- My favorite “Schurik” story (deniseelaineheap.substack.com)
Out on summer break, Alexander Schmorell and two friends decided to bike from Munich to Donauwörth, intending to catch a boat and float down the Danube to Austria. On paper, the 100-kilometer (60 mile) bike ride looked easy. The terrain was relatively flat, a biker’s paradise.
- Siliceous rock (Wikipedia)
Siliceous rocks are sedimentary rocks that have silica (SiO2) as the principal constituent. The most common siliceous rock is chert; other types include diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or some types of sponges.