Prognosis-search complex for mesothermal gold deposits. P. 3. Petrochemical and geochemical criteria
The relevance of the work is defined by the necessity to develop after hundred year investigations hydrothermal gold deposits formation theory instead of the four competing ones - granitogene, basaltogene, metamorphogene, polygene retaining in ore geology. The aim of the study: petrologic-geochemica...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | Russian |
| Published: |
Tomsk Polytechnic University
2019-05-01
|
| Series: | Известия Томского политехнического университета: Инжиниринг георесурсов |
| Subjects: | |
| Online Access: | http://izvestiya.tpu.ru/archive/article/view/1274 |
| Summary: | The relevance of the work is defined by the necessity to develop after hundred year investigations hydrothermal gold deposits formation theory instead of the four competing ones - granitogene, basaltogene, metamorphogene, polygene retaining in ore geology. The aim of the study: petrologic-geochemical in comparative aspect investigation of the ore-containing metasomatic haloes in gold deposits formed in crystal substratum and black shale series to prove their material-genetic uniformity or differences in the conditions for forming deposits of both totality; the development on the basis of the obtain results of petrochemical criteron and definition of geochemical prognosis - research criterion for territory gold appraisal. The methods used in the study is the field investigation of the ore-containing metasomatic haloes and testing rocks, determination of metasomatic minerals, total chemic silicate and atom-absorption on gold, silver, mercury and other elements analysis of rock samples, petrochemical counts on atom-volumetrical method of rocks chemic analysis, balance calculation for quantitative appraisal of migration and fixation of petrogenios components in metasomatic and ore-forming processes, calculations of statistic distribution parameters of metals in metasomatic haloes and rocks containing haloes to reconstruct geologic history of oregenous elements. The results: the author provs the material genetic uniformity of the mineralization formed into both media and appurtenance of ore metasomatic haloes to combination of metasomatic formation - beresitic ones in the rear zones and propylitic ones in the outlying zones. Formation of the contrasting anomalies of femic elements association in K, Ti, P, Mg, Fe, Ca, Mn composition in rear zones of haloes in framing of abyssal fractures at Ti and P content decrease as moving off fractures down to clark levels due to alkaline regime solutions inversion into acidiferous one and change of elements in inert state clears the possibilities to use femic specialization of auriferous beresites phenomenon in order to prove generation of metalliferous solutions in moderate-alkaline basaltic melts. As the petrochemical prognosis-search criteria these phenomena assure positive prognosis, determination of solution-bringing function of fractures, controlling accommodation of deposits, and localization of sections for searching mineralization including those non revealed by daily surface. As the result of geologic history of metals reconstruction in near ore space their subclark contents were defined, in particular, gold at the level of 0,5…3,0 mg/t in different crystalline rocks and black shale on and out of remote periphery of near-ore metasomatic haloes; distribution parameters of heightened and anomalous metal concentrations correlate directly with the intensity of near ore metasomatic transformations of rocks. Positive prognosis on the basis of totality of petrochemical, geochemical and other tectonic, geodynamic, petrologic criteria of prognosis-search complex offered by the author earlier in contrast to the existing popular ideas does not depend on the level (clark, superclark) of pre-ore gold content of black shales. |
|---|---|
| ISSN: | 2500-1019 2413-1830 |