Meaning of じわれができる

Question

その瞬間、まる子は、地割れができて、AとBとCの三人と、まる子とDとEに分けられてしまったような気がした。
Just then Maruko had a feeling that the group seemd to be divided into the three people A,B,C, and herself and D and E.

The only meaning I can find for 地割れ is "cracks in the ground". I get the general meaning that Maruko's friends are divided into two groups. But I can't figure out what 地割れができて means. Literally "able to make cracks"?

Also I'm a bit confused because there seems to be no subject for the verb 分ける. The subject is obviously her group of friends, but is it ok just to leave that out of the sentence?

Answer 1

In this sentence, できる means "be formed" not "be able to do", and 地割れ is compared to "the boundary you can't cross" (because the crack is too deep to cross over)

And it is okay to leave out the subject. If anything, it sounds a little odd if you put a subject in the sentence because it is obvious that the subject is her and her group of friends.