Benchmark Oxidation

[mloser]

I found this benchmark at the base of a high tension tower. It is the first that I have located that is so completely oxidized. While it might be random--sun exposure, deer urine, salt air (200 miles from the shore!), does anyone else think that it might be caused by the electrical field from the high tension lines?

 

[+jeff35080]

does anyone else think that it might be caused by the electrical field from the high tension lines?

 

Nope.

[+BlueDeuce]

Well a quick google check say that Brass is an alloy of copper and zinc. It turns a duller, darker color as it oxides and can turn green if left damp.

 

It's on the internet so it must be true!

Edited February 22, 2004 by TeamX40

[Cape Cod Cacher]

The patina actually helps bronze from 'melting' away, such as rust ( another type of oxidation) would do to iron and other ferrous materials. It protects it to a certain degree. The green is a form of cuprous oxide - CuO2. A sculptor friend told me when he was going to RISD, they used to leave bronzes out back of the foundry and pee on them to accelerate the patina. It forms a barrier coat of sorts. There are newer alloys that have aluminium added to help stabilize the bronze now.

 

pardon the mispellings....

[mloser]

OK, I found a couple other green ones today, so my theory about electrical currents was off. Seems like the deer pee one might be a possibility though! LOL

[Z15]

I have seen ones like that up here in Michigan. Its a natural reaction of the metal to the environment.

 

 

Many years back (1984) we found a uprooted triangulation station. The monument itself was only 2 ft deep in the ground so we covered over the underground disk and took the complete concrete post. Once back at the office, we broke up the concrete and discovered an interesting thing I have not seen since. The side of the disk that was showing in the monument was like the photo, U.S.C. & G. S. Triangulation station disk but on the other side was another agency's logo. It was the U.S.Geological Survey. One side USC&GS and the other USGS, the stem that held it in the concrete was brazed on. When I told the NGS advisor, he wanted to see it and I have never seen it again. He said a the time that he never seen that before.

 

The station

 

 

The NGS Data SheetSee file dsdata.txt for more information about the datasheet.DATABASE = Sybase ,PROGRAM = datasheet, VERSION = 6.98

1 National Geodetic Survey, Retrieval Date = FEBRUARY 22, 2004

QL0672 ***********************************************************************

QL0672 DESIGNATION - LORETTA RESET

QL0672 PID - QL0672

QL0672 STATE/COUNTY- MI/DICKINSON

QL0672 USGS QUAD - VULCAN (1955)

QL0672

QL0672 *CURRENT SURVEY CONTROL

QL0672 ___________________________________________________________________

QL0672* NAD 83(1994)- 45 46 21.19809(N) 087 46 08.66695(W) ADJUSTED

QL0672* NAVD 88 - 322.6 (meters) 1058. (feet) GPS OBS

QL0672 ___________________________________________________________________

QL0672 X - 173,485.563 (meters) COMP

QL0672 Y - -4,453,293.136 (meters) COMP

QL0672 Z - 4,547,856.542 (meters) COMP

QL0672 LAPLACE CORR- -3.73 (seconds) DEFLEC99

QL0672 ELLIP HEIGHT- 287.79 (meters) (07/17/02) GPS OBS

QL0672 GEOID HEIGHT- -34.76 (meters) GEOID03

QL0672

QL0672 HORZ ORDER - FIRST

QL0672 ELLP ORDER - FOURTH CLASS I

QL0672

QL0672.The horizontal coordinates were established by GPS observations

QL0672.and adjusted by the National Geodetic Survey in February 1997.

QL0672

QL0672.The orthometric height was determined by GPS observations and a

QL0672.high-resolution geoid model.

QL0672

QL0672.The X, Y, and Z were computed from the position and the ellipsoidal ht.

QL0672

QL0672.The Laplace correction was computed from DEFLEC99 derived deflections.

QL0672

QL0672.The ellipsoidal height was determined by GPS observations

QL0672.and is referenced to NAD 83.

QL0672

QL0672.The geoid height was determined by GEOID03.

QL0672

QL0672; North East Units Scale Factor Converg.

