Underground Markers

[+jeff35080]

While travelling on some roads that are 'off the beaten path' this weekend, I encountered the typical witness post and sign and stopped to investigate the site. I looked all around the sign and couldn't find the marker, so I created a waypoint and when I got home searched the site to find the benchmark. Take a look at this BM page:

 

http://www.geocaching.com/mark/details.asp?PID=DH2479

 

This is the first time I have seen a description that describes multiple BMs. Also this quote from the description puzzles me:

 

THE UNDERGROUND DISK IS SET IN THE TOP OF AN IRREGULAR MASS OF CONCRETE 42 INCHES BELOW THE GROUND SURFACE

 

What is the purpose of a marker that is intentionally set below the surface of the ground?

 

Jeff

http://www.StarsFellOnAlabama.com

http://www.NotAChance.com

If you hide it, they will come....

[survey tech]

The underground mark is typical, particularly for first order triangulation stations, which would be very difficult to precisely reset otherwise if the surface mark is damaged. If someone comes careening down the road and runs off the road and hits it, which happens surprisingly often on rural highways where people drive like The Dukes Of Hazard, the surface mark is ruined, but the subsurface mark would remain. The last part about the ASHD ROW marker is strange, since no data is provided for this marker, I suspect they intended to use it as an azimuth mark but never did.

[+jeff35080]

Thanks for the info surveytech! I would just hate to be the poor surveyor that has to dig the 4' holes to find the marks to use

 

Jeff

http://www.StarsFellOnAlabama.com

http://www.NotAChance.com

If you hide it, they will come....

[Z15]

I have dug the underground up a few times. Here's is a station one of our party's found. Read the 1995 recovery.

 

quote:

---

 

 

The NGS Data SheetSee file dsdata.txt for more information about the datasheet.DATABASE = Sybase ,PROGRAM = datasheet, VERSION = 6.71

1 National Geodetic Survey, Retrieval Date = FEBRUARY 3, 2003

RL1102 ***********************************************************************

RL1102 DESIGNATION - PAULDING

RL1102 PID - RL1102

RL1102 STATE/COUNTY- MI/ONTONAGON

RL1102 USGS QUAD -

RL1102

RL1102 *CURRENT SURVEY CONTROL

RL1102 ___________________________________________________________________

RL1102* NAD 83(1994)- 46 24 01.48403(N) 089 13 06.32336(W) ADJUSTED

RL1102* NAVD 88 - 490.370 (meters) 1608.82 (feet) ADJUSTED

RL1102 ___________________________________________________________________

RL1102 LAPLACE CORR- -3.66 (seconds) DEFLEC99

RL1102 GEOID HEIGHT- -31.54 (meters) GEOID99

RL1102 DYNAMIC HT - 490.381 (meters) 1608.86 (feet) COMP

RL1102 MODELED GRAV- 980,620.5 (mgal) NAVD 88

RL1102

RL1102 HORZ ORDER - FIRST

RL1102 VERT ORDER - SECOND CLASS 0

RL1102

RL1102.The horizontal coordinates were established by classical geodetic methods

RL1102.and adjusted by the National Geodetic Survey in February 1997.

RL1102

RL1102.The orthometric height was determined by differential leveling

RL1102.and adjusted by the National Geodetic Survey in June 1991.

RL1102

RL1102.The Laplace correction was computed from DEFLEC99 derived deflections.

RL1102

RL1102.The geoid height was determined by GEOID99.

RL1102

RL1102.The dynamic height is computed by dividing the NAVD 88

RL1102.geopotential number by the normal gravity value computed on the

RL1102.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45

RL1102.degrees latitude (g = 980.6199 gals.).

RL1102

RL1102.The modeled gravity was interpolated from observed gravity values.

RL1102

RL1102; North East Units Scale Converg.

