edge-seamn. a layer or seam of coal that has been tilted into a nearly vertical position.
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1802 J. PlayfairIllustr. Huttonian Theory 236 We obtain the same information from inspecting the edge-seams.
1805 R. ForsythBeauties Scotl. I. 269 The strata..receive the appellation of edge seams, from their descending, or almost upright position in the earth.