Definition of ironstone in English:



  • 1Sedimentary rock containing a substantial proportion of iron compounds.

    • ‘Most of the tectonic ironstones in Zimbabwe have previously been interpreted as sedimentary rocks.’
    • ‘The ironstones are not sedimentary banded iron formation but formed as a consequence of silicification and sulphide mineralization along shear zones.’
    • ‘A syngenetic origin of sulphides was suggested by early workers, mainly based on the stratiform and stratabound occurrence of the sulphides in ironstone.’
    • ‘Twenty thousand pounds in investment money had produced twelve tons of sugar; the soils were mainly ironstone and gravel entirely unsuitable for the growth of cane or anything else.’
    • ‘Brecciated and sheared ironstones were exploited for gold at several localities in the Mafic Formation.’
    • ‘They were pioneers in the use of local ores, albeit ironstones from coal measures rather than the celebrated haematites of the Carboniferous Limestone series.’
    • ‘The restricted occurrence of silicified and hematized sedimentary rocks in the vicinity of shear zones and ironstones indicates that silica and iron were introduced after deposition during shearing.’
    • ‘Oolitic ironstones only form at low sedimentation rates, where accommodation greatly exceeds supply.’
    • ‘In the Cheshire Formation of the Belingwe greenstone belt, tectonic ironstones formed along shear zones that now separate tectonically duplicated strata.’
    • ‘Such tectonic ironstones separate different lithostratigraphic units commonly regarded as autochthonous rock sequences.’
    • ‘Keith tells Richard how the limestone of Wenlock Edge was a key factor in the Industrial Revolution because it was used to extract iron from the ironstone.’
    • ‘In general terms, the sequences have a relatively simple transgressive-regressive pattern around a mid-cycle condensed interval represented by shellbeds, sideritic micritic limestones or ironstones.’
    • ‘The abundance of tectonic ironstones along the Bend-Manjeri contact is suggestive of a tectonic contact, although the contact may well have been unconformable before shearing.’
    • ‘It is important to note that iron oxides in the ironstones and associated rocks are derived from the weathering of sulphides, mainly pyrite, that occur in less weathered rocks or in the subsurface.’
    • ‘Tectonic ironstones are typically 5-10 m thick horizons that are continuous for hundreds of metres to several kilometres.’
    • ‘Many tectonic ironstones are rather massive, cherty rocks, suggesting that early structural fabrics were annihilated by late-stage chert replacement.’
    • ‘Chemical precipitation produces other deposits, such as evaporites, ironstones, and phosphates; and the accumulation of organic matter results in the formation of coal, oil shales, and hydrocarbons.’
    • ‘It is a shale-hosted flint, passing northward into marine shale and southward into marine clay ironstone.’
    • ‘Rocks adjacent to ironstones are strongly sheared, with the intensity of foliation and lineation decreasing away from ironstone horizon, signifying a pronounced strain gradient.’
    • ‘Zones of maximum subsidence along faults do not always form sites of rapid sedimentation, but can form areas of sediment starvation allowing the development of thick ironstones.’
  • 2[usually as modifier] A kind of dense, opaque stoneware.

    • ‘For those who would visualize Adobe Walls as a hardscrabble place, it should be noted that the restaurant run by Mrs. Olds served its food on imported white English ironstone dishes.’