Physical modelling of large-scale deformational systems in the South Polar Layered Deposits (Promethei Lingula, Mars): new geological constraints and climatic implications
Published:January 01, 2015
Luca Guallini, Cristina Pauselli, Francesco Brozzetti, Lucia Marinangeli, 2015. "Physical modelling of large-scale deformational systems in the South Polar Layered Deposits (Promethei Lingula, Mars): new geological constraints and climatic implications", Volcanism and Tectonism Across the Inner Solar System, T. Platz, M. Massironi, P. K. Byrne, H. Hiesinger
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Deformation systems (DSs) locally affect the South Polar Layered Deposits (SPLDs) along the margins of the Promethei Lingula ice sheet (part of the southern Martian ice-dome). One example is the ‘S2’ deformation system, characterized by a complex pattern of brittle and brittle–ductile structures related to kilometre-scale shear zones that deform the sequence. Moreover, soft-sediment structures affect one layer located at the base of the S2. An earlier structural analysis suggested that: (1) two deformation stages (D1, in which the shear zones developed, and D2, in which the D1 structures were reactivated by deep-seated gravitational slope deformation) occurred, driven by gravity; and (2) there are variations in the bulk composition of the SPLD (which is inferred to be mainly composed of water ice plus basaltic dust). This work supports these structural results through thermal and mechanical modelling of the S2 sequence. Our modelling results suggest that several layers within the S2 system are probably composed of, or are mixed with, CO2 ice, and that the development of the observed deformation is inconsistent with present-day physical conditions. Soft-sediment structures probably formed under warmer surface temperatures during the past, with those warmer temperatures favouring or even triggering ice flow/basal sliding of the Promethei Lingula.
The complete description of the stratigraphy of the analysed S2 sequence (in table format) is available at http://www.geolsoc.org.uk/SUP18746.
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Volcanism and Tectonism Across the Inner Solar System
Volcanism and tectonism are the dominant endogenic means by which planetary surfaces change. This book aims to encompass the broad range in character of volcanism, tectonism, faulting and associated interactions observed on planetary bodies across the inner solar system - a region that includes Mercury, Venus, Earth, the Moon, Mars and asteroids. The diversity and breadth of landforms produced by volcanic and tectonic processes is enormous, and varies across the inner solar system bodies. As a result, the selection of prevailing landforms and their underlying formational processes that are described and highlighted in this volume are but a primer to the expansive field of planetary volcanism and tectonism. This Special Publication features 22 research articles about volcanic and tectonic processes manifest across the inner solar system.