Geological modelling of clay diagenesis in sandstones

Clay Minerals ◽  
1982 ◽  
Vol 17 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Andrew Hurst ◽  
Hilary Irwin
Keyword(s):  
Meteoric Water ◽  
Sea Water ◽  
Water Flux ◽  
Sedimentary Basins ◽  
Hydraulic Head ◽  
Primary Sources ◽  
Diffusion Controlled ◽  
Dissolved Species ◽  
Marine Facies ◽  
Diagenetic Reactions

AbstractPorewater composition is the main control on diagenetic reactions in sandstones. Porewater has two possible contrasting primary sources: (i) fresh meteoric water, which is dilute and acidic, (ii) sea-water, which is alkaline and more concentrated than meteoric water. During burial, unstable minerals equilibrate with these porewaters, thus increasing the concentrations of dissolved species. A simple manometer model is used to describe the diagenesis of interconnected (fluvial or deltaic) sandstones. This model illustrates the following geological relationships: (a) a hydraulic head causes meteoric waters to penetrate deep into sedimentary basins, typically generating authigenic kaolinite; (b) decrease of the hydraulic head (by lowering the land level or by raising sea level) causes concentrated brines to rise within the basin, typically forming illitic cements; (c) enclosed sandstones (marine facies) are isolated from meteoric water flux and only receive fluxes when fault-induced or when uplifted. Kaolinite morphology and distribution are identified as being flux- or diffusion-controlled.

Net Fluxes of Water in the Isolated Gills of Anguilla Dieffenbachii

1974 ◽  
Vol 60 (3) ◽  
pp. 769-781
Author(s):  
T. J. SHUTTLEWORTH ◽  
R. F. H. FREEMAN
Keyword(s):  
Sea Water ◽  
Water Flux ◽  
Freshwater Teleost ◽  
Osmotic Permeability ◽  
Direct Measurements ◽  
Net Flux ◽  
Anguilla Dieffenbachii ◽  
Net Fluxes ◽  
Freshwater Eels ◽  
Net Water Flux

1. Measurements of net flux of water have been made on isolated gills removed from freshwater-adapted and seawater-adapted eels and incubated in various media of differing osmotic pressure. 2. From these measurements it has been possible to determine the osmotic permeability coefficient of the gill directly from the net water flux. The values obtained (0.50±0.14x10-5 cm.sec-1 for freshwater eels and 0.43±0.07x10-5 cm.sec-1 for seawater-adapted eels) indicate that there was no significant change in this parameter on adaptation of the eels to sea water. 3. The direct measurements made of the net water flux across the isolated gills appear to be compatible with the osmoregulatory pattern of eels as deduced by other workers using different techniques. In particular they illustrate and further emphasize the significance of drinking in the freshwater fish. 4. Calculations indicate that, for a freshwater teleost, the osmotic and ionic problems caused by drinking in fresh water have an insignificant energetic effect and hence, energetically, it matters little to the fish whether it drinks or not.

scholarly journals Removal of natural organic matter for wetland saline water desalination by coagulation-pervaporation

2019 ◽  
Vol 22 (3) ◽  
pp. 85-92 ◽  
Author(s):  
Aulia Rahma ◽  
Muthia Elma ◽  
Mahmud Mahmud ◽  
Chairul Irawan ◽  
Amalia Enggar Pratiwi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Room Temperature ◽  
Sea Water ◽  
Saline Water ◽  
Water Flux ◽  
Water Desalination ◽  
Salt Rejection ◽  
Coagulation Process ◽  
Other Hand

The high number of natural organic matter contain in wetland water may cause its water has brown color and not consumable. In other hand, intrusion of sea water through wetland aquifer create water become saline, notably on hot season. Coagulation is effective method to applied for removing of natural organic matter. However, it could not be used for salinity removal. Hence combination of coagulation and pervaporation process is attractive method to removing both of natural organic matter and conductivity of wetland saline water. The objective of this works is to investigate optimum coagulant doses for removing organic matter by coagulation process as pretreatment and to analysis performance of coagulation-pervaporation silica-pectin membrane for removing of organic matter and conductivity of wetland saline water. Coagulation process in this work carried out under varied aluminum sulfate dose 10-60 mg.L-1. Silica-pectin membrane was used for pervaporation process at feed temperature ~25 °C (room temperature). Optimum condition of pretreatment coagulation set as alum dose at 30 mg.L-1 with maximum removal efficiency 81,8 % (UV254) and 40 % (conductivity). In other hand, combining of coagulation-pervaporation silica-pectin membrane shows both of UV254 and salt rejection extremely good instead without pretreatment coagulation of 86,8 % and 99,9 % for UV254 and salt rejection respectively. Moreover, water flux of silica-pectin membrane pervaporation with coagulation pretreatment shown higher 17,7 % over water flux of wetland saline water without pretreatment coagulation. Combining of coagulation and pervaporation silica-pectin membrane is effective to removing both of organic matter and salinity of wetland saline water at room temperature.

