========================================================================= Date: Mon, 5 Jan 1998 10:26:34 -0700 Reply-To: dsew@packrat.aml.arizona.edu Sender: Radiocarbon Mailing List From: David Sewell Subject: Happy New Year from RADIOCARBON Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Dear C14-L list folks, A happy new year from Tucson to everyone! We have some information and a question for everyone. First, for RADIOCARBON subscribers, the next issue (Vol. 39, No. 2, 1997) is scheduled to ship this week. (We are 3-4 months behind our normative printing schedule.) Second, we are considering the addition of a secure-server page on our Web site that would allow people to order subscriptions and publications using a credit card. There is some cost connected with this, however. So it would help us to know how much interest there would be in this. If you have used WWW credit-card ordering services in the past and/or might want to use one that RADIOCARBON would establish, could you let me know by replying to this message? (To me directly, not the whole list.) Third, work on the proceedings of the International Radiocarbon Conference in Groningen is moving along fairly briskly, and we expect that the Proceedings volume to be finished this summer. Finally, a word on Renee Kra's health, for those of you who know her (our Managing Editor, on medical leave since 1996). She is having some neurological problems of indeterminate cause that affect balance and equilibrium, and has needed to stay close to home because she cannot drive as a result. I'm sure she would appreciate holiday or get-well cards from people; they can be mailed to our office or directly to her home address, 4801 N Via Entrada, Tucson, Arizona 85718 USA. David Sewell -- David Sewell, Acting Managing Editor dsew@packrat.aml.arizona.edu RADIOCARBON: An International Journal of Cosmogenic Isotope Research Department of Geosciences, University of Arizona 4717 E. Ft. Lowell Rd., Tucson, Arizona 85712 USA Telephone: +1 520 881 0857 Fax: +1 520 881 0554 WWW server: http://packrat.aml.arizona.edu/ ========================================================================= Date: Mon, 5 Jan 1998 13:33:15 -0700 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: David Sewell Subject: 8th International AMS Conference announced Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii We have just received the first circular announcing the 8TH INTERNATIONAL CONFERENCE ON ACCELERATOR MASS SPECTROMETRY to be held in Vienna, organized by the VERA Laboratory of Universitaet Wien, from 13-17 September 1999. To be placed on the mailing list for the next circular in a few months, which will give details on the organization of the conference, contact Conference Secretary Gabriele Kratschmann, gabikra@pap.univie.ac.at. (Tel. +43 1 40480-700; fax +43 1 4076200) -- David Sewell, Acting Managing Editor dsew@packrat.aml.arizona.edu RADIOCARBON: An International Journal of Cosmogenic Isotope Research Department of Geosciences, University of Arizona 4717 E. Ft. Lowell Rd., Tucson, Arizona 85712 USA Telephone: +1 520 881 0857 Fax: +1 520 881 0554 WWW server: http://packrat.aml.arizona.edu/ ========================================================================= Date: Mon, 5 Jan 1998 20:45:28 -0500 Reply-To: chubar@computextos.com.pe Sender: Radiocarbon Mailing List From: Chu Chinchayan Jose Fernando Subject: C-14 Procedures MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello! I am young archaeologist from Peru, South America. I would like if somebody could help me in the procedures in collecting and sending samples for C-14. Is any convention, the collecting procedures are equal in all the archaeological material? Also I would like to know the prices of this. Is the same price for carbon, bone or wood samples? Thanks for the help. Alejandro Chu Barrera chubar@computextos.com.pe ========================================================================= Date: Wed, 7 Jan 1998 09:08:13 -0800 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Zhou Weijian Organization: National Lab of Loess and Quaternary Geology Subject: Help Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Dear Colleague Happy New Year! I am searching for help to interprete magnetic susceptibility (MS)of peat.What does the peat MS indicate? The data I achieved range from 0.4-10(SI Unit). Dark peat has higher MS, while brown peat has lower MS. What does this mean? I would like to know if anyone will interprete it. Thanks for the help in advance. Best regard Zhou