QL0672;SPC MI N - 110,236.986 7,940,185.721 MT 0.99994262 -0 33 21.2

QL0672;SPC WI N - 69,777.304 773,493.398 MT 0.99996900 +1 36 33.6

QL0672;UTM 16 - 5,069,064.877 440,205.324 MT 0.99964396 -0 33 04.0

QL0672

QL0672! - Elev Factor x Scale Factor = Combined Factor

QL0672!SPC MI N - 0.99995488 x 0.99994262 = 0.99989751

QL0672!SPC WI N - 0.99995488 x 0.99996900 = 0.99992389

QL0672!UTM 16 - 0.99995488 x 0.99964396 = 0.99959886

QL0672

QL0672|---------------------------------------------------------------------|

QL0672| PID Reference Object Distance Geod. Az |

QL0672| dddmmss.s |

QL0672| QL0673 LORETTA RM 1 18.294 METERS 09140 |

QL0672| QL0675 LORETTA AZ MK 261.085 METERS 17840 |

QL0672| QL0674 LORETTA RM 2 14.045 METERS 18315 |

QL0672|---------------------------------------------------------------------|

QL0672

QL0672 SUPERSEDED SURVEY CONTROL

QL0672

QL0672 ELLIP H (02/03/97) 287.77 (m) GP( ) 4 1

QL0672 NAD 83(1994)- 45 46 21.20004(N) 087 46 08.66401(W) AD( ) 1

QL0672 NAD 83(1994)- 45 46 21.19359(N) 087 46 08.66675(W) AD( ) 3

QL0672 NAD 83(1986)- 45 46 21.19405(N) 087 46 08.66668(W) AD( ) 3

QL0672 NAD 27 - 45 46 21.33800(N) 087 46 08.22100(W) AD( ) 3

QL0672

QL0672.Superseded values are not recommended for survey control.

QL0672.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums.

QL0672.See file dsdata.txt to determine how the superseded data were derived.

QL0672

QL0672_U.S. NATIONAL GRID SPATIAL ADDRESS: 16TDR4020569065(NAD 83)

QL0672_MARKER: DH = HORIZONTAL CONTROL DISK

QL0672_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT

QL0672_STAMPING: LORETTA 1954 1984

QL0672_MARK LOGO: NGS

QL0672_PROJECTION: PROJECTING 3 CENTIMETERS

QL0672_MAGNETIC: N = NO MAGNETIC MATERIAL

QL0672_STABILITY: B = PROBABLY HOLD POSITION/ELEVATION WELL

QL0672_SATELLITE: THE SITE LOCATION WAS REPORTED AS SUITABLE FOR

QL0672+SATELLITE: SATELLITE OBSERVATIONS - May 30, 2001

QL0672

QL0672 HISTORY - Date Condition Report By

QL0672 HISTORY - 1984 MONUMENTED NGS

QL0672 HISTORY - 19840823 GOOD NGS

QL0672 HISTORY - 19840823 GOOD NGS

QL0672 HISTORY - 19920421 GOOD MIDT

QL0672 HISTORY - 20010331 GOOD NGS

QL0672 HISTORY - 20010530 GOOD UPENGN

QL0672

QL0672 STATION DESCRIPTION

QL0672

QL0672'DESCRIBED BY NATIONAL GEODETIC SURVEY 1984

QL0672'STATION IS LOCATED IN QUAD. 450874, ABOUT 8.05 KM (5.00 MI) EAST OF

QL0672'VULCAN, ON A SMALL BARE HILL ALONG THE RIGHT-OF-WAY OF A GRAVEL ROAD.

QL0672'TO REACH FROM THE INTERSECTION OF U.S. HIGHWAY 2 AND THE MAIN STREET

QL0672'IN NORWAY WITH THE CAUTION LIGHT, GO EASTERLY ON U.S. HIGHWAY 2 FOR

QL0672'3.86 KM (2.40 MI) TO A CROSSROAD IN THE NORTH EDGE OF VULCAN.

QL0672'CONTINUE EAST ON HIGHWAY 2 FOR 7.56 KM (4.70 MI) TO A GRAVEL ROAD

QL0672'LEFT. TURN LEFT AND GO NORTH ON GRAVEL ROAD FOR 0.32 KM (0.20 MI) TO

QL0672'THE AZIMUTH MARK ON LEFT OR WEST SIDE OF GRAVEL ROAD AS DESCRIBED.

QL0672'CONTINUE NORTH FOR 0.24 KM (0.15 MI) TO TOP OF SMALL HILL AND

QL0672'STATION ON LEFT OR WEST SIDE OF ROAD AS DESCRIBED.

QL0672'STATION PROJECTS ABOUT 1 INCH. IT IS 10.363 M (33.999 FT) WEST FROM

QL0672'THE CENTER OF THE GRAVEL ROAD, 1.524 M (5.000 FT) EAST FROM A

QL0672'NORTH-SOUTH FENCE LINE AND 0.457 M (1.499 FT) EAST FROM A MWP.

QL0672'A TRAVERSE CONNECTION WAS MADE TO THE AZIMUTH MARK USING ELECTRONIC

QL0672'DISTANCE MEASURING EQUIPMENT.

QL0672'HEIGHT OF TARGET SHOWN ABOVE THE MARK WAS 1.5 METERS.

QL0672'RECOVERED BY RONALD L. RAMSEY, NGS GEODETIC ADVISOR-MICHIGAN.

