Martina Bennick, 2019 EGGS alumni and current biology
graduate student, was selected as one of two student poster presentation winners in
the Geobiology and Geomicrobiology Division at the Geological Society of
America 2019 annual meeting in Phoenix, Arizona.
Her poster, entitled “Determining The Origin Of
Intracameral Deposits In The Orthocerid Genus Arionoceras” presented research
she conducted with Dr. Cindy Venn and Dr. Adrian Van Rythoven of the EGGS
department, which was an outgrowth of a senior research project supervised by
Dr. Alan Gishlick, also of the EGGS department.
Martina’s
project focused on determining
to what extent intracameral deposits were formed through biomineralization
versus post-mortem diagenetic alteration.
She first sliced the specimens longitudinally and treated one half with
dilute acid to differentiate the internal layering, clearly visible under a
high powered dissecting microscope. She then made a thin section of one of the
specimens to examine with a cathodoluminoscope to establish chemical
differences between the layers. Another etched specimen was examined using a
portable scanning electron microscope. Two
distinct internal layers were observed: an outer complex layer that she
inferred to be from biodeposition during life, and an internal layer of sparry
calcite consistent with what would be expected from chamber filling after
burial.
“As an
international scientific society, GSA serves members in academia, government,
and industry around the world. Since 1888, GSA’s meetings, publications, and
programs have enhanced the professional growth of geoscientists and fostered
geoscience stewardship and service. GSA encourages cooperative research and
public dialogue on geoscience issues and supports all levels of earth-science
education.” The 2020 GSA Annual meeting
will be held in Montreal, Canada.
