Tag: building stone

Airport Fossils

Trapped at SeaTac Airport in Seattle with nothing to do?  I am sure the people stranded there would rather be someplace else but the extra time will allow intrepid travelers to explore the many fossils found in the walls of the food court in concourse A.  The fossils make a captivating cast of characters that lived 155 million years ago in what became Germany.  During the Jurassic Period when dinosaurs roamed the land, a shallow sea covered much of Europe.  Many critters from that sea are now preserved in the tan to gray limestone cladding walls at SeaTac. 

155-million-year old ammonite – Good examples are in the pillars just past the security check, particularly the one nearest Ex-Officio.

The stone is known as the Treuchtlingen Marble, although it is not marble but limestone.  It was never metamorphosed.  As the animals died they settled to the bottom of the sea.  The most common fossils are sponges, bottom dwelling, filter feeders that formed small mounds.  They may be round, straight, or irregularly shaped and are darker than the surrounding limestone.  Also common are ammonites, coiled-shell animals that resemble a top down view of a cinnamon roll.  The biggest ones in the German limestone are about five-inches across, whereas the largest ones that ever lived were six feet wide.  Ammonites were prevalent marine predators in the Jurassic but went extinct at the end of the Cretaceous.  Their modern relatives include squids, chambered nautiluses, and octopi.  

You can also find another squid relative, belemnites, which look like a cigar.  They are dark brown and somewhat shiny.  Also seek out brachiopods, clam-shaped animals known as lampshells due to their resemblance to ancient oil lamps.  Unlike clams, brachiopods cannot move and feed by opening their shell and consuming bits that float by.  And finally, the white specks that look like oatmeal are single-celled sea dwellers called foraminifera. I hope this at least helps some people pass the time at SeaTac.

Gary Cooper and the Stones of San Francisco

With the upcoming AGU annual fall meeting, I want to look at some of the building stone used in San Francisco.  Despite the area’s abundant stone, the earliest fireproof granite building used stone quarried, cut, and fitted together in China.  Known as the Parrott Block, it was built in 1852.  The blocks had been labeled with Chinese characters and shipped to San Francisco, to be assembled by Chinese workers.  The three-story building survived the 1906 earthquake and fire but was razed in 1926 for the Financial Center Building, now remodeled as the Omni Hotel. 

Various rock trickled into San Francisco in the following decades. By the end of the century two of the most prominent were a sandstone quarried near Sites and a granite from Raymond.  Sites is about 100 miles north of the bay area, in the Sacramento Valley, whereas Raymond is 150 southeast in the foothills of the Sierras.  Both rocks reached the city by train. 

Colusa sandstone quarry – From: http://quarriesandbeyond.org/states/ca/quarry_photo/ca-colusa_photos.html

Two quarries in Sites provided stone.  A. D. Knowles opened his quarry in 1886, followed in 1890 by the John McGilvray Stone Company.  Known in the trade as Colusa Sandstone (the town of Colusa is about 25 miles away), the rock comes from the Upper Cretaceous Venado Formation, a several-hundred meter thick layer of submarine fan deposits.  They are part of the Great Valley Group, tens of thousands of feet of muds, silts, and sands that accumulated in a forearc basin found between the Sierra Nevada magmatic arc and the Franciscan subduction complex. 

The Ferry Building was the first great structure made of Colusa rock.  Other well-known buildings are the St. Francis Hotel, Music Temple in Golden Gate, and the Flood Building.  The stone was also shipped to Hawaii.  It is generally bluish gray or buff, though a recently opened quarry about one mile north of the original quarries markets the sandstone as a brownstone.  Like other sandstones during fires, the Sites rock spalled heavily during the post-1906 earthquake infernos. 

Raymond Granite Quarry – 1905 — From: http://www.sjvls.org/photoheritage

The Raymond granite quarry opened in 1888 on property locally known at the time as Dusy’s Rock Pile.  Light gray in color, the Raymond rock is classic, Sierra Nevada subduction zone granite, and is now sold as Sierra White by the quarry’s present owner Cold Spring Granite.  Raymond granite was used in the San Francisco Civic Center, City Hall, Palace Hotel, and numerous buildings on the UC Berkeley campus.  The new main San Francisco library, built in 1996, also has a granite façade from the Raymond quarry. 

The stone, or at least the quarries, achieved a bit of notoreity in 1949 in the movie adaptation of Ayn Rand’s The Fountainhead.  At a low point in his career, architect Howard Roark, played by Gary Cooper, retreats to a job in a quarry.  The quarry in the book is in Connecticut, but since the film was shot in California the Raymond quarries had to stand in for Connecticut.  Although limited, the scenes in the quarry with Cooper and Patricia Neal are some of the movie’s most famous and controversial because of their sexual imagery.  And for those inclined to stone, the shots do a fine job of depicting quarry technology.