Black swallows swooping or gliding In a flurry of entangled loops and curves The skaters skim over the frozen river And the grinding click of their skates as they impinge upon the surface Is like the?

the answer is meander

It is called a meander

the plateau will get flat

fu.u.ck yeah they do

Its name refers to the darkness of the river bed that has been lined with thick layers of decomposing vegetation.