A multi-layer approach for estimating the Energy Use Intensity on an urban scale

Various governments are planning their cities to be climate responsive by reducing the energy consumption and carbon emissions according to different scenarios whilst maintaining good indoor comfort conditions. A robust and reliable tool that can estimate the Energy Use Intensity (EUI) of a city is required. This paper presents a new bottom-up engineering-based multi-layer approach able to analyse the energy performance of existing settlements of every size by retaining as much information as possible about their complexities. The process involves i) creating a 3D model of the urban area, ii) building up templates representing different building characteristics such as functions, the age-band of the buildings and operating schedules, iii) running dynamic thermal simulations and iv) displaying the EUI or total energy demand in the 3D model which can be post-processed for further analysis. This approach offers a flexible simulation process according to various purposes, which is particularly useful in decision-making for urban energy retrofitting or planning for new areas. The hourly high-resolution outcomes would benefit the detailed analysis of energy efficiency strategies in order to achieve carbon reduction. The application of this approach is demonstrated for the case of Yuzhong district in Chongqing municipality, China

Laser Raman analysis results of mineral inclusions from deposit of skarn type distributed in the Middle and Lower Reaches Metallogenic Belt of Yangtze River, China and their geological-geochemical significance

Microthermometric data and phase compositions of melt and fluid-melt inclusions in a variety of silicate minerals from skarn deposits have led to proposal that a large amounts of skarns are of magmatic in origin of skarns. In this paper, we present results of Laser Raman spectroscoic analysis of melt inclusions and fluid-melt inclusions hosted in garnet and pyroxene from a number of skarn deposits along the Middle-Lower Yangtze Metallogenic Belt (MLYMB) to confirm the magmatic origin of the skarns investigated and associated Cu-Fe-Au deposits. Our results show that the melt inclusions contain only the solid phase and the trace gas phase. The fluid-melt inclusions contain, in addition to a large amount of solid phase, a trace fluid phase and a gas phase and a gas phase that is not detected by the instrument. The solid phases are of the same or similar to the host mineral of the inclusions, the fluid phases predominantly are water or salt aqueous solutions and gaseous phases including C6H6, C-3 H-6 C-3 H-8, CH4, CO2 and O-2. We suggest that the melt and fluid-melt inclusions are best representatives of the pristine magmas, and thus demonstrate the formation of the skarn assemblages by direct crystallization from a parent magma. In addition, we discuss the formation temperature, distribution range and scale of the magmatic skarns, the formation mechanism and the genetic relationship with Cu-Fe-Au mineralization

Relationship between Uranium Minerals and Pyrite and Its Genetic Significance in the Mianhuakeng Deposit, Northern Guangdong Province

Granite-related uranium ore is an important uranium resource type in China and worldwide. Whether the uranium geochemical theory “U6+ oxidative migration and U4+ reductive precipitation” is applicable to the granite-related uranium mineralization theory has not been determined. Detailed field and petrographic work, as well as scanning electron microscopy energy spectrum analysis, are conducted in this study to analyze the relationship between uranium minerals and pyrite from different ore types and evaluate the mechanism for the precipitation and enrichment of uranium in the Mianhuakeng uranium deposit of northern Guangdong. Uranium ore bodies in the Mianhuakeng deposit generally occur as vein-filling or vein-disseminated types. Four different kinds of ores are recognized: fluorite, carbonate, siliceous, and reddening types. Despite differences in the mineral assemblages, veined ores share similar characteristics and show that uranium minerals (1) occur in the central part or periphery of vein-filling ores or in interphase arrangements with syn-ore fluorite, quartz, or calcite veins; (2) occur as veinlets or are disseminated in cataclastic altered granite; (3) are inlaid with gangue minerals, primarily calcite, fluorite, and microcrystalline quartz; and (4) are closely associated with pyrite in aggregates or relatively independent states, forming straight boundaries with syn-ore gangue minerals that have euhedral and intact crystals and show mosaic growth features. All these results indicate that both pyrite and uranium minerals are co-crystallized products of the ore-forming fluid. Combined with previous research suggesting that the reducing fluid was sourced from mantle, this study shows that decreased pressure and temperature, as well as changes in pH and the solubility (saturation) of changes, rather than the redox reaction, caused the uranium precipitation in the Mianhuakeng deposit

