SciFi and Fantasy Book Club discussion

Looking for a book that I read not long before I joined goodreads, although the book is probably older than this, it was a tatty hardback I had from the library.

Mostly it was about this tribe of people who live in the sides of a deep ravin, in large caves. They board everything up at night time because these creatures fly around then. The people believe they're the spirits of their dead or something. And they have a creepy tradition when a girl passes puberty before she gets married she gets put out at night so the creatures can impregnate her. Occasionally the creatures attack the girl instead and these ones don't get married, they're shunned and they cover up so no one can see their scars.
The main characters I can remember are two girls that were very close, possibly in love before they reach marriage age, then one of them gets married and one of them gets scarred up by the creatures.

Theres also something about a trek down the ravine to a place where theres a giant plug hole that leads to another planet or something. And something about planets being taken over by some sort of evil thing.

I don't remember anything about the author. But I think the title might have involved a girl character's name, possibly beginning with S. I think the cover had a picture of the ravines.

I wasn't even sure that I enjoyed the book, but I can't get it out of my head, so I'd like to find it again!

Sath, it sounds very similar to Sherri S. Tepper's The Flight of Mavin Manyshaped. I had read it many years ago and it had such vivid imagery that it stuck in my mind as well.

The plot synopsis is a little different than what you have said, but you are close enough that I suspect it's the same book. Mavin is a shapechanger looking for her sister when she discovers the colony of people that live in the ravine, building houses on the immense tree roots that line the ravine. Something is rotting the roots. Ultimately, in return for her sister, she agrees to lead an expedition to the bottom of the ravine.

http://www.goodreads.com/review/show/...

Carol, it sounds like it has many similarities, but unfortunately its not the book I was looking for. Does look interesting tho. Thanks.