Maria, my wife has Alcorta's on her mother side of the family. Her mother was a San Miguel married to Munoz. My wife's mother's parents were Jacobo San Miguel and Maria Cayetana Alcorta.
Maria Cayetana's parents were Jose Gumecindo Alcorta and Ysabel Peres.
We have been working on my wife's family tree for about three years and have found information dated to 1730.