Chavez, a Spanish version of the Portuguese surname, Chaves, which derives from a Portuguese place name. The original name was Aquae Flavae, Latin, meaning "yellow (sulphurous?) waters". This turned into something like Aguas Chaves, then the water part got lost.
Holguín, this name has driven me mad for years. There is a place in Cuba called Holguín, but that will be called after a person or family. The ancestry website suggests the following -http://www.ancestry.com/learn/facts/Fact.aspx?fid=10&ln=Holguin
but that's just a guess. Another source claims it as being of French origin, but I don't believe it. If you ever find out let me know.