Description: "Nature's
Secret" is composed of three different elements. The first element consists
of five large pieces of Anamosa limestone. This rock is found in the
east central part of Iowa and was formed by the ancient seas in the Silurian
era, 425 million years ago. This type of limestone is typified by its fine
grained sedimentary nature and creamy buff color.
Inset into each of the five stones are seven bronze
cylinders. The cylinders indicate the positions of the main stars that make
up the asterism known as the Big Dipper. At first glance you may not
recognize the Big Dipper on some of the limestone pieces. This is because
each stone displays the Big Dipper at different times. The five limestone
slabs show the configuration of the stars of the Big Dipper as they appeared
one million years ago, five hundred thousand years ago, one hundred thousand
years ago, their current locations and their locations one hundred thousand
years from now.
The final element of the sculpture is a group of three
spherical forms with a barb-like surface to represent microscopic ragweed
pollen grains. Pollen grains preserved in fossil plant remains provide
an important clue to the vegetative and climatic changes in the ancient landscape.
Approximately 7,700 years ago, the prairie had become well established
across the state of Iowa, with grasses, wormwood, sunflowers and ragweed
making up the majority of it.
The sculpture viewed as a whole suggests a sense of
time measured in geological, paleontological and astronomical time scales,
as well as showing the scale of change on a microscopic and macroscopic (or
telescopic) scale.