> as lemmas

1836 J. Phillips Illustr. Geol. Yorks. II. i. 26 These dun ‘courses’ are said to throw the veins which run east and west, four or five fathoms laterally.

1877 A. H. Green Geol. for Students: Physical Geol. (ed. 2) vii. §2. 276 Ribs of Magnesian Limestone are met with in the Carboniferous L. of Yorkshire where they are known as Dun Courses.

1944 Q. Jrnl. Geol. Soc. 100 251 Dolomitization along faults is common in Wharfedale, making ‘dun courses’.