Clay mineral variation in Tertiary sediments from the eastern flank of the Niger Delta

Clay Minerals ◽  
1986 ◽  
Vol 21 (2) ◽  
pp. 211-224 ◽  
Author(s):  
S. P. Braide ◽  
W. D. Huff
Keyword(s):  
Clay Mineral ◽  
Niger Delta ◽  
Size Fraction ◽  
Clay Mineralogy ◽  
Burial Diagenesis ◽  
Carbonate Cement ◽  
Eastern Flank ◽  
Marine Facies ◽  
Diagenetic Reactions ◽  
The Relationship

AbstractDetailed clay mineralogical and chemical analyses of well cuttings of Tertiary sediments from two wells, Uruan-1 and Uda-1, on the eastern flank of the Niger delta, have been made in an attempt to investigate clay mineral burial diagenesis. The clay mineralogy indicates a transformation of smectite to an interstratified illite-smectite (I/S) phase. The relationship between ordered and random interlayering, however, is nonsystematic. The chemistry of the <0·1 µm size fraction shows some tendency towards a net gain in K2O and Al2O3 and a net loss in SiO2 with depth, but the relationship does not correlate well with the thermal gradient. The distribution of kaolinite and chlorite in both wells appears to be unrelated in any regular way to smectite transformation and these two minerals are considered to be either the products of other diagenetic reactions affecting various stratigraphic levels, or the result of primary sediment deposition. In well Uda-1, kaolinite decreases in relative abundance with depth. This trend has been interpreted elsewhere as indicative of a transition from nonmarine to marine facies. The results of this study indicate that lack of ion mobility, rather than availability, is a significant factor in retarding the formation of ordered I/S with depth, and that lithology, overpressuring, carbonate cement, and original smectite layer charge may be controlling factors in the smectite → illite transformation.

Secondary K-feldspar at the Precambrian–Paleozoic unconformity, southwestern Ontario

1995 ◽  
Vol 32 (9) ◽  
pp. 1432-1450 ◽  
Author(s):  
David A. Harper ◽  
Fred J. Longstaffe ◽  
Moire A. Wadleigh ◽  
Robert H. McNutt
Keyword(s):  
Meteoric Water ◽  
Elevated Temperatures ◽  
Sea Water ◽  
Wide Distribution ◽  
Late Ordovician ◽  
Lower Paleozoic ◽  
Brine Migration ◽  
Rock Water Interaction ◽  
Granitoid Gneisses ◽  
Host Rocks

The Precambrian–Paleozoic boundary in the subsurface of southwestern Ontario commonly is characterized by secondary K-feldspar. In the weathered and altered Precambrian granitoid gneisses at the unconformity, secondary K-feldspar has replaced preexisting minerals, and also occurs as discrete crystals of adularia, overgrowths on altered minerals, and microcrystalline veinlets. The K-feldspar is chemically pure (Or99–100) and has high δ18O values (+18.9 to +21.4‰ Vienna Standard Mean Ocean Water), features that indicate crystallization at low temperatures. Secondary K-feldspar also occurs in Cambro-Ordovician clastic and carbonate rocks that immediately overlie the Precambrian basement. K/Ar (453 ± 9 to 412 ± 8 Ma) and Rb/Sr (440 ± 50 Ma) dates obtained for secondary K-feldspar from the Precambrian host rocks suggest that its crystallization is unrelated to Precambrian weathering or early diagenesis of the immediately overlying Cambro-Ordovician strata. Estimated crystallization temperatures for the secondary K-feldspar (≥100 °C) exceed presumed burial temperatures for the Precambrian–Paleozoic boundary in southwestern Ontario during Late Ordovician–Silurian time. We infer that secondary K-feldspar formed from a hot brine that moved preferentially along the Precambrian–Paleozoic unconformity. The wide distribution of secondary K-feldspar of Late Ordovician–Silurian age throughout mid-continental North America at the Precambrian–Paleozoic boundary records the regional extent of this process. Some Cambro-Ordovician rocks elsewhere in the mid-continent also contain secondary K-feldspar and illitic clay of Late Pennsylvanian–Early Permian age, suggesting more than one episode of fluid movement. Major pulses of orogenic activity may have initiated brine migration. We speculate that the brine originated as connate (sea) water trapped in lower Paleozoic strata, and was modified by rock–water interaction at elevated temperatures, and by mixing with meteoric water.

