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.
How to set a default web browser. If you're using OS X Yosemite or later: From the Apple (ï£¿) menu, choose System Preferences, then click General. Choose your web browser from the âDefault web browserâ pop-up menu.