Zircon and monazite U-Pb ages, chemical and Sr-Nd-Pb-Hf isotopic compositions of these Eocene-Miocene gabbroic diorite- granodiorite- leucogranite -pegmatite complex along the southeastern side of the Hindu Kushi
Cite as:
Zhang, Chuan-Lin; Zou, Hai-Bo; Sargazi, Masumeh (2025): Zircon and monazite U-Pb ages, chemical and Sr-Nd-Pb-Hf isotopic compositions of these Eocene-Miocene gabbroic diorite- granodiorite- leucogranite -pegmatite complex along the southeastern side of the Hindu Kushi. GFZ Data Services. https://doi.org/10.5880/fidgeo.2025.090
Status
I N R E V I E W : Zhang, Chuan-Lin; Zou, Hai-Bo; Sargazi, Masumeh (2025): Zircon and monazite U-Pb ages, chemical and Sr-Nd-Pb-Hf isotopic compositions of these Eocene-Miocene gabbroic diorite- granodiorite- leucogranite -pegmatite complex along the southeastern side of the Hindu Kushi. GFZ Data Services. https://doi.org/10.5880/fidgeo.2025.090
Abstract
In this contribution, we identified diverse Oligocene-Early Miocene intrusions along the southeastern margin of the Hindu Kushi between Pakistan and Afghanistan, including gabboric diorite, diorite, granodiorite and voluminous leucogranites- pegmatites. Field observations, petrography, ages and geochemistry of these diverse intrusions are presented. Integrating this work with the previous studies on the Eocene-Miocene igneous rocks at Pamir, we aim to have a better understanding the continental uplifting and geodynamic evolution processes of the Pamir Plateau after the final closure of the Neo-Tethys. Additionally, this study sheds new lights on our understanding of the rare metal mineralization in the Hindu Kushi orogenic belt.
Methods
Monazite U-Pb dating was carried in Tianjin Geology Survey Center, CGS. Monazite grains and the monazite standard 44069 (Wan et al., 2004) were mounted in epoxy mounts. The mounts were subsequently polished to section the crystals almost in half. All the monazite grains were documented with BSE images to reveal their inner structures. Monazite U-Pb ages were determined using the LA-ICPMS method. Detailed analytical procedures have been reported in Cui et al. (2012).
Whole-rock major elements were determined using X-ray fluorescence (XRF) spectroscopy method at the ALS Laboratory Group, an Australian ICP-MS analytical lab in Guangzhou (China). Before analysis, samples (2 g) were fused with a Li2B4O7 flux under a sample-to-flux ratio of 1:5 and temperature of 1150-1250°C to form glass fusion discs for XRF analysis. The analytical precision was better than 0.1% for all the oxides. Trace elements were analyzed using a PE Elan 600 ICP-MS at the Chinese Institute of Geochemistry of the Chinese Academy of Science, following procedures similar to those described by Li et al. (2006). In-run analytical precision for most elements was better than 2-5%.
Sr-Nd isotopic compositions were determined using a Micromass Isoprobe MC-ICPMS at the TIGMR, CGS, following the procedure of Li et al. (2006). Measured 87Sr/86Sr and 143Nd/144Nd ratios were normalized to 86Sr/88Sr = 0.1194 and 146Nd/144Nd = 0.7219, respectively. The reported 87Sr/86Sr and 143Nd/144Nd ratios were adjusted to the standard NBS SRM 987 of 87Sr/86Sr = 0.71025 and Shin Etsu JNdi-1 of 143Nd/144Nd = 0.512115, respectively.
The 20XPb/204Pb ratio tests were normalized to results of the well-accepted Standard Reference Material NBS 981 values of 208Pb/204Pb = 36.7262 ± 31, 207Pb/204Pb = 15.5000 ± 13, 206Pb/204Pb = 16.9416 ± 13 (Baker et al., 2004). One NIST 981 standard was measured for every ten samples analyzed. Analyses of the NBS SRM 981 standard yielded external precisions of 0.03 % (2RSD) for 20XPb/204Pb ratios. In addition, the USGS reference material BCR-2 (basalt) yielded results of 208Pb/204Pb = 38.737 ± 28, 207Pb/204Pb = 15.628 ± 3, 206Pb/204Pb = 18.757 ± 22 (2σ, n=61), respectively, which is identical within error of 0.03 % to their published values (Zhang and Hu, 2020).
