Ergative pattern is a term used for a situation in which one case marker or affix is used to mark the subject of intransitive verbs as well as the object of transitive verbs, while another case marker or affix is used for the subject of transitive verbs. The former case marker is called the Absolutive (ABS), and the latter, the Ergative (ERG).
The following examples from the paleosiberian language Chukchee are taken from Spencer (1991:24):
(i) @tl@g-e l_?unin ek-@k father-ERG saw son-ABS 'The father saw the son.' (ii) ek-@k k@tg@ntatg_?e son-ABS ran 'The son ran.
Spencer, A. 1991. Morphological Theory. Blackwell, Oxford.