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Jj Wilkinson - One of the best experts on this subject based on the ideXlab platform.
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chlorite and Epidote mineral chemistry in porphyry ore systems a case study of the northparkes district new south wales australia
Economic Geology, 2020Co-Authors: Jj Wilkinson, A PaceyAbstract:Propylitic alteration, characterized by the occurrence of chlorite and Epidote, is typically the most extensive and peripheral alteration facies developed around porphyry ore deposits. However, exploration within this alteration domain is particularly challenging, commonly owing to weak or nonexistent whole-rock geochemical gradients and the fact that similar assemblages can be developed in other geologic settings, particularly during low-grade metamorphism. We document and interpret systematic spatial trends in the chemistry of chlorite and Epidote from propylitic alteration around the E48 and E26 porphyry Cu-Au deposits of the Northparkes district, New South Wales, Australia. These trends vary as a function of both distance from hydrothermal centers and alteration paragenesis. The spatial trends identified in porphyry-related chlorite and Epidote at Northparkes include (1) a deposit-proximal increase in Ti, As, Sb, and V in Epidote and Ti in chlorite, (2) a deposit-distal increase in Co and Li in chlorite and Ba in Epidote, and (3) a pronounced halo around deposits in which Mn and Zn in chlorite, as well as Mn, Zn, Pb, and Mg in Epidote, are elevated. Chlorite Al/Si ratios and Epidote Al/Fe ratios may show behavior similar to that of Mn-Zn or may simply decrease outward, and V and Ni concentrations in chlorite are lowest in the peak Mn-Zn zone. In comparison to porphyry-related samples, chlorite from the regional metamorphic assemblage in the district contains far higher concentrations of Li, Ca, Ba, Pb, and Cu but much less Ti. Similarly, metamorphic Epidote contains higher concentrations of Sr, Pb, As, and Sb but less Bi and Ti. These chlorite and Epidote compositional trends are the net result of fluid-mineral partitioning under variable physicochemical conditions within a porphyry magmatic-hydrothermal system. They are most easily explained by the contribution of spent magmatic-derived ore fluid(s) into the propylitic domain. It is envisaged that such fluids experience progressive cooling and reduction in 𝑓s2 during outward infiltration into surrounding country rocks, with their pH controlled by the extent of rock-buffering experienced along the fluid pathway.
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The Anatomy of an Alkalic Porphyry Cu-Au System: Geology and Alteration at Northparkes Mines, New South Wales, Australia
'Society of Economic Geologists', 2020Co-Authors: Pacey A, Jj Wilkinson, Owens J, Priest D, Cooke Dr, Il MillarAbstract:The Late Ordovician-early Silurian (~455–435 Ma) Northparkes system is a group of silica-saturated, alkalic porphyry deposits and prospects that developed within the Macquarie island arc. The system is host to a spectacular and diverse range of rocks and alteration-mineralization textures that facilitate a detailed understanding of its evolution, in particular the nature and controls of porphyry-related propylitic alteration. The first intrusive phase at Northparkes is a pre- to early-mineralization pluton that underlies all the deposits and varies in composition from a biotite quartz monzonite to alkali feldspar granite. Prior to total crystallization, this pluton was intruded by a more primitive quartz monzonite that marks the onset of a fertile fractionation series. Toward its upper levels, the quartz monzonite is porphyritic and locally rich in Cu sulfides. Subsequently, a complex series of synmineralization quartz monzonite porphyries was emplaced. The quartz monzonite porphyry intrusions have a distinct pipe-like morphology and are ubiquitously K-feldspar–altered with a crystal-crowded porphyritic texture. The textures of the quartz monzonite porphyries and common occurrence of porphyry-cemented contact breccias indicate they were forcibly emplaced and of relatively low viscosity. The quartz monzonite porphyries are therefore interpreted as crystal-bearing, silicate melt-aqueous fluid slurries that represent the conduits through which deep-seated magmatic-derived ore fluid was discharged into the shallow crust (1–2 km depth). Each deposit is centered on a multiphase cluster of quartz monzonite porphyry intrusions that drove discrete hydrothermal systems. Initial fluid evolution was similar in all the deposits, with three major alteration facies developed as largely concentric