RL1102;SPC MI N - 182,115.848 7,829,435.929 MT 0.99990485 -1 36 12.4

RL1102;UTM 16 - 5,140,928.987 329,467.697 MT 0.99995748 -1 36 24.9

RL1102

RL1102: Primary Azimuth Mark Grid Az

RL1102:SPC MI N - PAULDING AZ MK 072 53 23.8

RL1102:UTM 16 - PAULDING AZ MK 072 53 36.3

RL1102

RL1102|---------------------------------------------------------------------|

RL1102| PID Reference Object Distance Geod. Az |

RL1102| dddmmss.s |

RL1102| CJ3451 PAULDING AZ MK 0711711.4 |

RL1102| RL1582 TROUT CREEK LOOKOUT TOWER USGS APPROX.18.0 KM 0755006.5 |

RL1102| RL1104 PAULDING RM 2 30.078 METERS 25505 |

RL1102| RL1604 TT 36 TX 11.945 METERS 27802 |

RL1102| RL1103 PAULDING RM 1 25.636 METERS 34028 |

RL1102|---------------------------------------------------------------------|

RL1102

RL1102 SUPERSEDED SURVEY CONTROL

RL1102

RL1102 NAD 83(1994)- 46 24 01.48164(N) 089 13 06.31877(W) AD( ) 1

RL1102 NAD 83(1986)- 46 24 01.48088(N) 089 13 06.31792(W) AD( ) 1

RL1102 NAD 27 - 46 24 01.67700(N) 089 13 05.80600(W) AD( ) 1

RL1102 NGVD 29 - 490.390 (m) 1608.89 (f) ADJ UNCH 2 0

RL1102

RL1102.Superseded values are not recommended for survey control.

RL1102.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums.

RL1102.See file dsdata.txt to determine how the superseded data were derived.

RL1102

RL1102_U.S. NATIONAL GRID SPATIAL ADDRESS: 16TCS2946840929(NAD 83)

RL1102_MARKER: DS = TRIANGULATION STATION DISK

RL1102_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT

RL1102_STAMPING: PAULDING 1939

RL1102_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO

RL1102+STABILITY: SURFACE MOTION

RL1102

RL1102 HISTORY - Date Condition Report By

RL1102 HISTORY - 1939 MONUMENTED CGS

RL1102 HISTORY - 1940 GOOD CGS

RL1102 HISTORY - 1948 GOOD NGS

RL1102 HISTORY - 1952 GOOD CGS

RL1102 HISTORY - 1975 GOOD NGS

RL1102 HISTORY - 1975 GOOD NGS

RL1102 HISTORY - 19951011 MARK NOT FOUND MIDT

RL1102 HISTORY - 20010617 GOOD USPSQD

RL1102

RL1102 STATION DESCRIPTION

RL1102

RL1102'DESCRIBED BY COAST AND GEODETIC SURVEY 1939 (FBQ)

RL1102'STATION IS ABOUT 2 MILES WEST OF THE TOWN OF PAULDING AND ON

RL1102'LAND OWNED BY THE MICHIGAN CONSERVATION DEPARTMENT. IT IS IN THE

RL1102'NORTHWEST QUARTER OF SECTION 8, T. 46 N., R. 39 W., 39.19

RL1102'FEET EAST OF THE PAULDING LOOKOUT TOWER WHICH IS ON THE

RL1102'HIGHEST PART OF THE HILL. IT IS 92 FEET SOUTHEAST OF A WELL

RL1102'PUMP AND ABOUT 27 YARDS EAST-SOUTHEAST OF THE SOUTHEAST CORNER

RL1102'OF THE RANGERS HOUSE. THE MARK PROJECTS

RL1102'ABOUT 8 INCHES ABOVE THE GROUND AND IS STAMPED PAULDING 1939.

RL1102'

RL1102'TO REACH THE STATION FROM THE TOWN OF PAULDING, AT THE RAILROAD

RL1102'CROSSING DRIVE NORTH ON U.S. HIGHWAY 45 FOR 0.1 MILE TO A

RL1102'T-ROAD WEST, TURN LEFT, AND DRIVE WEST ON THE MAIN GRAVEL ROAD

RL1102'FOR 2.1 MILES TO A SIGN STATE FIRE TOWER 1/8 MILE. TURN

RL1102'LEFT AND DRIVE UPHILL 0.2 MILE TO THE LOOKOUT TOWER AND THE

RL1102'STATION.

RL1102'

RL1102'REFERENCE MARK NO. 1 IS 84.01 FEET, HORIZONTAL DISTANCE,

RL1102'NORTH-NORTHWEST OF THE STATION AND 57 FEET NORTHEAST OF THE

RL1102'WELL PUMP. IT IS ABOUT 5 FEET LOWER THAN THE STATION. THE

RL1102'MARK PROJECTS 8 INCHES ABOVE GROUND AND IS STAMPED

RL1102'PAULDING NO 1 1939.

