The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Jiuyang Jiang - One of the best experts on this subject based on the ideXlab platform.
-
petrogenesis of the early carboniferous xilinhot gabbro Diorite pluton in central inner mongolia magma evolution and tectonic significance
Lithos, 2020Co-Authors: Jiuyang JiangAbstract:Abstract The Xilinhot gabbro–Diorite pluton in central Inner Mongolia comprises a microgabbro–hornblende gabbro–quartz Diorite suite and Diorite–microDiorite–quartz microDiorite suite, which intrude the Erdaojing complex in the northern orogenic belt of the southeastern Central Asian Orogenic Belt (CAOB). Zircons separated from hornblende gabbro and quartz Diorite yielded sensitive high-resolution ion microprobe U–Pb ages of 326.8 ± 3.4 and 324.0 ± 1.9 Ma, respectively. There are two types of hornblende in the hornblende gabbro: isolated hornblende and hornblende clusters surrounding orthopyroxene. Only hornblende clusters occur in the quartz Diorite. The amphibole is edenite in the Diorite, whereas the microDiorite and quartz microDiorite contain hornblende. The isolated hornblende formed at higher P–T–H2Omelt conditions (3.3–5.0 kbar; 749–814 °C; 7.4–8.3 wt% H2O) than the hornblende clusters in the hornblende gabbro (0.9–2.2 kbar; 670–731 °C; 3.8–5.5 wt% H2O). Edenite in the Diorite crystallized at higher P–T and lower H2Omelt conditions (1.8–4.8 kbar; 777–979 °C; 3.2–5.2 wt% H2O) than hornblende in the microDiorite (1.3–1.5 kbar; 697–711 °C; 5.0–5.6 wt% H2O). These thermodynamic parameters reveal a multi-level magmatic storage system. Hornblende gabbro, quartz Diorite, Diorite, microDiorite, and quartz microDiorite are generally characterized by flat middle to heavy rare earth element patterns and no Eu anomalies. Geochemical modeling of heavy rare earth element concentrations in hornblende gabbro suggest that the magma was generated by >17.5% partial melting of spinel lherzolite. Slab-derived fluid input can account for the enrichments in Sr, Th, and light rare earth elements, and depletions in Nb and Ta. The multi-level magmatic storage system and slab-derived fluid input suggest that the early Carboniferous magmatism was generated in an arc-related tectonic setting. The northern orogenic and Hegenshan ophiolite belts constitute an early Carboniferous fore-arc basin–arc–back-arc basin system.
-
Petrogenesis of the early Carboniferous Xilinhot gabbro–Diorite pluton in central Inner Mongolia: Magma evolution and tectonic significance
Lithos, 2020Co-Authors: Jiuyang JiangAbstract:Abstract The Xilinhot gabbro–Diorite pluton in central Inner Mongolia comprises a microgabbro–hornblende gabbro–quartz Diorite suite and Diorite–microDiorite–quartz microDiorite suite, which intrude the Erdaojing complex in the northern orogenic belt of the southeastern Central Asian Orogenic Belt (CAOB). Zircons separated from hornblende gabbro and quartz Diorite yielded sensitive high-resolution ion microprobe U–Pb ages of 326.8 ± 3.4 and 324.0 ± 1.9 Ma, respectively. There are two types of hornblende in the hornblende gabbro: isolated hornblende and hornblende clusters surrounding orthopyroxene. Only hornblende clusters occur in the quartz Diorite. The amphibole is edenite in the Diorite, whereas the microDiorite and quartz microDiorite contain hornblende. The isolated hornblende formed at higher P–T–H2Omelt conditions (3.3–5.0 kbar; 749–814 °C; 7.4–8.3 wt% H2O) than the hornblende clusters in the hornblende gabbro (0.9–2.2 kbar; 670–731 °C; 3.8–5.5 wt% H2O). Edenite in the Diorite crystallized at higher P–T and lower H2Omelt conditions (1.8–4.8 kbar; 777–979 °C; 3.2–5.2 wt% H2O) than hornblende in the microDiorite (1.3–1.5 kbar; 697–711 °C; 5.0–5.6 wt% H2O). These thermodynamic parameters reveal a multi-level magmatic storage system. Hornblende gabbro, quartz Diorite, Diorite, microDiorite, and quartz microDiorite are generally characterized by flat middle to heavy rare earth element patterns and no Eu anomalies. Geochemical modeling of heavy rare earth element concentrations in hornblende gabbro suggest that the magma was generated by >17.5% partial melting of spinel lherzolite. Slab-derived fluid input can account for the enrichments in Sr, Th, and light rare earth elements, and depletions in Nb and Ta. The multi-level magmatic storage system and slab-derived fluid input suggest that the early Carboniferous magmatism was generated in an arc-related tectonic setting. The northern orogenic and Hegenshan ophiolite belts constitute an early Carboniferous fore-arc basin–arc–back-arc basin system.