Weijian My email address is weijian@loess.llqg.ac.cn ========================================================================= Date: Wed, 7 Jan 1998 08:11:25 +0200 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Bas van Geel Subject: interpretation magnetic susceptibility Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Dear Zhou Weijian, Probably the darker peat was formed in drier local conditions than the lighter peat. As a consequence of a higher degree of decomposition the accumulation rate of the darker peat will be lower. In case the influx of 'magnetic' particles was constant, the concentrations of these particles will be higher in the peat that was accumulating in a slower way because of the drier local conditions. In other words: a one cm thick sample in the darker peat probably represents more time than a similar sample in the lighter peat. The decomposition rate of the peat may also reflect different climatic conditions. During periods of drier climate, more aerosols (among which soil dust) may have come down from the air and became embedded in the peat. Happy New Year, Bas van Geel >Dear Colleague > Happy New Year! > I am searching for help to interprete magnetic susceptibility (MS)of >peat.What does the peat MS indicate? The data I achieved range from >0.4-10(SI Unit). Dark peat has higher MS, while brown peat has lower >MS. What does this mean? I would like to know if anyone will interprete >it. Thanks for the help in advance. >Best regard >Zhou Weijian >My email address is weijian@loess.llqg.ac.cn +--------------------------+-------------------------------------+ | Dr Bas van Geel | Internet E-mail :vanGeel@bio.uva.nl | | University of Amsterdam | Phone secr. :+31-20 525 7844 | | Faculty of Biology | Direct phone :+31-20 525 7664 | | Kruislaan 318 | Fax :+31-20 525 7662 | | NL - 1098 SM Amsterdam | | | The Netherlands | | | | | The Netherlands Centre for Geo-ecological Research (ICG) | +--------------------------+-------------------------------------+ ========================================================================= Date: Fri, 9 Jan 1998 09:31:20 -0800 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Zhou Weijian Organization: National Lab of Loess and Quaternary Geology Subject: Thanks Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Dear Friends: I would like to thank you all for the interpretation and discussion on peat.May I add a few words? Generally, peat has very low non-organic component and the medium tends to oxidize the magnetite and maghemite. I learned a lot. Thank you again Best regards Weijian ========================================================================= Date: Tue, 13 Jan 1998 18:07:02 -0700 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Alwynne Beaudoin Subject: Summary: AMS dating of pollen Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Greetings! A few weeks ago, I posted an enquiry to this list, requesting information on AMS dating of pollen. I received a number of helpful replies off-list. Since then, I have received several requests for the information I received. Accordingly, since I feel that this may be of general interest, I have combined three of the lengthiest replies into this summary message, which I am reposting back to the list. The messages are reposted here with the permission of the senders. I am grateful to everyone who took the time and trouble to respond to my query. I trust that this information is useful to others. Best regards, Alwynne From Eric Grimm >I suggest you get a hold of the following dissertation: > >Brown, Thomas Alexander. 1994. Radiocarbon dating of pollen by accelerator >mass spectrometry. Ph.D. Dissertation. University of Washington, Seattle. > >As far as I know Brown was the person who developed this technique. However, >after reading the thesis, I am rather disenchanted about the prospect of >routinely dating pollen, at least by his methods. Basically, he treats the >sample as you would for pollen preparation, then sieves the material to end >up with a concentrate of pollen-sized stuff. The problem is that, depending >on the sediment, this stuff can include a lot of non-pollen. > >For our Great Plains sites we've been having good luck dating charcoal. We >sieve ths sample as for macrofossils, then pick out small pieces of >charcaol, typically less than 1 mm in length. We'll sometimes pick out >50-100 pieces for a date. > >Cheers, Eric > > >******************************************************************* >Dr. Eric C. Grimm Office: 217-785-4846 >Illinois State