pp. 1 – 2
1. "DOLOMITIZATION" RECONSIDERED
pp. 3 – 23
What diagenesis? – Models of "dolomitization" –
High–temperature syntheses – Replacement – Laboratory
evidence – Huntite and norsethite – Solid state diffusion
– Microtextures – Discussion.
In this first chapter the process known as "dolomitization"
is being reconsidered. It is shown, that it is a historical
misunderstanding to believe, that at room temperature and under
atmospheric pressure calcium carbonate will ever react with magnesium
in solution to give dolomite.
2. SOLID SOLUTION OR SUPERLATTICE ?
pp. 24 – 54
Mixed crystals – Structural chemistry – X–
Ray analysis – Diffraction signal – Stacking faults–
Stoichiometry – Magnesium calcites – Calcite, aragonite and
dolomite – Discussion.
The phase relations in the system of the anhydrous carbonate CaCO3
and MgCO3 are discussed in chapter 2. It is concluded on the basis
of a variety of physicochemical considerations, that the magnesium cation is
far too different from the calcium cation to allow for any solid solutions.
Mixed crystals between CaCO3 and MgCO3 consist of
stacking sequences (as in the Mg calcites) or of superlattices (as in dolomite
3. NEODOLOMITE RE–EXAMINED
pp. 55 – 74
The precursor – Superstructure reflections – Degree of order
– Formation of superlattices – Exsolution – Phase
relations – Disordered dolomite? – Discussion.
At times the suggestion is being made, that a phase described as "
protodolomite" (originally: "neodolomite") must be the
precursor to dolomite sensu stricto. However the structural chemistry
of "protodolomite" is identical with that of a magnesium calcite.
Moreover the suggested conversion of "protodolomite" into true
dolomite has never been observed to take place under conditions of room
temperature & atmospheric pressure.
4. REGIONAL ASPECTS
pp. 75 – 160
Introduction – Afghanistan – Australia – Austria
– Bahamas – Belize – Bonaire – Botswana –
Brazil – Canada – Chad – Colombia – Denmark
– France – Germany – Ghana – Greece –
Hungary – India – Indonesia – Israel – Italy
– Jamaica – Japan – Libya – Mexico –
Netherlands – Pacific atolls – Persian Gulf – Russia
– Spain – Tanzania – Tunisia – Turkey –
United Kingdom – United States – Dolomite in deep–sea
sediments – Dolomite in caves – Discussion.
As will be demonstrated in Chapter 4 on the regional aspects of dolomite
formation, there is a bewildering mass of indications as to the possible
significance of fluctuations in the low–temperature formation of
dolomite. Additional evidence was found in "static controls":
in those environments lacking any marked fluctuations no dolomite was
found. Mere deduction leads to the conclusion, that all it takes to form
dolomite in the sedimentary environment is some form of fluctuation. With
this observation in mind almost all of the known local parageneses of modern
dolomite are being reviewed.
5. ORGANIC OR INORGANIC ?
Introduction – Dolomite in reefs – Dolomite in peat and coal
– Dolomite in dogs – Dolomite in pearls – Dolomite and
algae – Dolomite and bacteria – Discussion.
In Chapter 5 the question concerning an organic or inorganic origin of
dolomite will be considered. For numerous indications are known, pointing
in the direction of active participation of for example algae or of
bacteria in the low–temperature formation of dolomite.
6. MAGNESITE AND HUNTITE
pp. 188 – 212
A. Magnesite: Introduction – Syntheses of magnesite –
Occurrences of Recent magnesite – Amorphous magnesium carbonate
– Hydrated magnesium carbonates – Dehydration barrier –
Magnesia alba and hydromagnesite
B. Huntite: Introduction – Recent deposits of huntite.
In Chapter 6 almost all occurrences of modern magnesite are being reviewed,
and speculations are offered concerning the possible dehydration of
magnesium cations. In addition most of the information on the formation
of huntite in the sedimentary environment is discussed.
7. DOLOMITE SYNTHESES
pp. 213 – 275
General remarks – Irreproducible results – Scheerer´s
experiment – Experiment by Pfaff – Experiments by Linck –
Leitmeier´s experiments – Experiments of Lalou –
Experiments of Zeller, Saunders & Siegel – Erenburg´s
experiments – Budzinski´s experiment – Experiments by
Oppenheimer & Master – Liebermann´s experiments –
Experiments by Glover & Sippel – Experiment by Donahue &
Donahue – McCunn´s experiments – Experiments by Mirsal
& Zankl – Deelman´s experiments.
In Chapter 7 all of the known dolomite syntheses, that is to say all of the
known claims on the low–temperature synthesis of dolomite, are not only
being discussed, but also the duplications carried out are being described.
8. MECHANISM OF DOLOMITE FORMATION
pp. 276 – 327
Nucleation and statistics – Stability and metastability –
Breaking Ostwald´s Rule – Reversible or irreversible ?
– Formation of magnesite – Dolomite formation –
Replacement ? – Looking back (and forward).
The last chapter centres on the principle of "Breaking Ostwald
´s Rule", i.e., the way in which fluctuations are capable of
changing the precipitation of mainly the metastable phase into
precipitation of mainly the stable phase.
pp. 328– 364
In the main text of each chapter notes are indicated by superscript numerals.
A – D
pp. 365 – 390
E – K pp. 391 – 424
L – R pp. 425 – 458
S – Z pp. 459 – 483
A TRIBUTE TO OTTO LIEBERMANN
pp. 484 – 485
TABLE II pp. 486 – 493
THE LIFE AND TIMES OF DÉODAT DE DOLOMIEU pp. 494 – 515
*) LOW-TEMPERATURE NUCLEATION OF MAGNESITE AND DOLOMITE, Neues Jahrbuch für Mineralogie, Monatshefte, Jg.1999, pp.289–302.
**) LOW-TEMPERATURE SYNTHESIS OF EITELITE, Na2CO3·MgCO3, Neues Jahrbuch für Mineralogie, Monatshefte, Jg.1984, pp.468–480.
|Contact the author at:||J.C.Deelman@demon.nl|