Axel Gerdes - One of the best experts on this subject based on the ideXlab platform.
-
sr nd and hf isotope composition of rocks of the reft gabbro Diorite tonalite complex eastern slope of the middle urals petrological and geological implications
Geochemistry International, 2018Co-Authors: V. N. Smirnov, K. S. Ivanov, Yu. L. Ronkin, P. A. Serov, Axel GerdesAbstract:This paper reports Rb–Sr and Sm–Nd isotope data on the gabbro–Diorite–tonalite rock association of the Reft massif (eastern margin of the Middle Urals) and Lu–Hf isotope data on zircon populations from these rocks. In terms of Nd and Hf isotope composition, the rocks of the studied association are subdivided into two distinctly different groups. The first group consists of gabbros and Diorites, as well as plagioclase granites from thin dikes and veins cutting across the gabbros. In terms of 43Nd/144Nd i = 0.512518–0.512573 (eNd(T) = +8.6...+9.7) and 176Hf/177Hf i = 0.282961–0.283019 (eHf(T) = +15.9...+17.9), these rocks are practically identical to depleted mantle. Their Nd and Hf model ages show wide variations, but in general are close to their crystallization time. The second group is represented by tonalites and quartz Diorites, which compose a large body occupying over half of the massif area. These rocks are characterized by the lower values of 143Nd/144Nd i = 0.512265–0.512388 (eNd(T) = +3.7...+6.0) and 176Hf/177Hf i = 0.282826–0.282870 (eHf(T) = +11.1...+12.7). The TDM values of the second group are much (two–three times) higher than their geological age (crystallization time), which indicates sufficiently long crustal residence time of their source. The initial 87Sr/86Sr in the rocks of both the groups varies from 0.70348 to 0.70495. This is likely explained by the different saturation of melts with fluid enriched in radiogenic Sr. The source of this fluid could be seawater that was buried in a subduction zone with oceanic sediments and released during slab dehydration. Obtained data make it possible to conclude that the formation of the studied gabbro–Diorite–tonalite association is a result of spatially and temporally close magma formation processes in the crust and mantle, with insignificant contribution of differentiation of mantle basite magma.
-
Sr, Nd, and Hf Isotope Composition of Rocks of the Reft Gabbro–Diorite–Tonalite Complex (Eastern Slope of the Middle Urals): Petrological and Geological Implications
Geochemistry International, 2018Co-Authors: V. N. Smirnov, K. S. Ivanov, Yu. L. Ronkin, P. A. Serov, Axel GerdesAbstract:This paper reports Rb–Sr and Sm–Nd isotope data on the gabbro–Diorite–tonalite rock association of the Reft massif (eastern margin of the Middle Urals) and Lu–Hf isotope data on zircon populations from these rocks. In terms of Nd and Hf isotope composition, the rocks of the studied association are subdivided into two distinctly different groups. The first group consists of gabbros and Diorites, as well as plagioclase granites from thin dikes and veins cutting across the gabbros. In terms of ^43Nd/^144Nd_ i = 0.512518–0.512573 (ε_Nd(T) = +8.6...+9.7) and ^176Hf/^177Hf_ i = 0.282961–0.283019 (ε_Hf(T) = +15.9...+17.9), these rocks are practically identical to depleted mantle. Their Nd and Hf model ages show wide variations, but in general are close to their crystallization time. The second group is represented by tonalites and quartz Diorites, which compose a large body occupying over half of the massif area. These rocks are characterized by the lower values of ^143Nd/^144Nd_ i = 0.512265–0.512388 (ε_Nd(T) = +3.7...+6.0) and ^176Hf/^177Hf_ i = 0.282826–0.282870 (ε_Hf(T) = +11.1...+12.7). The T_DM values of the second group are much (two–three times) higher than their geological age (crystallization time), which indicates sufficiently long crustal residence time of their source. The initial ^87Sr/^86Sr in the rocks of both the groups varies from 0.70348 to 0.70495. This is likely explained by the different saturation of melts with fluid enriched in radiogenic Sr. The source of this fluid could be seawater that was buried in a subduction zone with oceanic sediments and released during slab dehydration. Obtained data make it possible to conclude that the formation of the studied gabbro–Diorite–tonalite association is a result of spatially and temporally close magma formation processes in the crust and mantle, with insignificant contribution of differentiation of mantle basite magma.