Dual layer hollow fiber PVDF ultra-filtration membranes containing Ag nano-particle loaded zeolite with longer term anti-bacterial capacity in salt water

2016 ◽  
Vol 73 (9) ◽  
pp. 2159-2167 ◽  
Author(s):  
Huyan Shi ◽  
Lixin Xue ◽  
Ailin Gao ◽  
Qingbo Zhou
Keyword(s):  
Hollow Fiber ◽  
Polyvinylidene Fluoride ◽  
Sea Water ◽  
Hollow Fiber Membrane ◽  
Salt Water ◽  
Water Flux ◽  
Composite Membranes ◽  
High Water ◽  
Nano Particles ◽  
Ultra Filtration

Dual layer polyvinylidene fluoride (PVDF), antibacterial, hollow fiber, ultra-filtration composite membranes with antibacterial particles (silver (Ag) nano-particles loaded zeolite (Z-Ag)) in the outer layer were prepared with high water flux and desired pore sizes. The amounts of Ag+ released from the composite membranes, freshly made and stored in water and salt solution, were measured. The result indicated that dual layer PVDF antibacterial hollow fiber containing Z-Ag (M-1-Ag) still possessed the ability of continuous release of Ag+ even after exposure to water with high ionic content, showing a longer term resistance to bacterial adhesion and antibacterial activity than membrane doped with Z-Ag+ (M-1). Results from an anti-adhesion and bacteria killing test with Escherichia coli supported that the antibacterial efficiency of dual hollow fiber PVDF membranes with Z-Ag was much higher than those with Z-Ag+ after long time storage in water or exposure to phosphate buffered saline (PBS) solution. This novel hollow fiber membrane may find applications in constructing sea water pretreatment devices with long term antifouling capability for the desalination processes.

scholarly journals Early hypogene Carbonic Acid Speleogenesis in unconfined limestone aquifers by upwelling deep-seated waters with high CO<sub>2</sub> concentration: A first modelling approach

2020 ◽  
Author(s):  
Franci Gabrovšek ◽  
Wolfgang Dreybrodt
Keyword(s):  
Meteoric Water ◽  
Carbonic Acid ◽  
Water Flux ◽  
Intrinsic Property ◽  
Unconfined Aquifer ◽  
Forced Flow ◽  
High Pco2 ◽  
Fracture Aperture ◽  
Dissolution Rates ◽  
Cave System

Abstract. Hypogene caves originate from upwelling deep-seated waters loaded with CO2 that mix with meteoric waters in a limestone aquifer. Here we present first results on digital modelling of Carbonic Acid Speleogenesis (CAS). We study an unconfined aquifer where meteoric water seeps through the vadose zone and becomes saturated with respect to calcite when it arrives at the water table. From below deep-seated water with high pCO2 and saturated with respect to calcite invades the limestone formation by forced flow. Two flow domains arise that host exclusively water from the meteoric or the deep-seated source. They are separated by a water divide. There by dispersion of flow, a fringe of mixing arises and widening of the fractures is caused by mixing corrosion (MC). The evolution of the cave system is determined by its early state. At sites with high rates of fracture widening regions of higher hydraulic conductivity are created. They attract flow and support one by one mixing with maximal dissolution rates. Therefore, the early evolution is determined by karstification originating close to the input of the upwelling water and at the output at a seepage face. In between these regions, a wide fringe of moderate dissolution is present. In the later stage of evolution, this region is divided by constrictions that originate from statistical variations of fracture aperture widths that favour high dissolution rates and focus flow into this region. This MC-fringe-instability is an intrinsic property of cave evolution and is present in all scenarios studied. We have investigated the influence of defined regions with higher fracture aperture widths. These determine the cave patterns and suppress MC-fringe-instabilities. We have discussed the influence of the ratio of upwelling water flux rates to the rates of meteoric water. This ratio specifies the position of the mixing fringe and consequently that of the cave system. In a further step, we have explored the influence of time dependent meteoric recharge. Furthermore, we have modelled scenarios where waters are undersaturated with respect to calcite. These findings give important insight into mechanisms of hypogene speleogenesis. They also have implications to the understanding of sulfuric acid speleogenesis (SAS).

scholarly journals Early hypogenic carbonic acid speleogenesis in unconfined limestone aquifers by upwelling deep-seated waters with high CO<sub>2</sub> concentration: a modelling approach

2021 ◽  
Vol 25 (5) ◽  
pp. 2895-2913
Author(s):  
Franci Gabrovšek ◽  
Wolfgang Dreybrodt
Keyword(s):  
Meteoric Water ◽  
Carbonic Acid ◽  
Water Flux ◽  
Intrinsic Property ◽  
Unconfined Aquifer ◽  
Forced Flow ◽  
High Pco2 ◽  
Fracture Aperture ◽  
Dissolution Rates ◽  
Cave System

