I have played with an XSL stylesheet called EAD2RDF with good success.
Archivists use EAD as their “MARC” records. EAD has its strengths and weakness, just like any metadata standard, but EAD is a flavor of XML. As such it lends itself to XSLT processing. EAD2RDF is a stylesheet written by Pete Johnston. After running it through an XSLT 2.0 processor, it outputs an RDF/XML file. (I have made a resulting RDF/XML file available for you to peruse.) The result validates against the W3C RDF Validator but won’t have a graph created, probably because there are so many triples in the result.
I think archivists as well as computer technologists working in archives ought to take a closer look at EAD2RDF.