Museum Database: 217-524-0493 >Research and Collections Center Fax: 217-785-2857 >1011 East Ash Street E-mail: grimm@museum.state.il.us >Springfield, IL 62703 USA 39d,46m,48s N, 89d,38m,34s W >******************************************************************* > > From Christine Prior > >Dear Dr Beaudoin, >I saw your message on the C14-L listserver and, indeed, just about >everybody I know forwarded me a >copy ("hey, look Chris, somebody's *finally* interested in your research"). >For a little over a year now I have been working on an improved method for >the extraction of pollen from >sediments for AMS dating. The results I have obtained so far were >presented as a poster at the 16th >International Radiocarbon Conference in Groningen last June. > >I have been working with Prof. John Flenley from Massey University. >Basically, the method I am >working on is a modification of his published techniques (Forster R.M. and >Flenley, J.R. (1993) "Pollen >purification and fractionation by equilibrium density gradient >centrifugation" _Palynology_ 17:137-155). >I have been using conventional pollen lab methods (KOH, Na4P2O7, HF) up to >the point at which you >might normally do acetolysis. Instead of acetolysis, I used Sodium >Polytungstate and performed a >series of density separations using solutions of decreasing sp.gr. from 1.4 >to 1.2 to separate the >pollen/spores from the other organic fragments. I had to do a lot of >fiddling to adjust the specific gravity >of the SPT until I could get the pollen to stay in the supernatant while >the other organics sank, but I >finally managed to get a fairly clean, almost pure pollen fraction which I >then AMS dated. The results >were fairly encouraging: the pollen-only dates matched almost exactly with >the previously-obtained >bulk carbon dates from the same level. That reassured me that I hadn't >introduced any contaminants >with the treatment procedure. > >Using some form of density separation seems to be the technique-of-choice >in the current literature. >(c.f. Eriksson, et.al. (1996) "An improved method for preparing a pollen >concentrate suitable for 14C >dating" _Grana_ 35:47-50 or Zhou, Donahue & Jull (1997) "Radiocarbon >AMS dating of pollen >concentrated from eolian sediments: implications for monsoon climate change >since the late >Quaternary" _Radiocarbon_ 39(1):19-26.) >I plan to continue my work in the technique, but I have been very please >with the results that Sodium >Polytungstate gave and will continue to use it rather than the other heavy >liquids cited in the literature. >I think there might be reasons why pollen might be the most appropriate >material for dating from some >sediments. Right now, I have only dated the entire pollen concentrate. >There is some reason to think >that with appropriate adjustment of the densities (perhaps the creation of >a gradient in the centrifuge >tube) it might be possible to separate and obtain AMS dates on individual >taxa. > >If you or your contact wishes to discuss any further details concerning >pollen dating, please feel free to >contact me. Depending upon the nature of the samples, the pollen density >per gram of sediment, and >what Prof Flenely says about the samples I am doing so far for him, I >suppose I could tentatively state >that the Rafter AMS lab is in a position to offer pollen extraction and >dating as a service. But I think >some discussion about the samples, the deposit, extraneous organics, etc. >would be in order before >any such undertaking. > >I hope you receive a satisfactory response to your listserver inquiry. >Please do not hesitate to contact >me if you have any additional questions about the project I did. > >Best wishes, >Chris Prior > >*********************************************************** >Christine A. Prior, Ph.D. >Rafter Radiocarbon Laboratory >Inst. of Geological & Nuclear Sciences >30 Gracefield Road, P.O. Box 31--312 >Lower Hutt, NEW ZEALAND >tel: +64--4--570--4634 fax: +64--4--570--4657 >e--mail: C.Prior@gns.cri.nz >URL: http://www.gns.cri.nz/nuclear/c14/rr_lab1.htm >************************************************************ From: Brian Haskell >We have done pollen dating in our target preparation laboratory (African >lake sediments). Most of the pollen preparation was done by a graduate >student who has now left us, but she trained a very good undergraduate >technician (Jim Baldrica). I can ask him if he would be able to undertake >the pollen preparation. The sample is then prepared for AMS dating in our >laboratory using normal procedures