We don't have synonyms for marle yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are mare, marble and male.
(n) :
(now UK dialect) Alternative form of marl. [A mixed earthy substance, consisting of carbonate of lime, clay, and possibly sand, in very variable proportions, and accordingly designated as calcareous, clayey, or sandy.]
(n) :
(now UK dialect) Alternative form of marl. [A mixed earthy substance, consisting of carbonate of lime, clay, and possibly sand, in very variable proportions, and accordingly designated as calcareous, clayey, or sandy.]