-
the sr nd and hf isotopic geochemistry of rocks of the gabbro Diorite tonalite association from the eastern segment of the middle urals as an indicator of the age of the continental crust in this area
Doklady Earth Sciences, 2017Co-Authors: V. N. Smirnov, K. S. Ivanov, Yu. L. Ronkin, P. A. Serov, V A Koroteev, Axel GerdesAbstract:According to isotopic analysis of rocks of the Reft gabbro–Diorite–tonalite complex (Middle Urals), gabbro and related Diorite and dikes and vein-shaped bodies of plagiogranitoids, crosscutting gabbro, are similar to the depleted mantle substance in eNd(T) = 8.6–9.7 and eHf(T) = 15.9–17.9. Their model Hf ages are correlated with the time of crystallization. Here, the tonalites and quartz Diorites constituting most of the Reft massif are characterized by lower values: eNd(T) = 3.7–6.0, eHf(T) = 11.1–12.7, and T DM values significantly exceeding the age datings. This is evidence that Neoproterozoic crustal rocks were a source of parental magma for these rocks. The primary 87Sr/86Sr ratio in rocks of both groups is highly variable (0.70348–0.70495). The data obtained allow us to reach the conclusion that the Reft gabbro–Diorite–tonalite complex was formed as a result of nearly synchronous processes occurring in the crust and the mantle within a limited area.
-
Krasnotur’insk Skarn copper ore field, Northern Urals: The U-Pb age of ore-controlling Diorites and their place in the regional metallogeny
Doklady Earth Sciences, 2014Co-Authors: A. I. Grabezhev, V. N. Puchkov, Yu. L. Ronkin, Axel Gerdes, M. Yu. RovnushkinAbstract:The Krasnotur’insk skarn copper ore field known from the theoretical works of Academician K.S. Korzhinskii is located in the western part of the Tagil volcanic zone (in the area of the town of Krasnotur’insk). The ore field is composed of layered Devonian (Emsian) volcanosedimentary rocks intruded by small plutons of quartz Diorites, Diorites, and gabbroDiorites. Widespread pre-ore and intra-ore dikes of similar composition control the abundance of the andradite skarns formed after limestones and the magnetitesulfide and sulfide ore bodies formed after skarns. The LA-ICP-MS U-Pb concordant age of zircon from the quartz Diorite of the Vasil’evsko-Moskalevskii pluton calculated by 16 analyses (16 crystals) is 407.7 ± 1.6 Ma (MSWD = 1.5). Taking into account the geological and petrogeochemical similarity of Diorites of small plutons and intra-ore dikes, it is assumed that this age corresponds to the period of formation of the ore-magmatic system of the Krasnotur’insk skarn copper ore field. It was probably formed somewhat earlier than the Auerbakh montzonitic pluton and the accompanying skarn magnetite deposits in the south.
Hesham M Harbi - One of the best experts on this subject based on the ideXlab platform.
-
utilization of spot 5 data for mapping gold mineralized Diorite tonalite intrusion bulghah gold mine area saudi arabia
Arabian Journal of Geosciences, 2014Co-Authors: Hesham M Harbi, Ahmed MadaniAbstract:The present study utilizes the processed SPOT 5 data to discriminate and to generate 1:10,000 geologic image map to delineate the mineralized Diorite–tonalite intrusion around Bulghah gold mine area, Saudi Arabia. The rock units exposed in the area include gossan, marble, Hulayfah volcanics, Diorite–tonalite, gneissose granite, and alkali granite. Gold mineralization at Bulghah mine is hosted mainly by Syn- to Late-tectonic Diorite–tonalite intrusion aligned along N–S direction and is associated mainly with cataclastic zones and quartz veins. Gossans and jasparoidal gossans (Hulayfah group), recorded at the western side of Bulghah mine area as discontinuous small lenses, can be easily discriminated on 4/2 and 4/3 band ratio SPOT images by their white and black image signatures, respectively. Granitoids (gneissose granite and alkali granite) are easily discriminated in 3/2 ratio image, in which gneissose granite has gray image signature, whereas alkali granite has dark gray image signature. On the SPOT false color composite band ratios image (3/2 R, 4/2 G, and 4/3 B), gossan, marble, Hulayfah volcanics, Diorite–tonalite, gneissose granite, and alkali granite have sky blue, blood red, bluish light brown, orange, brick red, and deep blue colors, respectively. Fusion of the false color composite SPOT ratios image (3/2 R, 4/2 G, and 4/3 B) with the high spatial resolution SPOT pan image is performed using IHS transformation method. The fused image is used to delineate the mineralized Diorite–tonalite intrusion and to produce 1:10,000 geologic image map for Bulghah gold mine area. The present study reveals the usefulness of the processed SPOT 5 data for adding new extensions at the southern and northern boundaries of Diorite–tonalite intrusion.
