Syngenetic deposition

Volcano-sedimentary ore deposits are syngenetic deposits precipitated from sea water enriched in metals by submarine volcanic activity. Deposits of this type are also called submarine exhalative-sedimentary deposits. Stratabound lead-zinc-copper deposits associated with marine sedimentary volcanic sequences belong to this category. Important examples are Kuroko deposit in Japan, Mt. Isa in Australia, Sullivan deposit in British Columbia, Canada, Rammelsberg in Germany and Rampura-Agucha in Rajasthan, India. 

Force, E.R. Maynard, J.B. 1991. Manganese Syngenetic Deposits on the Margins of Anoxic Basins. In Force, E.R., Eidel, J.J., Maynard, J. B. (eds.), Sedimentary and Diagenetic Mineral... 

Force E. R. and Maynard J. B. (1991) Manganese syngenetic deposits on the margins of anoxic basins. In Sedimentary and Diagenetic Mineral Deposits A Basin Analysis Approach to Exploration (eds. E. R. Force, J. J. Eidel, and J. B. Maynard). Society of Econ. Geologists, El Paso, TX, pp. 147-159. 

The evidence reviewed above suggests that cystine, cysteine, mercaptocarboxylic acids, and other organosulfur ligands may contribute to the speciation of metals and sulfur in ore-forming processes responsible for syngenetic deposition of metal sulfides in low-temperature subaqueous... 

Kuroko deposits are strata-bound and massive in form (Fig. 1.7) and syngenetically formed on the seafloor and/or sub-seafloor environment. Vein-type deposits are fissure-filling and epigenetically formed (Fig. 1.8). 

By far the most important ores of iron come from Precambrian banded iron formations (BIF), which are essentially chemical sediments of alternating siliceous and iron-rich bands. The most notable occurrences are those at Hamersley in Australia, Lake Superior in USA and Canada, Transvaal in South Africa, and Bihar and Karnataka in India. The important manganese deposits of the world are associated with sedimentary deposits the manganese nodules on the ocean floor are also chemically precipitated from solutions. Phosphorites, the main source of phosphates, are special types of sedimentary deposits formed under marine conditions. Bedded iron sulfide deposits are formed by sulfate reducing bacteria in sedimentary environments. Similarly uranium-vanadium in sandstone-type uranium deposits and stratiform lead and zinc concentrations associated with carbonate rocks owe their origin to syngenetic chemical precipitation. 

The Brunswick Subduction Complex (BSC) is best know as the host sequence to world class, syngenetic volcanogenic massive sulfide deposits of the Bathurst Mining Camp (BMC) hosting deposits such as the giant Brunswick No. 12 VMS deposit (>300 Mt of massive sulfides). Less well known are the syntectonic, precious-metal breccia and (or) vein deposits/occurrences in the BSC. The shear zone-hosted Middle River gold deposit (MRG) is the most significant of these and has returned assays of up to 7.44 g/t Au over 6.5 m (DDH MR-05-06). 

Irish-type SEDEX deposits are carbonate-hosted stratiform to stratabound sulfide deposits that occur as syngenetic exhalative to early diagenetic replacement bodies (Coleman et al. 1989). Many SEDEX deposits have formed in Proterozoic intracontinental rifts and Phanerozoic deposits occur in similar... 

Dr. Gluskoter. What is the evidence for a syngenetic origin for the uranium minerals in the Swiss anthracite Why could this not be secondary deposition along planes of weakness (bedding) ... 

Mineral Group Transported by Water or Wind Newly Formed Deposited in Fissures, Cleats, and Cavities (Coarsely Intergrown) Transformation of Syngenetic Minerals (Intimately Intergrown)... 

An interesting BIF of Algoma type is found in northwestern Canada on the Yukon-Mackenzie divide (Gross, 1972). Traces of mud flows, tuffs, ash, conglomerates, and syngenetic breccias—i.e., products testifying to deposition in a tectonically active basin with explosive volcanic activity—have been established in these cherty iron-formations. 

Leventhal J. S. (1983b) Organic carbon, sulfur, and iron relationships as an aid to understanding depositional environments and syngenetic metals in recent and ancient sediments. In US Geological Survey Circular, Report C 0822 (eds. T. M. Cronin, W. F. Cannon, and R. Z. Poore). US Geological Survey, Reston, VA, pp. 34-36. 

Syngenetic of minerals or ore deposits, formed contemporaneously with the enclosing rocks. 

The distributions of minerals within the Lower Kittanning seam can be related to depositional environment. Pyrite content is highest in areas which may have experienced brackish conditions. This distribution reflects the availability of iron and sulfur, and pH conditions within the swamp. Whereas much of the pyrite formed syngenetically, observations of sulfide modes of occurrence suggest that marcasite formed epigenetically. 

Fraser, D. C. (1961a). A syngenetic copper deposit of recent age. Econ. Geol. 56,95l-%2. 

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