Notifications
Clear all

Another Triumph of Records Management!

12 Posts
4 Users
0 Reactions
161 Views
Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

The task was simple enough. A client had bought two 20-acre lots in a 500-acre subdivision that I had laid out and platted in 1995 and he was planning to have the lots separately fenced. Yes, I could find the corners and mark the lines for fencing.

All of the rod and cap markers I had set to mark the boundaries of the two lots and showed on the subdivision plat remained in place except for one. That had fallen victim to a new driveway sometime in the last few months. It happens. Rod and Cap No. 469 shown above is now 21 years old and is for all practical purposes in as good a shape as when set. The punchmark is unmistakable and the stamping legible.

In reviewing the file, I discovered that about twenty years ago I had marked the common line of the two lots for fencing that had never gotten built, setting 5/8-inch rebars with punchmarks at various convenient points along the line, all in drill holes in the rocky ground. That was a simplication, i.e. to just find the old rebar line stakes and verify that they were as accurately set as I had thought them to be twenty years ago.

Two side lines remained, but along one I found steel tee posts alongside 5/8-inch rebars with punchmarks. Lo and behold, I had set those also. I haven't found the record of that yet, but the markers were obviously mine. They were 5/8-inch rebars driven into drill holes with a rebar driver that rounded the edges of the top over exactly as mine does and had a punchmark at the center of the bar exactly as I leave rods I find and set. It's sort of funny that the combination would be unique, but it is.

I'd like to tell you that I had already set line stakes on the other side lot line, but that was only partially true. I did find a rebar about 150 ft. back along the line running from the front corner. I set those thoughout the subdivision (after platting) to show prospective buyers the direction in which the lines ran and to give the future lot owners a clue as to where to brush out the lines that ran for about a quarter mile back from the road on average.

These days, the entire effort would have been one Star*Net project showing all of the original survey and subsequent work connected to a common control network and I wouldn't have needed to scrounge through various project files. I guess I didn't imagine twenty years ago that I would still be returning for more of the same just as the Texas Indians who left this scraper or preform on the ground about 8,000 years ago probably didn't think that anyone would ever think it unusual.

 
Posted : October 25, 2016 7:35 pm
paden-cash
(@paden-cash)
Posts: 11088
Supporter
 

Kent's Invoice:

Review of documents 4 hrs.
Investigative field work 6 hrs.
Staking fence line 2 hrs.
Rooting around looking
for arrowheads and taking
photos of windmills 12 hrs.
total time 24 hrs.

 
Posted : October 25, 2016 7:45 pm
Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

paden cash, post: 396883, member: 20 wrote: Kent's Invoice:

Review of documents 4 hrs.
Investigative field work 6 hrs.
Staking fence line 2 hrs.
Rooting around looking
for arrowheads and taking
photos of windmills 12 hrs.
total time 24 hrs.

LOL! Some of the oldest projectile points I've found came from that very ranch, Early Stemmed points that to my mind are either immediately before or after the Angostura culture. One has to have priorities.

 
Posted : October 25, 2016 7:52 pm
paden-cash
(@paden-cash)
Posts: 11088
Supporter
 

I am not near as well versed on pre-historic Okies as you are with your Texan counterparts. But I can tell you there are localized "sweet spots" to locate ancient flint tooling around here also.

There are several hay and wheat fields near a small town south of here named Rosedale. These fields are adjacent to the Canadian River. When the fields are plowed and you're lucky enough to catch a good rain, the flints make themselves prominent to the eye with sunshine. Several people can be seen rooting through the fields during those times of year and I guess the local rancher doesn't seem to mind.

Rather than picturing 600 acres of native Americans napping flint on their haunches, I am of the opinion they are debris from somewhere upstream ( western Oklahoma) that were probably deposited in the alluvium during some high water event in the past. Either that or it was the site of the largest bison killing party in unrecorded history..

 
Posted : October 25, 2016 8:08 pm
stlsurveyor
(@stlsurveyor)
Posts: 2491
Supporter
 

That picture looks like a landscape that may become a painting this winter..

