The Isotope and Trace Element Budget of the Cambrian Devil River Arc System, New Zealand: Identification of Four Source Components

The Takaka Terrane in the South Island of New Zealand containsa well-preserved Cambrian arc system (Devil River Volcanics)that displays a complete assemblage of interbedded low- to high-Karc rocks, back-arc rocks and boninites. Most volcanic rocksare mafic. A coherent dataset was obtained including major elements,trace elements and Sr–Nd–Pb isotope compositionsfrom clinopyroxene and amphibole separates. With time, ²⁰⁷Pb/²⁰⁴Pbin the arc rocks become more unradiogenic and ¹⁴³Nd/¹⁴⁴Nd moreradiogenic, and Th/Yb and La/Yb increase. La/Yb values rangefrom one in the boninites and back-arc rocks to 30 in the high-Karc rocks. Corresponding     

The Aucellaelv stade at Aucellaelv, the first Weichselian glacier advance in Scoresby Sund, East Greenland

The first major Weichselian ice advance in Scoresby Sund, during the Aucellaelv stage, deposited thick till beds along the coast of Jameson Land between > 107 ka and 140 ka. and is correlated with isotope substage 5d in the marine record. This is shown by stream-cut sections at the mouth of the Aucellaelv. Jameson Land, which contain a scquence of shallow marine, fluvial and glacigene sediments extending from the Scoresby Sund glaciation (≅Saalian) to the Flakkerhuk stade (Late Weichselian). The sequence is dated by palaeoceanographic correlation with the deep-sea record, U/Th and luminescence dating, and correlated with the record in adjacent areas by mapping of marker horizons, and by mollusc fauna assemblages and amino acid analyses.