<sup>40</sup>Ar/<sup>39</sup>Ar age constraints on the Haifanggou and Lanqi formations: When did the first flowers bloom?
Su-Chin Chang
Haichun Zhang
Sidney R. Hemming
Gary T. Mesko
Yan Fang
10.6084/m9.figshare.3453200.v1
https://geolsoc.figshare.com/articles/dataset/_sup_40_sup_Ar_sup_39_sup_Ar_age_constraints_on_the_Haifanggou_and_Lanqi_formations_When_did_the_first_flowers_bloom_/3453200
<p>Well-preserved Mesozoic terrestrial fossils were discovered in the Haifanggou Formation and the overlying Lanqi Formation
(or their correlative strata) in NE China. The recent discoveries of <em>Schmeissneria sinensis</em> and <em>Xingxueanthus sinensis</em> from the middle and upper Jurassic Haifanggou Formation provide evidence that the origin of angiosperms could be predate
the Early Cretaceous. In addition to the finding of pre-Cretaceous angiosperms from the Haifanggou Formation, the overlying
Lanqi Formation yields a rich and varied terrestrial flora. The high diversity and abundance of the palaeoflora from these
formations provide a unique window to understand floral evolution and its diversification in the Mesozoic. Two tuff samples
and one andesite sample collected from the Haifanggou and Lanqi formations near Beipiao City, Liaoning, NE China yield robust
<sup>40</sup>Ar/<sup>39</sup>Ar age results. Our <sup>40</sup>Ar/<sup>39</sup>Ar age of 166.7 ± 1.0 Ma for plagioclases from one tuff interbedded in the fossiliferous horizons of the middle Haifanggou
Formation provides accurate age calibration for the pre-Cretaceous angiosperms for the first time. Moreover, our age results
for these fossil-bearing formations will improve our knowledge of the Jurassic environment in general, including the link
between plants and atmospheric CO<sub>2</sub>.
</p>
2016-06-21 11:12:53
Haifanggou Formation
Lanqi formations
NE China
angiosperm
Jurassic Haifanggou Formation
CO
Lanqi Formation yields
middle Haifanggou Formation
Ar
Geology