Island in the sea of time

"Through a freak of nature, the island of Nantucket is transported 3,000 years back in time. The novel describes the way its inhabitants adjust to primitive living and the reaction of the Indians on the mainland. By the author of The Ship Avenged."@en
"During a perfect spring evening on Nantucket, a violent storm erupts and a dome of crawling, colored fire blankets the island. When the howling winds subside and the night skies clear, the stars appear to have shifted. The island of Nantucket has been swept in the the long-ago past -- 1250 B.C."@en
""Suite à un violent orage, les habitants de l'île de Nantucket, aux Etats-Unis, se retrouvent plongés dans un lointain et sauvage passé. Vont-ils pouvoir survivre ?"
"It's spring on Nantucket and everything is perfectly normal, until a sudden storm blankets the entire island. When the weather clears, the island's inhabitants find that they are no longer in the late twentieth century...but have been transported instead to the Bronze Age! Now they must learn to survive with suspicious, warlike peoples they can barely understand and deal with impending disaster, in the shape of a would-be conqueror from their own time."@en