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McCrea R.T.,Peace Region Palaeontology Research Center | McCrea R.T.,University of Alberta | Buckley L.G.,Peace Region Palaeontology Research Center | Buckley L.G.,University of Alberta | And 6 more authors.
Cretaceous Research | Year: 2015

This is the first detailed report of vertebrate tracks from alluvial plain deposits of the Boulder Creek Formation (Lower Cretaceous: middle to ?upper Albian) from outcrop exposures in northeastern British Columbia. Several in situ dinosaur tracks observed in vertical section are described, as well as the recovery and description of an isolated track slab discovered in the Boulder Gardens recreation area south of Tumbler Ridge, British Columbia. The vertebrate ichnites consist of three small tridactyl theropod dinosaur prints, one tetradactyl ornithopod print, and 72 small tridactyl tracks of avian affinity which are described as a new ichnotaxon herein. The avian prints are small (under 30mm length) and are characterised by a large divarication between digits II and III and comparatively lesser divarication between digits III and IV. The pace and stride are short and the pace angulation is high. The tracks are similar to those produced by extant shorebirds and the track-maker likely occupied a similar niche. The avian prints are described herein as a new ichnotaxon, Paxavipes babcockensis ichnogen. et isp. nov. Two of the theropod footprints are identified as Irenichnites gracilis, an ichnotaxon described in 1932 by C.M. Sternberg from the Lower Cretaceous (Aptian) Gething Formation near Hudson's Hope, British Columbia. One of the Irenichnites gracilis prints displays skin impressions associated with the digital pads of digit III and the metatarsal pad. This is the first record of skin impressions from prints of Irenichnites gracilis. The ornithopod track is partial and unidentifiable to a particular ichnotaxon, but displays skin impressions on the metatarsal pad and at the base of the second digit impression. The skin impressions from the ornithopod track differ from the Irenichnites gracilis skin impressions. © 2015 Elsevier Ltd.

Gao L.-Z.,Chinese Academy of Geological Sciences | Liu Y.-X.,Chinese Academy of Geological Sciences | Ding X.-Z.,Chinese Academy of Geological Sciences | Song Z.-R.,Jiangxi Institute of Geological Survey | And 4 more authors.
Geological Bulletin of China | Year: 2013

This paper will report some SHRIMP U-Pb ages (1132 Ma±8 Ma, 1140 Ma±7 Ma, 1143 Ma±9 Ma and 1172 Ma±10 Ma) of meta-rhyolite of the Tieshajie Formation in the Jiao-Shao fault zone, which belongs to the Northern margin of Cathaysia. Combine of those dating, we will try to discuss the tectonic set of the Tianli schist, Zhoutan Complex and Wanyuan Complex. According to the isotopic dating, it is important for limit the strata correlation and tectonic evolution in the Jiao-Shao fault zone. The dating above mentioned shows the depositional strata of an ace-basin system in 1.1 Ga, which is represented inner ace between the Yangtze and Cathayasia and the Huaiyu area is an extensional basin of the back-are. The chronostratigraphic dating of the Tieshajie Formation proved the reliable isotopic evidence for the correlation of the metamorphosed strata in the Jiang-Shao fault zone.

Gao L.,Chinese Academy of Geological Sciences | Ding X.,Chinese Academy of Geological Sciences | Yin C.,Chinese Academy of Geological Sciences | Zhang C.,China University of science | Ettensohn F.R.,University of Kentucky
Acta Geologica Sinica | Year: 2013

The Qingbaikouan System is the lowest unit of the Neoproterozoic Erathem in Chinese stratigraphic succession, and it now provides a precise geochronological framework and geological time scale for mapping and stratal correlation in China. However, a sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon age date (1368±12 Ma) obtained from a bentonite in the Qingbaikouan Xiamaling Formation indicates that it belongs to the Mesoproterozoic Erathem instead. This change is a milestone in understanding the Precambrian Stratigraphic Time Scale in China, and it has had great influence on Precambrian correlations in Asia. Otherwise, a large amount of geochronological work has been done in the " Jiangnan Orogen Belt" of South China, and new isotopic data have redefined the traditional recognition of metamorphosed Mesoproterozoic strata from the Sibao orogeny to the Neoproterozoic Erathem. Based on SHRIMP zircon U-Pb age data, the authors regard the Sibao orogeny (equal to the Wuling orogeny) as a movement at ca 820 Ma, meaning that the Sibao orogeny was not equivalent to the Grenvillian orogeny. Finally, we report here the first SHRIMP U-Pb age of the boundary between the top of the Qingbaikouan Gongdong Formation (786.8±5.6 Ma) and the bottom of the Chang'an (diamictite) Formation (778.4±5.2 Ma), which is the age of the lowest diamictite of the Nanhuan System in China. © 2013 Geological Society of China.

Gao L.-Z.,Chinese Academy of Geological Sciences | Zhang C.-H.,China University of science | Chen S.-M.,Chinese Academy of Geological Sciences | Liu P.-J.,Chinese Academy of Geological Sciences | And 4 more authors.
Geological Bulletin of China | Year: 2010

The upper limit line of the deposition of the Diaoyutai Formation is given by distributional pattern of detrital zircon age from the Diaoyutai Formation, Xihe Group, Qingbaikou System. The main volume of the distributional pattern of detrital zircon age is 1.6 Ga and the youngest age is 1075 Ma, which reflects the depositional age is younger than 1.0 Ga. According to the distributional pattern of detrital zircon age from the Diaoyutai Formation, Xihe Group, it shows that the Diaoyutai Formation has different rock sources with North China Block, and they have different ages. The paper confirms the Late Precambrian Geological Time Scale by some new zircon SHRIMP U-Pb dating results, e.g. Changcheng System(Ch, Pt2 1) limit is in 1.8-1.6 Ga; Jixian System (Jx, Pt2 2) limit is in 1.6-1.4 Ga; unnamed system (Pt2 3-4) limit is in 1.4-1.0 Ga; Qingbaikou System (Qb, Pt3 1) limit is in 1000-780 Ma; Nanhua System (Nh, Pt3 2) limit is in 780-635 Ma and Sinian (Z, Pt3 3) limit is in 635-542 Ma.

McCrea R.T.,Peace Region Palaeontology Research Center | McCrea R.T.,University of Alberta | Tanke D.H.,Royal Tyrrell Museum of Palaeontology | Buckley L.G.,Peace Region Palaeontology Research Center | And 8 more authors.
Ichnos:an International Journal of Plant and Animal | Year: 2015

Literature concerning dinosaur footprints or trackways exhibiting abnormal gait or morphology reflecting pathology (ichnopathology) is rare. We report on a number of Jurassic and Cretaceous occurrences of theropod footprints from western North America with unusual morphologies interpreted herein as examples of inferred pathologies, or ichnopathologies. The majority of ichnopathologies are primarily manifested in the digit impressions and include examples of swelling, extreme curvature, dislocation or fracture, and amputation. A number of occurrences are single tracks on ex situ blocks with substantial deformation (inferred dislocation or fracture), or absence of a single digit impression. Two occurrences are from in situ natural mould trackways, one of which is a lengthy trackway of a presumed allosauroid with no noticeable deformation of the digits or feet but with strong inward rotation of the left footprint toward the midline and a pronounced, waddling limp. The other is a tyrannosaurid trackway consisting of three footprints (one right, two left) with the two left prints exhibiting repetitive ichnopathology of a partially missing Digit II impression. © 2015, Copyright © Taylor & Francis Group, LLC.

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