox state is difficult to predict. Here we measured the “stable” uranium isotope composition (U/U) in globally representative hydrogenous ferromanganese crusts in order to reconstruct the redox evolution of the global ocean throughout the Cenozoic. Samples averaging 3 M...

We present a new reconstruction of the mid-Cretaceous (100 Ma) paleogeography of the United States and Canadian Cordillera, based on (a) restoring displacements within the major Late Cretaceous to Cenozoic contractional and extensional belts, and (b) restoring displacements along the major Late Cretaceous to Cenozoic dextral strike-slip faults of the northern Cordillera. The reconstruction move...

Incidences of non-deposition or erosion at the modern seabed and hiatuses within the pelagic caps of guyots and seamounts are evaluated along with paleo-temperature and physiographic information to speculate on the character of Late Cenozoic internal tidal

The eggs of amniotes exhibit a remarkable variety of shapes, from spherical to elongate and from symmetrical to asymmetrical. We examine eggshell geometry in a diverse sample of fossil and living amniotes using geometric morphometrics and linear measurements. Our goal is to quantify patterns of morphospace occupation and shape variation in the eggs of recent through to Mesozoic birds (neornithe...