I can't remember what the base package for gnome is called but, along with libraries and so on, there will be a few of them. You could do this...
rpm -qa | grep -i gnome
Then, for each package returned, check what it is...
rpm -qi <rpm_package>
and check the dependencies...
rpm -q --whatrequires <rpm_package>
and then remove it...
rpm -e <rpm_package>
John
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