More recently introduced terms such as 'annually laminated' are synonymous with varve. Of the many rhythmites in the geological record, varves are one of the most important and illuminating in studies of past climate change. Varves are amongst the smallest-scale events recognised in stratigraphy.
PCs are designed to shut down automatically when heat endangers the hardware. To find out if this is your problem, download and install Speedfan. It's small and free. Although Speedfan's basic job is controlling the speed of your PC's fans (you probably guessed that by the name), it also provides the CPU temperature.
Shutting down from the Start button. In Windows 8.1 and Windows RT 8.1, there's a faster way to shut down desktops and laptops. Move your mouse to the bottom-left corner of the screen and right-click the Start button or press Windows logo key +X on your keyboard. Tap or click Shut down or sign out and choose Shut down.