Following the publication of the paper (noted below) on the epithermal portion of the Recsk metallogenic system in Hungary here are 3D models from the entirely concealed Cu-Au mineralized intrusive bodies and related Cu-Au skarns and outbound Zn-Pb replacement bodies.
A 3D fly-though of the Recsk Cu-Au deposit showing the drilling, channel samples and interpolated copper grade shells. A full set of 100 metre spaced section steps through the deposit from north to south over several kilometres.
A section through the Recsk deposit with drilling and copper grade shells. The section is 200 metres thick and the 0.3% grade shell is 800 metres high and 1,000 metres wide. The Cu-Au skarn mineralisation can be seen dipping gently away from the large intrusive body. The intrusion is open at depth below 1,200 metres. The top of the 10.3% copper grade shell is approximately 400 metres below the surface.
This 3D Model is based upon 156,000 metres of surface drilling over 35 square kilometres, 9km of underground development and 90,000 metres of underground drilling.
The Recsk metallogenic centre consists of a deep and entirely preserved mineralised intrusive and intermediate and high sulphidation epithermal deposits exposed at surface. The epithermal deposits are located close to the apex of the intrusion. The diorite intrusion is hosted by a thick sequence of Eocene carbonates unconformably overlain by a volcanic edifice. Adjacent to the intrusion the carbonates host thick Cu-Au skarns. Outbound of the Cu-Au skarns, Zn-Pb replacement bodies have been intersected in wide spaced drillholes. In this video we present a section through the deposit. The 3D model is based upon 156,000 metres of drilling from surface, 9 km of underground sampling on the 700 and 900 metre levels and 89,000 metres of underground diamond drilling. Underground access was provided by two 1,200 metre deep shafts, 2,000 metres apart. The shafts have an 8 metre internal diameter and are concrete lined. No mining has been undertaken at the deeper Recsk mineralisation aside from bulk metallurgical sampling.
A very interesting study in Cell Metabolism demonstrates that energy-controlled high-fat low carbohydrate diets are not detrimental to health, but rather a ketogenic diet (with a very high proportion of fat) extends lifespan and slows age-related decline in physiological function in mice.
Graphical abstract. Study shows increased longevity, improved motor function and memory in aging mice and no weight gain where calorific intake is managed.
Calorie restriction (CR) has long been shown to increase longevity in animal models. However longitudinal studies in humans are not possible. The exact mechanism for contributing to increased longevity in CR animal models remains unresolved however it has long been recognised that CR induces a shift from carbohydrate to fat metabolism. Low carbohydrate diets (LCD) have been shown to induce a shift from carbohydrate towards fatty acid oxidation metabolism.
In this paper the authors have studied the most extreme LCD, the ketogenic diet in an animal model. They studied mice by strictly regulating their diet and generated three cohorts: LCD group fed 70% of their kcal as fat, a KD group fed 89% of their kcal as fat and a control group fed 65% of their kcal as carbohydrate.
The results of the study have confirm earlier studies which showed that a KD promoted an anti-inflammatory metabolic state with elevated blood ketone levels comparable to CR. This study however goes well beyond previous studies following the population from birth to post-mortem. The primary objective of this study was the evaluate the influence of LCD and KD on longevity and health-markers in mice.
The results of this study include:
The results clearly demonstrate that lifespan is increased in mice consuming a KD when a feeding strategy is followed that mitigates weight gain in adult mice. It is often assumed that a high-fat diet will shorten life expectancy however, this study indicate that a calorie-controlled LCD started in middle-aged mice does not have a negative impact on aging. Further evidence does not support the idea that level of protein is primarily responsible for the increased longevity;
This study shows that a KD slows cognitive decline and preserves motor function in aging mice. KD maximizes and preserves forelimb grip strength with age. Respiratory quotient was decreased by an LCD or a KD compared to a control diet.