for organic material. The pollen >concentration procedure used is similar to that used for pollen counting, >but there are a number of modifications. You do end up with a bulk pollen >sample, and there are some sediment (not procedural) contamination >possibilities. If you are in an area with lignite then that will be >incorporated into the sample, and possibly some resistant algal material. >This really depends upon the setting in which you are working. We have an >instrument that would allow us to pick out some undesirable material, but >that adds signinficantly (and sometimes prohibitively) to the time. >Pollen dating isn't as good as finding a nice chunk of wood, but it is >certainly better than doing bulk organics, and your decision is based upon >how much you want to know how old your sediment is. Unless you have >serious contamination I would guess that you probably wouldn't be off more >than a couple of hundred years, and in some lakes you may have NO idea of >sediment age and any date is better than pure guessing. > >Pricing and timing depend upon how many samples you have, when we get >them, and to whom we send the graphite for analysis. Currently our >turn-around for organic material is a few months (most of that being the >delay at the AMS labs). Several pollen samples can be prepared at once, >making that somewhat cheaper. I would have to consult with Jim and our >lab manager (Dawn Graber) before quoting a price, but I would hazard a >guess at $US 50 per sample for pollen preparation, plus our normal AMS >dating charges (minus sample pre-preparation charges). That is >lab-dependent but would be around $300 per sample (includes the actual AMS >analysis). Check our webpage at: http://lrc.geology.umn.edu/services/AMS >for details about the normal dating. > >Please contact me if you have any questions. > >Cheers, > >Brian Haskell > >-- > _/ _/_/_/ _/_/ Dr. Brian J. Haskell Tel:(612) 624-7005 > _/ _/ _/ _/ _/ Limnological Research Center Tel:(612) 378-3242 > _/ _/_/_/ _/ University of Minnesota Fax:(612) 625-3819 > _/ _/ _/ _/ _/ 310 Pillsbury Drive. S.E. http://lrc.geo.umn >_/_/_/ _/ _/ _/_/ Minneapolis, MN 55455-0219 .edu/people/haskell > Alwynne B. Beaudoin PhD, Archaeological Survey, Provincial Museum of Alberta 12845-102nd Avenue, Edmonton, Alberta, T5N 0M6, Canada E-mail: abeaudoi@gpu.srv.ualberta.ca ========================================================================= Date: Wed, 14 Jan 1998 15:18:48 +1200 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: "PRIOR, CHRISTINE" From: Hugh W. Jarvis (hjarvis) To: LITHICS-L@LISTSERV.ACSU.BUFFALO.EDU Date: Tuesday 13 January, 1998 6:52 am Subject: SLOWPOKE Facility at U of T closure imminent! All of you who care about archaeometry will be shocked to hear that the wonderful SLOWPOKE Reactor facility at the University of Toronto is being shut down. This closure appears to be solely for the sake of the expanding medical school. The medical school is currently a hot area for the university, receiving lots of attention, money, and acclaim. They want the nearby land the reactor building occupiess, and reactors can't just be moved out of the way. U of T seems to have low regard for SLOWPOKE. Once before they tried to close it and attracted the outrage of hundreds if not thousands of university, public, government, and corporate past users. This time the protest seems to be falling on deaf ears. Perhaps a more international attention will help persuade them that we have need of effective research facilities. The SLOWPOKE reactor has been carrying out extremely high caliber neutron activation analyses of materials (including artifacts) for decades. Their prices are very low and typically the staff provide free advice and even their own time to their clients. This is an international caliber facility which is run on the budget and with the warmth of a family business! Sadly, the closure appears to be going ahead despite sponsors being willing to put up a million dollars to replace the core and revamp the equipment!! Again, this event is imminent. The final decision may be taking place this week! If you would like to express your outrage, or inquire further, please do so ASAP! Contact the University at Toronto at: JRS PRICHARD President, University of Toronto Simcoe Hall, 27 King's College Circle, Room 206 Toronto, Ontario, Canada M5S 1A1 General Inquiry 416-978-4163 President 416-978-2121 FAX 416-971-1360 http://www.utoronto.ca Please send a copy of any correspondence to: RGV Hancock Director, SLOWPOKE Reactor SLOWPOKE