Chlorite coatings

Pittman E. D. and Lumsden D. N. (1968) Relationship between chlorite coatings on quartz grains and porosity, Spiro Sand, Oklahoma. J. Sedim. Petrol. 38, 668-670. 

An explanation as to why the upper part of the Norphlet sand lenses has slightly less continuous chlorite coatings on detrital grains is not readily apparent from the data and observations presented in this study. Seismic and well data... 

Disinfectant Formulations and Sterilization. Hundreds of appHcations covering disinfectant compositions using sodium chlorite have been described in U.S. and foreign patents. Some examples of these are as antimicrobial additives for latexes (166), marine antifouling agents (see Coatings, marine) (167,168), antimildew detergent compositions (169), toothpaste and solution compositions for prevention and treatment of periodontal oral disease (see Dentifrices) (170—172), and compositions for the disinfection of contact lenses (qv) (173). 

A 25-mL, round-bottomed flask equipped with a Teflon-coated magnetic stirring bar is charged with 26 mg (0.18 mmol) of (R)-a-methylbenzenepropanal, 4.0 mL of 2-methyl-2-propanol, 1.0 mL (2.0 mmol) of a 2.0 M solution of 2-methyl-2-butene in tetrahydrofuran (purchased from Aldrich Chemical Company, Inc., and used as received), and a solution of 0.17 g (1.9 mmol) of sodium chlorite (Aldrich Chemical Company, Inc. 80% technical grade) and 0.20 g (1.4 mmol) of sodium dihydrogen... 

Ehrenberg, S.N. 1993 Preservation of anomalously high porosity in deeply buried sandstones by grain-coating chlorite examples from the Norwegian continental shelf. Am. Assoc. Pet. Geol. Bull., 77 1260-1286. 

Chlorite replaces kaolinite, clay pseudomatrix, infiltrated clays, micas and heavy minerals. It occurs as rims composed of platelets oriented perpendicularly to grain surfaces. The rims were formed by replacing infiltrated smectitic clay coatings, which were originally oriented tangentially to grain surfaces (Fig. 14A) (see Moraes De Ros, 1990). These infiltrated clays were presumably introduced into the vadose zone of alluvial continental sediments under semi-arid conditions by episodic floods (Walker et al., 1978 Moraes De Ros,... 

Typically, mechanically infiltrated clays are originally detrital smectites formed under semi-arid weathering conditions (see Keller, 1970 Walker et al., 1978). This is evidenced by the dominance of smectitic clays in the mudstone samples and in the mud intraclasts. Infiltrated coatings and derived chloritized rims are conspicuous, particularly in medium-grained sheet-flood sandstones (up to 2.7 vol%). 

Illite is a minor diagenetic constituent occurring as fibres closely associated with chloritized pseudomatrix and infiltrated coatings. The presence of honeycombed mixed-layer illite/smectite (I/S) might indicate that illitization occurred via this intermediate stage. 

Although both cores display floodplain mudstones and sheet-flood sandstones, the Middle Lunde samples in 34/7-A-3H are dominated by fine- to medium-grained sheet-flood sandstones. The elevated initial porosity and permeability of these sandstones compared with the mudstones, siltstones and very fine to fine-grained sandstones has perhaps allowed larger amounts of mechanically infiltrated clays, which are preserved as smectitic coatings and/or transformed into chloritic or C/S and I/S rims in the sandstones. 

Sandstones with potentially better porosity preservation are characterized by (i) coarser grain size and better sorting (ii) lower tendency to host extensive eogenetic carbonate cement than the finer sediments, which are more represented by well 34/4-1 samples and (iii) chlorite rims evolved from the infiltrated clay coatings, which are more abundant in coarse-grained sands which inhibited precipitation of pore-occluding quartz and carbonate cements. 

Authigenic clay minerals identified by SEM/EDS include minor amounts of kaolinite, chlorite, illite and mixed-layer illite/smectite, which form grain coatings, platelets or fibrous cements. 

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