========================================================================= Date: Tue, 6 May 1997 17:49:10 +0900 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Koji Okumura Subject: parchment dating MIME-Version: 1.0 Content-Type: text/plain; charset=iso-2022-jp Dear 14C folks: My friend philologist wishes to have Medieval parchment dated with AMS. We'd need practical advice on the dating. 1. How much sample is necessary? --The parchment weighs at 10 to 15 mg/sq cm, and wasting a couple of sq cm of about 500 sq cm sheet will be too much to bear. 2. How can the amount of sample be the least? --It's pretty precious. 3. What kind of contaminant will affect the date? --Is that crucial for the date? Thanks in advance. ---------------------------------------------------------- Koji Okumura, Department of Geography Hiroshima University, Higashi-Hiroshima, 739, JAPAN Fax: +81-824-240320, Phone: +81-824-246657 ***** http://www.ipc.hiroshima-u.ac.jp/~kojiok/ ***** ========================================================== ========================================================================= Date: Tue, 6 May 1997 09:33:42 -0700 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Timothy Jull Subject: Re: parchment dating In-Reply-To: <199705060842.RAA28855@ue.ipc.hiroshima-u.ac.jp> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear Dr. Okumura, I think we can measure your sample on perhaps 0.3sq cm (5mm x 5mm) if the sample is in good condition. We need 5-10mg of sample. We clean the sample to remove contaminants. The only problem will be if the parchment is not well preserved and has a lot of degradation of the material. Then, its harder to clean well. We can do this measurement for you if we can get a small piece of the sample. We usually charge $400 to academic institutes, $500 commercial for a measurement. Best wishes, Tim Jull -------------------------------------------------------------- A. J. Timothy Jull tel. (520) 621-6816 NSF Arizona AMS Facility, fax. (520) 621-9619 Physics Building, University of Arizona, Tucson, AZ 85721 University of Arizona AMS Lab Web-Page: http://www.physics.arizona.edu/ams/www1.html ========================================================================= Date: Wed, 7 May 1997 08:30:35 +1200 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: "SPARKS, RODGER" Subject: parchment dating - Reply Dating your parchment is certainly a possibility. We will fax you further details. ========================================================================= Date: Thu, 8 May 1997 08:45:54 -0700 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: David Sewell Subject: Cosmic ray flux and global cloud cover (fwd) Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit [I am forwarding this to C14-L at the request of the author, Dr. Bas van Geel. He is not subscribed to C14-L, so if you reply to the list, you might want to Cc him a courtesy copy. --DS] Dear colleagues, You may have heard about the new (popular-science) book by Nigel Calder. Its title is "The Magic Sun". Calder brings in discussion the role of CO2 as a greenhouse gas: the rise of the atmospheric content of carbon dioxide possibly is less important as a factor for climate change than most of us believed up to now. The studies of the three Danish scientists Svensmark, Friis-Christensen and Lassen (meteorologists-physicists) play an essential role in Calder's book. It is my opinion that Calder too much emphasised scientific controversies, but that is maybe what we can expect in the work of a journalist. It is not my intention to start a discussion about the argumentation in Calder's book. But the scientific background is very interesting and should come on the foreground: the following recent article is worth while reading for all of you that are interested in climate change in the past and the future: Svensmark, H. and Friis-Christensen, E. (1997) Variation of cosmic ray flux and global cloud coverage - a missing link in solar-climate relationships. Journal of Atmospheric and Solar-Terrestrial Physics 59:1225-1232. In search of a physical mechanism that could account for reported correlations between solar activity parameters and climate, Svensmark & Friis-Christensen investigated the global cloud cover observed by satellites. Their study revealed that cosmic radiation plays a dominant role in cloud formation. That may also explain the observed parallel between increases of delta 14C (former 14C-content of the atmosphere) in the past, and rising water levels in lakes (Magny 1993a,b), bogs (Kilian et al., 1995) and soils (van Geel et al., 1996). Changing solar activity may be the forcing mechanism behind the observed changes because during periods of reduced solar activity the earth's magnetic field is weaker and more cosmic rays can reach the atmosphere. It is hypothesized that this radiation stimulates cloud formation and precipitation, and at the same time causes increased 14C production (14C is formed in the atmosphere by the interaction of cosmic rays with nitrogen). The variation in solar activity is relatively small, so that for some time it was considered as being too small to be a factor in climate change. The study by Svensmark and Friis-Christensen probably indicates the existence of a very effective amplifying mechanism for climate forcing, because the energy needed to change cloudiness is small compared with the resulting changes in solar radiation received at the Earth's surface! Best wishes, Bas van Geel --------------------- references: Kilian, M.R., van der