Phyllis Pfeiffer, former Marin Independent Journal publisher and former ad director at the Chronicle, has been appointed publisher of a group of Southern California weeklies including the La Jolla Light. The Light, the Del Mar Times, the Carmel Valley Leader, the Rancho Santa Fe Record and the Solana Beach Sun are all part of MainStreet Media Group, a growing chain of small and mid-size newspapers in California. At the Chron, Pfeiffer was replaced in September by Michael LaBonia, who came from the Minneapolis Star Tribune. At the time, the Chron said Pfeiffer was taking a position with Hearst Newspapers.