zones around the quartz monzonite porphyry complexes. The innermost zone is host to Cu sulfide ore and dominated by K-feldspar alteration. This transitions outward through a shell of magnetite ± biotite alteration, with pyrite and minor chalcopyrite, to an outer halo of propylitic alteration. Generally, Epidote, chlorite, and pyrite are abundant in the most deposit-proximal propylitic zone, with a decrease in the abundance of pyrite, and then Epidote, with increasing distance away from deposit centers. Propylitic alteration, particularly within relatively low permeability rocks, is fracture-controlled and a hierarchy of veins is observed. Veins of chlorite-quartz-pyrite ± calcite ± hematite ± Epidote ± chalcopyrite (P1) appear to represent the principal fluid conduits. They are surrounded by pervasive and intense alteration halos with a distinct mineralogical zonation from vein-proximal chlorite-sericite (phengite) ± Epidote ± pyrite, through hematite-sericite-chlorite ± Epidote, ultimately to a vein-distal hematite-albite ± chlorite ± Epidote assemblage. These P1 veins are surrounded by regions in which smaller Epidote-chlorite ± calcite ± quartz ± pyrite veins (P2) are abundant, again with zoned alteration envelopes: vein-proximal chlorite-sericite (phengite) ± Epidote ± pyrite grades out into an Epidote-rich zone, which in turn transitions into vein-distal albite-hematite ± chlorite ± Epidote. Areas of weakest propylitic alteration, distant from both P1 and P2 veins, are characterized by small Epidote-only veinlets (P3) with albite-hematite halos. Mineralogical transitions across the propylitic zone are therefore repeated in the evolution from P1 to P3 veins, as well as in the halos around these veins. It is the overall vein abundance and overlap of associated alteration halos that controls the intensity and appearance of propylitic alteration in most rocks. Such scale invariance and spatial relationships strongly suggest the transition from P1 to P3 veins reflects a broadly decreasing outward flux of (magmatic-derived?) fluid that passed through the fracture network and progressively reacted with country rocks. Further support for this hypothesis comes from crosscutting relationships and Rb-Sr dating of Epidote (returning an age of 450 ± 11 Ma), which demonstrate the bulk of propylitic alteration was coeval with mineralization and potassic alteration. Late-stage fluid evolution at each deposit was unique. Much of the E48 orebody, and locally the GRP314 deposit, was overprinted by texturally destructive, white sericite-albite-quartz-alunite ± chlorite alteration. In the E26 deposit and in regions of the GRP314 deposit a series of quartz-anhydrite ± pyrite ± Cu sulfide veins with distinctive, vein-proximal, sericite-dominant alteration halos cuts the primary, deposit-concentric alteration facies. The vein-distal mineralogy of these alteration halos is controlled by their distance from deposit centers, changing from K-feldspar ± biotite in deposit-proximal veins to chlorite ± Epidote-albite in depositdistal veins. Late-mineralization quartz monzonite porphyries at E26 and GRP314 also appear to be related to the generation of anhydrite-quartz ± sphalerite veins and a set of quartz-calcite-pyrite-sphalerite ± chalcopyrite ± galena veins. Postmineralization magmatic activity produced relatively primitive and barren monzonite porphyries and younger alkali basalt dikes.The attached document is the author(’s’) final accepted/submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it
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Chlorite and Epidote mineral chemistry in porphyry ore systems: a case study of the Northparkes District, New South Wales, Australia
'Society of Economic Geologists', 2020Co-Authors: Pacey A, Jj Wilkinson, Cooke DrAbstract:Propylitic alteration, characterized by the occurrence of chlorite and Epidote, is typically the most extensive and peripheral alteration facies developed around porphyry ore deposits. However, exploration within this alteration domain is particularly challenging, commonly owing to weak or nonexistent whole-rock geochemical gradients and the fact that similar assemblages can be developed in other geologic settings, particularly during low-grade metamorphism. We document and interpret systematic spatial trends in the chemistry of chlorite and Epidote from propylitic alteration around the E48 and E26 porphyry Cu-Au deposits of the Northparkes district, New South Wales, Australia. These trends vary as a function of both distance from hydrothermal centers and alteration paragenesis.The spatial trends identified in porphyry-related chlorite and Epidote at Northparkes