Plicht, J. and van Geel, B. (1995) Dating raised bogs: new aspects of AMS 14C wiggle matching, a reservoir effect and climatic change, Quaternary Science Reviews 14, 959-966. Magny, M. (1993a) Solar influences on Holocene climatic changes illustrated by correlations between past lake-level fluctuations and the atmospheric 14C record, Quaternary Research 40, 1-9. Magny, M. (1993b) Un cadre climatique pour les habitats lacustres préhistoriques?, Compte Rendu de l'Académie des Sciences Paris 316, Série II, 1619-1625. van Geel, B., Buurman, J. and Waterbolk, H.T. (1996) Archaeological and palaeoecological indications of an abrupt climate change in The Netherlands, and evidence for climatological teleconnections around 2650 BP. Journal of Quaternary Science 11, 451-460. +--------------------------+-------------------------------------+ | 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 May 1997 02:54:28 -0400 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: "David S. Farrier" Subject: Excel-based Automated LSC Data Analysis Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List Members, I thought it might be of interest to those who might be looking for an easy LIMS-type managment of their LSC data to take a look at Metabase at my web site at http:/www.bright.net/~dfarrier Metabase is an automated, Excel-based software tool for collection, management, databasing, calculation and reporting of LSC and associated sample processing data. The program was initially designed to handle discrete radio-labeled tracer studies for pharmaceutical or environmental-type studies. However, it can readily be adapted to other purposes. Should this be of interest, a full description and demo copy of Metabase can obtained at the indicated web site. I'd be glad to respond to any questions. Thanks, David Dr. David S. Farrier Summit Research Services 1374 Hillcrest Drive Ashland, OH 44805 USA Telephone: (419)-289-9207 E-mail: dfarrier@bright.net Internet: http://www.bright.net/~dfarrier ========================================================================= Date: Thu, 15 May 1997 10:02:49 -0700 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: Billie Young Subject: Re: parchment dating Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" I am sorry this is not my email. you have the wrong address. please do not send anymore mail to this address. thank you. >Dear 14C folks: > >My friend philologist wishes to have Medieval parchment >dated with AMS. We'd need practical advice on the dating. > >1. How much sample is necessary? > --The parchment weighs at 10 to 15 mg/sq cm, > and wasting a couple of sq cm of about 500 > sq cm sheet will be too much to bear. > >2. How can the amount of sample be the least? > --It's pretty precious. > >3. What kind of contaminant will affect the date? > --Is that crucial for the date? > >Thanks in advance. > > > > > > > > ---------------------------------------------------------- > Koji Okumura, Department of Geography > Hiroshima University, Higashi-Hiroshima, 739, JAPAN > Fax: +81-824-240320, Phone: +81-824-246657 > ***** http://www.ipc.hiroshima-u.ac.jp/~kojiok/ ***** > ========================================================== > > ========================================================================= Date: Fri, 30 May 1997 11:06:53 -0700 Reply-To: duPree@ogp.noaa.gov Sender: Radiocarbon Mailing List From: David Sewell Subject: NOAA Grants for Paleoclimatology, Carbon Cycle research Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii This will be of interest to people eligible for U.S. government grant funding only. The Climate and Global Change Program of the National Oceanic and Atmospheric Administration (NOAA) has research grants available for the 1998 fiscal year that are applicable to people doing radiocarbon or other isotope work that is connected with global climate models, atmospheric chemistry, ocean-land- atmosphere exchange, etc. The deadline for letters of intent has just passed (May 23), but these letters are not obligatory; deadline for full proposals is 15 AUGUST 1997. Of particular interest to C14-L subscribers might be the Ocean-Atmosphere Carbon Exchange Study (OACES) and the Paleoclimatology program. The program announcement is available on the WWW at: http://www.ogp.noaa.gov/C&GC/AO/98ao.html (Note that if you're feeding that URL to a command line on a Unix system you should surround it with "" to escape the '&' symbol.) Or contact Irma DuPree at duPree@ogp.noaa.gov for further information. ========================================================================= Date: Fri, 30 May 1997 17:14:52 -0400 Reply-To: Radiocarbon Mailing List Sender: Radiocarbon Mailing List From: "David S. Farrier" Subject: Automating LSC Data Collection Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Dear Colleagues, This may be of interest to researchers looking for a low cost solution to handling LSC data runs. My web site provides a downloadable demo of a LIMs-like Excel software program called METABASE. The program performs the critical functions of collection and databasing of sample processing and LSC data, calculation of results, and user-defined reporting. Because the program is written with VBA in Excel, it can be easily modified to fit specific instruments, workflows, and calculation needs. I'd be pleased to answer any questions. Thanks, David Dr. David S. Farrier Summit Research Services 1374 Hillcrest Drive Ashland, OH 44805 USA Telephone: (419)-289-9207 E-mail: dfarrier@bright.net Internet: http://www.bright.net/~dfarrier