TY - JOUR
T1 - Exhumation history of the north-central Shanxi Rift, North China, revealed by low-temperature thermochronology
AU - Clinkscales, Christopher
AU - Kapp, Paul
AU - Wang, Houqi
N1 - Funding Information:
We thank Lin Ding and Fulong Cai from the Institute of Tibetan Plateau Research, Chinese Academy of the Sciences for their logistical support during our field work. We thank Stuart Thomson, Barbara Carrapa, Peter Reiners, and Uttam Chowdhury for their assistance with data collection and analysis. We thank Mark Allen and an anonymous reviewer for their comments to help clarify this manuscript, and An Yin for editorial handling. This research was funded by National Science Foundation Office of International Science and Engineering grant #1545859.
Funding Information:
We thank Lin Ding and Fulong Cai from the Institute of Tibetan Plateau Research, Chinese Academy of the Sciences for their logistical support during our field work. We thank Stuart Thomson, Barbara Carrapa, Peter Reiners, and Uttam Chowdhury for their assistance with data collection and analysis. We thank Mark Allen and an anonymous reviewer for their comments to help clarify this manuscript, and An Yin for editorial handling. This research was funded by National Science Foundation Office of International Science and Engineering grant # 1545859 .
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/4/15
Y1 - 2020/4/15
N2 - We present new apatite U-Th-Sm/He (AHe; n = 51), apatite fission track data (AFT; n = 12), and zircon U-Th/He (ZHe; n = 8) data for two elevation transects in the north-central Shanxi Rift, North China. Low-temperature thermochronologic data combined with forward and inverse time-temperature history models reveal a Precambrian to Quaternary thermal history characterized by: (1) cooling to <∼50 °C during the Proterozoic, consistent with the development of a regional unconformity above Neoarchean–Paleoproterozoic cratonic basement rocks; (2) reheating to <∼180 °C due to sediment burial during the Paleozoic to Mesozoic; (3) cooling at a rate >3.5 °C/Ma during the Late Jurassic to earliest Cretaceous Yanshanian orogeny; (4) a possible ca. 120-90 Ma reheating event due to elevated geothermal gradients and/or local sediment burial; (5) Late Cretaceous (ca. 110-65 Ma) cooling contemporaneous with regional extension in eastern Asia and denudation of the paleo-Taihangshan highlands; and finally, (6) post ca. 10 Ma cooling associated with extension in the Shanxi Rift. AFT dates from the deepest exhumed structural positions of the sampled footwall blocks are mostly >65 Ma and AHe dates tend to be highly dispersed within samples. AFT inverse and AHe forward model results indicate that samples were at temperatures of <∼75 °C by ca. 70 Ma. Despite the early Cenozoic and older AFT and AHe dates, metamict zircon grains with high effective uranium (eU >∼750 ppm) yield young ZHe dates of ca. 13-9 Ma, consistent with Late Miocene exhumation. We argue for the onset of latest cooling by ca. 10 Ma based on these ZHe dates; however, the precise timing for the onset of rifting remains uncertain. The results further suggest that Late Miocene–Quaternary extension in the north-central Shanxi Rift is responsible for ≤∼2.5 km of exhumation, such that published Quaternary extension and fault throw rates are significantly (>100%) higher than long-term rates inferred from the thermochronologic data.
AB - We present new apatite U-Th-Sm/He (AHe; n = 51), apatite fission track data (AFT; n = 12), and zircon U-Th/He (ZHe; n = 8) data for two elevation transects in the north-central Shanxi Rift, North China. Low-temperature thermochronologic data combined with forward and inverse time-temperature history models reveal a Precambrian to Quaternary thermal history characterized by: (1) cooling to <∼50 °C during the Proterozoic, consistent with the development of a regional unconformity above Neoarchean–Paleoproterozoic cratonic basement rocks; (2) reheating to <∼180 °C due to sediment burial during the Paleozoic to Mesozoic; (3) cooling at a rate >3.5 °C/Ma during the Late Jurassic to earliest Cretaceous Yanshanian orogeny; (4) a possible ca. 120-90 Ma reheating event due to elevated geothermal gradients and/or local sediment burial; (5) Late Cretaceous (ca. 110-65 Ma) cooling contemporaneous with regional extension in eastern Asia and denudation of the paleo-Taihangshan highlands; and finally, (6) post ca. 10 Ma cooling associated with extension in the Shanxi Rift. AFT dates from the deepest exhumed structural positions of the sampled footwall blocks are mostly >65 Ma and AHe dates tend to be highly dispersed within samples. AFT inverse and AHe forward model results indicate that samples were at temperatures of <∼75 °C by ca. 70 Ma. Despite the early Cenozoic and older AFT and AHe dates, metamict zircon grains with high effective uranium (eU >∼750 ppm) yield young ZHe dates of ca. 13-9 Ma, consistent with Late Miocene exhumation. We argue for the onset of latest cooling by ca. 10 Ma based on these ZHe dates; however, the precise timing for the onset of rifting remains uncertain. The results further suggest that Late Miocene–Quaternary extension in the north-central Shanxi Rift is responsible for ≤∼2.5 km of exhumation, such that published Quaternary extension and fault throw rates are significantly (>100%) higher than long-term rates inferred from the thermochronologic data.
KW - North China tectonics
KW - intracontinental rifting
KW - low-temperature thermochronology
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U2 - 10.1016/j.epsl.2020.116146
DO - 10.1016/j.epsl.2020.116146
M3 - Article
AN - SCOPUS:85079892403
VL - 536
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
SN - 0012-821X
M1 - 116146
ER -