Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic Belt
The acquisition of the timing and duration of metamorphic mineral growth is the key to understanding the evolution of metamorphic belts. Garnet Lu–Hf geochronology is becoming increasingly powerful in this aspect. It is believed that garnet Lu–Hf radiometric systems are preserved during low-temperat...
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MDPI AG
2023-02-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/13/2/276 |
| _version_ | 1797619124553121792 |
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| author | Chi Cao Hao Cheng |
| author_facet | Chi Cao Hao Cheng |
| author_sort | Chi Cao |
| collection | DOAJ |
| description | The acquisition of the timing and duration of metamorphic mineral growth is the key to understanding the evolution of metamorphic belts. Garnet Lu–Hf geochronology is becoming increasingly powerful in this aspect. It is believed that garnet Lu–Hf radiometric systems are preserved during low-temperature metamorphism. However, this hypothesis has not been systematically tested. To examine the Lu–Hf systematics of garnets during low-temperature metamorphism, we conducted radiometric dating on individual garnet crystals of different sizes from a single micaschist in the North Qilian orogenic belt. The garnet Lu–Hf dates correlate well with the grain sizes and their core Mn concentrations. The positive correlation between the ages and grain sizes suggests that grain size is a proxy for preserving garnet nucleation and growth history. Small grains nucleated and grew later than large crystals. The Lu–Hf date of the individual garnet crystals faithfully recorded the total growth time span. The date difference of ~16 Myr is the minimum duration of the total garnet growth. The age discrepancy between the micaschist and the eclogite indicates they may not have experienced the same subduction and exhumation in the North Qilian orogenic belt. |
| first_indexed | 2024-03-11T08:22:40Z |
| format | Article |
| id | doaj.art-e6ea8573ef1b4a3bbcc06fd718a26a3c |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-11T08:22:40Z |
| publishDate | 2023-02-01 |
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| series | Minerals |
| spelling | doaj.art-e6ea8573ef1b4a3bbcc06fd718a26a3c2023-11-16T22:19:17ZengMDPI AGMinerals2075-163X2023-02-0113227610.3390/min13020276Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic BeltChi Cao0Hao Cheng1State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, ChinaState Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, ChinaThe acquisition of the timing and duration of metamorphic mineral growth is the key to understanding the evolution of metamorphic belts. Garnet Lu–Hf geochronology is becoming increasingly powerful in this aspect. It is believed that garnet Lu–Hf radiometric systems are preserved during low-temperature metamorphism. However, this hypothesis has not been systematically tested. To examine the Lu–Hf systematics of garnets during low-temperature metamorphism, we conducted radiometric dating on individual garnet crystals of different sizes from a single micaschist in the North Qilian orogenic belt. The garnet Lu–Hf dates correlate well with the grain sizes and their core Mn concentrations. The positive correlation between the ages and grain sizes suggests that grain size is a proxy for preserving garnet nucleation and growth history. Small grains nucleated and grew later than large crystals. The Lu–Hf date of the individual garnet crystals faithfully recorded the total growth time span. The date difference of ~16 Myr is the minimum duration of the total garnet growth. The age discrepancy between the micaschist and the eclogite indicates they may not have experienced the same subduction and exhumation in the North Qilian orogenic belt.https://www.mdpi.com/2075-163X/13/2/276Lu–Hfsingle garnetQilian |
| spellingShingle | Chi Cao Hao Cheng Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic Belt Minerals Lu–Hf single garnet Qilian |
| title | Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic Belt |
| title_full | Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic Belt |
| title_fullStr | Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic Belt |
| title_full_unstemmed | Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic Belt |
| title_short | Lu–Hf Geochronology on Single Garnets in a Micaschist from the North Qilian Orogenic Belt |
| title_sort | lu hf geochronology on single garnets in a micaschist from the north qilian orogenic belt |
| topic | Lu–Hf single garnet Qilian |
| url | https://www.mdpi.com/2075-163X/13/2/276 |
| work_keys_str_mv | AT chicao luhfgeochronologyonsinglegarnetsinamicaschistfromthenorthqilianorogenicbelt AT haocheng luhfgeochronologyonsinglegarnetsinamicaschistfromthenorthqilianorogenicbelt |