Sandstone: Rock for Crack Climbing. Sandstone is a sedimentary rock, a rock type that encompasses a wide variety of characteristics and is deposited directly on the earthâs surface. Roughly 75% of the earthâs land surface is covered with some type of sedimentary rock. Sedimentary rocks like sandstone form when minute rock particles, often from granite, are deposited by wind and water on earth surfaces.
8. 1  Other Causes. 2  Diabetes causes arms or hands and feet to fall asleep even when one is awake and relaxed. 3  Hand surgery and arthritis damage or irritate the nerves.
Saturday 15 March 2008 20.13 EDT. Question: When I have to sit still for long periods I fall asleep. This can happen at the theatre, at the cinema or, most embarrassingly, during meetings at work. It's almost painful trying to keep myself awake, and I become dizzy and disoriented.