Reactor Facility Haultain Building, University of Toronto, Toronto, Ontario, Canada M5S 1A1 General Inquiry 416-978-7129 Thank you. These guys helped me through all three of my degrees, and a great many others too. Ron is also a fundamental participant in the international archaeometry community (incl. helping with the International Archaeometry Symposium and the Archaeometery journal). Cheers, Hugh Jarvis - - - - - - - Hugh Jarvis...hjarvis@acsu.buffalo.edu - - - - - - - - - ...tis better to be silent and thought a fool, than to reply and remove all doubt... (oops!) http://www.acsu.buffalo.edu/~hjarvis - unabashed rampant empiricist & geological opportunist - ========================================================================= Date: Wed, 14 Jan 1998 15:19:52 +1200 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: "PRIOR, CHRISTINE" From: Hugh W. Jarvis (hjarvis) To: ARCH-L@postal.tamu.edu Date: Wednesday 14 January, 1998 10:40 am Subject: Follow-up on SLOWPOKE closing Apparently I have over-emphasised any role the medical school has in the closing of the University of Toronto SLOWPOKE reactor facility. While the medical school may well be the physical recipient of the space the reactor building occupies (but don't quote me on that!), the U of T administration vehemently denies that the medical school expansion is the reason for the closure of SLOWPOKE. So our attacking "the medical school takeover of the facility" is probably just going to make our letters look misinformed or even foolish. Instead, please just address the genral demise of the facility. Sorry, but no more specific details are available. Thanks!! Hugh Jarvis Anthropology Dept University at Buffalo - - - - - - - Hugh Jarvis...hjarvis@acsu.buffalo.edu - - - - - - - - - ...tis better to be silent and thought a fool, than to reply and remove all doubt... (oops!) http://www.acsu.buffalo.edu/~hjarvis - unabashed rampant empiricist & geological opportunist - ========================================================================= Date: Wed, 14 Jan 1998 00:39:35 -0600 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Brian Haskell Subject: Exploding bulk sediment organic samples In-Reply-To: <9801141524.44bc2fc6.GNS@wpo.gns.cri.nz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Our lab receives a number of samples to date organic matter in bulk sediment (for lack of anything else). The samples all undergo an acid-base-acid pretreatment. We add a combination of copper oxide, copper metal, and silver, and combust the carbon in a sealed quartz tube in an oven at 800'C. Normally there are no problems. Recently I received some lacustrine sediments with relatively low (0.4 wt %, probably less after leaching the humic acids) organic carbon, and used 400 mg subsamples for the combustion. All three samples literally blew up, one by one, in the oven. This has happened to us before, with sediments from another lake, and once with some marine sediments. In all cases we had to use relatively large subsamples to get the desired amount of carbon. What I don't understand is what is causing these samples to blow up. The samples are all pumped down adequately, and if all they contain is small amounts of carbon plus supposedly inert material then I would not expect them to behave any differently from higher organic samples. The only other factor I have considered is that the lake samples had relatively high (15 - 20 %) biogenic silica which might have released water upon being heated, but then so does organic carbon when you burn it. I suppose clays might also release some water. Has anybody else experienced problems along these lines, and if so, how did you overcome them? I tried using a larger diameter tube, but that did not help the most recent batch. I don't want to use smaller amounts in several tubes as that will introduce more error/contamination in the final combined gas sample. Thanks, Brian Haskell -- _/ _/_/_/ _/_/ Dr. Brian J. Haskell Tel:(612) 624-7005 _/ _/ _/ _/ _/ Limnological Research Center Tel:(612) 378-3242 _/ _/_/_/ _/ University of Minnesota Fax:(612) 625-3819 _/ _/ _/ _/ _/ 310 Pillsbury Drive. S.E. http://lrc.geo.umn _/_/_/ _/ _/ _/_/ Minneapolis, MN 55455-0219 .edu/people/haskell ========================================================================= Date: Wed, 14 Jan 1998 09:20:09 -0700 Reply-To: along@geo.Arizona.EDU Sender: Radiocarbon Mailing List From: Austin Long Organization: Geosciences / University of Arizona Subject: Re: Summary: AMS dating of pollen MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit You might also check out Long et al (1992) "Separation and dating of pure pollen from lake sediments: nanofossil AMS dating" Radiocarbon vol 34, p557-560. Austin Long Alwynne Beaudoin wrote: > Greetings! > A few weeks ago, I posted an enquiry to this list, requesting > information on AMS dating of pollen. I received a number of helpful replies > off-list. Since then, I have received several requests for the information I > received. > Accordingly, since I feel that this may be of general interest, I have > combined three of the lengthiest replies into this summary message, which I > am reposting back to the list. The messages are reposted here with the > permission of the senders. > I am grateful to everyone who took the time and trouble to respond to > my query. > I trust that this information is useful to others. > Best regards, > Alwynne > > >From Eric Grimm > > >I suggest you get a hold of the following dissertation: > > > >Brown, Thomas Alexander. 1994. Radiocarbon dating of pollen by accelerator > >mass spectrometry. Ph.D. Dissertation. University of Washington, Seattle. > > > >As far as I know Brown was the person who developed this technique. However, > >after reading the thesis, I am rather disenchanted about the prospect of > >routinely dating pollen, at least by his methods. Basically, he treats the > >sample as you would for pollen preparation, then sieves the material to end > >up with a concentrate of pollen-sized stuff. The problem is that, depending > >on the sediment, this stuff can include a lot of non-pollen. > > > >For our Great Plains sites we've been having good luck dating charcoal. We > >sieve ths sample as for macrofossils, then pick out small pieces of > >charcaol, typically less than 1 mm in length. We'll sometimes pick out > >50-100 pieces for a date. > > > >Cheers, Eric > > > > > >******************************************************************* > >Dr. Eric C. Grimm Office: 217-785-4846 > >Illinois State Museum Database: 217-524-0493 > >Research and Collections Center Fax: 217-785-2857 > >1011 East Ash Street E-mail: grimm@museum.state.il.us > >Springfield, IL 62703 USA 39d,46m,48s N, 89d,38m,34s W > >******************************************************************* > > > > > > >From Christine Prior > > > >Dear Dr Beaudoin, > >I saw your message on the C14-L listserver and, indeed, just about > >everybody I know forwarded me a > >copy ("hey, look Chris, somebody's *finally* interested in your research"). > >For a little over a year now I have been working on an improved method for > >the extraction of pollen from > >sediments for AMS dating. The results I have obtained so far were > >presented as a poster at the 16th > >International Radiocarbon Conference in Groningen last June. > > > >I have been working with Prof. John Flenley from Massey University. > >Basically, the method I am > >working on is a modification of his published techniques (Forster R.M. and > >Flenley, J.R. (1993) "Pollen > >purification and fractionation by equilibrium density gradient > >centrifugation" _Palynology_ 17:137-155). > >I have been using conventional pollen lab methods (KOH, Na4P2O7, HF) up to > >the point at which you > >might normally do acetolysis. Instead of acetolysis, I used Sodium > >Polytungstate and performed a > >series of density separations using solutions of decreasing sp.gr. from 1.4 > >to 1.2 to separate the > >pollen/spores from the other organic fragments. I had to do a lot of > >fiddling to adjust the specific gravity > >of the SPT until I could get the pollen to stay in the supernatant while > >the other organics sank, but I > >finally managed to get a fairly clean, almost pure pollen fraction which I > >then AMS dated. The results > >were fairly encouraging: the pollen-only dates matched almost exactly with > >the previously-obtained > >bulk carbon dates from the same level. That reassured me that I hadn't > >introduced any contaminants > >with the treatment procedure. > > > >Using some form of density separation seems to be the technique-of-choice > >in the current literature. > >(c.f. Eriksson, et.al. (1996) "An improved method for preparing a pollen > >concentrate suitable for 14C > >dating" _Grana_ 35:47-50 or Zhou, Donahue & Jull (1997) "Radiocarbon > >AMS dating of pollen > >concentrated from eolian sediments: implications for monsoon climate change > >since the late > >Quaternary" _Radiocarbon_ 39(1):19-26.) > >I plan to continue my work in the technique, but I have been very please > >with the results