Florian Fusseis

Microtomography of Partially Molten Rocks: Three-Dimensional Melt Distribution in Mantle Peridotite

As mantle rocks melt, an interconnected network of liquid drives the ascent of magma to the sea floor. The permeability of the upper mantle controls melt segregation beneath spreading centers. Reconciling contradictory geochemical and geophysical observations at ocean ridges requires a better understanding of transport properties in partially molten rocks. Using x-ray synchrotron microtomography, we obtained three-dimensional data on melt distribution for mantle peridotite with various melt fractions. At melt fractions as low as 0.02, triple junctions along grain edges dominated the melt network; there was no evidence of an abrupt change in the fundamental character of melt extraction as melt fraction increased to 0.2. The porosity of the partially molten region beneath ocean ridges is therefore controlled by a balance between viscous compaction and melting rate, not by a change in melt topology.

Classification of Refold Structures

Structural geology textbooks distinguish among four end members of three‐dimensional refold structures established from their two‐dimensional interference patterns. Here it is shown that six different end members of three‐dimensional refold structures exist. These end members can be described by a reduced direction cosines matrix \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Thermal‐elastic stresses and the criticality of the continental crust

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First Steps Towards Modeling a Multi-Scale Earth System

\end{document} . The classical types 1–3 are extended to have three new counterparts types 01–03, which are derived by 90° rotation of the superposed fold around its fold axis. The matrix \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Networking of shear zones at the brittle-to-viscous transition (Cap de Creus, NE Spain)

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Landslides, Ice Quakes, Earthquakes: A Thermodynamic Approach to Surface Instabilities

\end{document} can be used to characterize the angles between the two fold generations in a simple triangle plot illustrating the six end members and even any intermediate refold structure.