IPA: //ʌnˈstrætɪfaɪd//
KK: /ʌnˈstrætɪfaɪd/
Not having distinct layers or levels; mixed together without separation.
The unstratified sediment was difficult to analyze because it contained various materials mixed together.
Unstratified → It is formed from "un-" (meaning not) and "stratified" (from Latin "stratum", meaning layer). The word means not arranged in layers or not having distinct layers.
Think of 'not' ('un-') having 'layers' ('stratum') — that's why unstratified means something that does not have layers.