Question

do earthquakes occur in areas without identified large faults?


The key words you use are "identified" and "large." As far as I know, earthquakes occur at fault lines, <I>whether or not</I> they have been identified or are large.

Since this is not my area of expertise, I searched Google under the key words "<I>earthquakes faults</I>" to get these possible sources:

http://www.tinynet.com/faults.html
http://hometown.aol.com/jillconway/quakes.html
http://earthquake.usgs.gov/learning/faq.php
http://www.earthquakecountry.info/roots/basics.html
http://www.gns.cri.nz/what/earthact/earthquakes/earthquakefaq.html

I hope this helps. Thanks for asking.