scholarly journals Controls on Associations of Clay Minerals in Phanerozoic Evaporite Formations: An Overview

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 974
Author(s):  
Yaroslava Yaremchuk ◽  
Sofiya Hryniv ◽  
Tadeusz Peryt ◽  
Serhiy Vovnyuk ◽  
Fanwei Meng

Information on the associations of clay minerals in Upper Proterozoic and Phanerozoic marine evaporite formations suggests that cyclic changes in the (SO4-rich and Ca-rich) chemical type of seawater during the Phanerozoic could affect the composition of associations of authigenic clay minerals in marine evaporite deposits. The vast majority of evaporite clay minerals are authigenic. The most common are illite, chlorite, smectite and disordered mixed-layer illite-smectite and chlorite-smectite; all the clay minerals are included regardless of their quantity. Corrensite, sepiolite, palygorskite and talc are very unevenly distributed in the Phanerozoic. Other clay minerals (perhaps with the exception of kaolinite) are very rare. Evaporites precipitated during periods of SO4-rich seawater type are characterized by both a greater number and a greater variety of clay minerals—smectite and mixed-layer minerals, as well as Mg-corrensite, palygorskite, sepiolite, and talc, are more common in associations. The composition of clay mineral association in marine evaporites clearly depends on the chemical type of seawater and upon the brine concentration in the evaporite basin. Along with increasing salinity, aggradational transformations of clay minerals lead to the ordering of their structure and, ideally, to a decrease in the number of minerals. In fact, evaporite deposits of higher stages of brine concentration often still contain unstable clay minerals. This is due to the intense simultaneous volcanic activity that brought a significant amount of pyroclastic material into the evaporite basin; intermediate products of its transformation (in the form of swelling minerals) often remained in the deposits of the potassium salt precipitation stage.

2021 ◽  
Vol 1-2 (183-184) ◽  
pp. 110-129
Author(s):  
Аnatoliy Galamay ◽  
Andriy Poberezhskyy ◽  
Sofiya Hryniv ◽  
Serhiy Vovnyuk ◽  
Dariya Sydor ◽  
...  

Studies of evaporites provide new data to characterize the seawater chemistry in the Early Paleozoic and Middle Mesozoic. In particular, we studied the fluid inclusions in halite from Ordovician (China) and Cretaceous (Laos) evaporites. The corresponding sections on the plot of Ca/SO4 oscillations curve in the Phanerozoic seawater are updated. The calcium content in seawater concentrated to halite precipitation stage was 45.6 mol %, 485 million years ago and 24.3 mol % 112.2–93.5 million years ago. By analyzing the previously published and new factual material, it is established that in Permian evaporites the sulfur isotopic composition is inversely correlated with the sulfate ion content in evaporite basin brines. Thus, the evolution of seawater chemistry in Permian is confirmed by the evolution of the isotopic composition of dissolved seawater sulfate. According to the generalization of 38 Phanerozoic marine evaporite formations, it was found that the peculiarities of the clay minerals associations correlate with the change of the seawater chemical type. Clay minerals associations precipitated from the SO4-rich seawater are characterized by a larger set of minerals, among which smectite and mixed-layered minerals often occur; Mg-rich clay minerals (corensite, paligorskite, sepiolite, talc) also occur. Instead, in the associations of evaporite clay minerals formed from the Ca-rich seawater are represented by the smaller amount of minerals, and Mg-rich minerals are extremely rare. The increased content of magnesium in seawater of SO4-rich type is the main factor in the formation of Mg-rich silicates in evaporites. The composition of clay minerals associations depends on the evaporate basin brine concentration; with its increase, unstable minerals are transformed, which theoretically leads to a decrease in the number of minerals in the associations. However, it was found that evaporite deposits of higher stages of brine concentration often still contain unstable clay minerals – products of incomplete transformation of a significant amount of pyroclastic material from coeval volcanic activity. The main factor determining the composition of clay minerals associations of Phanerozoic evaporites was the seawater (and basin brines) chemical type. Geochemical studies of scattered organic matter and fluid inclusions with hydrocarbon phase in evaporites of the Upper Pechora Basin (overlying oil and gas deposits) indicate the presence of allochthonous bitumoids and allow to use this method to predict oil and gas potential of other areas. Analysis of the results of oil and gas exploration in a number of areas of the Transcarpathian Trough indicates the presence of fluid-saturated reservoirs and the prospects for the discovery of new accumulations of hydrocarbons. Geochemical studies proved the effectiveness of gas-flow survey method for oil and gas exploration, assessing the prospects for fluid saturation of seismic structures.