N10,000, E7,000, Z100.00 PLS - MO, KS, CO, MN, KY

 
Posted : October 25, 2016 8:09 pm

Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

paden cash, post: 396888, member: 20 wrote: I am not near as well versed on pre-historic Okies as you are with your Texan counterparts. But I can tell you there are localized "sweet spots" to locate ancient flint tooling around here also.

Central Texas about 8,000 years ago was probably one of the most populated places in North America. That particular site had it all: a high hill between a spring-fed creek and a river that flowed for most of the year, at the edge of a buffalo praire, and among abundant and high quality chert deposits. One of the hilltops still had plenty of debitage from the manufacture of stone tools, which tells me that it was a nice place to hang out, surveying the prairie and enjoying the breeze.

 
Posted : October 25, 2016 8:17 pm
anonymous
(@Anonymous)
Posts: 0
Guest
 

There's something deeply satisfying from going back to old jobs 20, 30, 40.. years ago and finding marks and that you actually agree with previous measurements.
That find is fantastic. Probably excite me far more than some marks from an ancient surveyor retracing his own work. That's me Kent, not inferring you.

Can you hold onto such or are you supposed to declare them?

I knew a geologist who did a lot of work around here and he mentioned how he occasionally found stone axe heads. But he never let it be known.
I tend to keep finds like such quiet, happy to know their existence but not for the whole world to bicker over.
Some of our earlier ancestors descendants can't agree between themselves so I don't offer anything to cause further disruption.
Not sure what it's like over there.

 
Posted : October 25, 2016 8:28 pm
Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

Richard, post: 396896, member: 833 wrote: There's something deeply satisfying from going back to old jobs 20, 30, 40.. years ago and finding marks and that you actually agree with previous measurements.

My choice of mark is intended to leave absolutely no doubt in the minds of future surveyors as to its identity since the i.d. number is noted on the subdivision plat of record. I had one amusing call from a surveyor who seemed to be enjoying letting me know that his field party had found one marker nominally 20 ft. (or some similar amount) out of position until I asked him what the i.d. number of the monument his field party had found was. They had found a marker that was in fact set in that exact position and shown just so on the plat. Field party hadn't apparently even bothered to examine the record plat. It was definitely worth the extra two dollars to "help them out" as I did.

That find is fantastic. Probably excite me far more than some marks from an ancient surveyor retracing his own work. That's me Kent, not inferring you.

Can you hold onto such or are you supposed to declare them?

In Texas, there are no laws protecting such antiquities on private land, although on projects where public monies are spent, and particularly on public lands, there are protections. Virtually everything I find is on the surface. That particular artifact was lying in a dirt driveway, practically under a tire track, for example. My view is that anyone who collects ancient artifacts of cultural significance is obligated to document them in some way so that the collection isn't completely without a context.

That particular area (speaking in terms of square miles and hundreds of properties) is so rich in ancient Indian artifacts that isolated surface finds aren't nearly as important as stratified deposits in burned rock middens or associated with charcoal susceptible to Carbon-14 dating. The burned rock middens and rock art are important cultural treasures and landowners need to be enlisted in protecting them.

 
Posted : October 25, 2016 8:52 pm
Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

paden cash, post: 396888, member: 20 wrote: Rather than picturing 600 acres of native Americans napping flint on their haunches, I am of the opinion they are debris from somewhere upstream ( western Oklahoma) that were probably deposited in the alluvium during some high water event in the past. Either that or it was the site of the largest bison killing party in unrecorded history.

If the lithic material still has clean edges from knapping, I think you can discard the hypothesis that it was transported with other river alluvium.

You have to remember that the first peoples in Oklahoma were there for probably at least 8,000 years (before ultimately moving to Texas, of course), so it isn't remarkable at all that there would be extensive accumulations of lithic debris from tool manufacture over millenia at some sites.

 
Posted : October 25, 2016 9:16 pm
Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

paden cash, post: 396888, member: 20 wrote: Rather than picturing 600 acres of native Americans napping flint on their haunches, I am of the opinion they are debris from somewhere upstream ( western Oklahoma) that were probably deposited in the alluvium during some high water event in the past. Either that or it was the site of the largest bison killing party in unrecorded history..