QL0672

QL0672 STATION RECOVERY (1984)

QL0672

QL0672'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1984 (CLN)

QL0672'THE STATION MARK WAS FOUND WITH THE TOP PART OF MONUMENT BROKEN OFF

QL0672'AND LAYING ON ITS SIDE. REFERENCE MARKS 1 AND 2 AND THE AZIMUTH MARK

QL0672'WAS FOUND IN GOOD CONDITION. ALL MARK ARE NOW FLUSH WITH GROUND. THE

QL0672'UNDERGROUND STATION MARK WAS RECOVERED AND THIS POINT WAS HELD TO SET

QL0672'A NEW SURFACE DISK. THE DIRECTION FROM THE AZIMUTH MARK TO REFERENCE

QL0672'MARK 2 CHECKED THE OLD DATA, THE DISTANCE TO REFERENCE MARK 2 WAS

QL0672'FOUND TO BE SHORTER BY 0.041 METER (0.135 FT) THE DIRECTION FROM THE

QL0672'AZIMUTH MARK TO REFERENCE MARK 1 DID NOT COMPARE WITH THE OLD DATA NOR

QL0672'DID THE ANGLE BETWEEN REFERENCE MARK 1 AND 2. THE DISTANCE TO

QL0672'REFERENCE MARK 1 WAS ALSO FOUND TO BE SHORTER BY 0.026 OF A METER.

QL0672'THE TO REACH FOR THIS STATION IS STILL ADEQUATE TO FIND THE STATION.

QL0672'

QL0672'THE STATION IS A STANDARD NGS DISK STAMPED--LORETTA 1954 1984--, SET

QL0672'INTO THE TOP OF A ROUND CONCRETE MONUMENT, 10 INCHES (30 CM) IN

QL0672'DIAMETER, PROJECTING 1 INCH (3 CM) ABOVE THE GROUND. THE STATION IS

QL0672'LOCATED 10.363 METERS (33.999 FT) WEST FROM THE APPROXIMATE CENTERLINE

QL0672'OF GRAVEL ROAD, 1.524 METERS (5.000 FT) EAST FROM A NORTH-SOUTH FENCE

QL0672'LINE AND 0.457 METERS (1.499 FT) EAST FROM A METAL WITNESS POST.

QL0672'

QL0672'REFERENCE MARK NO 1 IS A STANDARD CGS DISK STAMPED--LORETTA NO 1

QL0672'1954--, SET INTO THE TOP OF A SQUARE CONCRETE MONUMENT, 10 INCHES

QL0672'(30 CM) IN DIAMETER, FLUSH WITH GROUND. THE STATION IS LOCATED

QL0672'7.315 METERS (23.999 FT) EAST FROM THE APPROXIMATED CENTERLINE OF

QL0672'GRAVEL ROAD, 0.305 METERS (1.001 FT) WEST FROM A NORTH SOUTH FENCE

QL0672'LINE AND 0.305 METERS (1.001 FT) NORTH FROM A WITNESS POST AND 1.2

QL0672'METERS (3.9 FT) HIGHER THAN THE STATION.

QL0672'

QL0672'REFERENCE MARK NO 2 IS A STANDARD CGS DISK STAMPED--LORETTA NO 2

QL0672'1954--, SET INTO THE TOP OF A SQUARE CONCRETE MONUMENT, 10 INCHES

QL0672'(30 CM) IN DIAMETER, FLUSH WITH GROUND. THE STATION IS LOCATED

QL0672'11.582 METERS (37.999 FT) WEST FROM THE APPROXIMATE CENTERLINE OF

QL0672'GRAVEL ROAD, 0.305 METERS (1.001 FT) EAST FROM A NORTH SOUTH FENCE

QL0672'LINE AND 0.305 METERS (1.001 FT) NORTH FROM A WITNESS POST AND 0.5

QL0672'METER (1.6 FT) LOWER THAN THE STATION.

QL0672'

QL0672'AZIMUTH MARK NO 1 IS A STANDARD CGS DISK STAMPED--LORETTA 1954--, SET

QL0672'INTO THE TOP OF A SQUARE CONCRETE MONUMENT, 10 INCHES (30 CM) IN

QL0672'DIAMETER, FLUSH WITH GROUND. THE STATION IS LOCATED 10.363 METERS

QL0672'(33.999 FT) WEST FROM THE APPROXIMATE CENTERLINE OF GRAVEL ROAD,

QL0672'0.914 METERS (2.999 FT) NORTH FROM A 4 X 4 INCH WHITE WOODEN

QL0672'WITNESS POST, 0.610 METERS (2.001 FT) EAST FROM A NORTH-SOUTH FENCE

QL0672'LINE AND 0.305 METERS (1.001 FT) EAST FROM A METAL WITNESS POST.

