Page 20 - visitorGuide

■ Serpentinite Boulder
The massive serpentine, in the small garden in the center of the front walk­
way, came from the Mother Lode area of the Sierra Nevada, California. It is
from the same outcrop as the serpentine rock in the north atrium.

This large boulder is made up of metamorphic serpentine minerals that
contain high concentrations of magnesium and iron. Serpentine soils and the
runoff from serpentinite outcrops can be so acidic that many plant species
cannot survive them without the addition of potassium and lime. Conversely,
certain plant species grow only in serpentine soils.
Gift from John A. Huberty, collected by Christopher W.H. Hulbe and students from Sacramento City College, California,
through Bennie W. Troxel, former science editor for the Society.

■ Society Seal
The Society’s seal, adopted in 1891, is reproduced on the wall in front of the
building. It is a gift from Mrs. Barbara Campbell in memory of her husband,
Arthur B. Campbell (1924–1971), a Fellow of the Society. At the time of
his death, Campbell was chief of the branch of Rocky Mountain Envi­
ronmental Geology, U.S. Geological Survey.

A commemorative plaque of the same stone, Spartan Pink granite
from a stone quarry in Georgia, is set on top of the wall above the seal.
Cutting and emplacement of the seal and plaque were by Milton Erickson, Erickson Memorial Co., Denver, Colorado.

Before you reach the garnet specimen ahead, on your left you will see stairs and a
pathway leading down to the Eaton Terrace, which is located near the southeast side
of the building. The terrace was made possible through a contribution from Gordon P.
and Virginia G. Eaton. From the terrace, you can view GSA’s staff garden and the
southern portion of the Society’s land.

■ Garnet-Bearing Rock
Looking to the left of the serpentine garden, you will see a dark, spotted boulder.
The red crystals embedded in the rock are garnet, a complex iron-magnesium-
aluminum silicate mineral. Outlining the garnets are borders of black horn­
blende. Small, clear crystals of garnet are highly prized as gems, but these are
not of gem quality; they are used for abrasives (garnet paper, for example, is a
much better abrasive than sandpaper and is correspondingly more expensive).

This monolith is from the main ore zone of the garnet deposits at Gore
Mountain in the southeastern part of the Adirondack Mountains of New York.
The deposit has been mined continuously for more than 100 years and is the
only commercial source of graded garnet abrasive powders obtained from a
bedrock deposit. Gift from Barton Mines Corporation, North Creek, New York, through Charles B. Sclar, Lehigh Uni-
versity, Bethlehem, Pennsylvania.

■ Memorial Fountain
Next you will see giant clam shells fashioned into a fountain. The shells are
from the largest living bivalve Mollusca family.They occur in the western and
southern Pacific Ocean.

This display is in memory of Charles Lee McGuinness (1914 –1971), who, at
the time of his death, was chief of the ground water branch, U.S. Geological
Survey, and chairman of the Hydrogeology Division of GSA.
Gift from the Hydrogeology Division of GSA.

10 VISITOR GUIDE