There were quarry sites where chert was reduced to blanks for trade or transport. If there are outcrops of high-quality chert or other knappable materials nearby, that would also account for the large amount of debitage. Examination of the flakes and cores (if they exist) would tell the story. The material itself should indicate a place of origin.

As I mentioned above, transport with river alluvium will give the material a tumbled appearance, smoothing any sharp edges so that the flakes are not longer sharp (to the tongue).

 
Posted : October 27, 2016 6:23 pm

Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

One of the interesting things about revisiting old work is seeing how well it was done previously. In the course of finding the corners of the two 20.00 acre lots I'd surveyed and platted in 1995, the line I was most interested in was the common side line of the lots. It was a line that was shown on the plat as running for N87å¡49'38"W, 1483.26 ft. from a punchmark on an aluminum-capped 5/8-inch rebar identified as No.470 to a punchmark on another aluminum-capped rebar, No.469 seen in the photo above.

The two had originally been set from control that was only very indirectly connected, i.e. one from a traverse that ran up a new road I was laying out and one from the traverse of the subdivision boundary, but not highly interconnected, which was why I was interested to compare the actual bearing and distance between the two to my best estimate via Star*Net in 1995.

The boundary of the 1995 plat was based upon a survey that I'd made in 1992, oriented to grid North of the Texas Coordinate System of 1927 (South Central Zone) via solar observations. The distance between 470 and 469 was expressed on the subdivision plat as a surface distance derived using a Combined Grid Factor of 0.999906, so the plat distance of 1483.26 ft. was equivalent to a grid distance of:

1483.26 ft. x 0.999906 = 1483.12 ft.

Aside from the assignment of False Eastings and Northings, the Sough Central Zones of the Texas Coordinate Systems of 1927 and 1983 use the same Lambert projection parameters, i.e. same standard parallels and same central meridian, but of course referring to NAD 27 and NAD 83, respectively. The grid bearings of lines in either system between two points should differ by only a fraction of a second of arc.

The scale difference introduced by the Texas Coordinate System of 1927 being a projection using the NGVD 29 geoid as the reference surface and that of 1983 using an ellipsoid that is nominally 84 ft. above the geoid in the vicinity of Nos. 470 and 469 is 4ppm. In other words the grid distance from 470 to 469 in the Texas Coordinate System of 1983 should be 4ppm greater.

1483.12 ft. x 1.000004 = 1483.125 ft., for most practical land surveying purposes the same distance.

How did the bearing and grid distance from 470 to 469 compare when checked by GPS twenty-one years later?

From analysis of uncertainties in Star*Net, the bearing and grid distance is:

469-470 N87å¡49'44"W +/- 4.1" 1483.089 +/- 0.028 ft.

Both of the uncertainties are at 95% confidence. So, the resurvey found a line that in 1995 had been determined by conventional methods to bear N87å¡49'38"W, 1493.12 ft.(grid) to be nearly identical with the bearing and length of the same actually on the ground as found twenty-one years later.

At the time I staked the subdivision, I was using a tolerance of about 0.03 ft. for setting out. That is, the rebars had to be set in drill holes made in the rocky ground and the procedure was to position the template, drill the hole, drive the bar, punch the center and check it. If it was within 0.03 ft. of the target coordinates, the bar was capped and punched in the center. Remarkably, the noise introduced by that tolerance would nearly account for all of the difference between 1995 and 2016.

 
Posted : October 27, 2016 8:18 pm
Kent McMillan
(@kent-mcmillan)
Posts: 11419
Member
Topic starter
 

and of course that should read :

"Both of the uncertainties are at 95% confidence. So, the resurvey found a line that in 1995 had been determined by conventional methods to bear N87å¡49'38"W, 1483.12 ft.(grid) to be nearly identical with the bearing and length of the same actually on the ground as found twenty-one years later."

 
Posted : October 27, 2016 9:29 pm