Relationship between Uranium Minerals and Pyrite and Its Genetic Significance in the Mianhuakeng Deposit, Northern Guangdong Province

Granite-related uranium ore is an important uranium resource type in China and worldwide. Whether the uranium geochemical theory “U6+ oxidative migration and U4+ reductive precipitation” is applicable to the granite-related uranium mineralization theory has not been determined. Detailed field and petrographic work, as well as scanning electron microscopy energy spectrum analysis, are conducted in this study to analyze the relationship between uranium minerals and pyrite from different ore types and evaluate the mechanism for the precipitation and enrichment of uranium in the Mianhuakeng uranium deposit of northern Guangdong. Uranium ore bodies in the Mianhuakeng deposit generally occur as vein-filling or vein-disseminated types. Four different kinds of ores are recognized: fluorite, carbonate, siliceous, and reddening types. Despite differences in the mineral assemblages, veined ores share similar characteristics and show that uranium minerals (1) occur in the central part or periphery of vein-filling ores or in interphase arrangements with syn-ore fluorite, quartz, or calcite veins; (2) occur as veinlets or are disseminated in cataclastic altered granite; (3) are inlaid with gangue minerals, primarily calcite, fluorite, and microcrystalline quartz; and (4) are closely associated with pyrite in aggregates or relatively independent states, forming straight boundaries with syn-ore gangue minerals that have euhedral and intact crystals and show mosaic growth features. All these results indicate that both pyrite and uranium minerals are co-crystallized products of the ore-forming fluid. Combined with previous research suggesting that the reducing fluid was sourced from mantle, this study shows that decreased pressure and temperature, as well as changes in pH and the solubility (saturation) of changes, rather than the redox reaction, caused the uranium precipitation in the Mianhuakeng deposit

Petrogenesis and tectonic setting of the Shanzhuang monzogranites in central Jiangxi Province, South China: Evidence from lithology, geochemistry and zircon U-Pb geochronology

This paper presents a systemic study on geochronology, geochemistry and Sr-Nd isotopes of the northern monzogranite from Shanzhuang granitic pluton located on the southern part of the Qinhang Metallogenic Belt in central Jiangxi Province which comprises monzogranite and granodiorite to constrain its emplacement age, petrogenesis and tectonic setting. All zircons from the monzogranite are confirmed to be of magmatic origin by CL imaging, Th/U ratio and diagrams of (Sm/La)(N)-La and Ce/Ce*-(Sm/La)(N) and are divided into three groups. The weighted mean age (420 similar to 419Ma) of the first group is interpreted as crystallization age of the monzogranite. The Shanzhuang monzogranite, which has SiO2 content of 71.48% similar to 66.20%, K2O/Na2O ratio of 1.24 similar to 0.99 and A/CNK ratio of >1.1, with the emergences of muscovite and garnet as well as ACF diagram and negative correlations of Rb with Th and Y, belongs to high K calc-alkaline, strongly peraluminous S-type granite. Meanwhile, this type rock defined by a depletion in large ion lithophile elements Ba and Sr and high field strength elements Nb and Ta is interpreted as a product of partial melting of the crust-derived materials. The ratios of CaO/Na2O (0.14 similar to 0.07), Rb/Sr (8.27 similar to 3.83) and Rb/Ba (1.48 similar to 0.82), the content of FeOT + MgO + TiO2 (2.4 similar to 1.8) and the t(2DM) ages (2031 similar to 1971Ma) together suggest that the protolith of the monzogranite is Paleoproterozoie clay-rich argillaceous rocks. Moreover, the monzogranite is likely formed at a temperature condition (722 similar to 720 degrees C) constrained by saturation- and Ti temperatures of zircon, and a pressure condition of 2.71 similar to 3.21kbar constrained by the Ti-in-biotite geothermometer. Combined with the Paleozoic tectonic development of South China, the diagram of Rb-(Y + Nb) shows that the geological setting of Shanzhuang granitic pluton is post-collision. In summary, the Shanzhuang pluton was formed by partial melting of Paleoproterozoic clay-rich argillaceous rocks at a low temperature and a low pressure condition under post-collisional setting

