Early J(2) basalts in SE China

the incipience of large-scale late Mesozoic magmatism

Xin Xie, Xisheng Xu, Haibo Zou, Shaoyong Jiang, Ming Zhang, Jiansheng Qiu

Research output: Contribution to journalMeeting abstract

Abstract

Magmatism in SE China was dormant during 204~180
Ma, but was reactivated in 180~170 Ma (early J2), and then
became more and more intensive towards the end of early
Cretaceous. The small-scale early J2 magmatism is the
incipience to long term and large-scale magmatism in this
region. A near east-west (EW) trend volcanic belt distributed
across south Hunan, south Jiangxi and southwest Fujian was
formed during early J2 time. Along this belt from inland
toward coast, the lithology of basalts changes from alkali into
tholeiite, and the amount of erupted volcanic rocks and the
proportions of rhyolites coexisting with the basalts increase.
On the basis of geochemical characteristics of these basalts,
we infer that the melting degree of source rocks and the extent
of fractional crystallization and crustal contamination all
increased whereas the depth of mantle source decreased from
inland to coast, which led to the variations of geological
characteristics of the volcanic belt. In early J2, the western
spreading Pacific plate began to subduct underneath SE China
continental block, reactivating near EW trend deep fault that
was originally formed during Indosinian event. The stress of
the western spreading Pacific plate and the extent of
asthenosphere upwelling increased from inland to the coast,
which is consistent with the generation and evolution of early
J2 basalts.
References
Zhou X M and Li W X, (2000), Tectonophysics, 326, 269-
287.
Jung S and Masberg P, (1998), J. Vol. and Geol. Res., 86,
151-177.
Original languageEnglish
Pages (from-to)A110-A110
Number of pages1
JournalGeochimica et Cosmochimica Acta
Volume69
Issue number10 supplement
DOIs
Publication statusPublished - May 2005
EventGoldschmidt Conference (15th : 2005) - Moscow, United States
Duration: 20 May 200525 May 2005

Keywords

  • ORIGIN
  • ROCKS

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