About halfway between Interlaken and Bern, Thun is one of the latest sheets to appear in the 1:25 000 geological atlas of Switzerland planned series of 220 sheets. Thun adds to the recent publication of four geological maps extending along the river Aare and the Brienzersee up the Haaslital valley, in the headwaters of this tributary of the river Rhine and the longest river flowing entirely within Switzerland.
David A.G. Nowell (2026) studied this question.