Archive and ark

It occurred to me when Elaine and I were in Los Angeles a couple of weeks ago: the nouns archive and ark both have to do with containing and protecting. They must have a common origin. Right?

No, not right.

The Oxford English Dictionary gives this etymology for archive :

French archif, archive, < late Latin archīum, archīvum, < Greek ἀρχεῖον magisterial residence, public office, < ἀρχή government

And for ark:

Common Germanic: with Old English arc (earc, ærc, erc, erk), accusative arce, compare Old Frisian erke, Old High German archa, modern German arche, Old Norse örk (genitive arkar), Swedish, Danish ark, Gothic and Germanic arka, probably < Latin arca chest, box, coffer

What about arche- of, say, archetype? From the Greek ἀρχι-, first.

And arch?

< Old French arche < Latin arca chest, coffer; also, through some confusion, used in Old French for arc < Latin arcum bow

So it’s arch and and ark that share an ancestor. And stranger still: the OED gives “archive” as one of the meanings of arch: “The civile law . . . was laid up . . . in their Arches.”

I want to go back to Los Angeles, before I had time to look up this stuff.