Reuters: Royal Dutch Shell Plc has suspended production at its Canadian oil sands mine after environmental activists blockaded a massive dump truck and mining shovel to protest the impact of oil sands development, the company said on Tuesday. Greenpeace said 25 of its activists locked down the oil sands mining equipment at the Albian Sands Muskeg River mine in northern Alberta on Tuesday morning, a day before Canadian Prime Minister Stephen Harper meets U.S. President Barack Obama in …