5 Works

Complex ascent of mantle plumes in a phase-changing world

Anders Lillevang Vesterholt & Thorsten J. Nagel
Phase changes in the mantle have long been known to play a major role for convection in a one-component mantle. When considering cases with depleted ambient upper mantle and upwelling mantle either chemically or mechanically enriched with basaltic crust, very complex density-difference histories are possible for a wide range of realistic temperature-composition scenarios. We explore the ascent of enriched mantle plumes in ambient mantle using combined thermodynamic and themomechanical modelling. Plumes are unlikely to feel...

Thermobarometry at extreme conditions - what can possibly go wrong? An example

Thorsten Joachim Nagel & Kathrin Fassmer
We present eclogites and garnet pyroxenites from Danmarkshavn (Greenlandic Caledonides). So far, one ultra-high pressure (UHP) location has been described from NE Greenland. There, thermobarometry yielded conditions of 972 ºC/36 kbar (Gilotti and Ravna, 2002). Eclogites from Danmarkshavn show spectacular exsolution of Qtz from Cpx, which is known from UHP assemblages. The sample most suitable for unraveling precise conditions, however, is a garnet pyroxenite containing abundant Cpx and Opx, some Grt, minor accessory minerals as...

Validation of eating duration using an automatic feeding system

Emma Ternman, Marta Terré, Matthieu Bouchon, Bruno Meunier, Lene Munksgaard & Isabelle Veissier
Feed intake is important to consider when studying welfare, productivity and efficiency in ruminants, particularly cattle. Over the last decade, several methods for automatic intake recording have been developed. These methods have been described in the chapter on feed and water intake of the present book of methods. Automatic feed bins do not only record feed intake, but also feeding behaviour. The duration of feed bin visits estimated by the Insentec Roughage Intake Control system...

Hvor meget lignede neandertalerne os?

Paige Madison, Trine Kellberg Nielsen & Peter C. Kjærgaard

Depletion, Density, and Deposits through the mantle transition zone (MTZ)

Thorsten Joachim Nagel , Anders Vesterholt & Christian Schiffer
We present phase diagrams of variously enriched and depleted mantle rocks down to 800 kilometers depth and explore density as the parameter governing convection and compositional stratification. Some results are surprising and not all are included in present concepts and models: (1) Primitive and enriched mantle compositions are buoyant in the uppermost lower mantle compared to depleted mantle, especially, when they are warmer, but also at identical temperatures. Hence, if the upper mantle is depleted...

Registration Year

  • 2022
    5

Resource Types

  • Text
    5

Affiliations

  • Aarhus University
    5
  • National Research Institute for Agriculture, Food and Environment
    1
  • Institute for Research and Technology in Food and Agriculture
    1
  • Swedish University of Agricultural Sciences
    1
  • University of Copenhagen
    1
  • Uppsala University
    1
  • Universität Innsbruck
    1