Western female at border with oil rich peninsula (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

GAL="Western female" + LIP="border" + anagram/"rich" of oil for GAL, "Western" as in the genre of film for the anagram indicator, "rich" can mean 'ridiculous', 'absurd' e.g. ('that's rich coming from you!')