Paragenesis and fluid evolution of the Halasu III porphyry Cu deposit, East Junggar (NW China): Implications for the Paleozoic multiphase superimposing mineralization in the Central Asian Orogenic Belt

The Halasu III deposit, an important Cu deposit in the southernmost part of the Halasu porphyry Cu belt, is situated in the East Junggar block in NW China. Copper and Mo sulfide mineralization commonly occurs as disseminations or veinlets, and is mainly associated with Devonian granodiorite porphyry. Our detailed field geological investigation identified late-stage high grade Cu sulfide-bearing veining superimposed on the earlier porphyry Cu-Mo mineralization. Four hydrothermal alteration and mineralization stages were identified, namely the early epidote alteration (Stage I), porphyry-style alterations (Stage II comprising II-A potassic, II-B propylitic and II-C phyllic alteration sub-stages), late veining (Stage III) and supergene processes (Stage IV) in the northern- and southern mineralization zones at Halasu III. Multiphase granodiorite- and alkali granite dykes intruded the Beitashan Formation volcanic rocks, generating the early epidote alteration. Potassic alteration (Stage II-A) occurred in and around the NNW-treading granodiorite dykes, while the propylitic alteration (Stage II-B) occurred in the intrusions or volcanic wall rocks around the potassic zone. These early alteration assemblages were overprinted by the subsequent, structurally-controlled phyllic alteration (Stage II-C) confined within the granodiorite porphyry. Late veins (Stage III) include sulfide-bearing (Stage III-A) and sulfide-barren (Stage III-B) ones. Supergene process (Stage IV), represented by hematite and jarosite replacing primary sulfides, extends tens of meters down depth and is commonly fracture-controlled. Three fluid inclusion (FI) types were recognized, namely Type A (single-phase), B (liquid-vapor two-phase) and C (liquid-vapor-solid three-phase). For Type B FIs, those of potassic alteration homogenized at 183-347 degrees C, with corresponding salinities of 6.2-17.8 wt.% NaCl equiv. The propylitic and phyllic Fls homogenized at 172-425 T and 231-352 degrees C, respectively, with the corresponding salinities of 0.9-14.0 wt.% NaCl equiv. and 0.4-10.5 wt.% NaCl equiv. The sulfide-bearing vein Fls homogenized at 243-410 degrees C (Stage III-A-1), 260-362 degrees C (Stage III-A-2) and 117-235 degrees C (Stage III-A-3), along with the corresponding salinities of 1.9-9.2 wt.% NaCl equiv., 1.1-6.7 wt.% NaClequiv. and 65-17.1 wt.% NaCl equiv., respectively. The sulfide-barren vein FIs yielded homogenization temperatures of 260-380 T (Stage III-B-1) and 114-297 T (Stage III-B-2), with corresponding salinities of 1.7-9.8 wt.% NaCl equiv. and 0.2-13.6 wt.% NaCl equiv., respectively. We suggest that hydrothermal veins at Halasu III may have undergone complex and superimposing alteration due to the episodic reopening of the preexisting veins, with Stage III-A-3 veining overprinting the phyllic alteration and Stage III-A-2 veining. Stage Ill-B-2 veining superimposed on the potassic alteration, as well as on Stages III-A-1 and III-B-1 veining. Paragenetic sequence and fluid evolution at Halasu III indicate that these complex hydrothermal alteration stages were formed in accordance with the regional tectonic evolution. These various alteration and mineralization stages at Halasu III deposit reveal a prolonged history of magmatic and hydrothermal processes extending episodically from the Middle Devonian to Middle Permian, wherein early mineralization was overprinted by late hydrothermal events. Such superimposed mineralization may occur commonly in the Paleozoic Central Asia Orogenic Belt. (C) 2016 Elsevier B.V. All rights reserved