Gutter Casts, a new name for scour-and-fill structures: with examples from the Llandoverian of Ringerike and Malmöya, Southern Norway

A new term gutter east is defined and deseribed: it includes a number of seour-and-fill struetures previously ealled large groove easts, elongated flute easts, parallel seour struetures, priels, erosional ehannels, runnel easts and Rinnen. Typieal gutter easts with composite fillings of bioclastie limestone and ealcareous siltstone are deseribed from 6b to 6e (Lower Llandoverian) of Ringerike and 6b of Malmoya, southern Norway and are eompared with examples from other areas and horizons. The original hollows (gutter marks) are thought to have been eroded in firm mud by water moving along helieoidal paths with horizontal axes and so are seour marks in eontrast to groove marks made by tools.