Ancient walls
Virtual Guide assembled Summer 2011 by Paul Edison-Lahm and Clay Kelleher of the Geological Society of the Oregon Country in preparation for the “Ancient Walls” walk on August 6th, 2011. Text based on an earlier tour given by Clay circa 1993 and on Ralph S. Mason’s "Walls worth walking by: A tour of the South Park Blocks area of downtown Portland", Oregon Geology, November 1985. Descriptions in quotation marks are from Mason unless otherwise noted. Special thanks also to David B. Williams, Architectural Heritage Center, Cold Springs Granite, North American Research Group, and GGP for their essential contributions.
Pioneer Place Mall
(built in 1990)
(built in 1990)
Pioneer Place Atrium fountain...
fountain bollards capped with black limestone containing...
...tiny fossils crinoids
(relative of modern sea urchins and star fish)
(relative of modern sea urchins and star fish)
limestone floor tiles
(Jurassic age from Comblanchien France)
(Jurassic age from Comblanchien France)
clam fossil
(cross section)
(cross section)
Turritella shells
(longitudinal cross section)
(longitudinal cross section)
Turritella shells
(transverse cross sections)
(transverse cross sections)
fossil coral or moss animal
Standard Insurance Center (1968)
“The Quest” (1970)
Pentelic Greek marble
Pentelic Greek marble
granite wall
granite with alkali feldspar “Carlsbad” twins
Multnomah County Courthouse (1909)
Bedford, Indiana limestone,
on a base of Raymond. California “Sierra W hite” granite
on a base of Raymond. California “Sierra W hite” granite
“Sierra White” granite with flecks of hornblende & mica
Standard Plaza (1962)
...“pink twinned potassium feldspar crystals in the coarse-grained granite ashlar masonry walls”
granite (detail)
sandstone
crossbedding
exfoliation
1000 Broadway (1991)
Gneiss
Schnitzer Concert Hall (1928)
box office -
various marbles
various marbles
(detail)
First Congregational Church (1891)
Oregon basalt, Tenino sandstone, and mystery rock...
Pacwest Center (1984)
"Blue Pearl" larvikite
from Finland
from Finland
“Blue Pearl” (detail)
Cold Springs Granite “Agate” quarried in Ortonville, MN contains...
”intergrown orthoclase and microcline crystals”...
(McKelvey et al.)
(McKelvey et al.)
“as well as abundant quartz and scattered biotite”...
...“Black mica knots, pegmatite masses”
Unitas Plaza (1965)
(Unitas Plaza)
travertine
travertine
Wells Fargo Center (1972)
Carrera marble panels
Pegmatite
(detail)
KOIN Center (1984)
Limestone containing “fossils and pieces of chert and shale”
Echinoid “sand dollar”
mystery burrows
fountain with orbicular and Sardinian granite
Orbicular Granite
(detail from Bank of American Financial Center)
(detail from Bank of American Financial Center)
Sardinian Granite (granodiorite)
with xenolith
with xenolith
Lake Tai Limestone,
gift from Suzhou, China
gift from Suzhou, China
Justice Center (1983)
Italian travertine pillars
Italian travertine pillars
(detail)
Mark O. Hatfield
Federal Courthouse (1997)
Federal Courthouse (1997)
(Federal Courthouse)
limestone and “granite”
limestone and “granite”
Oolitic limestone
Gabbro
Union Bank of California Tower (1969)
Slate
731 SW Morrison
(former Carl Greve jewelers)
(former Carl Greve jewelers)
Morton Gneiss
3.6 billion years old
3.6 billion years old
A Virtual Geological Tour of
Downtown Portland
Downtown Portland