KD mice showed glucose intolerance however insulin sensitivity after a 4 hr fast was enhanced by a KD if compared to the LCD, indicating that insulin signalling is functioning normally in mice fed a KD
Ketones would appear to positively impact muscle homeostasis and may play an important role as neuro-protective signalling molecules
The level of acetylated p53, a key tumour suppressor protein, was 10-fold higher in liver after 1 month on a KD and as a likely consequence, incidence of tumours at time of death, particularly histiocytic sarcoma, was decreased with a KD
A Ketogenic Diet Extends Longevity and Healthspan in Adult Mice
Megan N. Roberts, Marita A. Wallace, Alexey A. Tomilov, Zeyu Zhou, George R. Marcotte, Dianna Tran, Gabriella Perez, Elena Gutierrez-Casado, Shinichiro Koike, Trina A. Knotts, Denise M. Imai,
Stephen M. Griffey, Kyoungmi Kim, Kevork Hagopian, Fawaz G. Haj,
Keith Baar, Gino A. Cortopassi, Jon J. Ramsey, Jose Alberto Lopez-Dominguez
ABSTRACT
Calorie restriction, without malnutrition, has been shown to increase lifespan and is associated with a shift away from glycolysis toward beta-oxidation. The objective of this study was to mimic this metabolic shift using low-carbohydrate diets and to determine the influence of these diets on longevity and healthspan in mice. C57BL/6 mice were assigned to a ketogenic, low-carbohydrate, or control diet at 12 months of age and were either allowed to live their natural lifespan or tested for physiological function after 1 or 14 months of dietary intervention. The ketogenic diet (KD) significantly increased median lifespan and survival compared to controls. In aged mice, only those consuming a KD displayed preservation of physiological function. The KD increased protein acetylation levels and regulated mTORC1 signaling in a tissue-dependent manner. This study demonstrates that a KD extends longevity and healthspan in mice.
This paper in the latest edition of Economic Geology by Ágnes Takács, Ferenc Molnár, Judit Turi, Aberra Mogessie, John C. Menzies examines the evolution of the outcropping epithermal mineralisation at Recsk in Hungary. The epithermal deposit sits close to the apex of a large intrusive body which does not outcrop but was defined by systematic diamond drilling to 1,200 metres over a 35km2 area. While the outcropping HS epithermal mineralisation was sporadically mined, the unexposed porphyry and related skarns and replacement bodies was not exploited. The deeper mineralisation has been evaluated with 156,000 metres of drilling from surface and 90,000 metres of diamond drilling from underground development on two levels accessible via two 1200 metre deep, 8 metre internal diameter concrete lined shafts. There is considerable potential for the discovery of both additional mineralised bodies (this paper suggests an as yet undiscovered intrusive to the north of the known body) and extensive skarn mineralisation around the periphery of the intrusion.
HIGHLIGHTS
Largely uneroded porphyry-skarn-epithermal metallogenic system of Paleogene age in a subduction-related magmatic hydrothermal environment within the Alpine-Carpathian region
Paleogene diorite intrusions and Mesozoic carbonate and silicic shale host rocks contain Cu(-Mo-Au)-porphyry, Cu-Zn(-Fe) skarn, and metasomatic Pb-Zn (carbonate replacement) mineralization from ~400- to at least 1,200-m depth below the surface.
