(Table 1) Potassium, radiogenic Argon 40 and dated age for DSDP Hole 94-608 sediments

K-Ar dates were obtained for three pillow basalt samples recovered from Site 608 (Samples 608-58-1, 103-109 cm; 608-59-1, 3-7 cm; 608-59-1, 48-53 cm). Reliable K-Ar dates cannot be routinely obtained for deep-sea igneous rocks, because they may be subject to inaccuracies related to seawater alteration (Seidemann, 1977, doi:10.1130/0016-7606(1977)88<1660:EOSAOK>2.0.CO;2) and/or the presence of excess radiogenic 40Ar (Dalrymple and Moore, 1968, doi:10.1126/science.161.3846.1132; Dymond, 1970, doi:10.1130/0016-7606(1970)81[1229:EAISBP]2.0.CO;2). Thus, the possibility that the samples dated in this study were subject to these sources of inaccuracy must be evaluated.

(Table 1) Concentrations and isotopic ratio of Argon in Cretaceous deep-sea basaltic glass of DSDP Hole 51-417D

The abundance and isotopic composition of rare gas in the mantle provides an important constraint on the origin and evolution of the Earth's atmosphere. One of sources of such information is basalts which erupted from ocean ridges. Ozima (1975, doi:10.1016/0016-7037(75)90054-X) stated that a high 40Ar/36Ar ratio in the mantle suggests sudden degassing at an early stage of the Earth's evolution. Several authors (Funkhouser et al., 1968, doi:10.1016/S0012-821X(68)80021-4; Darlymple and Moor, 1968, doi:10.1126/science.161.3846.1132) have reported excess 40Ar and high 40Ar/36Ar ratios in rapidly quenched rims of young deep-sea basalts. However, the Ar composition in old ridge basalts was not known. We report here a measurement of the isotopic composition of Ar in old deep-sea basalts. The Glomar Challenger drilled a Cretaceous ocean floor near the southern end of the Bermuda Rise in Deep Sea Drilling Project. The drilled site (Site 417) is on the magnetic anomaly MO which has been estimated to be 108 Myr old.

Radiocarbon dating, sedimentation rate, granulometry and organic carbon content of ODP Leg 182 sites

This data report presents sedimentological (grain size) and geochemical (X-ray diffraction, total organic carbon, accelerator mass spectrometry radiocarbon, and percent carbonate) information obtained from the western transect (Sites 1132, 1130, and 1134) and the eastern transect (Sites 1129, 1131, and 1127) in the Great Australian Bight during Leg 182. The purpose is to quantify changing rates of sediment accumulation and changes in sediment type from the late Pleistocene and Holocene, in order to relate these changes to the well-known sea level curve that exists for this time frame. Ultimately, these data can be used to more effectively interpret lithologic variations deeper in the Pleistocene succession, which most likely represent orbitally forced sea level events.

Horizontal profiles of longwave and shortwave radiation components over sea ice near Barrow, Alaska during the 2011 melt

An integrated instrument package for measuring and understanding the surface radiation budget of sea ice is presented, along with results from its first deployment. The setup simultaneously measures broadband fluxes of upwelling and downwelling terrestrial and solar radiation (four components separately), spectral fluxes of incident and reflected solar radiation, and supporting data such as air temperature and humidity, surface temperature, and location (GPS), in addition to photographing the sky and observed surface during each measurement. The instruments are mounted on a small sled, allowing measurements of the radiation budget to be made at many locations in the study area to see the effect of small-scale surface processes on the large-scale radiation budget. Such observations have many applications, from calibration and validation of remote sensing products to improving our understanding of surface processes that affect atmosphere-snow-ice interactions and drive feedbacks, ultimately leading to the potential to improve climate modelling of ice-covered regions of the ocean. The photographs, spectral data, and other observations allow for improved analysis of the broadband data. An example of this is shown by using the observations made during a partly cloudy day, which show erratic variations due to passing clouds, and creating a careful estimate of what the radiation budget along the observed line would have been under uniform sky conditions, clear or overcast. Other data from the setup's first deployment, in June 2011 on fast ice near Point Barrow, Alaska, are also shown; these illustrate the rapid changes of the radiation budget during a cold period that led to refreezing and new snow well into the melt season.