RL1102'

RL1102'REFERENCE MARK NO. 2 IS 98.70 FEET, HORIZONTAL DISTANCE,

RL1102'WEST-SOUTHWEST OF THE STATION AND 33 FEET SOUTH OF THE SOUTHEAST

RL1102'CORNER OF THE RANGERS HOUSE. IT IS ABOUT 5 FEET LOWER THAN

RL1102'THE STATION. THE MARK PROJECTS 8 INCHES ABOVE

RL1102'GROUND AND IS STAMPED PAULDING NO 2 1939.

RL1102'

RL1102'THE AZIMUTH MARK IS ABOUT 1.2 MILES EAST-NORTHEAST OF THE

RL1102'STATION. IT IS 28 FEET SOUTHWEST OF THE CENTER OF THE RAILROAD

RL1102'TRACKS, 21 FEET WEST OF A TELEPHONE POLE, 22 FEET NORTH OF

RL1102'THE CENTER OF THE GRAVEL ROAD, AND 109 FEET WEST-NORTHWEST

RL1102'OF THE CENTER OF THE RAILROAD AND GRAVEL ROAD CROSSING. THE

RL1102'MARK PROJECTS 8 INCHES ABOVE THE GROUND AND IS

RL1102'STAMPED PAULDING 1939.

RL1102'

RL1102'TO REACH THE AZIMUTH MARK FROM THE RAILROAD CROSSING IN

RL1102'PAULDING, DRIVE NORTH ON U.S. HIGHWAY 45 FOR 0.1 MILE THEN

RL1102'TURN LEFT AND DRIVE WEST ON A GRAVEL ROAD FOR 0.9 MILE TO

RL1102'A RAILROAD CROSSING AND THE MARK.

RL1102'

RL1102'ALL MARKS ARE WITNESSES WITH 4-INCH SQUARE WHITE WOODEN

RL1102'POSTS WHICH PROJECT ABOUT 2-1/2 FEET ABOVE THE GROUND.

RL1102'

RL1102'TT 36 TX 1938 (U.S.G.S.) IS 39.19 FEET WEST OF THE STATION

RL1102'AND ON THE HIGHEST PART OF THE HILL. IT IS A STANDARD U.S.

RL1102'GEOLOGICAL SURVEY BENCH MARK DISK SET FLUSH WITH THE SURFACE

RL1102'OF THE GROUND AND IN THE CENTER OF AN 8- BY 9-INCH CONCRETE

RL1102'POST. IT IS STAMPED TT 36 TX 1938. THE DISK IS UNDER THE

RL1102'APPROXIMATE CENTER OF THE PAULDING LOOKOUT TOWER, WHICH

RL1102'IS A STEEL STRUCTURE AND 90 FEET HIGH AND HAS A GLASS ENCLOSED

RL1102'LOOKOUT ROOM ON THE TOP. THE TOWER BELONGS TO THE MICHIGAN

RL1102'CONSERVATION DEPARTMENT.

RL1102'

RL1102'A 37-FOOT TOWER IS NEEDED TO SEE A 123-FOOT TOWER AT COPPS.

RL1102'

RL1102'A 37-FOOT TOWER IS NEEDED TO SEE A 77-FOOT TOWER AT BASS.

RL1102'

RL1102'A 37-FOOT TOWER IS NEEDED TO SEE A 103-FOOT TOWER AT BERGLAND.

RL1102'

RL1102'A 37-FOOT TOWER IS NEEDED TO SEE A 77-FOOT TOWER AT NORWICH.

RL1102'

RL1102'HEIGHT OF LIGHT ABOVE STATION MARK - 34 METERS.

RL1102

RL1102 STATION RECOVERY (1940)

RL1102

RL1102'RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1940 (KBJ)

RL1102'STATION RECOVERED AS DESCRIBED BY F.B. QUINN IN 1939. ALL

RL1102'MARKS WERE FOUND TO BE IN GOOD CONDITION. DISTANCES CHECK

RL1102'AS DESCRIBED. THE 1939 DIRECTIONS DO NOT AGREE WITH THOSE

RL1102'OF 1940.

