Non-metallic pin flags are useful in metal detector surveys for obvious
reasons. Once a metal pin flag is used to identify the location of a
target, it becomes another target masking other artifacts in close
proximity. Metal pin flags rust. PVC staff flags do not.
Blackburn Manufacturing: http://www.blackburnflag.com/store/index.php
Rich Green
Historic Archaeological Research
4338 Hadley Court
West Lafayette, IN 47906
Office: (765) 464-8735
Mobile: (765) 427-4082
www.har-indy.com
----- Original Message -----
From: "Benjamin Carter" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, September 15, 2010 11:36 AM
Subject: Re: Renting GPR or Magnetometer.
> All,
>
> Thank you for the many responses. They have all been very useful.
>
> Let me address some of your questions. I have used aerial photos from the
> 1930s, 1950s, 1960s and Google Earth images from 1992 until now. There is
> relatively little evidence from grass growth, etc. of where the structures
> may have been. I even took some current aerial photos using kite aerial
> photography, but there are no patterns present that would suggest
> sub-surface structures. One weekend, I did rent an inexpensive metal
> detector (Garrett ACE 250) and did a VERY informal and non-systematic
> survey of the site. I found that certain sections of the site had greater
> concentrations of "hits". These tended to be in the location where I
> suspected they would be based upon historic maps and where we currently
> have permission from the landowner to excavate.
>
> It looks like a GPR/magnetometer survey is essentially out of the question
> at this point.
>
> I am going to attempt to run a systematic metal detector survey at this
> point along with some test excavations.
>
> What do people use for 'flagging' hits with the metal detector? These need
> to be non-metallic, correct? Where can I get such a thing (perhaps in
> multiple colors)?
>
> Cheers,
> Ben
>
>
>
> On 9/14/2010 12:00 PM, Richard Lundin wrote:
>> Ben:
>>
>> I, heartily, agree that metal detecting is the FIRST thing to try. I use
>> relatively inexpensive units (around $125) available at most WALMART or
>> Big
>> 5 stores that are VLF systems with a "Bounty Hunter" technology. I run
>> my
>> surveys, first, with no discrimination and pin flag all anomalies with
>> YELLOW pin flags, then, AFTER I have shot in all of the anomalies with an
>> EDM or plane table and alidade (being old fashioned and wanting a map I
>> can
>> look at). I, then, run the entire area again with FULL discrimination and
>> place RED pin flags on the non-ferrous anomalies. Patterns will then
>> emerge. I, then, run a Class 1 (orientation) survey that involves a N-S
>> and
>> an E-W transect that cuts the patterns. Using this data, I set my grids
>> and
>> do radiometric, VLF-EM and moisture\pH surveys (very cheap) along a
>> series
>> of N-S or E-W Class 2 lines spaced 5 meters apart and with 1 meter
>> stations
>> on line, taking VLF-EM, radiometric and moisture\pH data as I go plotting
>> all the data on the plane table map and in profile.
>>
>> IF the metal detector data shows extensive areas with +3 YELLOW flags per
>> square meter (high ferrous content) I go, immediately, to resistivity,
>> VLF-EM, radiometric or portable X-Ray fluorescence (pXRF) methods which
>> are
>> relatively cheap and easy to do AND any magnetometer data will be nearly
>> useless. If NOT, then I go with a total field magnetic survey in a Class
>> 2
>> format as above with an older magnetometer that has +/- 1 gamma
>> sensitivity,
>> is easier to obtain, cheaper to rent and will give you just as good data
>> in
>> the iron-rich environment of a typical historic era site.
>>
>> I, then, plot the Class 2 data in profile while integrating the nearby
>> metal
>> detector anomalies as symbols on the profile, the radiometrics as an
>> indicator of K levels in the soil and the pH\moisture data as a possible
>> cause of resistivity\conductivity anomalies. Following up on the Class 2
>> surveys Class 3 (Grid) surveys with the Combined Survey format (CSF)
>> metal
>> detector, resistivity, radiometrics, VLF-EM, pXRF and pH\moisture data.
>>
>> As GPR is the most expensive to use and hardest to interpret, I use it
>> sparingly in a Class 3 (Grid) survey (usually with a 1000 mhz) antenna
>> over
>> the areas of interest from the Class 2-3 CSF archaeogeophysical and
>> archaeochemical (pXRF) anomalies. I then use the 1000 mhz GPR data to
>> image the anomalies in three dimensions.
>>
>> IF the site is vegetated, plant geochemistry MAY be very useful in
>> defining
>> activity areas. With a limited budget, this can be done with the taking
>> of
>> plant samples (same species, grasses work well back east as we are
>> finding
>> from our work a Cahokia) at the same locations as taking soil pXRF
>> readings,
>> solar drying the plant materials to a powder and then running the powder
>> by
>> pXRF.
