Robert,

If you are actually on the mainline through Reno, it seems unlikely to
me that these are burned coal deposits from steam locomotives. The
Central Pacific RR reached eastwards into Reno by 1868, and all of the
pictures of CP locomotives of this period clearly show wood in their
tenders. Indeed, the famous photo of the Jupiter meeting the UP
locomotive at Promontory Utah shows wood in both of their tenders, in a
very arid and non-woodsy section of the world. The CPRR's larger
successor, the Southern Pacific RR, kept burning wood in their steam
locomotives until they transitioned to heavy bunker oil in the 1890s.
The only SP division that  ran on coal that I'm aware of was through
Tucumcari, New Mexico, where the SP owned a coal mine. There's some
excellent technical data on CP/SP steam locomotives in:

Dunscomb, Guy L.
1968    A Century of Southern Pacific Steam Locomotives.

Could your deposit simply be coarse railroad sand? They used it for
both railbed ballast and for traction on the rails. The black could be
burned oil deposits from the many thousands of steam locomotives that
trundled past there in the first half of the 20th century. If you ever
saw pictures of a Cab Forward locomotive (or any of the SP's steamers)
working hard from Sparks to Reno you would see that they covered
everything within spitting distance of the tracks in a black greasy
dust.

Just some thoughts.

Best,

Robert Cromwell, M.A.
Archaeologist
Fort Vancouver National Historic Site
612 E. Reserve St.
Vancouver, WA 98661

On Oct 18, 2004, at 7:35 PM, Robert Leavitt wrote:

> Hi all.
>
>        I've been monitoring the excavation of a trench for the
> railroad through
> Reno, along the original transcontinental route. One of the things
> we've
> found is a substance that is similar to coarse sand in grain size,
> texture,
> and ability to pack (I couldn't get vertical walls, they all ended up
> being
> at the angle of repose...) and a uniform black that rubs off on your
> hands,
> clothes, etc. Normally, there's nothing else in the deposit. A couple
> of
> deposits have been rather random in shape, but one was in an
> approximately
> cubical hole about 1 meter on a side. I was thinking that it could be
> the
> remains of coal used in the train boilers, consequently subjected to
> high
> and extended heat. But coal isn't a common fuel in the Great Basin, so
> I
> have no idea what coal ash should look like. Could someone accustomed
> to
> coal-fired heat give me a clue what remains when coal is well burned?
> Ashy
> (like wood)? Mottled color or uniform? Black or shades of grey? Can I
> expect a scent after its been buried for a century (I detected none)?
> Or
> ??? Unfortunately, I have no picture, but visualize black sand.
>
> Robert C. Leavitt
>