-
spectroscopy of the mineralized tonalite Diorite intrusions bulghah gold mine area saudi arabia effects of opaques and alteration products on fieldspec data
Ore Geology Reviews, 2012Co-Authors: Ahmed Madani, Hesham M HarbiAbstract:Abstract This paper aims to reveal the spectral characteristics of the mineralized tonalite–Diorite intrusions exposed at Bulghah gold mine area, Saudi Arabia, using FieldSpec spectroradiometer and Landsat ETM + data. Gold mineralization at Bulghah gold mine is hosted mainly by Syn- to Late-orogenic tonalite–Diorite intrusions aligned in N–S direction and is associated mainly with cataclastic zones and quartz veins. Based on field, petrography and FieldSpec data two main tonalite–Diorite groups namely A and B are recognized. Group “A”, recorded at the mine area, is characterized by low flat spectral profiles with overall low reflectance values (~ 10%). These low values are attributed to the presence of high content of trans-opaque phases (hematite and goethite) as indicated by petrographic study. Spectral profiles of group “B”, recorded at Bulghah North area, show high reflectance values (~ 40%) with three main absorption features around the 1.45 μm, 2.20 μm and 2.35 μm wavelength regions. These absorption features are attributed mainly to the presence of clay minerals, sericite, chlorite and carbonate alteration products. To discriminate the above mentioned tonalite–Diorite groups, band ratios and Minimum Noise Fraction (MNF) techniques are conducted. Landsat false color composite band ratio image (7/4:R, 4/1:G and 4/5:B) discriminates easily the bluish brick red tonalite–Diorite intrusions from the surrounding rock units but failed to distinguish the above mentioned two tonalite–Diorite groups. On MNF3 image, the two tonalite–Diorite groups can be distinguished easily in which group “A” has white color whereas group “B” has gray color. The present study proved the usefulness of FieldSpec spectral profiles and the processed Landsat ETM + data for discriminating and delineating the mineralized tonalite–Diorite intrusions exposed at the study area.
J M Palin - One of the best experts on this subject based on the ideXlab platform.
-
beehive Diorite a late jurassic two pyroxene pluton at lake manapouri fiordland
New Zealand Journal of Geology and Geophysics, 2009Co-Authors: James M Scott, Alan Cooper, J M PalinAbstract:Abstract Beehive Diorite is a small but distinctive two‐pyroxene pluton exposed amongst the heterogeneous Hunter Intrusives on the shoreline of Lake Manapouri in Fiordland, New Zealand. This 149 Ma pluton has been partially re‐hydrated and deformed to amphibole‐bearing meta‐Diorite, but contains relict hypersthene‐augite primary assemblages in low strain domains. Mafic and felsic dikes that intrude Beehive Diorite recrystallised under amphibolite and then greenschist facies conditions. Geochemical composition indicates that Beehive Diorite is a calc‐alkaline cumulate derived from a primitive source in a volcanic arc setting, and provides a baseline for Darran Suite mafic magmatism at Lake Manapouri. The crosscutting mafic dikes also belong to the Darran Suite, but the felsic dikes belong to the Separation Point Suite. Beehive Diorite is petro graphic ally and geochemically similar to Hollyford Gabbronorite, and Diorite at Mt Underwood in northern Fiordland. This correlation indicates that subduction‐relat...
-
Beehive Diorite: A Late Jurassic two‐pyroxene pluton at Lake Manapouri, Fiordland
New Zealand Journal of Geology and Geophysics, 2009Co-Authors: James M Scott, Alan Cooper, J M PalinAbstract:Abstract Beehive Diorite is a small but distinctive two‐pyroxene pluton exposed amongst the heterogeneous Hunter Intrusives on the shoreline of Lake Manapouri in Fiordland, New Zealand. This 149 Ma pluton has been partially re‐hydrated and deformed to amphibole‐bearing meta‐Diorite, but contains relict hypersthene‐augite primary assemblages in low strain domains. Mafic and felsic dikes that intrude Beehive Diorite recrystallised under amphibolite and then greenschist facies conditions. Geochemical composition indicates that Beehive Diorite is a calc‐alkaline cumulate derived from a primitive source in a volcanic arc setting, and provides a baseline for Darran Suite mafic magmatism at Lake Manapouri. The crosscutting mafic dikes also belong to the Darran Suite, but the felsic dikes belong to the Separation Point Suite. Beehive Diorite is petro graphic ally and geochemically similar to Hollyford Gabbronorite, and Diorite at Mt Underwood in northern Fiordland. This correlation indicates that subduction‐relat...
