Both Uses of

cleave
in
Oryx and Crake

If he burst out of the bushes in his filthy tattered sheet, reeking, hairy, tumescent, leering like a goat-balled, cloven-hoofed satyr or a patch-eyed buccaneer from some ancient pirate film — Aarr, me hearties!†
p. 169.4

cloven = split (or divided in two)

Through the clefts in the overhead greenery he can see a handful of vultures, circling idly in the sky.†
p. 223.9 *

clefts = splits or cracks

Definitions:

(1) (cleave as in: cleave through)
to split or cut through something

Ironically, this word can mean to split in two or to hold together.

Note that you may see cleaved, cleft, clove, or cloven as the past tense of this sense of cleave.
(2) (cleave as in: cleave to)
to hold firmly to something -- such as an object, a person or idea

Ironically, this word can mean to split in two or to hold together.

Note that you may see cleaved, clove, or clave as the past tense of this sense of cleave.
(3) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

a proper noun or other word too rare to warrant focus