scholarly journals Hydrocarbon gases associated with alkaline igneous activity: evidence from compositions of fluid inclusions

1981 ◽  
Vol 103 ◽  
pp. 99-108
Author(s):  
J Konnerup-Madsen ◽  
J Rose-Hansen ◽  
E Larsen

The importance of volatile components in the generation and crystallization of alkaline rocks has been emphasized by a number of authors (see review by Kogarko, 1974). ane method of determining the character of the volatile components associated with natural magmatism is to study the volatiles trapped as fluid inclusions in minerals during formation of the rocks. Although there may often be difficulties in relating the volatiles observed in fluid inclusions in minerals to those present in the melt at the time of solidification, this approach is considered to provide a potential method for determining the characteristics of volatiles associated with formation of natural rocks.

1968 ◽  
Vol 5 (6) ◽  
pp. 1401-1407 ◽  
Author(s):  
Ronald Doig ◽  
Jackson M. Barton Jr.

Potassium-argon ages have been determined for alkaline rocks, including carbonatites, from some fifteen localities in Quebec. Nine centers of intrusion, including two previously documented localities, yield ages in the range 400 to 600 million years. All but two of these are located on or very near the northern boundary fault of the St. Lawrence graben system. Included in this group are four carbonatites with remarkably similar ages of intrusion (565 m.y.). The existence of this widespread coeval igneous activity along a 1200-mile segment of the lowland area and its westward extension supports the hypothesis that the St. Lawrence graben is a continuous structure, and indicates that the system has been active for at least 600 million years.


Author(s):  
Brendon Griffin

The determination of fluid compositions in geological processes is an essential but difficult problem. Many techniques have been developed based on the optical microscope. These are indirect analytical techniques, determining fluid composition by analogy. More sophisticated spectroscopic techniques, e.g. laser microprobes, are relatively inaccessible through high capital cost. Scanning electron microscopes [SEM’s] and electron microprobes have been used to identify the non-volatile components by decrepitating near-surface inclusions with an energetic electron beam and then analysing the residual.It is found that application of the cryo-SEM to the study of fluid inclusions with the common availability of windowless and low absorbance windowed Si(Li) detectors is a convenient and low cost technique. Suitable slabs (<1 mm) are frozen and then fractured. No coating is applied, to minimise element interference. The fresh surfaces are inspected using backscattered electron [BSE] imaging and exposed inclusions analysed.Studies of inclusions in quartz, fluorite and sphalerite have determined the presence of carbon dioxide, water and various daughter salts, including halite (NaCl) and hydrophilite (CaCl2).


LITOSFERA ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 172-197
Author(s):  
G. A. Belenitskaya

Research subject. An analysis of regional and global geological material characterizing the spatio-temporal relationships between alkaline magmatic and saline complexes allowed the author to propose and justify a new geological-genetic model of alkaline magmatism. This model considers saline complexes, located along the paths of the upward movement of deep magmas, as additional sources of alkaline and volatile components.Materials and methods. Three articles are devoted to the discussion and justification of this model. Two articles were devoted to geological aspects of the problem. The prerequisites and signs of the participation of ancient saline complexes in alkaline magmatism were characterized. It was shown that the presence of saline rocks in the deep zones of the earth's crust along the paths of the upward movement of deep magma flows is a geologically natural and common phenomenon. Natural alkaline-salt associations (spatio-temporal combinations of alkaline and salt objects) were indicated; their tectonic types were distinguished. A global overview of their different-age analogues (neo- and paleogeodynamic) was given.Results and discussion. The collected data made it possible to evaluate older (than magmas) salt-bearing complexes (deeply buried in the substrate) as a possible important and active participant in the ontogenesis of alkaline complexes, to give a positive assessment of the geological aspects of the “magma halocontamination” model and salt-magmatic interactions; to formulate the main geological-genetic provisions of this model.Conclusion. This article focuses on the discussion of the genetic aspects of the proposed model with an assessment of the probable role and significance of various halophilic components in the formation of alkaline magmas and their features. For this purpose, the similarity features in the spatial and quantitative distribution of halophilic and foydaphilic components in salt and alkaline rocks are considered; the probable role of various halophilic components in the formation of alkaline specialization of magmas, in the emergence of a rich set of unusual features of alkaline rocks (material, structural, morphological, etc.) is discussed. The probability of participation of the complex of paragenic (non-salt) members of the halophilic community (dolomites, anhydrites, black shales and associated ore components) in the interaction with hot magma is estimated. A comparative analysis of some basic provisions of the model under consideration with other geological-genetic models of alkaline petrogenesis is performed. The advantages of this model and its predictive capabilities are evaluated. A number of ideas have been proposed by the author for the first time, thus requiring further elucidation.


2021 ◽  
Vol 3-4 (185-186) ◽  
pp. 92-108
Author(s):  
Ihor Naumko ◽  
Yosyp Svoren

The innovative approach to the development of prospective technologies (methods) was substantiated on crystallogenic and physicochemical principles of the knowledge of mineral forming environments (fluids) (thermobarogeochemistry – mineralofluidology – fluid inclusions) as a new branch of geological knowledge within the framework of the new scientific direction in the geology – «thermobarometry and geochemistry of gases of veinlet-impregnated mineralization in deposits of oil- and gas-bearing areas and metallogenic provinces» as a natural phenomenon of the Earth’s lithosphere. According to him, the creation of radically new technologies and realization of prospecting for mineral deposits (first of all hydrocarbons and gold) simultaneously with the elucidation of the problem of genesis and synthesis of hydrocarbons at the atomic-molecular level fixed by such defects in the mineral crystals as fluid inclusions. Developed technologies, namely: determination of genesis of hydrocarbon gases; determination of prospects of oil and gas presence of a local area; local forecast of enriched areas of gold ore fields; express determination of potassium ions in inclusions for identification of gold-enriched and barren veinlet formations, – belong to the branch of the exploration geology and geochemistry and are used to ascertain genetic guestions, to solve tasks of the mineralogical-geochemical prediction and prospecting for mineral deposits in the local structures of oil- and gas-bearing areas and metallogenic provinces. The comparison of fluid inclusions of veinlets and host rocks based on the sections of a number of wells has shown the considerable possibilities of the developed technologies and prospects of the usage of thermobarogeochemical-mineralofluidological indicators in the complex with the geochemical and geophysical (petrophysical) methods, data of geological survey, deep-seated drilling while predicting hydrocarbon deposits in the local structures of the sedimentary strata promising for oil and gas and making necessary amendments in the directions of the following geological-prospecting works.


2007 ◽  
Vol 45 (3) ◽  
pp. 270-294 ◽  
Author(s):  
S. G. Kryvdik ◽  
V. A. Nivin ◽  
A. A. Kul’chitskaya ◽  
D. K. Voznyak ◽  
A. M. Kalinichenko ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document