Strong crashing waves from the violent nor’easter uncovered a 19th-century shipwreck buried under Nantucket sand as the storm battered the East Coast with heavy rain, gale-force winds and coastal flooding. A pallet of waterlogged timber held together by rusted nails and strands of seaweed was discovered on a beach on the south shore of the famed Massachusetts Island Saturday, according to video shared by the Nantucket Current on Saturday. The wooden segment is believed to be from the Warren Sawyer, a New Orleans-bound schooner that crashed on nearby Miacomet Beach in 1884. The ship, carrying cargo consisting of cotton and…