Keel Damage!

Hi During a wind storm last week my scot dragged her mooring and took a bit of a pounding to her rear end. Apart from a lot of chips to the gelcoat and a damaged rudder there appears to be a crack across the keel about 21 inches forward of the stern. It seems to be just across the keel and doesn't extend to the fiberglass each side. I dont think the balsa core starts for another few inches but what is the keel made of? Is it layered fiberglass or is there a wood core. Any suggestions how to repair it? Is it repairable? Simon FS173