I have found two repositories where download the archetypes:
http://uk.maven.org/maven2/archetype-catalog.xml
http://mirrors.ibiblio.org/pub/mirrors/maven2/archetype-catalog.xml
Also I have found a searcher of archetypes (http://search.maven.org/), and if I search "maven-archetype-webapp" I found this archetype with information for pom. Which is the utility of this information if I have the archetype?
Thanks a lot.
Fran