Here are a 2 sources that I discovered on the internet. I have used them extensively for my tree.
This one in French, "G?n?alogie de la famille Martineau-Lormi?re (branche du district de Montr?al) : suivie de notes g?n?alogiques et biographiques" http://www.nosracines.ca/f/toc.aspx?id=4747
This one in English and lists one of our ancestor as owning a piece of land (#33) under the name "Xaintonge" "Cadillac's Village or Detroit Under Cadillac"
An other excellent source, although in French, is on Ancestry.ca is the Tanguay Dictionaire de la famille Martineau". I have not been able to find it anywhere else.
If anyone has any other sources that they know about, please let me know.