include (1) a deposit-proximal increase in Ti, As, Sb, and V in Epidote and Ti in chlorite, (2) a deposit-distal increase in Co and Li in chlorite and Ba in Epidote, and (3) a pronounced halo around deposits in which Mn and Zn in chlorite, as well as Mn, Zn, Pb, and Mg in Epidote, are elevated. Chlorite Al/Si ratios and Epidote Al/Fe ratios may show behavior similar to that of Mn-Zn or may simply decrease outward, and V and Ni concentrations in chlorite are lowest in the peak Mn-Zn zone. In comparison to porphyry-related samples, chlorite from the regional metamorphic assemblage in the district contains far higher concentrations of Li, Ca, Ba, Pb, and Cu but much less Ti. Similarly, metamorphic Epidote contains higher concentrations of Sr, Pb, As, and Sb but less Bi and Ti.These chlorite and Epidote compositional trends are the net result of fluid-mineral partitioning under variable physicochemical conditions within a porphyry magmatic-hydrothermal system. They are most easily explained by the contribution of spent magmatic-derived ore fluid(s) into the propylitic domain. It is envisaged that such fluids experience progressive cooling and reduction i
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Using mineral chemistry to aid exploration: a case study from the resolution porphyry Cu-Mo deposit, Arizona
'Society of Economic Geologists', 2020Co-Authors: Cooke Dr, Jj Wilkinson, Baker M, Agnew P, Phillips J, Chang Z, Chen H, Cc Wilkinson, Inglis S, Hollings PAbstract:The giant, high-grade Resolution porphyry Cu-Mo deposit in the Superior district of Arizona is hosted in Proterozoic and Paleozoic basement and in an overlying Cretaceous volcaniclastic breccia and sandstone package. Resolution has a central domain of potassic alteration that extends more than 1 km outboard of the ore zone, overlapping with a propylitic halo characterized by Epidote, chlorite, and pyrite that is particularly well developed in the Laramide volcaniclastic rocks and Proterozoic dolerite sills. The potassic and propylitic assemblages were overprinted in the upper parts of the deposit by intense phyllic and advanced argillic alteration. The district was disrupted by Tertiary Basin and Range extension, and the fault block containing Resolution and its Cretaceous host succession was buried under thick mid-Miocene dacitic volcanic cover, obscuring the geologic, geophysical, and geochemical footprint of the deposit. To test the potential of propylitic mineral chemistry analyses to aid in the detection of concealed porphyry deposits, a blind test was conducted using a suite of Epidote-chlorite ± pyrite-altered Laramide volcaniclastic rocks and Proterozoic dolerites collected from the propylitic halo, with samples taken from two domains located to the north and south and above the Resolution ore zone. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data of Epidote provided indications of deposit fertility and proximity. Competition for chalcophile elements (As, Sb, Pb) between coexisting pyrite and Epidote grains led to a subdued As-Sb fertility response in Epidote, consistent with Epidote collected between 0.7 and 1.5 km from the center of a large porphyry deposit. Temperature-sensitive trace elements in chlorite provided coherent spatial zonation patterns, implying a heat source centered at depth between the two sample clusters, and application of chlorite proximitor calculations based on LA-ICP-MS analyses provided a precisely defined drill target in this location in three dimensions. Drilling of this target would have resulted in the discovery of Resolution, confirming that Epidote and chlorite mineral chemistry can potentially add value to porphyry exploration under cover
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The Anatomy of an Alkalic Porphyry Cu-‐Au System: Geology and Alteration at Northparkes Mines, NSW, Australia
'Society of Economic Geologists', 2019Co-Authors: Pacey A, Jj Wilkinson, Owens J, Priest D, Cooke Dr, Il MillarAbstract:The Late Ordovician-Early Silurian (~455-435 Ma) Northparkes system is a group of silica-saturated, alkalic porphyry deposits and prospects which developed within the Macquarie Island Arc. The system is host to a spectacular and diverse range of rocks and alteration-mineralization textures that facilitate a detailed understanding of its evolution, in particular into the nature and controls of porphyry-related propylitic alteration. The first intrusive phase at Northparkes is a pre- to early-mineralization pluton that underlies all the deposits and varies in composition from a biotite quartz monzonite (BQM) to alkali feldspar granite (AFG). Prior to total crystallization, this pluton was