de·tri·tus 
(dĭ-trītəs)
(dĭ-trītəs)n. pl. detritus
1. Loose fragments or grains that have been worn away from rock.
2. Disintegrated or eroded matter; debris: the detritus of past civilizations.
[French détritus, from Latin dētrītus, from past participle of dēterere, to lessen, wear away; see DETRIMENT.]
de·trital (-trītl) adj.