Important geological concepts were established as naturalists began studying the rock formations of the Alps in the 18th century. In the mid-19th century the now defunct theory of geosynclines was used to explain the presence of "folded" mountain chains but by the mid-20th century the theory of plate tectonics became widely accepted.
ঊনবিংশ শতাব্দীর মাঝামাঝি সময়ে ভাঁজ করা পর্বতশৃঙ্গের উপস্থিতি ব্যাখ্যা করার জন্য কী ব্যবহৃত হয়েছিল?
theory of geosynclines