Proportions Of Dolomite Research Articles

Analisis Mineralogi dan Kimia Dolomit Kabupaten Bone Bolango, Provinsi Gorontalo

Characterization of dolomite samples from Bone Bolango, Gorontalo Province have been performed with the objective to find out their mineralogical and chemical compositions. Observation and mineral analyses were carried out by means of microscopy and X-ray diffraction methods respectively; whereas chemical composition was determined by using X-ray fluorescence spectrometer. Result of XRD analysis shows that samples contain dolomite [CaMg(CO3)2], calcite [CaCO3] and [SiO2]. The proportion of dolomite is about 60.4% in average and its presence is as replacement of calcite in bioclast components and matrices in the rock. Dolomite crystals are characterized by mosaic texture with euhedral – subhedral in shapes. Spacially, dolomite content increase from west to the east of study area. The XRF analysis reveals that dolomite samples contain MgO ranging between 8.07 and 20.78% while CaO ranges between 30.04 and 56.13%. The SiO2 concentration ranges from 3.50 – 7.55%; whereas Al2O3 ranges from 1.07 – 1.84%. The average MgO content of dolomite about 12.89% can be categorized as calcium dolomite. Dolomite within the study area can be used directly in agriculture sector, but it less suitable as raw materials in glass, ceramic and refractory industries because the average content of MgO is less than 17%. However, it can be increased of their MgO with the application of selective mining or beneficiation process.

The Study of Lithology by Using the Cross-Section Profiles of The Logs of Shiranish and Mushorah Formations in Ain Zalah and Butmah Fields, Northwestern Iraq

This study deals with the determination of lithology in the Shiranish and Mushorah Formations in wells (Az-24, Az-29, and But-15). The graphical representation of the neutron porosity log (NØ) and the bulk density ρ)b(, shows that the Shiranish (Late Campanian – Early Maastrichtian) and Mushorah (Early Campanian) Formations consist of limestone and dolomite, as well as shale. The proportion of dolomite and chert increases at the expense ofcalcite in the Mushorah Formation. Also, the graphical representation results of the M-N profile for each well indicate that the limestone of the Mushorah Formation were affected by the dolomitization with the development of secondary porosity. Moreover, the limestones were suffered silicification in the form of chert nodules. The MID profile, used in this study to determine the mineralogy gives better and more precise results than that of the M-N profile. The results showed that the dominant minerals are calcite in the Shiranish Formation while dolomite and quartz in the Mushorah Formation, regardless of the gas effects within the studied wells.

Growth and Development of Seedlings of Scots Pine and European Spruce Container Seedlings Using Various Materials to Neutralise the Substrate

The article analyses the features of growth and development of seedlings of Scots pine and European spruce on substrates in which various materials were used to neutralise them, affecting the reaction of the environment. According to the research results, the highest germination of seeds of both woody species was established on substrates with a ratio of dolomite flour of 30% and chalk of 70%, while in the case of using pure chalk, seed germination was significantly lower. Scots pine seeds germination in the substrate ranged from 77.6% to 90.1%, and European spruce seeds – from 66.4% to 94.3%. During the cultivation of seedlings of Scots pine and European spruce container seedlings, differences in the content of mobile forms of phosphorus are noted in all variants of the experiment. However, no definite pattern was found depending on the share of participation of various types of lime material. In the substrate of seedlings of Scots pine at the end of the growing season, the content of nitrate nitrogen naturally increases from 1069.1 to 1323.6 mg/100 g of absolutely dry substrate with a decrease in the proportion of dolomite and an increase in the proportion of chalk in the lime neutralising material. Another pattern is manifested when growing seedlings of European spruce container seedlings: the lowest content of nitrate nitrogen (412.1 mg/100 g of absolutely dry substrate) is established in the case of mixing dolomite flour and chalk in equal proportions (option 3). Differences in the content of mobile forms of iron were revealed in all experimental versions of the substrate of both woody species. For the cultivation of Scots pine, its amount ranges from 16.67 to 28.81 mg/100 g of absolutely dry substrate, and European spruce – from 18.40 to 20.99 mg/100 g of absolutely dry substrate. In general, low content of mobile iron was observed in the substrate of growing pine and spruce seedlings in containers. In all experimental variants, the height of seedlings of Scots pine container seedlings exceeds the required average height of the aboveground part in accordance with national standard by 1.3-2.0 times, and for seedlings of European spruce the excess was 1.2-1.5 times. In seedlings of Scots pine and European spruce, according to the variants of the experiment, the average height of the aboveground part rises with an increase in the concentration of dolomite in the mixture of neutralising material from 50% and higher

A comparison of progressive hydrothermal carbonate alteration in Archean metabasalts and metaperidotites

Because of major differences in both bulk chemical composition and silicate mineralogy between metabasalts and metaperidotites, valid comparison of the degree or intensity of carbonate alteration cannot be made in terms of weight per cent CO2. Molar CO2/CaO is preferred as an index of the intensity of carbonate alteration in metabasalts; molar CO2/CaO in carbonatized metabasalts is independent of CaO/MgO and only mildly sensitive to bulk composition and to the proportions of tremolite and clinozoisite. Molar CO2/CaO reflect the proportions of calcite and dolomite in metabasalts and the proportions of dolomite and magnesite in metaperidotites. However, neither molar CO2/CaO nor the proportions of dolomite and magnesite are reliable measures of carbonate alteration in metaperidotites of variable composition because both are strongly dependent on MgO/CaO in the whole rock. The preferred alteration index in metaperidotites is m CO2/m (CaO + MgO + FeO), which represents the proportion of total relevant cations that exist in carbonate form. An empirical equation relating molar CO2/CaO in metabasalts (x) and MCO2/m(CaO+MgO+FeO) in metaperidotites (y) is: y=0.16+0.30 x.