that Sodium > >Polytungstate gave and will continue to use it rather than the other heavy > >liquids cited in the literature. > >I think there might be reasons why pollen might be the most appropriate > >material for dating from some > >sediments. Right now, I have only dated the entire pollen concentrate. > >There is some reason to think > >that with appropriate adjustment of the densities (perhaps the creation of > >a gradient in the centrifuge > >tube) it might be possible to separate and obtain AMS dates on individual > >taxa. > > > >If you or your contact wishes to discuss any further details concerning > >pollen dating, please feel free to > >contact me. Depending upon the nature of the samples, the pollen density > >per gram of sediment, and > >what Prof Flenely says about the samples I am doing so far for him, I > >suppose I could tentatively state > >that the Rafter AMS lab is in a position to offer pollen extraction and > >dating as a service. But I think > >some discussion about the samples, the deposit, extraneous organics, etc. > >would be in order before > >any such undertaking. > > > >I hope you receive a satisfactory response to your listserver inquiry. > >Please do not hesitate to contact > >me if you have any additional questions about the project I did. > > > >Best wishes, > >Chris Prior > > > >*********************************************************** > >Christine A. Prior, Ph.D. > >Rafter Radiocarbon Laboratory > >Inst. of Geological & Nuclear Sciences > >30 Gracefield Road, P.O. Box 31--312 > >Lower Hutt, NEW ZEALAND > >tel: +64--4--570--4634 fax: +64--4--570--4657 > >e--mail: C.Prior@gns.cri.nz > >URL: http://www.gns.cri.nz/nuclear/c14/rr_lab1.htm > >************************************************************ > > From: Brian Haskell > > >We have done pollen dating in our target preparation laboratory (African > >lake sediments). Most of the pollen preparation was done by a graduate > >student who has now left us, but she trained a very good undergraduate > >technician (Jim Baldrica). I can ask him if he would be able to undertake > >the pollen preparation. The sample is then prepared for AMS dating in our > >laboratory using normal procedures for organic material. The pollen > >concentration procedure used is similar to that used for pollen counting, > >but there are a number of modifications. You do end up with a bulk pollen > >sample, and there are some sediment (not procedural) contamination > >possibilities. If you are in an area with lignite then that will be > >incorporated into the sample, and possibly some resistant algal material. > >This really depends upon the setting in which you are working. We have an > >instrument that would allow us to pick out some undesirable material, but > >that adds signinficantly (and sometimes prohibitively) to the time. > >Pollen dating isn't as good as finding a nice chunk of wood, but it is > >certainly better than doing bulk organics, and your decision is based upon > >how much you want to know how old your sediment is. Unless you have > >serious contamination I would guess that you probably wouldn't be off more > >than a couple of hundred years, and in some lakes you may have NO idea of > >sediment age and any date is better than pure guessing. > > > >Pricing and timing depend upon how many samples you have, when we get > >them, and to whom we send the graphite for analysis. Currently our > >turn-around for organic material is a few months (most of that being the > >delay at the AMS labs). Several pollen samples can be prepared at once, > >making that somewhat cheaper. I would have to consult with Jim and our > >lab manager (Dawn Graber) before quoting a price, but I would hazard a > >guess at $US 50 per sample for pollen preparation, plus our normal AMS > >dating charges (minus sample pre-preparation charges). That is > >lab-dependent but would be around $300 per sample (includes the actual AMS > >analysis). Check our webpage at: http://lrc.geology.umn.edu/services/AMS > >for details about the normal dating. > > > >Please contact me if you have any questions. > > > >Cheers, > > > >Brian Haskell > > > >-- > > _/ _/_/_/ _/_/ Dr. Brian J. Haskell Tel:(612) 624-7005 > > _/ _/ _/ _/ _/ Limnological Research Center Tel:(612) 378-3242 > > _/ _/_/_/ _/ University of Minnesota Fax:(612) 625-3819 > > _/ _/ _/ _/ _/ 310 Pillsbury Drive. S.E. http://lrc.geo.umn > >_/_/_/ _/ _/ _/_/ Minneapolis, MN 55455-0219 .edu/people/haskell > > > Alwynne B. Beaudoin PhD, Archaeological Survey, Provincial Museum of Alberta > 