Re: Pitman's Miller Time


<richardalanforrest@xxxxxxxxxxxxxx> wrote in message
news:1183202279.439960.302340@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
| On 30 Jun, 11:45, Ernest Major <{$t...@xxxxxxxxxxxxxxxxx> wrote:
| > In message <1183180942.461680.177...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
| > Seanpit <seanpitnos...@xxxxxxxxxxxxxxxxxxxxxxxxxxx> writes
| >
| >
| >
| > >On Jun 29, 4:25 pm, Ernest Major <{$t...@xxxxxxxxxxxxxxxxx> wrote:
| >
| > >> >How thick do you think that the chalk beds of southern and eastern
| > >> >England and the southern North Sea basin are?
| >
| > >> As Dr. Pitman doesn't seem to be addressing this point ...
| >
| > >> Figures for the total thickness of the Chalk in England include 500m
in
| > >> the Isle of Wight, 300m at Portsdown, 440m in north Norfolk and 415m
on
| > >> the Yorkshire coast (rounded from figures in Anderton et al, A
Dynamic
| > >> Stratigraphy of the British Isles). (Over in Ulster it's only 50m,
but
| > >> it approaches 900m in the English North Sea.)
| >
| > >> Elsewhere I find quoted thicknesses of over 2500m for parts of the
| > >> Netherlands North Sea, for a band across northern Denmark (and I
think
| > >> for the Munster Basin in Germany as well), but these figures include
| > >> redeposited chalk from adjacent shallower areas.
| >
| > >> >Where do you think your hypothetical algal blooms got all that
Calcium
| > >> >Carbonate from? (When we talk of the Chalk Sea we don't mean that
the
| > >> >sea was composed of chalk, rather than water.)
| >
| > >> So lets take 1000m as an estimate of the amount of thickness of Chalk
to
| > >> be explained.
| >
| > >> Calcium Carbonate is about 0.1% by mass of sea water. Chalk is about
2.5
| > >> times as dense as water. (Less dense than much other Calcium
Carbonate.)
| > >> So to produce 1000m of chalk we need to extract the Calcium Carbonate
| > >> from a column of water 2.5 million meters deep, that's 2500
kilometers
| > >> (Noah's flood was a minnow by comparison), or produce the Chalk
| > >> sufficiently slowly that the Calcium Carbonate in the photic zone
(40m)
| > >> can be replenished.
| >
| > >Sure, if you were to assume present day concentrations of calcium
| > >carbonate. If one assumes a balanced steady-state model, it does
| > >appear that at present the slow input of calcium carbonate into the
| > >oceans from rivers, etc., may be a major limiting factor in carbonate
| > >skeletal production and preservation in the ocean. The question here
| > >though is what would happen to all of these numbers during and after a
| > >huge worldwide catastrophe that includes massive floods, huge
| > >volcanoes, large-scale organic decay, and warm oceans/seas?
| >
| > <McEnroe>
| > You CAN NOT be serious.
| > </McEnroe>
| >
| > You can only increase the Calcium Carbonate concentration of sea water
| > by so much; water does not have an infinite capacity for the dissolution
| > of Calcium Carbonate. Perhaps you can cut the depth of the water column
| > required to 1000 km, rather than 2500 km, but you're postulating a water
| > column that's more chalk than water.
| >
|
| It's worth noting that the biological activity which converts the
| calcium carbonate in sea water into the shells of the microorganisms
| which make up the chalk can only occur in the photic zone, which is
| the few meters of sea closest to the surface. It's rather limiting -
| after all, if there is a greater concentration of living organisms
| they cut out the light and *reduce* the depth of the photic zone. So
| it doesn't matter if the water column is 1000km or 10 meters deep, the
| rate of calcium conversion is the same.

Well I think it's more than a few meters in most places. I believe the
photic zone is defined as above the 1% light level. That can be very deep
absent bloom conditions where self shading can significantly cut the light
level and reduce the photic zone depth dramatically.

In my "worst case," I threw out self shading because the Ca flux issue will
still be too low to account for the mass of CaCO3 in a few thousand years.
The {Ca}and pCO2 will be lowered to near zero during a bloom, as hopefully
Sean realizes, so it's the flux of these constituents (plus all the other
cellular constituents including notably N and P) into the vicinity that can
be most easily seen as negating a few thousand year scenario of the chalk
formations.

sharon

.

Relevant Pages

  • Re: Pitmans Miller Time
    ... ||>>> sufficiently slowly that the Calcium Carbonate in the photic zone ... ||> You can only increase the Calcium Carbonate concentration of sea water ... Perhaps you can cut the depth of the water column ...
    (talk.origins)
  • Re: Pitmans Miller Time
    ... The formation of the chalk layers in the ... |>England and the southern North Sea basin are? ... assume sufficient light levels the entire depth of the water column) ... | So to produce 1000m of chalk we need to extract the Calcium Carbonate ...
    (talk.origins)
  • Re: Pitmans Miller Time
    ... produced very thick chalk layers in very short order. ... How thick do you think that the chalk beds of southern and eastern England and the southern North Sea basin are? ... Calcium Carbonate is about 0.1% by mass of sea water. ...
    (talk.origins)
  • Re: Pitmans Miller Time
    ... |>>I have looked into the formation of chalk formations. ... assume sufficient light levels the entire depth of the water column) ... | So to produce 1000m of chalk we need to extract the Calcium Carbonate ...
    (talk.origins)
  • Homebrew Digest #5492 (February 01, 2009)
    ... TODAY'S HOME BREW DIGEST BROUGHT TO YOU BY: ... How much increase in alkalinity as CaCO3 should 1ppm CaCO3 cause? ... A few weeks back I decided to write another brewing water calculation ... showing an imbalance when chalk was used. ...
    (rec.crafts.brewing)