I have a large document with about 200 references linked to footnotes at end of pages. Is there any simple way I can create a separate chapter called “references” and move all of the footnotes into that chapter? The thought of moving them all manually is none too appealing.
There is no elegant way of achieving what you require IMO but there may be a workaround. I am unclear about exactly what you mean by “references linked to footnotes”. Are the references in the footnotes or are you using the cross-reference function to point to the footnotes from the text body? If the latter then you may have a real problem that cannot only be addressed by manually changing each and every footnote.
One possible hack is to edit the XML directly and change your footnotes to endnotes. A footnote uses text:note-class="footnote" as a property of the text:note element, while an endnote uses text:note-class="endnote". There is also an associated style:parent-style-name="Footnote" property of the style:style element that will need changing to “Endnote”. So long as you are not mixing footnotes and endnotes in the same work you can probably perform a global change on the content.xml file in the ODT. This thread is related.
You can then decide on where (using a section) you would like the endnotes to be placed. This thread shows how you can do this and add a heading to where the endnotes are gathered.