Abstract. Here we present results of digital modelling of a specific setting of hypogenic carbonic acid speleogenesis (CAS). We study an unconfined aquifer where meteoric water seeps through the vadose zone and becomes saturated with respect to calcite when it arrives at the water table. From below, deep-seated water with high pCO2 and saturated with respect to calcite invades the limestone formation by forced flow. Two flow domains arise that host exclusively water from the meteoric or deep-seated source. They are separated by a water divide. There by dispersion of flow, a fringe of mixing arises and widening of the fractures is caused by mixing corrosion (MC). The evolution of the cave system is determined by its early state. At sites with high rates of fracture widening, regions of higher hydraulic conductivity are created. They attract flow and support one-by-one mixing with maximal dissolution rates. Therefore, the early evolution is determined by karstification originating close to the input of the upwelling water and at the output at a seepage face. In between these regions, a wide fringe of moderate dissolution is present. In the later stage of evolution, this region is divided by constrictions that originate from statistical variations of fracture aperture widths that favour high dissolution rates and focus flow into this region. This MC-fringe instability is an intrinsic property of cave evolution and is present in all scenarios studied. We have investigated the influence of defined regions with higher fracture aperture widths. These determine the cave patterns and suppress MC-fringe instabilities. We have discussed the influence of the ratio of upwelling water flux rates on the rates of meteoric water. This ratio specifies the position of the mixing fringe and consequently that of the cave system. In a further step, we have explored the influence of time-dependent meteoric recharge. Furthermore, we have modelled scenarios where waters are undersaturated with respect to calcite. These findings give important insight into mechanisms of CAS in a special setting of unconfined aquifers. They also have implications for the understanding of corresponding sulfuric acid speleogenesis (SAS).

scholarly journals Major element concentrations in Mangrove Pore Water, Sepetiba Bay, Brazil

2012 ◽  
Vol 60 (1) ◽  
pp. 33-39
Author(s):  
Christian J. Sanders ◽  
Renato G. S. Barcellos ◽  
Emmanoel V. Silva-Filho
Keyword(s):  
Pore Water ◽  
Major Element ◽  
Sea Water ◽  
Water Flux ◽  
Mangrove Ecosystem ◽  
Major Elements ◽  
Atlantic Rain Forest ◽  
Molar Ratios ◽  
Element Concentrations

Concentrations of cations and anions of major elements (Na+, Ca2+, Mg2+, K+, Cl-, SO4 2-) were analyzed in the pore water of a mangrove habitat. Site specific major element concentrations were identified along a four piezometric well transect, which were placed in distinct geobotanic facies. Evapotranspiration was evident in the apicum station, given the high salinity and major element concentrations. The station landward of an apicum was where major element/Cl- ratios standard deviations are greatest, suggesting intense in situ diagenesis. Molar ratios in the most continental station (4) are significantly lower than the nearby freshwater source, indicating a strong influence of sea water flux into the outer reaches of the mangrove ecosystem and encroaching on the Atlantic rain forest. Indeed, the SO4 2-/Cl- and Ca2+/Cl- ratios suggest limited SO4 2- reduction and relatively high Ca2+/Cl- ratios indicate a region of recent saltwater contact.

ANALYSIS OF GRAVITY DATA NEAR CONTINENTAL MARGINS

1974 ◽  
Vol 14 (1) ◽  
pp. 114
Author(s):  
A. J. Flavelle ◽  
Y. Yoshimura
Keyword(s):  
Continental Margin ◽  
Sea Water ◽  
Gravity Data ◽  
Bouguer Anomaly ◽  
Sedimentary Basins ◽  
Continental Margins ◽  
Upper Crust ◽  
Anomaly Map ◽  
Bouguer Anomaly Map ◽  
Thickness Variations

In general large, thick sedimentary basins are delineated by negative gravity features. The gravity data are usually expressed in the form of Bouguer anomaly contours.Ordinary Bouguer anomaly data fail as a direct indicator of approximate sedimentary thickness in zones on and adjacent to the continental margin. Rapid variations in crustal and ocean thickness cause gravitational variations which are not removed during the computation of Bouguer anomaly values.If crustal thickness variations are known or can be calculated then gravitational corrections can be made which take this factor into account. Similar corrections for variations in sea water attraction can be made. The resultant Bouguer anomaly map, corrected for those variations, will indicate in more definite terms density variations in the material of the upper crust. In particular Bouguer anomaly patterns over continental areas adjacent to the continental slope can be more easily interpreted in terms of sedimentary thickness.

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