intruded by a more primitive quartz monzonite (QMZ) that marks the onset of a fertile fractionation series. Towards its upper levels, the QMZ is porphyritic and locally rich in Cu sulfides. Subsequently, a complex series of syn-mineralization quartz monzonite porphyries (QMP) were emplaced. The QMP intrusions have a distinct pipe-like morphology and are ubiquitously K-feldspar altered with a crystal-crowded porphyritic texture. The textures of the QMPs and common occurrence of porphyry-cemented contact breccias indicate they were forcibly emplaced and of relatively low viscosity. The QMPs are therefore interpreted as crystal-bearing, silicate melt-aqueous fluid slurries that represent the conduits through which deep-seated magmatic-derived ore fluid was discharged into the shallow crust (1-2 km depth). Each deposit is centred on a multiphase cluster of QMP intrusions that drove discrete hydrothermal systems. Initial fluid evolution was similar in all the deposits, with three major alteration facies developed as largely concentric zones around the QMP complexes. The innermost zone is host to Cu sulfide ore and dominated by K-feldspar alteration. This transitions outwards through a shell of magnetite ± biotite alteration, with pyrite and minor chalcopyrite, to an outer halo of propylitic alteration. Generally, Epidote, chlorite and pyrite are abundant in the most deposit-proximal propylitic zone, with a decrease in the abundance of pyrite, and then Epidote, with increasing distance away from deposit centers. Propylitic alteration, particularly within relatively low permeability rocks, is fracture-controlled and a hierarchy of veins is observed. Veins of chlorite-quartz-pyrite ± calcite ± hematite ± Epidote ± chalcopyrite (P1) appear to represent the principal fluid conduits. They are surrounded by pervasive and intense alteration halos with a distinct mineralogical zonation from vein-proximal chlorite-sericite (phengite) ± Epidote ± pyrite, through hematite-sericite-chlorite ± Epidote, ultimately to a vein-distal hematite-albite ± chlorite ± Epidote assemblage. These P1 veins are surrounded by regions in which smaller Epidote-chlorite ± calcite ± quartz ± pyrite veins (P2) are abundant, again with zoned alteration envelopes: vein-proximal chlorite-sericite (phengite) ± Epidote ± pyrite grades out into an Epidote-rich zone, which in turn transitions into vein-distal albite-hematite ± chlorite ± Epidote. Areas of weakest propylitic alteration, distant from both P1 and P2 veins, are characterised by small Epidote-only veinlets (P3) with albite-hematite halos. Mineralogical transitions across the propylitic zone are therefore repeated in the evolution from P1 to P3 veins, as well as in the halos around these veins. It is the overall vein abundance and overlap of associated alteration halos which controls the intensity and appearance of propylitic alteration in most rocks. Such scale-invariance and spatial relationships strongly suggests the transition from P1 to P3 veins reflects a broadly decreasing outward flux of (magmatic-derived?) fluid that passed through the fracture network and progressively reacted with country rocks. Further support for this hypothesis comes from cross cutting relationships and Rb-Sr dating of Epidote (returning an age of 450 ± 11 Ma), which demonstrate the bulk of propylitic alteration was coeval with mineralization and potassic alteration. Late-stage fluid evolution at each deposit was unique. Much of the E48 orebody and locally the GRP314 deposit was overprinted by texturally-destructive, white sericite-albite-quartz-alunite ± chlorite alteration. In the E26 deposit, and in regions of the GRP314 deposit, a series of quartz-anhydrite ± pyrite ± Cu sulfide veins with distinctive, vein-proximal, sericite-dominant alteration halos cut the primary, deposit-concentric alteration facies. The vein-distal mineralogy of these alteration halos is controlled by their distance from deposit centers, changing from K-feldspar ± biotite in deposit-proximal veins to chlorite ± Epidote-albite in deposit-distal veins. Late-mineralization QMPs at E26 and GRP314 also appear to be related to the generation of anhydrite-quartz ± sphalerite veins and a set of quartz-calcite-pyrite-sphalerite ± chalcopyrite ± galena veins. Post-mineralization magmatic activity produced relatively primitive and barren monzonite porphyries and younger alkali basalt dikes.© 2019 Economic Geology This document is the author’s final accepted version of the journal article. You are advised to consult the published version if you wish to cite from it
Liangqing Cheng - One of the best experts on this subject based on the ideXlab platform.
