Several transitions of Lower to Middle Turonian pelagic marl–limestone-cycles into Oceanic Red Beds were studied at high resolution to gain a better understanding of the Tethyan marine system before and during red bed initiation and development. Samples were analysed for mineralogy, geochemistry, and stable isotope composition. In particular, carbonate geochemistry of diagenetically largely una...

Ridge jumps occurred during the spreading process of South China Sea. Recent research on lower crustal reflectors event seismic profiles found at least two southward ridge jumps, but only one has been confirmed by geomagnetic data. Based magnetic anomalies in northern Sea and “two jumps” model, this study identified that an early jump anomaly C10n (28.3 Ma), with a 20 km. According to lineation...

The response of an atmosphere–ocean general circulation model (AOGCM) to perturbations of freshwater fluxes across the sea surface in the North Atlantic and Southern Ocean is investigated. The purpose of this study is to investigate aspects of the so-called bipolar seesaw where one hemisphere warms and the other cools and vice versa due to changes in the ocean meridional overturning. The experi...

Holocene climate variability is investigated in the North Pacific and North Atlantic realms, using alkenone-derived sea-surface temperature (SST) records as well as a millennial scale simulation with a coupled atmosphere-ocean general circulation model (AOGCM). The alkenone SST data indicate a temperature increase over almost the entire North Pacific from 7 cal kyr BP to the present. A dipole p...

We have simulated the steady-state distribution of helium in the deep sea to investigate the magnitude and spatial and temporal variability of mantle degassing and to characterize deep-sea circulation and ventilation. The simulation was produced by linking a simple source function for helium injected at mid-ocean ridges with an oceanic general circulation model (GCM). By assuming that the flux ...

Ž . We investigate seismic layering i.e., discontinuities, regions of anomalous velocity gradients, and anisotropy and its Ž . lateral variability in the upper mantle by comparing seismic models from three tectonic regions: old ;100 Ma Pacific Ž . plate, younger ;40 Ma Philippine Sea plate, and Precambrian western Australia. These models were constructed by combining two data sets: ScS-reflecti...

Ophiolites are the remnants of ancient oceanic crust and upper mantle that were tectonically emplaced into continental margins. They display the only evidence for magmatic, tectonic, and hydrothermal processes associated with seafl oor spreading prior to 170 Ma because no oceanic lithosphere older than this age is preserved in the modern oceans. The occurrence of sheeted dikes, side-byside tabu...