ALBERT

Description: From April 8,1965 until April 20,1965, C.S. Stanley Angwin (2,500-ton gross) surveyed the route for the Tortola-Bermuda telephone cable which will provide the northern outlet for the 21-million W.I. dollar project in the Eastern Caribbean to improve inter-island and international telecommunications. The route passes northward over the following regions: Virgin Islands Bank, Puerto Rico Trench, Outer Ridge, Nares Abyssal Plain and Bermuda Rise.

Description: Cores, submarine photography and dredges described in this report were taken during the R/V Eltanin Cruise 12 in 1964 by the Department of Geology, Florida State University. Cores and dredges were recovered for 30 stations along with bottom photography and are available at the Antarctic Research Facility, Florida State University for sampling and study.

Description: Cores, submarine photography and dredges described in this report were taken during the R/V Eltanin Cruise 13 in 1964 by the Department of Geology, Florida State University. Cores and dredges were recovered for 31 stations along with bottom photography and are available at the Antarctic Research Facility, Florida State University for sampling and study.

Description: Thorium and uranium isotopes were measured in a diagenetic manganese nodule from the Peru basin applying alpha- and thermal ionization mass spectrometry (TIMS). Alpha-counting of 62 samples was carried out with a depth resolution of 0.4 mm to gain a high-resolution Th-230(excess) profile. In addition, 17 samples were measured with TIMS to obtain precise isotope concentrations and isotope ratios. We got values of 0.06-0.59 ppb (Th-230), 0.43-1.40 ppm (Th-232), 0.09-0.49 ppb (U-234) and 1.66-8.24 ppm (U-238). The uranium activity ratio in the uppermost samples (1-6 mm) and in two further sections in the nodule at 12.5+/-1.0 mm and 27.3-33.5 mm comes close to the present ocean wa ter value of 1.144+/-0.004. In two other sections of the nodule, this ratio is significantly higher, probably reflecting incorporation of diagenetic uranium. The upper 25 mm section of the Mn nodule shows a relatively smooth exponential decrease in the Th-230(excess) concentration (TIMS). The slope of the best fit yields a growth rate of 110 mm/Ma up to 24.5 mm depth. The section from 25 to 30.3 mm depth shows constant Th-230(excess) concentrations probably due to growth rates even faster than those in the top section of the nodule. From 33 to 50 mm depth, the growth rate is approximately 60 mm/Ma. Two layers in the nodule with distinct laminations (11-15 and 28-33 mm depth) probably formed during the transition from isotopic stage 8 to 7 and in stage 5e, respectively. The Mn/Fe ratio shows higher values during interglacials 5 and 7, and lower ones during glacials 4 and 6. A comparison of our data with data from adjacent sediment cores suggests (a) a variable sb supply of hydrothermal Mn to sediments and Mn nodules of the Peru basin or (b) suboxic conditions at the water sediment interface during periods with lower Mn/Fe ratios.

Description: Cores, submarine photography and dredges described in this report were taken during the R/V Eltanin Cruise 10 in 1963 by the Department of Geology, Florida State University. Cores and dredges were recovered for 35 stations along with bottom photography and are available at the Antarctic Research Facility, Florida State University for sampling and study.