Many-layered family drama; Country of Broken Stone, by Nancy Bond. New York: Atheneum. $10.95.

"Country of Broken Stone" is both a contemporary family story of remarriage and adjustment and a story of an archaeological dig. These are interwoven with an unusual backdrop and a persistent, unsettling sense of history repeating itself.

The setting is the site of a second-century Roman fort built on the edge of Hadrian's Wall in northern England. At the center of the story is 14-year-old Penelope. Her father, edward Ibbetson, an English mystery writer, has recently married Valerie Prine, an American archaeologist who is supervising the dig. Their marriage brings together Edward's children, Penelope and her older brother , Martin, and Valerie's children, 12- year-old twins Mark and Luke, and 8 -year-old Louisa.

For Penelope, the marriage has brought many changes: "The pattern she was used to had been rudely shattered by the addition of four new people, and she only realized when it was far too late to prevent it that the damage was irreparable. But she was sensible enough to see, once the panic subsided, that she had a choice: either she could mourn uselessly over the rubble, or she could set to work to build something new for herself."

Bright and sensitive, Penelope knows her own family well: her charming, demanding father with his writer's moods and temper, and her stubborn, rebellious brother. She is accustomed to their friction, but she is also quick to sense the potential trouble spots in her new combined family: Valerie, busy and preoccupied with work; Martin, enjoying the dig but consistently irritated with this father; the twins, bored, foolhardy, and self-absorbed; Lou, lonely and left out; and Edward, about to immerse himself in a new book. The needs and expectations of each often seem to put them at odds.

Interfamily conflicts are played off against the historic and contemporary conflicts at the archaeological site. Historically, the Roman invaders attempted to subdue the native barbarians and eventually failed. In a contemporary version of this, archaeologists have reclaimed land from a resentful native farmer, and the bitter struggle is far from over. It is a struggle for territory. The archaeologists hope for coexistence.

Independence and coexistence are central themes for the Ibbetson-Prine family as well. They struggle to work out a balance, with each child looking for his place in the new family and both parents still sorting through their new responsibilities and adjustments.

In all of this, Penelope is determined to resist the role of housekeeper/baby sitter. She needs time and privacy for her drawing and reading and for her secret friendship with Ran, the youngest son in a local farm family involved in the feud with the archaeologists. Their friendship joins the two threads of the story. Through Ran, Penny better understands the anger and frustration of this farm family. Yet she also understands the importance of the dig, and cannot accept the farmer's violence.

"Country of Broken Stone" is a many-layered story with complex, believable characters and strong personal relationships. IT is enriched by lively dialogue , complete with true-to-life arguments and 12-year-olds' jokes, and by luxurious detail: descriptions of the countryside, its weather and its people, information about the history of the wall and the workings of the dig. It is a long book with room for local color, character development, and mounting suspense.