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heavy mineral assemblages and sedimentation rates of eastern central asian loess paleoenvironmental implications
Palaeogeography Palaeoclimatology Palaeoecology, 2020Co-Authors: Hong Chang, Yougui Song, Liangqing Cheng, Rustam Orozbaev, Mengxiu Zeng, Huifang LiuAbstract:Abstract Central Asian loess deposits record the evolution of aridification across the Asian interior. However, paleoclimatic proxies are strongly influenced by the variation of the dust source and accumulation process. In order to decipher the paleoenvironmental changes, a sensitive paleoclimatic proxy with clear source and accumulation process will be needed. In this study, heavy mineral assemblages and sedimentation rates were investigated in a 30-kyr loess section in the Ili Basin, Xinjiang, northwestern China. During Marine Isotope Stage (MIS) 2, trends in dust sedimentation rate were similar to those of the Chinese Loess Plateau (CLP), in anti-phase with Northern Hemisphere Summer Insolation (NHSI) at 65°N. Amphibole/Epidote ratios (contents and mean grain size) were low during cold phases, such as the late Last Glacial Maximum (LGM) and Heinrich Event (H) 1; their ratios were higher during adjacent warm periods; this was attributed to aeolian sorting during transportation. Namely, greater sorting between amphibole and Epidote occurred in warmer phases, and weaker sorting occurred in colder phases. The amphibole/Epidote ratio could serve as a proxy for wind intensity, and thus the Siberian High (SH) intensity. Amphibole/Epidote ratio was a more appropriate proxy to record wind intensity than dust sedimentation rate which was also influenced by sediment availability. A higher amphibole/Epidote ratio corresponded to a more negative East Asian stalagmite δ18O, indicating an anti-phase relationship between the SH and East Asian Summer Monsoon (EASM) during the MIS 2.
Rustam Orozbaev - One of the best experts on this subject based on the ideXlab platform.
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heavy mineral assemblages and sedimentation rates of eastern central asian loess paleoenvironmental implications
Palaeogeography Palaeoclimatology Palaeoecology, 2020Co-Authors: Hong Chang, Yougui Song, Liangqing Cheng, Rustam Orozbaev, Mengxiu Zeng, Huifang LiuAbstract:Abstract Central Asian loess deposits record the evolution of aridification across the Asian interior. However, paleoclimatic proxies are strongly influenced by the variation of the dust source and accumulation process. In order to decipher the paleoenvironmental changes, a sensitive paleoclimatic proxy with clear source and accumulation process will be needed. In this study, heavy mineral assemblages and sedimentation rates were investigated in a 30-kyr loess section in the Ili Basin, Xinjiang, northwestern China. During Marine Isotope Stage (MIS) 2, trends in dust sedimentation rate were similar to those of the Chinese Loess Plateau (CLP), in anti-phase with Northern Hemisphere Summer Insolation (NHSI) at 65°N. Amphibole/Epidote ratios (contents and mean grain size) were low during cold phases, such as the late Last Glacial Maximum (LGM) and Heinrich Event (H) 1; their ratios were higher during adjacent warm periods; this was attributed to aeolian sorting during transportation. Namely, greater sorting between amphibole and Epidote occurred in warmer phases, and weaker sorting occurred in colder phases. The amphibole/Epidote ratio could serve as a proxy for wind intensity, and thus the Siberian High (SH) intensity. Amphibole/Epidote ratio was a more appropriate proxy to record wind intensity than dust sedimentation rate which was also influenced by sediment availability. A higher amphibole/Epidote ratio corresponded to a more negative East Asian stalagmite δ18O, indicating an anti-phase relationship between the SH and East Asian Summer Monsoon (EASM) during the MIS 2.
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petrology of metamorphic rocks from the atbashy complex southern tien shan kyrgyzstan
Geoscience frontiers, 2017Co-Authors: Maksatbek Satybaev, Rustam Orozbaev, Lin Ding, Akira Takasu, Apas Bakirov, Kadyrbek Sakiev, Fulong Cai, Janybek Usonbekovich BaslakunovAbstract:Abstract The high- to ultrahigh-pressure metamorphic rocks of the Atbashy complex were petrologically investigated. The eclogites of the Choloktor Formation show a prograde evolution from Epidote-blueschist facies (P = 17–21 kbar and T = 450–515 °C) to peak eclogite-UHP conditions (P = 26–29 kbar and T = 545–615 °C) with a subsequent Epidote-amphibolite and greenschist facies overprint. The mica-schists of the Choloktor Formation also show a clockwise P-T path from blueschist/Epidote-blueschist facies conditions through peak eclogite facies conditions (P = 21–23 kbar and T = 530–580 °C) to retrograde Epidote-amphibolite and greenschist facies stages. A comparison of the P-T paths in the eclogites and mica-schists of Choloktor Formation reveal that they may have shared their P-T history from peak to retrograde stages. The mica-schists of the Atbashy Formation record peak metamorphism of P = 10–12 kbar and T = 515–565 °C, which indicates that the highest grade of regional metamorphism in the Atbashy Ridge was Epidote-amphibolite facies. The newly obtained P-T conditions for the mica-schists of Choloktor Formation indicate that sheets of sedimentary rocks were brought to great depths along the subduction zone and they metamorphosed under eclogite facies HP conditions. The eclogite blocks were amalgamated with mica-schists of Choloktor Formation in the eclogite facies HP conditions and together they experienced isothermal decompression to ∼40 km. During this path, the eclogites and mica-schists of Choloktor Formation docked with mica-schists of Atbashy Formation at 10–12 kbar and 515–565 °C, and from this depth (∼40 km) the whole sequence was exhumed together. These new results improve our understanding of high-pressure metamorphism in subduction-related accretionary prism zones and the exhumation processes of deeply-seated rocks in the Atbashy HP-UHP complex.