RL1102

RL1102 STATION RECOVERY (1948)

RL1102

RL1102'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1948

RL1102'2.6 MI W FROM PAULDING.

RL1102'ABOUT 0.25 MILE NORTH ALONG U.S. HIGHWAY 45 FROM THE POST

RL1102'OFFICE AT PAULDING, THENCE ABOUT 2.15 MILES SOUTHWEST ALONG A

RL1102'GRAVEL ROAD, THENCE ABOUT 0.25 MILE SOUTH ALONG A ROAD, AT THE

RL1102'PAULDING FIRE LOOKOUT TOWER, 26 FEET EAST OF THE SOUTHEAST

RL1102'LEG OF THE TOWER, 95 FEET EAST OF THE SOUTHEAST CORNER OF A LOG

RL1102'BUILDING, 85 FEET SOUTH-SOUTHEAST OF R.M. NO. 1, 5 FEET SOUTHEAST

RL1102'OF A 3 1/2 INCH PINE TREE, AND SET IN THE TOP OF A CONCRETE

RL1102'POST PROJECTING 8 INCHES.

RL1102

RL1102 STATION RECOVERY (1952)

RL1102

RL1102'RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1952 (LFW)

RL1102'THE STATION WAS RECOVERED AND ALL MARKS WERE FOUND IN GOOD

RL1102'CONDITION. AS SEVERAL DISCREPANCIES WERE FOUND IN THE ORIGINAL

RL1102'DESCRIPTION A COMPLETE NEW DESCRIPTION FOLLOWS.

RL1102'

RL1102'THE STATION IS LOCATED ABOUT 2.0 MILES WEST OF PAULDING

RL1102'ON A WOODED HILL NEAR THE PAULDING LOOKOUT TOWER.

RL1102'

RL1102'TO REACH THE STATION FROM THE GENERAL STORE IN PAULDING,

RL1102'GO NORTH ON U.S. HIGHWAY 45 FOR 0.2 MILE TO A BRIDGE. CROSS

RL1102'BRIDGE AND CONTINUE NORTH ON HIGHWAY 0.1 MILE TO A GRAVEL

RL1102'ROAD TO THE LEFT. TURN LEFT, GO WEST 0.9 MILE TO THE AZIMUTH

RL1102'MARK ON THE RIGHT AS DESCRIBED BELOW. CONTINUE WESTERLY

RL1102'1.2 MILES TO A ROAD LEFT. TURN LEFT, GO SOUTHERLY 0.2 MILE

RL1102'TO THE TOP OF THE HILL AT THE SITE OF THE LOOKOUT TOWER

RL1102'AND STATION.

RL1102'

RL1102'THE STATION MARK IS STAMPED PAULDING 1939. IT IS A STANDARD

RL1102'DISK SET IN A CONCRETE MONUMENT.

RL1102'THE MARK PROJECTS 7 INCHES AND IS LOCATED 39 FEET EAST OF

RL1102'THE CENTER OF THE LOOKOUT TOWER AND 3 FEET NORTH OF A WHITE

RL1102'WITNESS POST.

RL1102'

RL1102'REFERENCE MARK 1 IS STAMPED PAULDING NO 1 1939. IT IS A

RL1102'STANDARD DISK SET IN A CONCRETE.

RL1102'THE MARK PROJECTS 3 INCHES AND IS LOCATED 2.5

RL1102'FEET SOUTH OF A WHITE WITNESS POST.

RL1102'

RL1102'REFERENCE MARK 2 IS STAMPED PAULDING NO 2 1939. IT IS A

RL1102'STANDARD DISK SET IN A CONCRETE.

RL1102'THE MARK PROJECTS 6 INCHES AND IS LOCATED 2.5

RL1102'FEET EAST OF A WHITE WITNESS POST.

RL1102'

RL1102'THE AZIMUTH MARK IS STAMPED PAULDING 1939. IT IS A STANDARD

RL1102'DISK SET IN A CONCRETE MONUMENT.

RL1102'IT PROJECTS 4 INCHES AND IS LOCATED 21 FEET NORTH OF THE

RL1102'CENTERLINE OF A GRAVEL ROAD, 21 FEET WEST OF TELEPHONE POLE

RL1102'NO. 476 AND 3 FEET WEST OF A WHITE WITNESS POST.

