Sentence:  <WSD>Caliche</WSD> in various forms, namely powdery, nodule, tube, fracture-infill, laminar crust, hard laminated crust (hardpan) and pisolitic crust, is widespread in the Mersin area in southern Turkey (Eren et al., 2008; Kadir and Eren, 2008). 
Meaning of the word marked with <WSD> tags:  A layer of hard clay subsoil or sedimentary rock; hardpan.