Definition of arkose in English:



mass nounGeology
  • A coarse-grained sandstone which is at least 25 per cent feldspar.

    • ‘Conglomerate clasts are principally volcanic rocks and greenish gray chert, with subordinate arkose, graywacke, siltstone, red chert, quartzite, white quartz, and limestone.’
    • ‘The matrix ranges from sandstone to arkose, and is frequently just fine-grained conglomerate.’
    • ‘Soils on basalt had a higher pH and were higher in most micronutrients, but lower in Iron, than soils on arkose.’
    • ‘When the sandstone contains appreciable quantities of feldspar the rock is called arkose.’
    • ‘Ghanem et al. referred to the Hammamat Group as molasse-type sediments that consist of polymictic conglomerate, arkose, greywacke, siltstone and minor mudstone.’


Mid 19th century: from French, probably from Greek arkhaios ‘ancient’.