QL0672'STATION IS LOCATED ABOUT 5.0 MILES (8.0 KM) EAST OF VULCAN ON A SMALL

QL0672'BARE HILL ALONG THE RIGHT-OF-WAY OF A GRAVEL ROAD. TO REACH FROM THE

QL0672'INTERSECTION OF U.S HIGHWAY 2 AND THE MAIN STREET IN NORWAY GO

QL0672'EASTERLY ON U.S HIGHWAY 2 FOR 2.4 MILES (3.9 KM) TO A CROSSROADS IN

QL0672'THE NORTH EDGE OF VULCAN. CONTINUE EAST ON HIGHWAY 2 FOR 4.7 MILES

QL0672'(7.6 KM) TO A PAVED ROAD LEFT WHICH TURNS INTO GRAVEL. TURN LEFT AND

QL0672'GO NORTH FOR 0.2 MILE (0.3 KM) TO THE STATION ON LEFT AS DESCRIBED.

QL0672

QL0672 STATION RECOVERY (1992)

QL0672

QL0672'RECOVERY NOTE BY MICHIGAN DEPARTMENT OF TRANSPORTATION 1992 (BRT)

QL0672'STATION IS LOCATED IN QUAD. 450874, ABOUT 2 MILES (3.2 KM) EAST OF

QL0672'LORETTO, ABOUT 3-3/4 MILES WEST ALONG UNITED STATES HIGHWAY 2 FROM THE

QL0672'DICKINSON - MENOMINEE COUNTY LINE, NEAR CENTER OF SECTION 16, T-39-N,

QL0672'R-28-W, WAUCEDAH TOWNSHIP, AND ON THE VULCAN QUADRANGLE MAP.

QL0672'

QL0672'TO REACH FROM THE FLASHING TRAFFIC LIGHT ON UNITED STATES HIGHWAY 2 IN

QL0672'LORETTO PROCEED 2.25 MI (3.62 KM) EAST ALONG UNITED STATES HIGHWAY 2

QL0672'TO A PAVED ROAD NORTHEAST. FOLLOW PAVED ROAD 0.15 MI (0.24 KM) TO

QL0672'WHERE PAVED ROAD BECOMES GRAVEL. CONTINUE ON GRAVEL ROAD 0.15 MI

QL0672'(0.24 KM) TO STATION ON LEFT AT TOP OF HILL.

QL0672'

QL0672'STATION IS SET IN CONCRETE MONUMENT 5.0 FT (1.5 M) EAST OF FENCE LINE,

QL0672'29.0 FT (8.8 M) WEST OF CENTER OF ROAD, 46.0 FT (14.0 M) NORTH OF

QL0672'LORETTA NO 2, 60.0 FT (18.3 M) WEST OF LORETTA NO 1, AND 1.0 FT (0.3

QL0672'M) EAST OF A CARSONITE WITNESS POST. NOTE AZIMUTH MARK NOT SEARCHED

QL0672'FOR.

QL0672

QL0672 STATION RECOVERY (2001)

QL0672

QL0672'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 2001 (DB)

QL0672'THIS REPORT WAS SUBMITTED BY THE US POWER SQUADRONS.

QL0672

QL0672 STATION RECOVERY (2001)

QL0672

QL0672'RECOVERY NOTE BY UP ENGINEERS AND ARCHITECTS INC 2001 (ERF)

QL0672'RECOVERED IN GOOD CONDITION.

 

*** retrieval complete.

Elapsed Time = 00:00:02

Edited February 23, 2004 by elcamino

[+Black Dog Trackers]

Interesting question on the color of benchmarks.

 

Brass is an alloy of Copper and Zinc. Bronze is an alloy of Copper and Tin. Both brass and bronze are used in the survey caps. There are of course many other varieties of these alloys, some with both Zinc and Tin, others with Aluminum, Iron, Lead, Silicon, or other elements.

 

The metal that gives most of the coloring is the copper. Different copper compounds have different colors; some in the brown color range and some in the green color range.

 

The chemical color coating of metals from oxidation is called a patina. I think you can discount exotic differences like deer pee or electrical fields causing the different patinas. These different colors of copper oxidation are everywhere.

 

Different metals oxidize in different ways. The red oxide of iron (rust) is porous. The porous rust holds water, which causes even more rust to form, until the iron is totally oxidized. Brass, bronze, aluminum, and other metals have oxidation coatings that are not porous, won't soak up water, and thereby tend to protect the metal further oxidation.

 

A check with the benchmark gallery shows a striking difference between the green and the brown disks!

 

From what I can gather, copper (or the copper in brass or bronze) is first oxidized to a copper oxide. The color of copper oxide is brown. The copper oxide slowly reacts with water and carbon dioxide to form copper carbonate (probably a slightly acidic environment is needed). The copper carbonate has blue and green colors.

 

So, as the disk continues to be exposed to air, water, and other local chemistry of the soil that splashes onto it, it will first turn brown, then slowly change to greenish or bluish with further exposure.