Antipodean explorer Mosman Oil and Gas had a quiet first morning's dealings on AIM on Thursday after its undersubscribed initial public offer.The company raised £1.5m at 8p a share, which allowed it to secure its two cornerstone assets, including its most immediate focus at the encouragingly named Petroleum Creek in New Zealand.This was short of the £2.5m the company had hoped to raise, which would have funded the firm for the next two years.Chairman John Barr, with whom AIM investors may be familiar from his time at Aquarius Platinum and Thor Mining, said directors had made significant investments in the company prior to listing and were hoping to discover low-cost oil at Petroleum Creek, which is at the southern tip of the proven Taranaki oil system.This project has a mean unrisked recoverable prospective resource of 26m barrels of oil, with drilling planned for mid-2014 on two shallow targets.Barr added: "This is complemented with the large Officer Basin Project (in Western Australia), which is one of the last remaining onshore frontier exploration areas where large petroleum discoveries may still be made."Mosman owns 25% of a 22,500 parcel of land in Officer Basin, where native title negotiations are ongoing and could result in certain administration payments and overrides.OH