RL1102'

RL1102'A U.S. GEOLOGICAL SURVEY BENCH MARK, STAMPED TT 36 TX 1938,

RL1102'IS SET IN A CONCRETE MONUMENT, FLUSH WITH THE GROUND AND

RL1102'LOCATED IN THE CENTER OF THE BASE OF THE LOOKOUT TOWER.

RL1102

RL1102 STATION RECOVERY (1975)

RL1102

RL1102'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1975 (JLC)

RL1102'NO MEASUREMENT BETWEEN THE RMS DUE TO TREES ON LINE.

RL1102'

RL1102'THE STATION MARK, REFERENCE MARKS 1 AND 2, THE AZIMUTH MARK AND THE

RL1102'USGS MARK WERE RECOVERED AND FOUND IN GOOD CONDITION. THE

RL1102'HORIZONTAL DIRECTIONS AND THE DISTANCE TO THE REFERENCE MARKS

RL1102'CHECKED THE 1939 OBSERVATIONS ADEQUATELY, HOWEVER, HORIZONTAL

RL1102'DIRECTIONS TO THE USGS MARK WAS IN DIFFERENCE OF 4 MINUTES AND 34

RL1102'SECONDS SMALLER, THE DISTANCE CHECKED ADEQUATELY. A COMPLETE

RL1102'NEW DESCRIPTION FOLLOWS.

RL1102'

RL1102'THE STATION IS LOCATED ABOUT 10 MILES NORTH-NORTHWEST OF WATERSMEET,

RL1102'10 MILES SOUTH-SOUTHWEST OF BRUCE CROSSING, 1-1/2 MILES WEST OF

RL1102'PAULDING AND ON LAND OF THE US FOREST SERVICE, MR. JAMES A. CARON,

RL1102'DISTRICT RANGER, WATERSMEET RANGER STATION, WATERSMEET, MICHIGAN.

RL1102'

RL1102'TO REACH THE STATION FROM PAULDING, GO NORTH ON U.S. HIGHWAY 45 FOR

RL1102'0.2 MILE TO A BRIDGE, CONTINUE NORTH FOR 0.1 MILE TO A GRAVELED SIDE

RL1102'ROAD LEFT. TURN LEFT AND GO WEST ON THE GRAVELED ROAD FOR 0.95

RL1102'MILE TO THE AZIMUTH MARK ON THE RIGHT, CONTINUE WEST ON THE

RL1102'GRAVELED ROAD FOR 1.2 MILES TO A SIDE ROAD LEFT. TURN LEFT AND GO

RL1102'SOUTHERLY, UPHILL, FOR 0.2 MILE TO THE TOP OF HILL AND

RL1102'STATION.

RL1102'

RL1102'STATION MARKS ARE STANDARD DISKS STAMPED PAULDING 1939. THE SURFACE

RL1102'DISK IS SET IN THE TOP OF A 12-INCH SQUARE CONCRETE MONUMENT THAT

RL1102'PROJECTS 12 INCHES ABOVE THE GROUND SURFACE. IT IS 39 FEET EAST OF

RL1102'A METAL WITNESS POST, 14 FEET SOUTH OF AN 18-INCH PINE TREE AND 4

RL1102'FEET NORTH OF A METAL WITNESS POST. THE UNDERGROUND DISK IS SET IN

RL1102'THE TOP OF AN IRREGULAR MASS OF CONCRETE 40 INCHES BELOW THE

RL1102'GROUND SURFACE.

RL1102'

RL1102'REFERENCE MARK 1, A STANDARD DISK STAMPED PAULDING NO 1 1939, IS SET

RL1102'IN THE TOP OF A 12-INCH SQUARE CONCRETE MONUMENT THAT PROJECTS 4

RL1102'INCHES ABOVE THE GROUND SURFACE. IT IS 12 FEET SOUTH OF THE CENTER

RL1102'OF TRACK ROAD AND 2 FEET EAST OF A METAL WITNESS POST.

