Middle Jurassic to Early Cretaceous dinoflagellate assemblage zones in eastern Heilongjiang Province, northeast China

2007 ◽  
Vol 28 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Youhua Zhu ◽  
Chengquan He
2009 ◽  
Vol 47 (2) ◽  
pp. 93-102 ◽  
Author(s):  
Shuang-Xing GUO ◽  
Jin-Geng SHA ◽  
Li-Zeng BIAN ◽  
Yin-Long QIU

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Xin Wang

Angiosperms are the single most important plant group in the current ecosystem. However, little is known about the origin and early evolution of angiosperms. Jurassic and earlier traces of angiosperms have been claimed multiple times from Europe and Asia, but reluctance to accept these records remains. To test the truthfulness of these claims, palaeobotanical records from continents other than Europe and Asia constitute a crucial test. Here I document a new angiosperm fruit, Dilcherifructus mexicana gen. et sp. nov, from the Middle Jurassic of Mexico. Its Jurassic age suggests that origin of angiosperms is much earlier than widely accepted, while its occurrence in the North America indicates that angiosperms were already widespread in the Jurassic, although they were still far away from their ecological radiation, which started in the Early Cretaceous.


2018 ◽  
Vol 469 (1) ◽  
pp. 305-340 ◽  
Author(s):  
R. M. C. H. Verreussel ◽  
R. Bouroullec ◽  
D. K. Munsterman ◽  
K. Dybkjær ◽  
C. R. Geel ◽  
...  

2017 ◽  
Vol 8 (1) ◽  
pp. 93-106 ◽  
Author(s):  
Wei Yan ◽  
Tailiang Fan ◽  
Hongyu Wang ◽  
Chen Zhu ◽  
Zhiqian Gao ◽  
...  

2012 ◽  
Vol 49 (12) ◽  
pp. 1463-1477 ◽  
Author(s):  
Gang Li ◽  
Georgia Pe-Piper ◽  
David J.W. Piper

The tectonic and geomorphological evolution of the Scotian margin and its hinterland is poorly known between Late Triassic rifting and the Early Cretaceous progradation of major deltas. This study determined sedimentary provenance of Middle Jurassic Mohican Formation sandstones from three wells using heavy minerals and mineral chemistry. Indicator minerals such as xenotime, altered ilmenite, and varietal types of garnet and tourmaline are similar to those in Hauterivian–Barremian sandstones in the western Scotian Basin, which are almost exclusively derived from the Meguma terrane. The wells adjacent to the Canso Ridge have more zircon and less ilmenite, indicating a greater contribution of polycyclic reworking, but with an ultimate source in the Meguma terrane. Zircon and ilmenite were likely derived in part from Carboniferous sandstones in eastern mainland Nova Scotia and Cape Breton Island. Any river drainage from the inboard terranes of the Appalachians either was diverted through the Fundy Basin or entered the easternmost Scotian Basin, where the Mohican Formation is 5.5 km thick, along the linear continuation of the southwest Grand Banks transform. Such sediment did not reach the Canso Ridge, suggesting that the Cobequid–Chedabucto fault zone in Orpheus graben was not a significant physiographic feature. This tectonically controlled paleogeography in the Middle Jurassic is quite different from that during active rifting in the Late Triassic – Early Jurassic. Middle Jurassic quiescence was followed in the Tithonian – Early Cretaceous by renewed tectonic uplift associated with rifting of Grand Banks from Iberia and Labrador from Greenland.


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