Chalk alteration

Obviously there are major differences between the 13c content of Jamaican chalks altered in the vadose meteoric environment and that of Shatsky Rise limestones. However, as Land (1979b) pointed out, if chemical stabilization of the Jamaican chalks had occurred in the phreatic meteoric environment with little influence from soil CO2, Sr and 180 depletions would be observed with little change in 8l3C. The limestones formed would be more homogeneous and virtually indistinguishable geochemically from Shatsky Rise sediments. 

Verrecchia, E. P. Dumont, J.-L. (1996). A biogeochemical model for chalk alteration by fungi in semiarid environments. Biogeochemistry, 35, 447-70. 

LCPs are slightly altered by one year of outdoor exposure, with a light surface chalking, but after a 2000 h exposure in a Weather-Ometer, retention of mechanical properties is superior to 90%. 

By using a similar mixture of plastic clay, in which a proportion of leurite, instead of the necessary amount of potassa, was present, a well-glazed porcelain was obtained, though somewhat spotted. When lime was employed in place of chalk, or the quartz-sand was replaced by flint, no alteration in the properties of the normal mass was observed. 

It may also be beneficial to alter the wettability (see Section 3.5.3) of the reservoir rock, particularly in order to shift oil-wetting regions towards neutral wetting, which is probably about the optimum for improved oil recovery [158]. Figure 3.23 (see Section 3.5.3) shows how surfactant adsorption can alter wettability, but not always in a simple manner. Such surfactant-induced wettability alteration might be considered for predominantly oil-wetting reservoirs such as chalk reservoirs in the North Sea. 

Burial diagenesis and subsequent alteration of chalk The Overall Diagenetic Pathway... 

Heat flow affects the rate of alteration of pelagic ooze to chalk the higher the temperature, the greater the degree of cementation of the sediment. This effect on the ooze/chalk transition has been convincingly demonstrated by Wetzel (1989) in a study of compositionally similar pelagic carbonate sediments at DSDP sites 504 and 505 located south of the Costa Rica Rift zone. 

Wettability Alteration by Seawater Injection into Chalk Formation... 

Standnes, D.C., Austad, T., 2000. Wettability alteration in chalk 2. Mechanism for wettability alteration from oil-wet to water-wet using surfactants. J. Pet. Sci. Eng. 28, 123-143. 

Zhang, P., Tweheyo, M.T., Austad, T., 2007a. Wettability alteration and improved oil recovery by spontaneous imbibition of seawater into chalk Impact of the potential determining ions Ca % Mg, and SO/. Colloids and Surfaces A Physicochemical Engineering Aspects 301, 199-208. 

Alteration of Soil. A soil high in organic acids can be made less corrosive by surrounding the metal structure with limestone chips. A layer of chalk (CaCOs) surrounding buried pipes has been used in some soil formations likely to produce microbiologically influenced corrosion [16]. 

Calcimine kal-s9- inin [alter, of kakomine] (ca. 1859) n. Also spelled kalsomine . Essentially, chalk and glue ready to mix with... 

All these factors make the rainwater which infiltrates and circulates through the chalk massif not to be capable of reproducing or activating past karst dynamics. This is true only when human action does not alter the conditions of balance of the surroundings. 

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