Ahmed Madani - One of the best experts on this subject based on the ideXlab platform.
-
utilization of spot 5 data for mapping gold mineralized Diorite tonalite intrusion bulghah gold mine area saudi arabia
Arabian Journal of Geosciences, 2014Co-Authors: Hesham M Harbi, Ahmed MadaniAbstract:The present study utilizes the processed SPOT 5 data to discriminate and to generate 1:10,000 geologic image map to delineate the mineralized Diorite–tonalite intrusion around Bulghah gold mine area, Saudi Arabia. The rock units exposed in the area include gossan, marble, Hulayfah volcanics, Diorite–tonalite, gneissose granite, and alkali granite. Gold mineralization at Bulghah mine is hosted mainly by Syn- to Late-tectonic Diorite–tonalite intrusion aligned along N–S direction and is associated mainly with cataclastic zones and quartz veins. Gossans and jasparoidal gossans (Hulayfah group), recorded at the western side of Bulghah mine area as discontinuous small lenses, can be easily discriminated on 4/2 and 4/3 band ratio SPOT images by their white and black image signatures, respectively. Granitoids (gneissose granite and alkali granite) are easily discriminated in 3/2 ratio image, in which gneissose granite has gray image signature, whereas alkali granite has dark gray image signature. On the SPOT false color composite band ratios image (3/2 R, 4/2 G, and 4/3 B), gossan, marble, Hulayfah volcanics, Diorite–tonalite, gneissose granite, and alkali granite have sky blue, blood red, bluish light brown, orange, brick red, and deep blue colors, respectively. Fusion of the false color composite SPOT ratios image (3/2 R, 4/2 G, and 4/3 B) with the high spatial resolution SPOT pan image is performed using IHS transformation method. The fused image is used to delineate the mineralized Diorite–tonalite intrusion and to produce 1:10,000 geologic image map for Bulghah gold mine area. The present study reveals the usefulness of the processed SPOT 5 data for adding new extensions at the southern and northern boundaries of Diorite–tonalite intrusion.
-
spectroscopy of the mineralized tonalite Diorite intrusions bulghah gold mine area saudi arabia effects of opaques and alteration products on fieldspec data
Ore Geology Reviews, 2012Co-Authors: Ahmed Madani, Hesham M HarbiAbstract:Abstract This paper aims to reveal the spectral characteristics of the mineralized tonalite–Diorite intrusions exposed at Bulghah gold mine area, Saudi Arabia, using FieldSpec spectroradiometer and Landsat ETM + data. Gold mineralization at Bulghah gold mine is hosted mainly by Syn- to Late-orogenic tonalite–Diorite intrusions aligned in N–S direction and is associated mainly with cataclastic zones and quartz veins. Based on field, petrography and FieldSpec data two main tonalite–Diorite groups namely A and B are recognized. Group “A”, recorded at the mine area, is characterized by low flat spectral profiles with overall low reflectance values (~ 10%). These low values are attributed to the presence of high content of trans-opaque phases (hematite and goethite) as indicated by petrographic study. Spectral profiles of group “B”, recorded at Bulghah North area, show high reflectance values (~ 40%) with three main absorption features around the 1.45 μm, 2.20 μm and 2.35 μm wavelength regions. These absorption features are attributed mainly to the presence of clay minerals, sericite, chlorite and carbonate alteration products. To discriminate the above mentioned tonalite–Diorite groups, band ratios and Minimum Noise Fraction (MNF) techniques are conducted. Landsat false color composite band ratio image (7/4:R, 4/1:G and 4/5:B) discriminates easily the bluish brick red tonalite–Diorite intrusions from the surrounding rock units but failed to distinguish the above mentioned two tonalite–Diorite groups. On MNF3 image, the two tonalite–Diorite groups can be distinguished easily in which group “A” has white color whereas group “B” has gray color. The present study proved the usefulness of FieldSpec spectral profiles and the processed Landsat ETM + data for discriminating and delineating the mineralized tonalite–Diorite intrusions exposed at the study area.