Gilboa - Fossil Ecosystems of North America: A Guide to the Sites and their Extraordinary Biotas - page 89

storage power scheme on Brown
Mountain, just north of Gilboa near the
township of North Blenheim. New works
were constructed ( 90 ), so that water can
be pumped to a holding reservoir at the
top of the mountain using spare power
capacity in slack times, which can then be
released through turbines back down to
the Blenheim-Gilboa Lower Reservoir
when the grid needs additional power. Yet
again, the residents of Gilboa suffered
the loss of farmland and some homes,
in addition to disruption during
the building phase. However, the
Power Authority was very helpful to
paleontologists, and there is now a visitor
center which explains the electricity
project from a vantage point overlooking
the reservoirs, and also gives some
information on the fossils discovered
during the works. During construction of
the dam for the lower reservoir, a lens of
rock packed with plant stems was
discovered by local schoolteacher
Raymond A. Baschnagel. The find was
studied by Banks, Grierson, and
colleague Patricia M. Bonamo from the
State University of New York at
Binghamton (Banks et al ., 1972), who
erected a new genus and species,
Leclercqia complexa , for the plant stems.
What was significant about their work was
that they were able to macerate the rock,
a fine mudstone, in hydrofluoric acid

(HF), which dissolves the siliceous matrix
but leaves the organic matter intact.
Normally, with burial under thousands of
feet of overburden, organic matter loses
its volatiles (as oil and gas) and reduces
to carbon. At the Brown Mountain
locality, the organic matter is still a brown
colour, rather than black carbon, and so
fine details of the plant anatomy could be
seen under the microscope. Leclercqia is
an herbaceous lycopod; other plants
found at this locality were Haskinsia ,
another lycopod, and Rellimia , a
progymnosperm.
The most exciting finds at Brown
Mountain, however, were excellently
preserved remains of tiny arthropods:
various arachnids such as scorpions,
pseudoscorpions, mites, trigonotarbids,
and spiders; centipedes and other
myriapods; and possibly the earliest insect
relatives. At that time (1970s) the oldest
known land animals came from the early
Devonian site at Rhynie, Scotland (Selden
and Nudds, 2004, Chapter 5); although
younger than these, the Gilboa material
represented the earliest known land
animals ever found in North America
(Shear et al ., 1984). The preservation of
the animals was so remarkable that
Bonamo and Grierson had to make sure
that they were not looking at
contamination by modern animals which
had fallen into the acid during

90

90 View of the lower
Schoharie Reservoir and
powerhouse at Brown
Mountain from the Blenheim
Gilboa Visitor Centre.