ALBERT

Description: Calcium absorbtion was measured in fasting human beings after oral administration of Ca^45 in a solution containing 10 to 500mg stable calcium and an intravenous dose of Ca^47. Absorbtion was determined from the ratio of specific activities of the two isotopes (oral dose/intravenous dose) in calcium of urine collected more than 24 hours later. The accuracy of this calculation was confirmed by comparison with absorbtion calculated from recovery of the oral dose in stools (the completeness of collection being determined from recovery of simultaneously given Cr2O2or Cr^51 labeled protein and a correction for endogenous calcium being made from the fecal recovery of the intravenouse dose of Ca^47). In 20 tests, the average difference between the two calculations of per cent absorbtion was 2.2 and the coefficient of variation, 1.6. The Conditions under which the double isotope procedure gives an accurate result were evaluated and the results of its use with 3 different doses of calcium given to normal subjects are reported

Description: This paper summarizes the hydrogeology of the thick carbonate-evaporite sequence that extends from land surface to the oil horizons at depths of about 11,500 feet below sea level in southern Florida. It sets forth the few known facts about the hydrology of the deep water-bearing rocks and discusses a hypothesis concerning the cyclic flow of salt water related to geothermal heating in the Floridan aquifer. Meinzer (1923, p. 30) defined an aquifer as a "formation, a group of formations, or part of a formation that is water bearing." The connotation of quantity was included by the statement: "Few if any formations are entirely devoid of gravity ground water, but those that do not contain enough to be of consequence as a source of supply are not rated as water bearing." The quality of the water does not enter the definition, for if it did, a change in quality (as by salt-water encroachment) would correspondingly convert aquifers to nonaquifers. This paper treats permeable water-bearing beds as aquifers even though the contained water might be a brine seven times as salty as sea water and, therefore, normally not considered a source of supply.

Description: Sedimentary iron and heavy-metal deposits of undetermined size have been found in the middle of the Red Sea some 2000 meters below the surface of the sea (Fig. 1). This discovery has been made from the Research Vessel Atlantis II, which is still at sea engaged in a series of oceanographic investigations which ultimately will end in November 1965, after the ship has circumnavigated the globe. The discovery is significant because the environment and the processes controlling deposition of heavy metals are observable and appear to be still active.

Description: Two thousand and twenty well-characterized coral specimens from 17 localities have been analyzed for Sr. Seventy-three genera and subgenera, mostly hermatypic scleractinians, are represented. For some genera, specimens living in surface reef environments are compared with those from 18.3 m depths on the same reefs. Growth rates for some species have also been measured at these depths at one of the sampling sites. Skeletal strontium for a given genus decreases with increasing water temperature, a relationship which previously eluded detection. Aragonite deposited by corals living on the reef at a depth of 18.3 m contains more strontium than the skeletal aragonite of the same coral genera from shallow-water, surface environments. Quantitative treatment of the data for Acropora, one of the most abundant and widely distributed of the reef-building corals, suggests that the observed strontium variations may reflect variations in the rate of skeletal calcification, rather than direct dependence upon temperature or water depth. There is evidence for ‘species effects’, apparently unrelated to growth rate differences, in that certain coral genera are consistently enriched or depleted in skeletal strontium content relative to other genera living in the same reef environments under identical ambient conditions. Temperature, salinity, water depth, seawater composition, and/or other such parameters may in part determine the levels of trace element concentration in carbonates deposited by corals and other marine invertebrates, but it would appear that these variables more directly affect physiological processes which in turn control skeletal chemistry.

Description: When determining vertical velocity spectra from temperature time series and the mean vertical temperature gradient, restrictions may arise friom the existence of fine-structre. Phillips (1971) and Garrett and Munk (1971_ have shown that the fine-structure contamination of internal gravity wave spectra can be written as a function of some statistical properties of the internal wave field and the vertical wave number spectrum of the fine-structure. A consistent set of current and temperature data was obtained during an experiment at Site D to study this problem. The wave number spectrum of the vertical temperature fine-structure and the apparent frequently spectrum of internal waves are determined from these data. In contrast to the asasumptions in the above models, our fine-structure data imply a wave number spectrum proportional to (wave number)−3 in the range which is important here. Using the above set of data, a model is suggested to describe the effect of fine-structure on vertical velocity spectra computed with the mean vertical temperature gradient. It indicates a maximum fine-structure contamination of the true frequency spectrum of internal gravity waves in the middle of the internal wave band, with less contamination at low and high frequencies.

Description: Volcanic ash layers, which represent the products of volcanic activity within the ocean basins, are common in sedimentary cores taken near Cobb Seamount and on the actively spreading Gorda and Juan de Fuca Ridges. Petrographic and chemical analyses of the glass shards from these deposits have revealed that they are unaltered and are as chemically representative of local volcanic events as are the glassy margins of fresh pillow basalts recovered from the same areas. The presence of unhydrated glass shards in samples as old as 3.8 my is in direct conflict with published hydration rates of both terrestrial and submarine volcanic glasses. A study of a sequence of ash layers from Cobb Seamount, which spans in time much of the Seamount's history, indicates that the volcanic products from Cobb Seamount have had alkaline affinities and that its eruptions have been becoming progressively enriched in Al2O3. Recent experimental petrological evidence and the data on the chemical compositions of Cobb Seamount and the adjacent Juan de Fuca Ridge magmas are in agreement with the hypothesis that magmas are being generated at progressively greater depths beneath Cobb Seamount as it migrates away from the Juan de Fuca Ridge.