Dolostone popouts in asphalt, Kingston, Ontario

Standard physical tests for aggregate indicate that most of the carbonate bedrock in the Kingston, Ontario area meets the requirements for asphaltic coarse aggregate. However, when used, some of the aggregate particles have proven to be prone to aggregate loss, also called popping. Studies utilizing the polarizing microscope, the scanning electron microscope, and X-ray diffraction and fluorescence techniques indicate that the aggregate particles which are prone to popping contain a significantly higher proportion of dolomite than calcite, and the crystals are much better formed. The large dolomite crystals result in a poorer aggregate–bitumen bond and contribute to an increased probability of splitting of the aggregate. Both conditions cause aggregate loss from the road surface.

Dolomite-insoluble residue relationships in the Ten Mile Creek Dolomite (Middle Devonian) near Toledo, Ohio

ABSTRACT Analyses of 70 samples of the Ten Mile Creek Dolomite show complete lack of correlation of dolomite/calcite ratios with percent insoluble residue, percent clay minerals, identity of clay minerals, or percent silica. This roughly parallels results reported by other workers from similar analyses of the Lockport Formation and the Ellenburger Group. Earlier reports of direct correlations between percent dolomite and percent insoluble residue in some carbonate rocks need not reflect a cause-and-effect relationship between insoluble content and proportion of dolomite. The correlations may be explained in other ways. Several reported occurrences of modern dolomite strongly suggest a primary or penecontemporaneous origin independent of quantity or quality of terrigenous detritus. Surely many ancient dolomites similarly reflect an environment of deposition rather than a secondary origin related to the mineralogy of associated clastics.

AN INVESTIGATION OF THE INTERCEPT METHOD FOR DETERMINING THE PROPORTION OF DOLOMITE AND CALCITE IN MIXTURES OF THE TWO: II. Experimental rates of solution of dolomite and calcite in samples consisting of a number of crystals

Experimental results are presented which support conclusions derived from a theoretical analysis of the log V vs. t plot, representing the rate of solution of dolomite consisting of a number of crystals. Experimentally determined rates of solution of dolomite and calcite are presented. The intercept method for determining the proportion of dolomite and calcite in mixtures of the two is evaluated on the basis of the theoretical and experimental results.

AN INVESTIGATION OF THE INTERCEPT METHOD FOR DETERMINING THE PROPORTION OF DOLOMITE AND CALCITE IN MIXTURES OF THE TWO: I. Theoretical aspects of the rate of solution of dolomite when a number of crystals are present

The nature of the log V vs. t plot, representing the rate of solution of dolomite consisting of a number of crystals, has been analysed theoretically. The plot may be concave either upwards or downwards, depending on the size distribution of the crystals. Nevertheless, the deviations from linearity, during the time required to dissolve about 50 per cent of the smallest crystal, are always within limits. These limits are calculated and their significance in relation to the line of best fit is discussed.

THE LOWER ANHYDRITE SEAMS OF THE TEES AREA

Recent drilling by the D’Arcy Exploration Co. and by Imperial Chemical Industries Ltd. (Wilton Works) in the Wilton area (fig. 2) has provided considerable information as to the nature and distribution of the anhydrite seams, particularly of those lower members which lie at the top of, and within, the main mass of the Permian Magnesian Limestone. This information can be used, to a certain extent, in the correlation of strata in the boreholes put down in the Billingham area. Wilton - Guisborough Area The only boreholes to reach the Carboniferous were Kirkleatham Nos. 1 and 2. However, the Tocketts bore, in the south-east of the area, though apparently just failing to reach Carboniferous strata, showed such a strong similarity to Kirkleatham No. 1 that it has been thought reasonable to consider the section of the latter as being typical of the area as a whole. Considering this section then (fig. 3), the Carboniferous beds are overlain by a conglomerate which passes upwards into the Magnesian Limestone. The outstanding feature of the latter is the presence of two anhydrite zones, apparently similar in character, lying at 277 to 406 feet and at 478 to 611 feet below the Main Anhydrite. The upper zone, cored throughout, consists of dolomite with blebs of pale blue anhydrite at the base, but, passing upwards, the pro-portion of dolomite with blebs of pale blue anhydrite at the base, but, passing upwards, the proportion of anhydrite gradually increases until a homogeneous mass of anhydrite containing dolomitic stringers …

Sedimentation of the Pico Formation in the Ventura Quadrangle, California

The rocks of the Ventura quadrangle are sedimentary strata ranging from Cretaceous to Recent. The pre-Pliocene beds reach a thickness of 22,000 feet, and crop out in parallel, east-west belts. They consist of conglomerates, sandstones, and shales, with minor proportions of dolomite and limestone. The Pliocene beds comprise the Pico and Saugus formations, which crop out south of the older formations. The Pico formation is divided for convenience of discussion into a lower member 9,300 feet thick and an upper member 3,000 feet thick. The lower Pico consists of heavy conglomerates, sandstones, and clays containing many cross-laminated beds, ripple-marks, and cut-and-fill structures; while the upper Pico consists of monotonously even-bedded, homogeneous, silty clay. A comparison of the petrology of the older formations and of the Pico indicates that the Pico sediments were derived from these older rocks. During lower Pico time short, swift streams carried detritus from a youthful land-mass located just north of the present outcrop of the formation, to a marine basin. Deposition took place rapidly, and the bottom was recurrently depressed while the adjacent land-mass was recurrently uplifted. By upper Pico time the land-mass had been reduced to maturity or old age, and only the finer debris was carried to the basin.