Dear Istvan,
  The vertical delta 18O profile of lakes can be influenced  by many
phenomena which relate to  sources, seasonally dependent processes (
evaporation, ice cover formation, turnover), and extent of mixing. There may
be subsurface inputs at different levels. Surface stream inputs may slip
under or over the surface of lake waters dependent upon relative densities
if there is non turbulent flow. Water flow is lamellar. In the absence of
turbulence, two waters can flow adjacent to each other vertically and
horizontally over long distances with very slow lateral mixing. Some lakes
have bee  stratified for very long periods of time with perhaps more saline
bottom waters and fresher overlying waters (especially if there is ice
cover).  Some lakes are stratified for part of the year and then undergo
turnover. My colleagues and I have published on some of the above phenomena.
Is your question a general one or is it related to a specific process? ( You
mentioned surface evaporation).
  Roy Krouse

  ----- Original Message -----
  From: "Forizs Istvan" <[log in to unmask]>
  To: <[log in to unmask]>
  Sent: Wednesday, April 27, 2005 12:21 AM
  Subject: lake d18O profile


  > Dear Listmembers,
  >
  > could any of you tell me a publication about the vertical d18O profile
  > of lake water (if there is any)?
  > I think that during strong evaporation the uppermost warm water layer is
  > enriched in 18O, but I do not know any published data.
  >
  > Best regards
  > Istvan Forizs
  >
  >
  > --

 > -------------------------------------------------------------------------
  > Dr. FÓRIZS István ......... Istvan FORIZS Ph.D.
  > Magyar Tudományos Akadémia, Geokémiai Kutatóintézet
  > Institute for Geochemical Research, Hungarian Academy of Sciences
  > Cím/Address: H-1112 Budapest, Budaörsi út 45.   Hungary
  > Tel./Phone: (36-1)-309-2600/ mellék/extension 1151
  > Fax: (36-1)-319-3137
  > Http://www.geokemia.hu/people/forizs_hu.html

 > -------------------------------------------------------------------------
  >


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