There is something that draws me also towards thinking that there might have been earlier civilizations lost completely... such a rich and fascinating topic! Have you read this post from JMG on the subject? https://www.ecosophia.net/notes-on-the-lemurian-deviation/
I admit that he is hard to decipher sometimes, but if you let all your guards down and open your mind large enough there is quite a lot to learn... Have fun :)