1. National Aeronautics and Space Administration
www.nasa.gov
Introduction & Theory
Hydrogen in Rocks
An Energy Source for Deep Microbial Communities
Garrett J. Benjamin
California State University Fresno
Science Teacher and Researcher (STAR) Program
Dr. Friedemann T. Freund
Principle Investigator at the SETI Institute
Senior Scientist at the NASA Ames Research Center
It is believed, that the first organisms to inhabit earth were
chemoautotrophs. That later evolved into both aerobic animal
like organisms and photosynthetic plant like organisms.
Chemoautotrophs generally use hydrogen as a primary energy
source(Wheelies 2007). Though H2 can be produced when water
reacts with fresh mineral surfaces and oxidizes iron. This
reaction is unreliable since it depends upon the exposure of fresh
rock surfaces and high temperatures. However, there is a more
pervasive reaction that puts H2 into essentially every mineral
grain in igneous or metamorphic rock (Freund, Dickinson, and
Cash. 2002). This is possibly the answer to what was needed to
sustain the hydrogen in these microbial communities. Our
experiment wants to show how much Hydrogen is in these rocks.
The science behind the project is of relevance to the early
Earth and Mars. Giving us a mechanism for the oxidation of our
atmosphere. It is also, important to Astrobiology through the
availability of molecular H2 in the rock column. This is an
energy source for microbes for the sustainability of life in
underground environments.
Methodology
Abstract
Results
Conclusion
Future work
Acknowledgements
References
-Hydrogen Leak Detector H2000
-30-ton hydraulic press
-Crushing chamber
-Steel cylinders for press
-DalTool 1020TS Tile Saw
-Thirty 15-20 gram pieces of rock
(gabbro, anorthosite, and
granite)
-H2 calibrating Gas
-Labview 7.1
SETI Institute, NASA Ames, STAR Program, National Science Foundation
California State University Fresno, J. Thomas Dickinson, Michele Cash,
Pamela Harman, Bob Dahlgren, Gary Cry, and John Keller.
H2 in minerals and rock is of wide importance to many
different fields. The energy source for microbes in deep ocean
biota. The origin of life with regards to abiogenic synthesis
and their release to the surface environment through
weathering of rocks. Concentration of peroxy in regards to
earthquake prediction and for the global oxidation of the early
Earth through the release of H2 O2 during weathering of the
earths crust.
This experiment expects to obtain information on the amount of
hydrogen contained in the rock column and its availability to deep microbial
communities. This will be done by measuring the rapid release of hydrogen
after crushing rocks in vacuum using a hydrogen detector, sensitive over
the 0.01- 50 molar ppm range. At the time of this publication there are no
additional findings to report. So the following is from the research done by
Dr. Friedemann Freund, J. Thomas Dickinson, and Michele Cash on the
Hydrogen in Rocks: An Energy Source for Deep Microbial Communities
that was published in ASTROBIOLOGY in 2002.
The experimental results from 2002 indicate that H2 molecules can be
derived from small amounts of H2O dissolved in minerals in the form of
hydroxyl, OH-, or O3Si–OH, whenever such minerals crystallized in an
H2O-laden environment. At least 70 nmol of H2/g diffused out of coarsely
crushed andesite, equivalent at standard pressure and temperature to
5,000 cm3 of H2/m3 of rock.
Wheelies, Mark. Principles of modern microbiology. Jones & Bartlett
Publishers, 2007. 164-171
Freund, Friedemann., Dickinson, Thomas., and Cash, Michele. “Hydrogen
in Rocks: An energy Source for Deep microbial Communities.” Astrobiology
2.1 (2002): 83-93.
Freund, F., Staple, A., Gosling, P., and Belles, W. 9200) Weathering of
rocks and inextricable path toward a bluedot. AGU 2000 Spring Meeting,
Session M61-A-12. Available at: http//www.aug.org/meeting/sm00top.html
Equipment
The experiment involves
crushing rocks to create fresh
fractured surfaces where H2
can diffuse out. So rock
needs to be cut down into
pieces that will fit in the
chamber to be crushed by the
Hydraulic press. This
experiment will be motored
by the Labview 7.1. Every
run will be repeated 15
times, with each lasting 7
minutes from start to finish.
Figures left to right: 30 ton hydraulic press, steel
press cylinders, crushing chamber, and tile saw.
Hydrogen Leak
Detector H2000
Figures left to right: Artist rendering of
primordial earth and Earth.
Figure 1: Crushing experiments
with andesite, granite, and
labradorite, using an epoxy
crushing device. Upon crushing,
at time t=0, H2 was released. Since
each sample crushed differently
the amounts of H2 released varied
from run to run. H2 partial
pressures that increased with time
suggest slow H2 release from the
sample. H2 partial pressures that
decreased with time were due to
leaky O-ring seals.
Figure 3 shows results from crushing the rock samples. In all cases, the
H2 concentrations in the crusher compartment increased instantly from the
fracturing of the rock. The rock samples were irregular in shape and size
and because they crushed differently in each run, the initial and final
volumes in the crusher chamber could not be accurately determined. The
H2 increased with time indicating continuing H2 release after the crushing.
In some runs the integrity of the O-ring seal was compromised the H2
concentration decreased with time.
Each crushing run produced powders with a large portion of fine pieces
and a few remaining large pieces. Despite this, moderate differences in the
amount of H2 released per gram of rock where found. At least 70 nmol of
H2/g diffused out of coarsely crushed andesite, equivalent at standard
pressure and temperature to 5,000 cm3 of H2/m3 of rock.
The experiments indicate that the H2 concentration in the
mineral grains is significantly high. Thus, we propose that
the rock column contains comparatively large amounts of H2,
formed inside nominally anhydrous minerals. This H2 would
be available to sustain deep microbial communities.