Also known as negative
grading or reverse
An upward increase in mean grain size in a sedimentary bed, implying that the sedimenting grains were independantly mobile and deposited under the influence of grain-grain interactions.
IE, smaller grains are found at the bottom of the sedimentary bed, larger grains at the top, where the reverse of this is expected.
A term used in the fields of geology, palaeontology, soil engineering, environmental engineering, ecological studies and could probably apply to cooking too.
See also Kinematic sieving.