RL1102'

RL1102'REFERENCE MARK 2, A STANDARD DISK STAMPED PAULDING NO 2 1939, IS SET

RL1102'IN THE TOP OF A 12-INCH SQUARE CONCRETE MONUMENT THAT PROJECTS 4

RL1102'INCHES ABOVE THE GROUND SURFACE. IT IS 22 FEET SOUTH-SOUTHEAST OF

RL1102'A 14-INCH SPRUCE TREE AND 2 FEET SOUTH OF A METAL WITNESS POST.

RL1102'

RL1102'AZIMUTH MARK, A STANDARD DISK STAMPED PAULDING 1939, IS SET IN THE

RL1102'TOP OF A 12-INCH SQUARE CONCRETE MONUMENT THAT PROJECTS 4 INCHES

RL1102'ABOVE THE GROUND SURFACE. IT IS 21 FEET NORTH OF THE CENTER OF THE

RL1102'GRAVELED ROAD AND 2 FEET EAST OF A METAL WITNESS POST.

RL1102'

RL1102'USGS MARK, A STANDARD U.S. GEOLOGICAL SURVEY BENCH MARK DISK STAMPED

RL1102'TT 36 TX 1938, IS SET IN THE TOP OF A 6-INCH SQUARE CONCRETE

RL1102'MONUMENT THAT IS FLUSH WITH THE GROUND SURFACE. IT IS 1 FOOT SOUTH

RL1102'OF A METAL WITNESS POST AND IN THE CENTER OF 4 CONCRETE

RL1102'FOOTINGS FOR THE OLD LOOKOUT TOWER.

RL1102'

RL1102'AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN--1-1/2 MILES WEST

RL1102'OF PAULDING.

RL1102'

RL1102'HEIGHT OF LIGHT ABOVE STATION MARK 85.3 FEET.

RL1102

RL1102 STATION RECOVERY (1975)

RL1102

RL1102'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1975

RL1102'0.3 MILE NORTH ALONG U.S. HIGHWAY 45 FROM THE NORTH EDGE OF PAULDING,

RL1102'THENCE 2.15 MILES WEST ALONG A GRAVELED ROAD, THENCE 0.2 MILE

RL1102'SOUTHERLY, UPHILL, ALONG A TRACK ROAD, 39 FEET EAST OF A METAL

RL1102'WITNESS POST, 14 FEET SOUTH OF AN 18-INCH PINE TREE AND 4.0 FEET WEST

RL1102'OF A METAL WITNESS POST, AND SET IN THE TOP OF A 12-INCH SQUARE

RL1102'CONCRETE MONUMENT THAT PROJECTS 12 INCHES ABOVE THE SURFACE OF THE

RL1102'GROUND. NOTE-- THE LOOKOUT TOWER THAT WAS PREVIOUSLY MENTIONED HAS

RL1102'BEEN TORN DOWN.

RL1102

RL1102 STATION RECOVERY (1995)

RL1102

RL1102'RECOVERY NOTE BY MICHIGAN DEPARTMENT OF TRANSPORTATION 1995 (BRT)

RL1102'MARK WAS FOUND REPLACED WITH AN IRON PIPE FROM REFERENCE MONUMENTS BY

RL1102'RICHARD L. DRAHN, US FOREST SERVICE, UNDERGROUND MARK WAS FOUND PILED

RL1102'IN STONES SURROUNDING FOREST SERVICE PIPE. PER INSTRUCTIONS FROM NGS

RL1102'STATE GEODETIC ADVISOR THE USFS MARK WAS REMOVED AND A NEW STATION WAS

RL1102'ESTABLISHED. FOR FURTHER INFORMATION CONTACT STATE GEODETIC ADVISOR.

RL1102

RL1102 STATION RECOVERY (2001)

RL1102

RL1102'RECOVERY NOTE BY US POWER SQUADRON 2001 (GG)

RL1102'RECOVERED IN GOOD CONDITION.

 

*** retrieval complete.

Elapsed Time = 00:00:05

 

---

[+jeff35080]

Ouch

 

Jeff

http://www.StarsFellOnAlabama.com

http://www.NotAChance.com

If you hide it, they will come....

[+GEO*Trailblazer 1]

If I remember correctly,there are always 2 marks one surface and one below the frost line.The reason being if the top one is destroyed the other can be located.It is also used for land shifts,to show how far if any the upper mark moved from the lower mark,these are still in use for the study of earthquakes and major land movements.Seismology,Richter scale.

 

When all else fails Geotry again.