Sentence:  Additionally, Mississippi River discharge could not explain the elevated hopane, sterane, and <WSD>diasterane</WSD> concentrations [23, 75 ] and depletion in natural abundance radiocarbon [63 ] in NE GoM surface sediments that are indicative of petroleum hydrocarbon input. 
Meaning of the word marked with <WSD> tags:  Any of a group of isomers of steranes formed during diagenesis