Zircon in situ Lu-Hf isotopes were determined using a New wave-193 nm ArF excimer laser-ablation system linked to a Neptune MC-ICPMS at TIGMR, CGS. GJ-1 zircon standard was used for external calibration. The analyses were conducted with a beam diameter of 50 μm, 8 Hz repetition rate with a laser power of 15 J/cm2. Detailed operating conditions for the laser ablation system, the MC-ICP-MS instrument, and the analytical method, were documented in Geng et al. (2011).
title: Zircon and monazite U-Pb ages, chemical and Sr-Nd-Pb-Hf isotopic compositions of these Eocene-Miocene gabbroic diorite- granodiorite- leucogranite -pegmatite complex along the southeastern side of the Hindu Kushi
CharacterString: Zircon and monazite U-Pb ages, chemical and Sr-Nd-Pb-Hf isotopic compositions of these Eocene-Miocene gabbroic diorite- granodiorite- leucogranite -pegmatite complex along the southeastern side of the Hindu Kushi
CharacterString: In this contribution, we identified diverse Oligocene-Early Miocene intrusions along the southeastern margin of the Hindu Kushi between Pakistan and Afghanistan, including gabboric diorite, diorite, granodiorite and voluminous leucogranites- pegmatites. Field observations, petrography, ages and geochemistry of these diverse intrusions are presented. Integrating this work with the previous studies on the Eocene-Miocene igneous rocks at Pamir, we aim to have a better understanding the continental uplifting and geodynamic evolution processes of the Pamir Plateau after the final closure of the Neo-Tethys. Additionally, this study sheds new lights on our understanding of the rare metal mineralization in the Hindu Kushi orogenic belt.
CI_OnLineFunctionCode (codeList=http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode codeListValue=http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode_information): information
CharacterString: Monazite U-Pb dating was carried in Tianjin Geology Survey Center, CGS. Monazite grains and the monazite standard 44069 (Wan et al., 2004) were mounted in epoxy mounts. The mounts were subsequently polished to section the crystals almost in half. All the monazite grains were documented with BSE images to reveal their inner structures. Monazite U-Pb ages were determined using the LA-ICPMS method. Detailed analytical procedures have been reported in Cui et al. (2012).
Whole-rock major elements were determined using X-ray fluorescence (XRF) spectroscopy method at the ALS Laboratory Group, an Australian ICP-MS analytical lab in Guangzhou (China). Before analysis, samples (2 g) were fused with a Li2B4O7 flux under a sample-to-flux ratio of 1:5 and temperature of 1150-1250°C to form glass fusion discs for XRF analysis. The analytical precision was better than 0.1% for all the oxides. Trace elements were analyzed using a PE Elan 600 ICP-MS at the Chinese Institute of Geochemistry of the Chinese Academy of Science, following procedures similar to those described by Li et al. (2006). In-run analytical precision for most elements was better than 2-5%.
Sr-Nd isotopic compositions were determined using a Micromass Isoprobe MC-ICPMS at the TIGMR, CGS, following the procedure of Li et al. (2006). Measured 87Sr/86Sr and 143Nd/144Nd ratios were normalized to 86Sr/88Sr = 0.1194 and 146Nd/144Nd = 0.7219, respectively. The reported 87Sr/86Sr and 143Nd/144Nd ratios were adjusted to the standard NBS SRM 987 of 87Sr/86Sr = 0.71025 and Shin Etsu JNdi-1 of 143Nd/144Nd = 0.512115, respectively.
The 20XPb/204Pb ratio tests were normalized to results of the well-accepted Standard Reference Material NBS 981 values of 208Pb/204Pb = 36.7262 ± 31, 207Pb/204Pb = 15.5000 ± 13, 206Pb/204Pb = 16.9416 ± 13 (Baker et al., 2004). One NIST 981 standard was measured for every ten samples analyzed. Analyses of the NBS SRM 981 standard yielded external precisions of 0.03 % (2RSD) for 20XPb/204Pb ratios. In addition, the USGS reference material BCR-2 (basalt) yielded results of 208Pb/204Pb = 38.737 ± 28, 207Pb/204Pb = 15.628 ± 3, 206Pb/204Pb = 18.757 ± 22 (2σ, n=61), respectively, which is identical within error of 0.03 % to their published values (Zhang and Hu, 2020).
Zircon in situ Lu-Hf isotopes were determined using a New wave-193 nm ArF excimer laser-ablation system linked to a Neptune MC-ICPMS at TIGMR, CGS. GJ-1 zircon standard was used for external calibration. The analyses were conducted with a beam diameter of 50 μm, 8 Hz repetition rate with a laser power of 15 J/cm2. Detailed operating conditions for the laser ablation system, the MC-ICP-MS instrument, and the analytical method, were documented in Geng et al. (2011).
Released
Dataset
Abstract
;Hohai University, Nanjing, China
Files