Clay Minerals ◽  
1978 ◽  
Vol 13 (1) ◽  
pp. 67-77 ◽  
Author(s):  
B.-M. Wilke ◽  
U. Schwertmann ◽  
E. Murad

AbstractXRD, DTA and IR patterns showed clay veins filling fissures in a granite of the Bayerischer Wald (eastern Bavaria) to consist mainly of hydrated halloysite of low crystallinity with traces of gibbsite, 2:1 (mixed layer) clay minerals and iron oxides. The halloysite forms thin plates which exhibit varying degrees and types of enrolment, resulting in platy, tubular and spheroidal crystals within the same sample. Concentrations of the trace elements Rb, Sr, Ba, Zr, Y, Ce, Pb, Zn and Cu indicate halloysite formation to have taken place via an aqueous phase under the influence of vadose waters circulating in fissures.


1987 ◽  
Vol 124 (3) ◽  
pp. 261-271 ◽  
Author(s):  
Julian E. Andrews

AbstractClay minerals from Middle Jurassic lagoonal mudrocks, siltstones and silty fine-grained sandstones of the upper Great Estuarine Group (Bathonian) are divided into four assemblages. Assemblage 1, the most common assemblage, is rich in mixed-layer illite–smectite with attendant illite and kaolinite. Assemblage 2 is dominated by smectitic clay. These assemblages are indicative of primary Jurassic deposition. Illite and kaolinite were probably derived from the weathering of older rocks and soils in the basin hinterland and were deposited in the lagoons as river-borne detritus. The majority of smectite and mixed-layer illite–smectite is interpreted as the argillization product of Jurassic volcanic dust, also deposited in the lagoons by rivers. Near major Tertiary igneous intrusions these depositional clay mineral assemblages have been altered. Assemblage 3 contains smectite-poor mixed-layer illite–smectite, whilst Assemblage 4 contains no smectitic clay at all. Destruction of smectite interlayers occurred at relatively shallow burial depths (< 2500 m) due to enhanced geothermal gradients and local convective hot-water circulation cells associated with the major Tertiary igneous intrusions.


Author(s):  
Hongbing Deng ◽  
Yang Wu ◽  
Iqra Shahzadi ◽  
Rong Liu ◽  
Yang Yi ◽  
...  

Clay Minerals ◽  
1970 ◽  
Vol 8 (4) ◽  
pp. 471-477 ◽  
Author(s):  
R. W. Tank ◽  
L. McNeely

AbstractX-ray analyses indicate that chlorite, illite and mixed-layer chloritesmectite are present in the < 2μ fraction of the Precambrian Gowganda Formation near Bruce Mines, Ontario. The mixed-layer material is restricted to the porous graywacke sandstones and is epigenetic in origin. The chlorite and illite are ubiquitous and may reflect high-grade diagenesis, low-grade metamorphism or a source rich in these minerals.


Author(s):  
V. B. Kurnosov ◽  
B. A. Sakharov ◽  
A. R. Geptner ◽  
Yu. I. Konovalov ◽  
E. O. Goncharov

Clay minerals (fraction <0.001 mm) of Upper Pleistocene clayey-sandy-silty sediments recovered by DSDP Holes 481 and 481A in the Northern Trough, Guaymas Basin, Gulf of California, were studied by X-ray based on the modeling of diffraction patterns and their comparison with experimental diffractograms. Terrigenous clay minerals are represented mainly by dioctahedral micaceous varieties (mixed-layer disordered illite-smectites, illite) with the chlorite admixture and by kaolinite in the upper section of unaltered sediments. Intrusion of hot basalt sills (total thickness of the complex is about 27 m) provoked alterations in the phase composition of clay minerals in sediments (7.5 m thick) overlying the sill complex. These sediments include newly formed triooctahedral layered silicates (mixed-layer chlorite-smectites, smectite). Sediments inside the sill complex include trioctahedral mixed-layer mica-smtctite-vermiculite or trioctahedral smectite. The trioctahedral mixed-layer chlorite-smectite coexisting with smectite was found in a single sample of the same complex.


