JiscMail Logo
Email discussion lists for the UK Education and Research communities

Help for BRITARCH Archives


BRITARCH Archives

BRITARCH Archives


BRITARCH@JISCMAIL.AC.UK


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

BRITARCH Home

BRITARCH Home

BRITARCH  December 2001

BRITARCH December 2001

Options

Subscribe or Unsubscribe

Subscribe or Unsubscribe

Log In

Log In

Get Password

Get Password

Subject:

Re: EH welcomes new UK industrial World

From:

[log in to unmask]

Reply-To:

British archaeology discussion list <[log in to unmask]>

Date:

Mon, 17 Dec 2001 18:12:05 +0000

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (117 lines)

Bea,

Although I agree with you that the Droitwich Springs are 'unique
worldwide' I have to dispute the figures for salt concentrations
that you quote.

You say that the concentration of sodium chloride in the water
at Droitwich is 25.926%, comparing well with:-
> 'The maximum amount of salts (all salts) that can be held in
>solution [which] is 26.395% at 60 degrees F (15.56 degreesC).'

Are you reproducing a regular typo here?  Reference tables
show that a saturated solution of sodium chloride (the 'maximum
amount ...that can be held in solution') at freezing point, 32
degrees F, contains 35.7% w/w salt, rising to 39.2% w/w at
boiling point.  The concentration at '60 degreesF' would be
between these two limits but much higher than the figure quoted
for the Droitwich brine.  The latter indeed represents a very
concentrated solution of sodium chloride (and other salts) but,
on the figures quoted, falls short of being a solution that will not
dissolve further salt(s).

I urge you to check the analytical figures that you have been
using.

Bill White
Museum of London Specialist Services
 ----------
From: [log in to unmask]
To: [log in to unmask]
Subject: Re: EH welcomes new UK industrial World
Date: 17 December 2001 16:54

Paul,
     I'm glad you asked.  Thats exactly the point, the NATURAL brine
springs at Droitwich are unique worldwide.  There are numerous brine
springs everywhere in the world.  What is unusual is a set of phenomena
that combine to produce virtually PURE brine containing only sodium
chloride (which is an important economic aspect in the recovery of salt).
 There are trace elements of one or two minerals that are usually
abundant in most springs, notably calcium carbonate, magnesium, ferric
oxide, sulfates (in volcanic areas)).  The maximum amount of salts (all
salts) that can be held in solution is 26.395% at 60 degrees F (15.56C).
These brine springs contain 25.926% sodium chloride - and that is MOST
UNUSUAL worldwide.  Salt is widely obtained from seawater which contains
2.9% sodium chloride out of a total dissolved solids of 3.7655% (high in
the magnesium and potassium bromides and chlorides). This means that 96%
water has to be evaporated to make salt, achieved more economically by
solar evaporation.  But even then it takes a lot of refining to produce
salt fit for preserving different types of food (let alone its other
uses).

     There are other factors: this brine lies only at 120-150 ft.deep.
Usually this concentration occurs only at greater depths.  When springs
occur close to the surface they are usually diluted with fresh
groundwater and thus become brackish and uneconomic to exploit. This did
not happen at Droitwich.

     Yet another factor was the brine flow.  There are three sites where
brine springs of equal strength occur, but there was a huge difference in
brine flow and only one pit, Upwich, provided 92% of the salt for the
industry there (the other 4 pits/springs together supplied 8%).  Two pits
at one site dried up in the 15th century.  Drought being another factor
which affects brine flow.  These three sites are only within a 1/4 mile
area, yet they differed significantly from the one principle pit.  This
pit is 30 ft.deep
and

      One would think that these conditions in natural springs must occur
somewhere else in the world, but so far in 30 years of searching I have
found none, from China to the Near East or in the New World that
duplicate these conditions.  I am working with several specialists in an
attempt to account for this phenomena and there are two possible theories
we are looking into.  Of course as technology advanced ways were found to
economically produce a pure salt, but even today it costs more to get it
to this stage of Droitwich purity.

Bea



On 12/15/01 11:05 PM Paul Barford writes:

>But then, is Droitwich a monument on a world scale? There are many other
>salt springs in western Europe, many of which have also long been in use
and
>some of continental significance, with authentic remains preserved. How
does
>Droitwich compete with these? To be on the WHL a monument does not simply
>have to be old but fulfil a mass of other criteria as laid down by the
>guidance notes of the Convention (which I understand are currently being
>modified). But you are right that the geology makes it a site which links
>the natural and historical heritage, which the World Heritage Committee
>seems to like at the moment.
>
>Paul Barford
>
>----- Original Message -----
>From: Bea Hopkinson <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Sunday, December 16, 2001 5:10 AM
>Subject: Re: EH welcomes new UK industrial World Heritage Sites
>
>
>> Although I am pleased to read the news below I still find it
extraordinary
>> that an industrial site as ancient as Droitwich has not been
recognized.
>> Not only ancient, but continuously worked and a natural geological
>> phenomena.  Yet not one word by the archaeological community to support
>> this British heritage  unique worldwide.
>>
>> Bea
>[...]>


Beatrice Hopkinson 73071,327@compuserve

Top of Message | Previous Page | Permalink

JiscMail Tools


RSS Feeds and Sharing


Advanced Options


Archives

September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003
December 2002
November 2002
October 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001
September 2001
August 2001
July 2001
June 2001
May 2001
April 2001
March 2001
February 2001
January 2001
December 2000
November 2000
October 2000
September 2000
August 2000
July 2000
June 2000
May 2000
April 2000
March 2000
February 2000
January 2000
December 1999
November 1999
October 1999
September 1999
August 1999
July 1999
June 1999
May 1999
April 1999
March 1999
February 1999
January 1999
December 1998
November 1998
October 1998
September 1998
August 1998
July 1998
June 1998
May 1998


JiscMail is a Jisc service.

View our service policies at https://www.jiscmail.ac.uk/policyandsecurity/ and Jisc's privacy policy at https://www.jisc.ac.uk/website/privacy-notice

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager