Today similar rounded sand grains are seen in modern desert dunes, formed when the wind picks up fine weathered rock fragments.
(similar rounded sand grains; are seen; L:in modern desert dunes; T:Today) (similar rounded sand grains; formed; T:when the wind picks up fine weathered rock fragments) (the wind; picks up; fine weathered rock fragments)
similar rounded sand grains similar rounded sand grains the wind
are seen formed picks up
L:in modern desert dunes T:Today
T:when the wind picks up fine weathered rock fragments
fine weathered rock fragments