Author(s):  
Henrik Tirsgaard ◽  
Martin Sønderholm

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Tirsgaard, H., & Sønderholm, M. (1997). Lithostratigraphy, sedimentary evolution and sequence stratigraphy of the Upper Proterozoic Lyell Land Group (Eleonore Bay Supergroup) of East and North-East Greenland. Geology of Greenland Survey Bulletin, 178, 1-60. https://doi.org/10.34194/ggub.v179.5076 _______________ The Late Proterozoic Lyell Land Group is an approximately 3 km thick succession of siliciclastic shelf deposits, within the upper part of the Eleonore Bay Supergroup. It is widely exposed in the region between Ardencaple Fjord in the north and Canning Land in the south. In this paper the seven formations named by Sønderholm & Tirsgaard (1993) are formally described. These are from base to top: the Kempe Fjord Formation (400-600 m thick), the Sandertop Formation (200-405 m thick), the Berzelius Bjerg Formation (250-450 m thick), the Kap Alfred Formation (500-640 m thick), the Vibeke Sø Formation (290-325 m thick), the Skjoldungebrae Formation (205-240 m thick) and the Teufelsschloss Formation (35-110 m thick). Five facies associations have been recognised. Outer shelf deposits dominated by dark green, brown to dark red mudstones with thin sandstone lenses are mainly found in the Sandertop, Kap Alfred and Skjoldungebræ Formations. Storm- and wave-dominated inner shelf deposits comprising fine-grained sandstones and dark heterolithic mudstones are common in the Sandertop, Kap Alfred, Vibeke Sø and Skjoldungebrae Formations and are also found in southern outcrops of the Teufelsschloss Formation. Tidally influenced shoreface deposits form stacks of laterally extensive sandstone bodies separated by heterolithic mudstones and are only found in the middle part of the Kap Alfred Formation. Storm- and wave-dominated shoreface deposits comprise highly mature, thick and laterally very extensive sandstone bodies of which a few may be traced for distances exceeding 150 km. This association is present in several intervals within all formations of the Lyell Land Group. Tidally dominated coastal plain deposits consist of stacked sandstone sheets forming laterally extensive, multistorey units separated by heterolithic mudstones and sandstones. These sediments form part of the Kempe Fjord and Berzelius Bjerg Formations and are also found in northern outcrops of the Teufelsschloss Formation. Evidence from palaeocurrent data combined with regional lithological variations suggest a consistent general N-S coastline with the basin deepening in an eastward direction. Deflection of geostrophic currents suggest a palaeolatitude on the southern hemisphere. The deposits of the Lyell Land Group are subdivided into four, large-scale sequences which overall show the same general sedimentary evolution through time reflecting large-scale, cyclic changes in relative sea-level. The sequences vary in thickness from 400-1000 m and are all readily traceable 300 km parallel and 100 km perpendicular to inferred palaeocoastline. The development of all sequences indicates that major regional translation of facies are related to large-scale forced regressions. Sequence stratigraphic considerations suggest that correlation of formations of the Lyell Land Group with units of the Petermann Bjerg Group some 75 km to the west may be very difficult to carry out. Citation: Tirsgaard, H. & Sønderholm, M. 1997: Lithostratigraphy, sedimentary evolution and sequence stratigraphy of the Upper Proterozoic Lyell Land Group (Eleonore Bay Supergroup) of East and North-East Greenland. Geology of Greenland Survey Bulletin 178, 60 pp.


Clay Minerals ◽  
1980 ◽  
Vol 15 (3) ◽  
pp. 263-274 ◽  
Author(s):  
V. A. Frank-Kamenetskii ◽  
N. V. Kotov ◽  
A. A. Rjumin

AbstractExperimental transformations of feldspars and muscovites following additions of magnesite and dolomite have been studied at PH2O = 1 kbar, T = 200–600°C. Formation of layer silicates such as smectite, 7 Å (Mg,Al)-serpentine, some mixed-layer phases and other minerals is shown to be a function of the composition of the starting materials, temperature and run duration. It is established that 1 M- and 2 M1-phlogopites are formed from 1 M- and 2 M1-muscovites, respectively, under Mg-bearing hydrothermal conditions. Some causes of variations in the composition of 7 Å (Mg,Al)-serpentines at elevated temperature as a function of the composition of hydrothermal media are given. These data may be used to explain the main characteristics of clay mineral formation from feldspar- and muscovite-bearing sedimentary rocks during their alteration in postdiagenetic and metasomatic processes.


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