|
October 12, 2006
IGPP Researcher and collaborators report evidence for Early
Life on Earth in Submarine Volcanoes
This month's feature article of GSA Today makes the case that submarine
volcanoes are the likely hosts of microbial activity that uses nutrients
and energy provided by volcanic glass, a common quench product of basaltic
lavas. These findings, reported by IGPP researcher Hubert Staudigel and colleagues, are
based on the discovery of micron-sized corrosion features in volcanic
glass. These features are either preserved as cavities in fresh glass
or by the replacement of these cavities with the mineral titanite.
Figure 1. Hubert Staudigel (foreground) and Harald
Furnes sampling pillow lavas in the 3.8 Ba Isua Supercrustal Belt
in Western Greenland August 2006.
They report such features for some of the oldest preserved volcanoes on
earth, the Pilbara Greenstone Belt in Western Australia and the Barberton
Greenstone Belt in South Africa. Both of these 3.5 Ba old volcanic
formations are associated with cherts that contain the currently most
widely accepted earliest microbial fossils on earth. Finding evidence for
life in volcanoes associated with these other fossil locations suggest
that microbial activity in submarine volcanoes has co-existed with or
maybe even preceeded the earliest life on earth in cherts.
Figure 2. Pillow Lavas in the Pilbara Greenstone
Belt Western Australia. Traces of microfossils were found in
Hyaloclastite between pillow lavas near the sample label.
This article also makes the case that microbial activity also influences the chemical
fluxes involved with water-rock interaction, providing evidence for the
complex interactions between lithosphere, hydrosphere and biosphere.
Further information:
|
