Thermochemical sulphate reduction (TSR) was probably the principal H 2S production mechanism for metal precipitation as indicated by: (1) delta 34S values of sulphides from -13.7 to +19.3‰ V-CDT; (2) the presence of evaporite-bearing horizons in the Triassic and Jurassic formations of the Pucara Gp., and (3) fluid inclusion homogenization temperature data. The sources of sulphate were probably Late Cretaceous seawater and also evaporite-bearing rocks of the Mid-Late Triassic and Late Jurassic. A comparison with twelve other MVT deposits/districts suggests that: (1) the most important metal precipitation mechanism in MVT systems appears to be TSR; (2) mixing between organic matter-derived H2S and ore fluids may be the next most important mechanism; and (3) carbonate associated with TSR usually has delta13C values typical of inorganic marine carbonate. The delta13C values of dolomite in the Bongara area (-3.2 to +1.9‰ PDB) indicate a predominant inorganic carbon source.Mineralization in the Bongara area, hosted by late Triassic-Jurassic carbonate rocks, shows definite similarities to Mississippi Valley type (MVT) systems worldwide. In the paragenetic sequence there are two dolomite types: early, pre-ore dolomite (D1), and late dolomite (D2). Fluid inclusions in dolomite and sphalerite are characteristic of MVT systems (∼78--187 0C; ∼15--23 wt% CaCl2 equivalent). The cathodoluminescence (CL) characteristics of carbonates correlate over ∼60 km, indicating a regional scale, interconnected hydrothermal system. CL observations indicate that D1 dolomite has no zonation, whereas D2 dolomite is characterized by four growth zones: D2-a, -b, -c and -d. The D2-b zone is closely associated with sphalerite and galena.Fluid inclusions in dolomite show a temperature decrease from north to south. Electron microprobe analysis shows a trend of lower Fe, Mn and Ca and higher Mg contents in D2-dolomite in the southern location, which also has some more enriched delta18O values than the northern and central locations. These variations suggest that a general southward regional hydrothermal fluid flow was responsible for mineralization in the Bongara area; the depth is estimated at ∼2000--3000 m. Fluid flow is interpreted to have been related to the Peruvian orogenic event (Late Cretaceous) in northern Peru/Ecuador.
|The Physical Object|
|Number of Pages||317|
If you are interested in understanding the fascinating world of mineralisation, especially zinc-lead mineralisation in the Bongara area of northern Peru, then the book "Post-early Cretaceous MVT Zinc-Lead Mineralisation, Bongara Area, Northern Peru: Fluid Characteristics and Constraints on Deposition Mechanisms" by Nurcahyo I. Basuki is a must-read. Published in 2006, this book delves deep into the fluid characteristics and deposition mechanisms that contribute to the mineralisation process.
MVT Zinc-Lead Mineralisation refers to Mississippi Valley Type deposits, which are important sources of zinc and lead. Understanding the characteristics and mechanisms behind the formation of these deposits can provide valuable insights for geologists, mining professionals, and researchers.
Nurcahyo I. Basuki is an esteemed geologist and researcher who has dedicated his career to studying mineralisation processes. His expertise and knowledge are reflected in this comprehensive book, which offers a detailed analysis of post-early Cretaceous MVT zinc-lead mineralisation in the Bongara area of northern Peru.
For anyone involved in the field of mineralisation, this book offers a comprehensive analysis that can enhance your understanding of post-early Cretaceous MVT zinc-lead mineralisation. By delving into fluid characteristics and deposition mechanisms, it provides valuable insights that can contribute to further research and practical applications.
If you are eager to explore the fascinating concepts presented in "Post-early Cretaceous MVT Zinc-Lead Mineralisation, Bongara Area, Northern Peru: Fluid Characteristics and Constraints on Deposition Mechanisms," you can download the book in various formats:
Downloading the book is quick and easy, allowing you to read it at your convenience.
If you are looking to read "Post-early Cretaceous MVT Zinc-Lead Mineralisation, Bongara Area, Northern Peru: Fluid Characteristics and Constraints on Deposition Mechanisms" for free, you can find it on our legal book download website. Our platform offers a vast collection of books that are available to read online or download for free. Simply visit our website and start exploring the world of mineralisation.
"Post-early Cretaceous MVT Zinc-Lead Mineralisation, Bongara Area, Northern Peru: Fluid Characteristics and Constraints on Deposition Mechanisms" by Nurcahyo I. Basuki is a significant contribution to the field of mineralisation studies. By understanding the fluid characteristics and deposition mechanisms involved, this book can expand your knowledge and contribute to advancements in the field. Download the book in your preferred format and unlock the fascinating world of MVT zinc-lead mineralisation.