Abstract
The geochemical signatures (i.e., high Sr/Y and La/Yb ratios) of adakitic rocks in continental settings, which are derived from the continental lower crust rather than from subducted slabs, may reflect high-pressure melting in the lower crust or may be inherited from their sources. The North China Craton (NCC) is an ideal place for investigation of this type of adakites due to its ubiquitous distribution. As an example, we explore the petrogenesis of the Jurassic (~ 163 Ma) adakitic rocks in western Liaoning, in the NE part of the NCC, using elemental and Sr–Nd isotopic analysis and crystallization modeling based on Rhyolite-MELTS. The modeling demonstrates that adakitic signatures can be generated by fractional crystallization of magmas within crust of normal thickness (i.e., 33 km). Partial-melting modeling based on the composition of the lower continental crust shows that only the adakitic rocks from orogenic belts require a thickened crust (i.e., 45 km). We suggest that continental adakitic rocks are not necessarily linked to high-pressure processes and their use as an indicator of thickened/delaminated continental crust should be regarded with caution.
| Language | English |
|---|---|
| Pages | 222-231 |
| Number of pages | 10 |
| Journal | Lithos |
| Volume | 272-273 |
| DOIs | |
| Publication status | Published - Feb 2017 |
Fingerprint
Keywords
- Continental adakitic rocks
- Variable bulk partition coefficients
- Continental crustal thickness
- North China Craton
Cite this
}
Generation of continental adakitic rocks : crystallization modeling with variable bulk partition coefficients. / Dai, Hong Kun; Zheng, Jianping; Zhou, Xiang; Griffin, W. L.
In: Lithos, Vol. 272-273, 02.2017, p. 222-231.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Generation of continental adakitic rocks
T2 - Lithos
AU - Dai, Hong Kun
AU - Zheng, Jianping
AU - Zhou, Xiang
AU - Griffin, W. L.
PY - 2017/2
Y1 - 2017/2
N2 - The geochemical signatures (i.e., high Sr/Y and La/Yb ratios) of adakitic rocks in continental settings, which are derived from the continental lower crust rather than from subducted slabs, may reflect high-pressure melting in the lower crust or may be inherited from their sources. The North China Craton (NCC) is an ideal place for investigation of this type of adakites due to its ubiquitous distribution. As an example, we explore the petrogenesis of the Jurassic (~ 163 Ma) adakitic rocks in western Liaoning, in the NE part of the NCC, using elemental and Sr–Nd isotopic analysis and crystallization modeling based on Rhyolite-MELTS. The modeling demonstrates that adakitic signatures can be generated by fractional crystallization of magmas within crust of normal thickness (i.e., 33 km). Partial-melting modeling based on the composition of the lower continental crust shows that only the adakitic rocks from orogenic belts require a thickened crust (i.e., 45 km). We suggest that continental adakitic rocks are not necessarily linked to high-pressure processes and their use as an indicator of thickened/delaminated continental crust should be regarded with caution.
AB - The geochemical signatures (i.e., high Sr/Y and La/Yb ratios) of adakitic rocks in continental settings, which are derived from the continental lower crust rather than from subducted slabs, may reflect high-pressure melting in the lower crust or may be inherited from their sources. The North China Craton (NCC) is an ideal place for investigation of this type of adakites due to its ubiquitous distribution. As an example, we explore the petrogenesis of the Jurassic (~ 163 Ma) adakitic rocks in western Liaoning, in the NE part of the NCC, using elemental and Sr–Nd isotopic analysis and crystallization modeling based on Rhyolite-MELTS. The modeling demonstrates that adakitic signatures can be generated by fractional crystallization of magmas within crust of normal thickness (i.e., 33 km). Partial-melting modeling based on the composition of the lower continental crust shows that only the adakitic rocks from orogenic belts require a thickened crust (i.e., 45 km). We suggest that continental adakitic rocks are not necessarily linked to high-pressure processes and their use as an indicator of thickened/delaminated continental crust should be regarded with caution.
KW - Continental adakitic rocks
KW - Variable bulk partition coefficients
KW - Continental crustal thickness
KW - North China Craton
UR - http://www.scopus.com/inward/record.url?scp=85008147842&partnerID=8YFLogxK
U2 - 10.1016/j.lithos.2016.12.020
DO - 10.1016/j.lithos.2016.12.020
M3 - Article
VL - 272-273
SP - 222
EP - 231
JO - Lithos
JF - Lithos
SN - 0024-4937
ER -