Huifang Liu - One of the best experts on this subject based on the ideXlab platform.
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heavy mineral assemblages and sedimentation rates of eastern central asian loess paleoenvironmental implications
Palaeogeography Palaeoclimatology Palaeoecology, 2020Co-Authors: Hong Chang, Yougui Song, Liangqing Cheng, Rustam Orozbaev, Mengxiu Zeng, Huifang LiuAbstract:Abstract Central Asian loess deposits record the evolution of aridification across the Asian interior. However, paleoclimatic proxies are strongly influenced by the variation of the dust source and accumulation process. In order to decipher the paleoenvironmental changes, a sensitive paleoclimatic proxy with clear source and accumulation process will be needed. In this study, heavy mineral assemblages and sedimentation rates were investigated in a 30-kyr loess section in the Ili Basin, Xinjiang, northwestern China. During Marine Isotope Stage (MIS) 2, trends in dust sedimentation rate were similar to those of the Chinese Loess Plateau (CLP), in anti-phase with Northern Hemisphere Summer Insolation (NHSI) at 65°N. Amphibole/Epidote ratios (contents and mean grain size) were low during cold phases, such as the late Last Glacial Maximum (LGM) and Heinrich Event (H) 1; their ratios were higher during adjacent warm periods; this was attributed to aeolian sorting during transportation. Namely, greater sorting between amphibole and Epidote occurred in warmer phases, and weaker sorting occurred in colder phases. The amphibole/Epidote ratio could serve as a proxy for wind intensity, and thus the Siberian High (SH) intensity. Amphibole/Epidote ratio was a more appropriate proxy to record wind intensity than dust sedimentation rate which was also influenced by sediment availability. A higher amphibole/Epidote ratio corresponded to a more negative East Asian stalagmite δ18O, indicating an anti-phase relationship between the SH and East Asian Summer Monsoon (EASM) during the MIS 2.
Hong Chang - One of the best experts on this subject based on the ideXlab platform.
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heavy mineral assemblages and sedimentation rates of eastern central asian loess paleoenvironmental implications
Palaeogeography Palaeoclimatology Palaeoecology, 2020Co-Authors: Hong Chang, Yougui Song, Liangqing Cheng, Rustam Orozbaev, Mengxiu Zeng, Huifang LiuAbstract:Abstract Central Asian loess deposits record the evolution of aridification across the Asian interior. However, paleoclimatic proxies are strongly influenced by the variation of the dust source and accumulation process. In order to decipher the paleoenvironmental changes, a sensitive paleoclimatic proxy with clear source and accumulation process will be needed. In this study, heavy mineral assemblages and sedimentation rates were investigated in a 30-kyr loess section in the Ili Basin, Xinjiang, northwestern China. During Marine Isotope Stage (MIS) 2, trends in dust sedimentation rate were similar to those of the Chinese Loess Plateau (CLP), in anti-phase with Northern Hemisphere Summer Insolation (NHSI) at 65°N. Amphibole/Epidote ratios (contents and mean grain size) were low during cold phases, such as the late Last Glacial Maximum (LGM) and Heinrich Event (H) 1; their ratios were higher during adjacent warm periods; this was attributed to aeolian sorting during transportation. Namely, greater sorting between amphibole and Epidote occurred in warmer phases, and weaker sorting occurred in colder phases. The amphibole/Epidote ratio could serve as a proxy for wind intensity, and thus the Siberian High (SH) intensity. Amphibole/Epidote ratio was a more appropriate proxy to record wind intensity than dust sedimentation rate which was also influenced by sediment availability. A higher amphibole/Epidote ratio corresponded to a more negative East Asian stalagmite δ18O, indicating an anti-phase relationship between the SH and East Asian Summer Monsoon (EASM) during the MIS 2.