A dyke (or dike) in geology is a type of later vertical rock between older layers of rock. Technically, it is any geologic body which cuts across:1  flat wall rock structures, such as bedding. dyke (or dike) in geology is a type of later vertical rock between older layers of rock. Technically, it is any geologic body which cuts across: 1  flat wall rock structures, such as bedding.
Another example would be the âdefault browserâ on your computer. Windows PCs come with Internet Explorer (the blue âEâ icon) as the default browser, just as Apple includes their own Safari browser as the default on their Mac computers.
1 In Internet Explorer, go to Tools > Internet Options. 2  Click the Programs tab. At the bottom of this window, check the box labeled Internet Explorer should check to see whether it is the default browser.  Click OK.