Die Tonminerale der Zechsteinformation

Füchtbauer, Hans; Goldschmidt, Heinrich

doi:10.1007/bf01150420

Cited by 20 publications

(10 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, talc has been reported many times. But talc is known to form in unmetamorphosed sediments (see for example FUCHTBAUER and GOLDSCHMIDT, 1959) in which the fugacity of C02 is sufficiently low. The important point is that, in units of favorable composition such.as the Kamoto Quartzose Dolostone, the transformation of dolomite + quartz into calcite -+-talc has obviously not taken place.…”

Section: General Petrological and Geochemical Features Of The Kamoto mentioning

confidence: 99%

Diagenetic Ore-forming Processes at Kamoto, Katanga, Republic of the Congo

et al. 1973

View full text Add to dashboard Cite

At Kamoto and in other Katangan deposits, copper and cobalt occur as sulfides (mostly digenite, chalcocite, bornite and carrollite) in two stratiform orebodies. The host rock is dolostone, chert and shale. There is no metamorphism. Mineralization was emplaced before major tectonic deformation.The two stratiform orebodies are separated by a barren interval. The lower one rests a few feet above an erosional surface which developed over consolidated red dolostone beds completely devoid of sulfides. Above the upper orebody, a sulfide fraction is present, consisting mostly of pyrite with some chalcopyrite.The mineralized sedimentary rocks present some of the features commonly observed in tidal-flat sediments. However, they have undergone a complex sequence of diagenetic transformations. Several authigenic (or partly authigenic) minerals have crystallized: dolomite, perhaps in part from hydromagnesite + CaC03; magnesite, from the remaining hydromagnesite; quartz; chlorite and other phyllosilicates; colorless tourmaline; pyrite; other sulfides: chalcopyrite, bornite, digenite, chalcocite, carrollite, etc ... New evidence is presented to show that this diagenesis took place at first in an environment devoid of copper and cobalt and then proceeded while the metals were brought in from an outside source.The features described may have resulted from a reaction between a hypersaline brine (with high pH and high Eh) flowing through the lower part of the Kamoto Dolostone, and a modified connate water (reducing and less alkaline because of abundant organic matter) present in the upper part.

show abstract

Section: General Petrological and Geochemical Features Of The Kamoto mentioning

confidence: 99%

Diagenetic Ore-forming Processes at Kamoto, Katanga, Republic of the Congo

et al. 1973

View full text Add to dashboard Cite

show abstract

“…Perm 0-Triassie evaporative sediments were first studied by Millot (1949) in the Paris basin, by Jeannette and Lucas (1955) in Morocco, by Füchtbauer and Goldschmidt (1959) in the German Zechstein, and are investigated in detail by Lucas (1962) in France, Spain, and Morocco. J. Lucas observes a correlation between the different clay associations identified and the lithologie, geographie, and stratigraphie distribution of sediments.…”

Section: General Featuresmentioning

confidence: 99%

Clay Sedimentology

Chamley¹

1989

864

449

View full text Add to dashboard Cite

“…Oriented slide specimens were prepared from material passing the 63 gm sieve after sedimentation in accordance with BS 1377 (Anon 1990). Four slides of each sample were prepared and treated in different ways as follows in order to identify kaolinite, chlorite, smectite and illite (Brown 1961;Fuchtbauer & Goldschmidt 1963):…”

Section: Mineralogymentioning

confidence: 99%

Swelling characteristics of Madinah clays

Hossain

Matsah

Sadaqah

1997

QJEGH

View full text Add to dashboard Cite

Six expansive clays from the city of Madinah, Saudi Arabia have been investigated. The expansive nature of these clays is due primarily to the presence of smectite. The basaltic lava around Madinah is considered to be the source of this mineral. Kaolinite and illite also present in these clays are thought to be derived by the alteration of smectite. Calcite occurs only in the 'white clayey silt' and in the 'upper brown clay'. Qualitative estimates using plasticity index and clay fraction data suggest 'low' to 'very high' swell potentials of these clays. Laboratory swell-consolidation tests indicate that for initial liquidity index in the range of -0.91 to +0.32, the percent swell for these clays is 1.02% to 13.2% and the swell pressure range is from 58 kPa to 770 kPa, the higher values of these two parameters being observed for grey-green clays with liquid limit less than 120% and particularly at low moisture contents. The swelling characteristics of expansive clays depends on numerous factors making the prediction of volume change and swell pressure difficult. This paper discusses the use of multi-variate analysis to aid the prediction of these parameters for the Madinah grey-green clays. The progressive lowering of the groundwater table in the Madinah area is likely to promote more severe desiccation of Madinah clays in the future. In view of the high swell potential of Madinah clays, there are important implications in relation to foundation design in Madinah.

show abstract

Die Tonminerale der Zechsteinformation

Cited by 20 publications

References 7 publications

Diagenetic Ore-forming Processes at Kamoto, Katanga, Republic of the Congo

Diagenetic Ore-forming Processes at Kamoto, Katanga, Republic of the Congo

Clay Sedimentology

Swelling characteristics of Madinah clays

Contact Info

Product

Resources

About