Enter a library either a physical library or a digital one with no idea about what you are looking for beyond the general topic of Lithosphere. While it can be fairly easy to randomly peruse books on a topic in a physical library, this might not be as easy to envision in a digital setting. Here are some ideas to make this exploration more random. Search a key term on the topic and peruse titles until you find one that interests you then read the third one after that title instead. Or you could select the first resource with a last name that starts with a particular letter of the alphabet. Or look at the bibliography of a resource and find the first resource it lists. Ask a librarian to suggest a resource on your topic. Or you can look for an author on the topic that shares your first or last name.