Glaciotectonically induced water-throughflow structures in a Late Pleistocene drumlin, Kanrawer, County Galway, western Ireland

AM MCCABE, GF DARDIS

    Research output: Contribution to journalArticle

    28 Citations (Scopus)

    Abstract

    During drumlinisation, brecciated bedrock was sheared over the proximal end of a Late Pleistocene drumlin at Kanrawer, western Ireland. High effective water pressures generated by shearing at the ice/substrate interface during this event created a marked proximal-to-distal hydrostatic gradient affecting about 60% of the diamict which forms most of the drumlin sediment pile. This resulted in large-scale sediment reorganisation by Darcian throughflow and closed-conduit flow of expelled pore waters and subglacial meltwater. Proximally, this is reflected in the development of integrated honeycomb gravel structures formed by glaciotectonic shunting and tortuous throughflow in the diamicts. Distally, the honeycomb structures give way to dish and pillar structures, which are connected to gravelly and laminated sandy channel fill facies, which cut obliquely across the long axis of the drumlin. This facies transition reflects throughflow of pore water rising through the sediment pile and expelled along Nye-type channels excavated on the distal drumlin surface. These proximal-to-distal sediment transformations suggest that current theoretical models of drumlin formation do not adequately represent the continuum of subglacial processes which accompany drumlinisation.
    LanguageEnglish
    Pages173-190
    JournalSedimentary Geology
    Volume91
    Issue number1-4
    DOIs
    Publication statusPublished - Jun 1994

    Fingerprint

    drumlin
    throughflow
    Pleistocene
    sediment
    porewater
    pile
    water
    glaciotectonics
    pillar
    hydrostatics
    meltwater
    gravel
    bedrock
    fill
    ice
    substrate

    Cite this

    @article{64c8200880c84d0e89cc46c01db7ac2f,
    title = "Glaciotectonically induced water-throughflow structures in a Late Pleistocene drumlin, Kanrawer, County Galway, western Ireland",
    abstract = "During drumlinisation, brecciated bedrock was sheared over the proximal end of a Late Pleistocene drumlin at Kanrawer, western Ireland. High effective water pressures generated by shearing at the ice/substrate interface during this event created a marked proximal-to-distal hydrostatic gradient affecting about 60{\%} of the diamict which forms most of the drumlin sediment pile. This resulted in large-scale sediment reorganisation by Darcian throughflow and closed-conduit flow of expelled pore waters and subglacial meltwater. Proximally, this is reflected in the development of integrated honeycomb gravel structures formed by glaciotectonic shunting and tortuous throughflow in the diamicts. Distally, the honeycomb structures give way to dish and pillar structures, which are connected to gravelly and laminated sandy channel fill facies, which cut obliquely across the long axis of the drumlin. This facies transition reflects throughflow of pore water rising through the sediment pile and expelled along Nye-type channels excavated on the distal drumlin surface. These proximal-to-distal sediment transformations suggest that current theoretical models of drumlin formation do not adequately represent the continuum of subglacial processes which accompany drumlinisation.",
    author = "AM MCCABE and GF DARDIS",
    year = "1994",
    month = "6",
    doi = "10.1016/0037-0738(94)90128-7",
    language = "English",
    volume = "91",
    pages = "173--190",
    journal = "Sedimentary Geology",
    issn = "0037-0738",
    publisher = "Elsevier",
    number = "1-4",

    }

    Glaciotectonically induced water-throughflow structures in a Late Pleistocene drumlin, Kanrawer, County Galway, western Ireland. / MCCABE, AM; DARDIS, GF.

    In: Sedimentary Geology, Vol. 91, No. 1-4, 06.1994, p. 173-190.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Glaciotectonically induced water-throughflow structures in a Late Pleistocene drumlin, Kanrawer, County Galway, western Ireland

    AU - MCCABE, AM

    AU - DARDIS, GF

    PY - 1994/6

    Y1 - 1994/6

    N2 - During drumlinisation, brecciated bedrock was sheared over the proximal end of a Late Pleistocene drumlin at Kanrawer, western Ireland. High effective water pressures generated by shearing at the ice/substrate interface during this event created a marked proximal-to-distal hydrostatic gradient affecting about 60% of the diamict which forms most of the drumlin sediment pile. This resulted in large-scale sediment reorganisation by Darcian throughflow and closed-conduit flow of expelled pore waters and subglacial meltwater. Proximally, this is reflected in the development of integrated honeycomb gravel structures formed by glaciotectonic shunting and tortuous throughflow in the diamicts. Distally, the honeycomb structures give way to dish and pillar structures, which are connected to gravelly and laminated sandy channel fill facies, which cut obliquely across the long axis of the drumlin. This facies transition reflects throughflow of pore water rising through the sediment pile and expelled along Nye-type channels excavated on the distal drumlin surface. These proximal-to-distal sediment transformations suggest that current theoretical models of drumlin formation do not adequately represent the continuum of subglacial processes which accompany drumlinisation.

    AB - During drumlinisation, brecciated bedrock was sheared over the proximal end of a Late Pleistocene drumlin at Kanrawer, western Ireland. High effective water pressures generated by shearing at the ice/substrate interface during this event created a marked proximal-to-distal hydrostatic gradient affecting about 60% of the diamict which forms most of the drumlin sediment pile. This resulted in large-scale sediment reorganisation by Darcian throughflow and closed-conduit flow of expelled pore waters and subglacial meltwater. Proximally, this is reflected in the development of integrated honeycomb gravel structures formed by glaciotectonic shunting and tortuous throughflow in the diamicts. Distally, the honeycomb structures give way to dish and pillar structures, which are connected to gravelly and laminated sandy channel fill facies, which cut obliquely across the long axis of the drumlin. This facies transition reflects throughflow of pore water rising through the sediment pile and expelled along Nye-type channels excavated on the distal drumlin surface. These proximal-to-distal sediment transformations suggest that current theoretical models of drumlin formation do not adequately represent the continuum of subglacial processes which accompany drumlinisation.

    U2 - 10.1016/0037-0738(94)90128-7

    DO - 10.1016/0037-0738(94)90128-7

    M3 - Article

    VL - 91

    SP - 173

    EP - 190

    JO - Sedimentary Geology

    T2 - Sedimentary Geology

    JF - Sedimentary Geology

    SN - 0037-0738

    IS - 1-4

    ER -