Mixed terrestrial and marine source material that can generate waxy oil is what type?

Mixed terrestrial and marine source material that can generate waxy oil is what type?

• A. Type III
• B. Type I
• C. Type II
• D. Type IV

Answer: (C)

In petroleum geology, the kind of organic matter preserved as kerogen determines what hydrocarbons a source rock can generate as it matures. When terrestrial material mixes with marine input, the kerogen is typically oil-prone, yet not purely marine. Type II kerogen fits this scenario best: it originates mainly from marine organic matter with some land-derived material and is known for producing oil as it mature, including oils with higher paraffin content that can appear waxy. This makes it the most likely match for a source with mixed terrestrial and marine input that yields waxy oil. Contrast this with other types: Type I is dominated by algal, lacustrine material and yields high oil but isn’t described by mixed terrestrial input; Type III is largely terrestrial plant material and tends toward gas rather than oil; Type IV is largely inert and generates little hydrocarbon. Hence, the description aligns with Type II.

In petroleum geology, the kind of organic matter preserved as kerogen determines what hydrocarbons a source rock can generate as it matures. When terrestrial material mixes with marine input, the kerogen is typically oil-prone, yet not purely marine. Type II kerogen fits this scenario best: it originates mainly from marine organic matter with some land-derived material and is known for producing oil as it mature, including oils with higher paraffin content that can appear waxy. This makes it the most likely match for a source with mixed terrestrial and marine input that yields waxy oil.

Contrast this with other types: Type I is dominated by algal, lacustrine material and yields high oil but isn’t described by mixed terrestrial input; Type III is largely terrestrial plant material and tends toward gas rather than oil; Type IV is largely inert and generates little hydrocarbon. Hence, the description aligns with Type II.