Dear Erhan,

I would recommend you read about sedimentary terrains where the underlying basement includes supracrustal rocks. This is one of the possibilities where quartzite may be the basement.

The proterozoic Martin Formation (Canada) has conglomerate at the unconformity boundary. The sequence above has no quartzite.

It is not per se the quartzite, it is the silica which can be found in pure quartz sand or in monomictic conglomerates or unconsolidated blankets of pure siliceous gravel. In German they are called "Restschotter" (= relict gravel beds). In general it heralds the separation of silica from the residual clay to give rise to duricrusts which used to be concentrated along paleosurfaces or in structural terms unconformities.

There are many papers which although not focusing on that central idea touch these various sedimentological processes of weathering, transport and deposition in a structural trap setting.

H.G.Dill

Well, I'd say that, generally, quartzites do not represent unconformities. However, on a global evolutionary scale, it could be that before terrestrial plants evolved, one could imagine land surface as exposed igneous/metamorphic rocks with no vegetation to trap the finer particles on-land. Therefore, much of the surface (at this time) could have been composed of SiO2 aeolian dunes. If this were the case, your argument might hold up for quartzites older than terrestiral plants (700 Ma) and directly overly basement.