Hi Barb/Jeff,

I agree with the "recycling" idea, and was really hoping that we would also
have exotic obsidian brought in with one of the outlying groups that came
in to the mission. But alas, no. Instead, what we have is all the typical
sources. What is apparent, however, is that the debitage patterns are very
different than those we see on pre-contact sites in our area.

Barb, ae there any published reports on the Presidio obsidian?

Linda

*Linda Hylkema*
*Cultural Resources Manager, Santa Clara University*
W: *408-554-4513* | C: *408-219-5748* | F: *408-551-1709* | 500 El Camino
Real, Santa Clara, CA 95053




On Wed, Apr 9, 2014 at 3:48 PM, Boyer, Jeffrey, DCA <
[log in to unmask]> wrote:

> Barb,
> Thanks for posting a positive message to Linda. I'm interested in
> situations in which OH has worked for folks. I'm not opposed to the
> technology, just not sure of how to evaluate the results I've seen so far.
> Our experimental results with temperature and depth (and in or out of
> shade) were disconcerting so I tend to be skeptical.
> Thanks again,
>
> Jeff
>
> Jeffrey L. Boyer, RPA
> Supervisory Archaeologist/Project Director
> Office of Archaeological Studies, Museum of New Mexico
>
>   *   The Center for New Mexico Archaeology
>   *   PO Box 2087
>   *   Santa Fe, New Mexico 87504
>   *   tel: 505.476.4426
>   *   e-mail: [log in to unmask]
>
> "There comes a time in every rightly-constructed boy's life when he has a
> raging desire to go somewhere and dig for hidden treasure."  -- Mark Twain,
> The Adventures of Tom Sawyer
>
>
> ________________________________________
> From: HISTORICAL ARCHAEOLOGY [[log in to unmask]] on behalf of Barbara Voss
> [[log in to unmask]]
> Sent: Wednesday, April 09, 2014 12:37 PM
> To: [log in to unmask]
> Subject: Re: Obsidian hydration on historic sites
>
> Hi Linda,
>
> One benefit of obsidian hydration for colonial-era deposits is that it
> allows us to answer questions of lithic recycling and scavanging. For
> example, if multiple dates (prehistoric and historic) are indicated on
> different flake scars that may indicate that mission residents were
> obtaining older lithic tools and flakes for new uses. We have found several
> examples of this at the Presidio of San Francisco.
>
> In the SF Bay area, colonization profoundly disrupted obsidian trade,
> changing the sources that were available to local Native Californians. I
> would subdivide your assemblage according to source, and then consult with
> your obsidian specialist about appropriate sampling for each source. We
> have
> worked with Origer & Assoc. on colonial-era assemblages with great results.
>
> --Barb
>
> -----------------------------------------------
> Barbara L. Voss, Associate Professor
> Department of Anthropology
> 450 Serra Mall, Bldg. 50, Main Quad
> Stanford University
> Stanford CA 94305-2034
> [log in to unmask]
>
>
> -----Original Message-----
> From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of
> Barbour,
> Matthew, DCA
> Sent: Wednesday, April 09, 2014 11:22 AM
> To: [log in to unmask]
> Subject: Re: Obsidian hydration on historic sites
>
> Jemez Historic Site includes the remains of at least one and possible two
> Spanish missions. Also located in the Jemez Mountains, we got a ton of
> obsidian. There hasn't been major excavations out at the site since the
> 1970s (maybe 60s) and a little in the early 2000s. However, in both cases,
> no one bothered with obsidian hydration. I am not saying it is not
> worthwhile, but if your emphasis is on chronometrics, dendro is going to be
> a better bet and in our case there were enough diagnostic ceramics to parse
> out what dated to when for the most part. All this being said, I do not
> think I have ever used obsidian hydration to date a site. I am no expert.
> If
> it works when dealing with such a refined date range, I would be surprised,
> but please let me know if you have success.
>
> Matt
>
>
>
> Matthew J. Barbour
> Site Manager
>
> Jemez Historic Site
> PO Box 143
> Jemez Springs, NM 87025
> email: [log in to unmask]
> office: 575.829.3530
> cell: 505.220.3270
>
> ________________________________________
> From: HISTORICAL ARCHAEOLOGY [[log in to unmask]] on behalf of Linda Hylkema
> [[log in to unmask]]
> Sent: Wednesday, April 09, 2014 11:59 AM
> To: [log in to unmask]
> Subject: Obsidian hydration on historic sites
>
> Hi all,
>
> We are starting the analysis phase of a major excavation on a California
> mission site (ca 1780-1840's). We have a number of pieces of obsidian
> (debitage and formal artifacts). My consultants are proposing hydration on
> 25 pieces from the assemblage. We have already sourced all of it (except
> pieces that are too small) with our XRF. Sources are the same as what has
> been traditionally found in pre-contact sites of the region. My questions
> are:
>
> 1. What would be gained from dating obsidian from a a site with such a
> tight
> temporal margin, and such a recent one at that? Establishing calibration
> markers for comparison for other late period sites??
>
> 2. If determined to be a relevant task, would would be a statistically
> valid
> sample from an assemblage of about 200 pieces that includes 20 projectiles?
> I know that's a hard, if not impossible, question without knowing more
> about
> my site, but any insight would be appreciated. If you'd like more details
> about the site to answer my questions, please feel free to contact me
> off-line. It's a rich site, and we excavated fifty-six discrete pit
> features
> full of mission trash, which is where all the obsidian is from.
>
> At this point, I'm not convinced that it will add substantially to our
> interpretation of the site.
>
> ANY insight is appreciated.
>
> Linda
>
>
> *Linda Hylkema*
> *Cultural Resources Manager, Santa Clara University*
> W: *408-554-4513* | C: *408-219-5748* | F: *408-551-1709* | 500 El Camino
> Real, Santa Clara, CA 95053
>