Tuesday, July 16, 2013

Highlights—The Critters Did It: Bioirrigation and Bioinfiltration

Burrowing organisms markedly alter marine sediment, impacting biogeochemistry  (through changing organic and inorganic particulate matter), and permeability (forming open burrows).  This contribution by Herringshaw and McIlroy demonstrates a suite of lab experiments that reveal that burrowing organisms also transport clay particles into permeable sediment when they irrigate their burrows. Since many marine sediments are bioturbated, and most bioturbating organisms irrigate their burrows, this mechanism may represent an important means of transporting suspended clay material into sediment.  Because these clay minerals can clog pores, can form precursors to diagenetic clay mineral cements, and may introduce organic nutrients that affect microbial productivity, bioinfiltration may markedly impact porosity and permeability in bioturbated sedimentary rocks.

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