Figure 4
From: A new macrofaunal limit in the deep biosphere revealed by extreme burrow depths in ancient sediments
Different scenarios to explain presence of macrofaunal communities preservation in injectites. (A) Sandy lobe unit, with bioturbation along the sand-to-mud interface at the base (B), several metres below the seabed. Overpressure at the edge of the sandy lobes after rapid burial by muds causes unconsolidated sand to forcible intrude into underlying mud outwards from lobe centre. Macrofauna form new living traces on the sand-to-mud contacts that form the margins of the sand intrusions (B). Scenarios where a pre-existing injectite network either formed connection to the seabed through extrusion (C) or exhumation (D) to be exploited by macrofauna. Average lobe thickness in (A) based on26.