12845-102nd Avenue, Edmonton, Alberta, T5N 0M6, Canada > E-mail: abeaudoi@gpu.srv.ualberta.ca ========================================================================= Date: Thu, 15 Jan 1998 13:41:04 +0000 Reply-To: jchartra@bournemouth.ac.uk Sender: Radiocarbon Mailing List From: "Jeffrey A. Chartrand" Organization: ConSci Bournemouth University Subject: Funding for Archaeological Science PhD Comments: To: Arch-l , britarch , ARCHCOMP-L MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="------------2B1DC1AA1CE8405BC093C18A" This is a multi-part message in MIME format. --------------2B1DC1AA1CE8405BC093C18A Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Appologies for Cross Posting - Please forward..... Applications are invited for a PhD Studentship in Archaeological Sciences at School of Conservation Sciences, Bournemouth University, UK. Any Project which can be supported by the facilities of the School will be considered but work in the following areas will be encouraged: Analysis of ancient artifacts Conservation of archaeological materials Osteoarchaeology Forensic Archaeology More details of the Studentship may be found on our web pages: http://csweb.bournemouth.ac.uk/consci/text/awards.htm (Studentships) http://csweb.bournemouth.ac.uk/consci/text/archgrp.htm (Archaeology Department Home Page) http://csweb.bournemouth.ac.uk/consci/text/ (School Home Page) Closing Date for Studentship is January 30th 1998 --------------2B1DC1AA1CE8405BC093C18A Content-Type: text/x-vcard; charset=us-ascii; name="vcard.vcf" Content-Transfer-Encoding: 7bit Content-Description: Card for Jeffrey A H Chartrand Content-Disposition: attachment; filename="vcard.vcf" begin: vcard fn: Jeffrey A H Chartrand n: Chartrand;Jeffrey A H org: School of Con Sci Bmth University email;internet: jchartra@bournemouth.ac.uk title: GIS Research Fellow x-mozilla-cpt: ;0 x-mozilla-html: TRUE version: 2.1 end: vcard --------------2B1DC1AA1CE8405BC093C18A-- ========================================================================= Date: Fri, 23 Jan 1998 10:36:17 -0500 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: James Martin Subject: AMS facility in NY In-Reply-To: <19971218112939.00170@packrat> MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII I've received an inquiry about New York labs equipped for AMS dating of historic textiles. Suggestions will be appreciated. James Martin Williamstown Center ========================================================================= Date: Wed, 28 Jan 1998 17:30:09 -0500 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: "Campbell, Ian" Subject: postdocs available MIME-Version: 1.0 Content-Type: text/plain Postdoctoral Fellowships available Two postdoctoral fellowships are expected to become available starting April 1, 1998 (contingent on funding approval). These positions will be held at the Canadian Forest Service offices and at the University of Alberta in Edmonton. Both positions will be involved with aspects of carbon cycling and budgets in forests, lakes, wetlands, and the forest-wetland-lake interfaces. Candidates should possess a basic understanding of the plant ecology of the boreal forest, wetlands, and/or lakes, as well an understanding of sedimentation processes and Holocene climate history (in one of the two positions). Some computer programming skill is desirable, preferably (but not necessarily) including experience with Visual C++. Familiarity with GIS an asset. Both positions will primarily involve modeling; little or no field work is anticipated. Candidates should also have a strong and proven commitment to publication of their results. While Canadian Citizens will be given preference, others will also be considered. These positions are to be funded by the Network of Centres of Excellence in Sustainable Forest Management, and remuneration is expected to be ca. $35,000 per annum. These positions are at present for one year only, but with the possibility of renewal for a second year. Applicants are asked to send a detailed academic CV and the names, addresses, telephone numbers and e-mail address of three referees to: Ian D. Campbell Canadian Forest Service 5320-122 St., Edmonton, AB T6H 3C8 Canada. Tel: (403)-435-7300 Fax: (403)-435-7359 e-mail: icampbel @nrcan.gc.ca ____________________________ Ian Campbell Canadian Forest Service 5320-122 St. Edmonton Alberta, T6H 3S5 Canada tel: 403-435-7300 fax: 403-435=7359 e-mail: icampbel@nrcan.gc.ca and Associate Editor, Palaeontologia Electronica http://www-odp.tamu.edu/paleo/1998_1/cover1.htm