According to a report in TechCrunch, Google has acquired Aardvark, a San Francisco start-up whose service melds Internet search and social networking for an estimated $50 million dollars.

Aardvark, which counts two ex-Google employees among its founders, has pioneered a new type of Internet search dubbed “social search.” Instead of looking at Web pages to find answers to search queries, Aardvark’s service taps a person’s network of social contacts.

The deal is Google’s sixth purchase announcement since September, as it picks up the pace of acquisitions.