Caribou observations on Queen Elizabeth Islands (Tab. 1 + 2)

The numbers and distributions of Peary caribou (Rangiier tarandus pearyi) on western Queen Elizabeth Islands, Northwest Territories were determined by aerial surveys based on a standard census strip method. Surveys were flown in March-April and July-August periods in 1972, 1973, and 1974. Comparison of the 1973 and 1974 survevs with those results of a comparable survey in 1961 showed an overall decline of 89% in numbers of caribou between 1961 and 1974. Percentage reduction of caribou numbers from 1961 to 1874 followed a west-cast gradient on the three major islands: Prince Patrick 72%, Melville 87% , and Bathurst 92%. The marked decrease in numbers of caribou is attributed to a combination of high winter mortality in some years and an overall low rate of births and recruitment from 1961 to 1974.

Oxygen, hydrogen, and carbon isotopic compositions in deep sea cherts, porcellanites, and coexisting carbonates from DSDP Legs 2, 3, 6, 7, 11, 14, 16, 17, and 20

Seventy four samples of DSDP recovered cherts of Jurassic to Miocene age from varying locations, and 27 samples of on-land exposed cherts were analyzed for the isotopic composition of their oxygen and hydrogen. These studies were accompanied by mineralogical analyses and some isotopic analyses of the coexisting carbonates. d18O of chert ranges between 27 and 39%. relative to SMOW, d18O of porcellanite - between 30 and 42%. The consistent enrichment of opal-CT in porcellanites in 18O with respect to coexisting microcrystalline quartz in chert is probably a reflection of a different temperature (depth) of diagenesis of the two phases. d18O of deep sea cherts generally decrease with increasing age, indicating an overall cpoling of the ocean bottom during the last 150 m.y. A comparison of this trend with that recorded by benthonic foraminifera (Douglas and Savin, 1975; http://www.deepseadrilling.org/32/volume/dsdp32_15.pdf) indicates the possibility of d18O in deep sea cherts not being frozen in until several tens of millions of years after deposition. Cherts of any Age show a spread of d18O values, increasing diagenesis being reflected in a lowering of d18O. Drusy quartz has the lowest d18O values. On-land exposed cherts are consistently depleted in 18O in comparison to their deep sea time equivalent cherts. Water extracted from deep sea cherts ranges between 0.5 and 1.4 wt %. dD of this water ranges between -78 and -95%. and is not a function of d18O of the cherts (or the temperature of their formation).