Peaks in France, Italy and Switzerland lie in the "<answer>Houillière zone</answer>", which consists of basement with sediments from the Mesozoic Era. High "massifs" with external sedimentary cover are more common in the Western Alps and were affected by Neogene Period thin-skinned thrusting whereas the Eastern Alps have comparatively few high peaked massifs. Similarly the peaks in Switzerland extending to western Austria (Helvetic nappes) consist of thin-skinned sedimentary folding that detached from former basement rock.
What area do peaks in France, Italy, and Switzerland lie in? 
Houillière zone