Just three to finish - any help appreciated - 14d Japanese prime minister who succeeded taro aso in September 2009 (5.8) YU_I__A_O_A_A, 15d either of two magistrates or officials holding a joint office in ancient rome (7 letters) -U--V-R, 27a dark fine-grained volcanic rock consisting of plagioclase feldspar, named after a south american mountain range (8 letters) -N-E--T-