Details
| Original language | English |
|---|---|
| Article number | 106262 |
| Number of pages | 13 |
| Journal | Journal of Asian earth sciences |
| Volume | 273 |
| Early online date | 17 Jul 2024 |
| Publication status | Published - Sept 2024 |
Abstract
Interstitial microstructures in layered intrusions can provide crucial insights into the formation, transport, evolution, and solidification processes of magma. The symplectites commonly observed in the Shangzhuang layered intrusions in Beijing, China, can be classified into three types based on their occurrence and related primocryst minerals. Regardless of variation in types, the vermicular symplectites consistently exhibit a volume ratio of magnetite to orthopyroxene at approximately 1:4. Orthopyroxene in the symplectites shows no geochemical difference from those primocrysts. Inter-cumulus hornblende formed during the late stage after the formation of symplectites so that the symplectites are always enclosed by hornblende. By utilizing the hornblende geothermobarometer, we have also constrained that the symplectites have been formed within a relatively wide temperature range of 1040–915 °C through a reaction between the interstitial immiscible Fe-rich melt and the primocryst olivine and orthopyroxene. The reaction can be simplified as Ol/Opx (primocryst) + Fe-rich melt → Opx (symplectite) + Mt (symplectite). Besides, based on the mass balance and reaction results, the Si/O ratio of Fe-rich melt is estimated to be 1:3. The study of these symplectites contributes to refining the processes of reactive melt flow in mafic layered intrusions during late-stage magmatic crystallization.
Keywords
- Fe-rich melt, Interstitial liquid immiscibility, Mafic layered intrusions, Reactive melt flow, Symplectite
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Earth-Surface Processes
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Journal of Asian earth sciences, Vol. 273, 106262, 09.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Formation of orthopyroxene-magnetite symplectites by reactive melt flow
T2 - Insights into the Shangzhuang layered intrusion in Beijing, China
AU - Wang, Sijia
AU - Hou, Tong
AU - Xie, Qiuhong
N1 - Publisher Copyright: © 2024 Elsevier Ltd
PY - 2024/9
Y1 - 2024/9
N2 - Interstitial microstructures in layered intrusions can provide crucial insights into the formation, transport, evolution, and solidification processes of magma. The symplectites commonly observed in the Shangzhuang layered intrusions in Beijing, China, can be classified into three types based on their occurrence and related primocryst minerals. Regardless of variation in types, the vermicular symplectites consistently exhibit a volume ratio of magnetite to orthopyroxene at approximately 1:4. Orthopyroxene in the symplectites shows no geochemical difference from those primocrysts. Inter-cumulus hornblende formed during the late stage after the formation of symplectites so that the symplectites are always enclosed by hornblende. By utilizing the hornblende geothermobarometer, we have also constrained that the symplectites have been formed within a relatively wide temperature range of 1040–915 °C through a reaction between the interstitial immiscible Fe-rich melt and the primocryst olivine and orthopyroxene. The reaction can be simplified as Ol/Opx (primocryst) + Fe-rich melt → Opx (symplectite) + Mt (symplectite). Besides, based on the mass balance and reaction results, the Si/O ratio of Fe-rich melt is estimated to be 1:3. The study of these symplectites contributes to refining the processes of reactive melt flow in mafic layered intrusions during late-stage magmatic crystallization.
AB - Interstitial microstructures in layered intrusions can provide crucial insights into the formation, transport, evolution, and solidification processes of magma. The symplectites commonly observed in the Shangzhuang layered intrusions in Beijing, China, can be classified into three types based on their occurrence and related primocryst minerals. Regardless of variation in types, the vermicular symplectites consistently exhibit a volume ratio of magnetite to orthopyroxene at approximately 1:4. Orthopyroxene in the symplectites shows no geochemical difference from those primocrysts. Inter-cumulus hornblende formed during the late stage after the formation of symplectites so that the symplectites are always enclosed by hornblende. By utilizing the hornblende geothermobarometer, we have also constrained that the symplectites have been formed within a relatively wide temperature range of 1040–915 °C through a reaction between the interstitial immiscible Fe-rich melt and the primocryst olivine and orthopyroxene. The reaction can be simplified as Ol/Opx (primocryst) + Fe-rich melt → Opx (symplectite) + Mt (symplectite). Besides, based on the mass balance and reaction results, the Si/O ratio of Fe-rich melt is estimated to be 1:3. The study of these symplectites contributes to refining the processes of reactive melt flow in mafic layered intrusions during late-stage magmatic crystallization.
KW - Fe-rich melt
KW - Interstitial liquid immiscibility
KW - Mafic layered intrusions
KW - Reactive melt flow
KW - Symplectite
UR - http://www.scopus.com/inward/record.url?scp=85199275128&partnerID=8YFLogxK
U2 - 10.1016/j.jseaes.2024.106262
DO - 10.1016/j.jseaes.2024.106262
M3 - Article
AN - SCOPUS:85199275128
VL - 273
JO - Journal of Asian earth sciences
JF - Journal of Asian earth sciences
SN - 1367-9120
M1 - 106262
ER -