Erich Draganits

Siliciclastic Stromatolites and Other Microbially Induced Sedimentary Structures in an Early Devonian Barrier-Island Environment (Muth Formation, NW Himalayas)

Microbially induced sedimentary structures, including spectacular siliciclastic domal stromatolites, up to 80 cm wide and 30 cm high, have been found in coastal quartzites of the Lower Devonian Muth Formation (Pin Valley, NW Himalayas). The microbial struc- tures occur in intervals of the formation associated with physical sed- imentary structures that indicate, at least temporally, emergent con- ditions. These observations support the interpretation of a peritidal setting for the microbial structures within the wave-dominated, bar- rier-island depositional environment of the Muth Formation. The sil- iciclastic domal stromatolites probably formed in a shallow subtidal to intertidal environment with high hydraulic energy, where periods of high sedimentation rates are interrupted by periods of low or zero sedimentation. Microbial gas pits and microbial gas domes were pro- duced by ascending gas from degrading buried organic material in a lower supratidal zone, influenced by tidal flushing. Multidirected ripple marks document a series of erosion events interfering with microbial stabilization in lower supratidal settings. Polygonal shrinkage cracks from supratidal environments indicate a semiarid paleoclimate. The replacement textures of the microquartz matrix in the stromatolites indicates the former existence of syngenetic carbonate cements, which may explain the preservation of the domal stromatolites in the high- energy, siliciclastic environments of the Muth Formation. The Muth stromatolites, commonly containing more than 60 vol. % siliciclastic grains, prove the existence of microbial activity in environments of higher sedimentary stress than generally thought and extend our knowledge of the capability of benthic microbial organisms to settle in siliciclastic shallow marine environments.

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 ndocumentclass{aastex}nusepackage{amsbsy}nusepackage{amsfonts}nusepackage{amssymb}nusepackage{bm}nusepackage{mathrsfs}nusepackage{pifont}nusepackage{stmaryrd}nusepackage{textcomp}nusepackage{portland,xspace}nusepackage{amsmath,amsxtra}nusepackage[OT2,OT1]{fontenc}nnewcommandcyr{nrenewcommandrmdefault{wncyr}nrenewcommandsfdefault{wncyss}nrenewcommandencodingdefault{OT2}nnormalfontnselectfont}nDeclareTextFontCommand{textcyr}{cyr}npagestyle{empty}nDeclareMathSizes{10}{9}{7}{6}nbegin{document}nlandscapen

Himalayan architecture constrained by isotopic tracers from clastic sediments

mathbf{L}^{mathbf{*}}

Giant submarine landslide grooves in the Neoproterozoic/Lower Cambrian Phe Formation, northwest Himalaya: Mechanisms of formation and palaeogeographic implications

nend{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 ndocumentclass{aastex}nusepackage{amsbsy}nusepackage{amsfonts}nusepackage{amssymb}nusepackage{bm}nusepackage{mathrsfs}nusepackage{pifont}nusepackage{stmaryrd}nusepackage{textcomp}nusepackage{portland,xspace}nusepackage{amsmath,amsxtra}nusepackage[OT2,OT1]{fontenc}nnewcommandcyr{nrenewcommandrmdefault{wncyr}nrenewcommandsfdefault{wncyss}nrenewcommandencodingdefault{OT2}nnormalfontnselectfont}nDeclareTextFontCommand{textcyr}{cyr}npagestyle{empty}nDeclareMathSizes{10}{9}{7}{6}nbegin{document}nlandscapen

Eohimalayan fold and thrust belt in the NW-Himalaya (Lingti- Pin Valleys): Shortening and depth to detachment calculation

mathbf{L}^{mathbf{*}}

Time-series studies of drainage pattern and morphological features along the Leitha river (Eastern Austria)

nend{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.