I am organizing geocultural trip in this area and would like to extend my explanations to local architecture.
Cathédrale Notre-Dame-des-Pommiers or the Sisteron Cathedral is Romanesque in style. It has round arches, minimal decorative features and is constructed from larger geometric shapes, notice the cones, octagonal tower and spire. I would love to see pictures of the interior.
Thank you for this additional information. I do not have any pictures of the interior. Sorry!
The architect Dr John James has written several big books about construction details of French Gothic cathedrals in particular. His "Ark of God", which I have not seen, contains thousands of detailed photos of building elements, focusing on foliate capitals, from structures built during the Romanesque to Gothic transition. His books about the Chartres cathedral are very detailed, right down to reporting on his inspection and measuring all (!!!) of its individual stones. The conclusions he reached after years of this study are fascinating, and demonstrate why this stone-level study is indispensable to a full understanding of how these structures got built. Viel Spass beim Besuchen und Untersuchen der Kirchen!
Thank you v ery much for this information. I will try to get more details about this book.
Dr James focused on Romanesque & Gothic in the Paris Basin, far north of your destination, but he would well understand the principles of the period if they applied to other regions, which I suspect they would have. He has been a well-known authority on the topic for so long that he would know everyone in the field. So in your position I would contact him with your questions. He seems to invite discussion. See:
http://www.johnjames.com.au/