Three stages of ore formation
Stage 1: Ore deposition in the porphyry-epithermal transition zone (pyrite, chalcopyrite, tennantite-tetrahedrite, galena, sphalerite; 260°–230°C; logfs2~–11 to –9; logfTe2~ –19 to –14)
Stage 2: High- and very high sulfidation state mineralization from tellurium-saturated fluids (e.g., enargite, luzonite, pyrite, native gold, calaverite, hessite, aikinite-bismuthinite; 240°–170°C; logfS2~–7 to –11; logfTe2~–14.8 to –10.5)
Stage 3: Late-stage mineralization from tellurium-oversaturated, locally oxidized fluids of an intermediate-sulfidation state (e.g., tennantite-goldfieldite, pyrite, hessite, petzite, native tellurium, kawa-zulite; logfs2~–11 to –15.5; logfTe2 ≥ –10.5)
Geology and mineralization of the Recsk ore complex. (A) Combined geological and topographical map of the studied area. The geology is modified after Pantó (1952) and the tectonics are modified after Rozlozsnik (1939) and Molnár et al. (2008). (B) Topographical map with contoured thickness of the subvolcanic diorite intrusion, mineralized bodies, and historical adits. The locations of high-sulfidation epithermal orebodies are based on the map from Földessy et al. (2008a), and the thicknesses of diorite intrusive stocks intercepted in the 1,200-m-deep drill holes completed in the area are from Baksa (1975). Abbreviations: HS = high-sulfidation, IS = intermediate-sulfidation.Estimated Ore Resources for the Recsk Ore Complex (data from Fodor et al., 1998; Kontsek et al., 2006)
ABSTRACT
The Recsk ore complex is an example of a largely uneroded porphyry-skarn-epithermal metallogenic system in a subduction-related magmatic hydrothermal environment within the Alpine-Carpathian region. Paleogene diorite intrusions and Mesozoic carbonate and silicic shale host rocks contain Cu(-Mo-Au)-porphyry, Cu-Zn(-Fe) skarn, and metasomatic Pb-Zn (carbonate replacement) mineralization from ~400- to at least 1,200-m depth below the surface. The Mesozoic sedimentary rocks are unconformably overlain by a stratovolcanic sequence of andesitic to dacitic composition that hosts epithermal Cu-Au-Ag and Au-Ag-Pb-Zn mineralization. This study focuses on the shallow high-sulfidation epithermal Cu-Au-Ag mineralization exposed and exploited on Lahóca Hill. The ore mineralogy combined with the microthermometry of quartz- and enargite-hosted fluid inclusions suggest three stages of the ore formation: (1) early-stage ore deposition in the porphyry-epithermal transition zone (pyrite, chalcopyrite, tennantite-tetrahedrite, galena, sphalerite; 260°–230°C; logfs2~–11 to –9; logfTe2~ –19 to –14); (2) high- and very high sulfidation state mineralization from tellurium-saturated fluids (e.g., enargite, luzonite, pyrite, native gold, calaverite, hessite, aikinite-bismuthinite; 240°–170°C; logfS2~–7 to –11; logfTe2~–14.8 to –10.5); and (3) late-stage mineralization from tellurium-oversaturated, locally oxidized fluids of an intermediate-sulfidation state (e.g., tennantite-goldfieldite, pyrite, hessite, petzite, native tellurium, kawa-zulite; logfs2~–11 to –15.5; logfTe2 ≥ –10.5). The observed differences in ore mineral assemblages and trace element compositions of sulfides reflect the temporal and spatial evolution of the ore-forming hydrothermal system. Results of fluid inclusion microthermometry performed by conventional and infrared-light microscopy and Raman spectroscopic studies support a model with lateral flow of shallow hydrothermal fluids. The spatial distribution of paleotemperature data within the high-sulfidation portion of the ore deposit suggests that the fluid flow system is offset from the closest apex of the related mineralized porphyry stock. This could be due to structural complexity related to syn- to postmineralization tectonism and/or due to the presence of an undiscovered intrusion to the north of the known mineralized stock.
Ore minerals and textures of the Lejtakna high-sulfidation epithermal mineralization. (A) Stage 1 assemblage sphalerite within enargite. (B) Intergrowth of stage 2 enargite and luzonite (crossed polars). (C) Resorbed textured and partially replaced enargite crystal fragments in a tennantite-tetrahedrite matrix. (D) Stage 3 assemblage from the central part of the Lejtakna deposit with textures not observed at Lahóca Hill. (E) Framboidal pyrite cemented by galena. (F) Collomorphic pyrite-chalcopyrite assemblage with tennantite-tetrahedrite and sphalerite. (G) Collomorphic pyrite-chalcopyrite-galena assemblage in barite. (H) Intergrowth of pyrite and galena crystals. (I) Planar and cross-laminated layers consisting of pyrite and quartz. Note: Samples E through I are from the shallowest parts of the Lejtanka deposit.