>>
>> As noted in previous posts, most of the geophysical equipment can be
>> easily
>> obtained for a weekend test program from university geosciences or
>> material
>> science departments, mining companies or engineering firms for the cost
>> of a
>> dinner and\or a few beers. The pXRF equipment is now pretty readily
>> available on loan\demonstration for short duration projects from
>> companies
>> such as OLYMPUS INNOV-X or THERMO Fisher Scientific NITON Analyzers and,
>> sometimes, if you have a really newsworthy project, the GPR equipment can
>> be
>> supplied by MALA on a demonstration basis. Training on this equipment can
>> come from the equipment manufacturers or the National Park Service has a
>> great (and inexpensive) training course run on a yearly basis by Steve
>> DeVore.
>>
>> As a minerals exploration geophysicist, geochemist and, NOW,
>> archaeogeophysicist and archaeochemist with over 40 years doing this sort
>> of
>> work and NOW doing these sorts of studies to find (and avoid) hidden
>> archaeological sites for our mineral industry and governmental clients, I
>> know that this phased approach works for finding and defining areas of,
>> even, very subtle traces of human activity that archaeologists often miss
>> with surface surveys.
>>
>> If you have any questions on this approach or need to discuss YOUR
>> project
>> please feel free to call me at WRI's Sonora California Office number:
>> (209)
>> 532-3873. Alternately, you can look Dr. Claudia Brackett and myself up at
>> the upcoming SHA Archaeochemical Workshop in Austin in January.
>>
>> Best of luck on YOUR project!
>>
>> Sincerely,
>>
>> Richard J. Lundin BA, MA, RPA, ISAP
>> Consulting Historical Archaeologist& Remote Sensing Specialist
>> (Archaeogeophysics)
>> Director, Wondjina Research Institute
>>
>> -----Original Message-----
>> From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of Paul
>> McLeod
>> Sent: Monday, September 13, 2010 8:33 PM
>> To: [log in to unmask]
>> Subject: Re: Renting GPR or Magnetometer.
>>
>> Hi Ben- I used to work as a mineral exploration geophysicist, and from
>> time
>> to time while out in the field, I would sometimes offer my services to
>> archaeologists for recon-level work just for fun. I had free access to
>> the
>> geophysics equipment, so the only thing it cost me was a little bit of my
>> time. I found magnetometry worked great on some sites and worked hardly
>> at
>> all on others- The place you are most likely to find cheap to free
>> geophysical equipment and/or services is university geophysics
>> departments You might find a student who is looking for a good project
>> for a class or
>> for a thesis who has access to the equipment who would work for free (or
>> for
>> beer). Another possibility to investigate is the engineering contractors
>> who do mineral exploration or environmental/geotechnical engineering. Of
>> course they charge lots of money for their services, but if you find a
>> sympathetic worker who is interested in archaeology, you might be able to
>> work out a deal.
>> Just some thoughts. Paul
>>
>>
>> --- On Mon, 9/13/10, Benjamin Carter<[log in to unmask]>
>> wrote:
>>
>>
>> From: Benjamin Carter<[log in to unmask]>
>> Subject: Renting GPR or Magnetometer.
>> To: [log in to unmask]
>> Date: Monday, September 13, 2010, 8:35 PM
>>
>>
>> All,
>>
>> I am in the process of studying a historic site (c. 1750) in eastern PA.
>> Based upon historic documents we have a good idea of the location of the
>> site and part of it falls within an open field. I have been over the site
>> multiple times and there are very few hints as to where within that field
>> the site may be. There may have been one structure that had a stone
>> foundation, but that may have been removed historically. There were
>> probably
>> approximately 35-50 other 'houses' that did not have stone foundations. I
>> want to try an relocate these structures based upon their post-holes,
>> trenches and artifacts, especially nails. At least one of the structures
>> was
>> burned so the nails should be distributed around that foundation. These
>> has
>> been some historic disturbance at the site, but I don't believe that
>> structures were buried, but they were likely plowed.
>>
>> I am trying to figure out the best way to relocate the site more
>> precisely.
>> I would love to use either GPR or Magnetometry, but the equipment can be
>> extremely pricey and I have a fairly limited budget. There are also a
>> myriad
>> of variations that I could potentially use and I am having a difficult
>> time
>> determining which would be the best.
>>
>> Does anyone have suggestions? Are there inexpensive GPR, etc. equipment
>> that
>> I could rent? I am considering using metal detectors in the organized
>> fashion laid out in previous posts to this list serve. That seems more
>> affordable and I may know a couple of people who have them and,
>> hopefully,
>> would help out. Unfortunately, that doesn't give me a great map like you
>> can
>> get from GPR. It is also limited because it gives little information
>> about
>> the item that has been detected.
>>
>> I greatly appreciate any and all assistance.
>>
>> Cheers,
>> Ben Carter
>>
>>
>>
>>
>>
>
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