Sentence:  With the exception of small <WSD>pingos</WSD>, most <WSD>pingo</WSD> ice cores have several ice types. The bulk of the core can be segregated ice, intrusive ice formed from the freezing of bulk water, or any combination of the twotypes. In addition, dilation-crack ice (tension-crack ice, Brown and Kupsch, 1974) is commonly the main ice type beneath the summit of <WSD>pingos</WSD> with craters. 
Meaning of the word marked with <WSD> tags:  A conical mound of earth with an ice core caused by permafrost uplift, particularly if lasting more than a year. (from 1920s)