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1

Jurassic ammonites of the Wulong area, Tingri County, Tibet

Morton N., Meister Ch., Ruellau L., Shi X.

Volumina Jurassica

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2015

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Vol. 13, no. 2

1--21

EN

The Jurassic succession west of Wulong village, Tingri County, southern Tibet, is described. Lithostratigraphical classification uses pre-existing terminology for formations, and an informal subdivision into members is proposed. An important structural dislocation, in the form of a small-scale flower structure, affects the Zhamure Formation straddling the Triassic/Jurassic boundary but does not affect the underlying Derirong Formation (Rhaetian) or the overlying Wulong Formation (Lower Jurassic). No other major structural discontinuities could be recognised. New finds of ammonites in situ include a new genus and species of possible schlotheimiid, Womalongiceras inflatum, with a probable age of Sinemurian or slightly younger. Two separate beds yielded rich assemblages of crushed ammonites identified as Nyalamoceras nyalamensis Chao and Wang (1956) here interpreted as a hammatoceratid. The age of these is reinterpreted as uppermost Aalenian on the basis of an accompanying specimen of ?Pseudolioceras (Tugurites) sp. nov. and poorly preserved ammonites from higher beds identified as graphoceratids (?Graphoceras).

2

Analysis of Saussurea species from tibet using HPLC-DAD-ESI-MS n

Dawa Z, Zhou Y., Bai Y., Gesang S, Liang J., Ding L.

Acta Chromatographica

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2010

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Vol. 22, no. 1

141--152

EN

An HPLC-DAD-ESI-MS n method has been developed for simultaneous quantification of eight major compounds in eight Saussurea species which have long been used as the traditional Tibetan medicines. The method was validated for sensitivity, precision, and accuracy. LODs were from 0.11 to 5.01 μg mL -1, overall intra-day and inter-day variation was less than 2.70%, and overall recovery was over 98.0%. The correlation coefficients ( r 2) of the calibration plots were >0.991. This newly established method was successfully used to reveal difference among the chemical profiles and analytes contents of eight Saussurea species collected in Tibet. In addition, by comparison of UV and mass spectra with those of authentic compounds, a total of fifteen peaks were identified. It can be concluded that this is an effective method for quantification and evaluation of the flavonoids and coumarins in the eight species of the genus Saussurea . It can be used as an efficient reference method for development and use of the eight traditional Tibetan medicines by comparing their different characteristics.

3

Facies and carbon isotope studies in southern Tibet suggest that the Toarcian extinction was diachronous

Hallam A.

Volumina Jurassica

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2006

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Vol. 4, no. 1

168-168

EN

A record of the Toarcian (Early Jurassic) mass extinction is reported from eastern Tethyan (Tibetan) locations for the first time, using both nannopalaeontological and carbon isotope evidence. These show a similar succession of events to those seen in western Tethys and Boreal northern Europe but with a considerable delay in their timing. Thus, transgression and spread of oxygen-poor bottom waters is seen, but the onset of the dysaerobic deposition occurs late in the stage in Tibet whilst in western Tethyan and Boreal locations they develop near the base of the stage. The benthic extinctions were similarly delayed, with the result that the two principal victims of the crisis in the western Tethyan Realm, the lithiotid bivalves and the lituolid Foraminifera, persisted until high in the Toarcian in eastern Tethys. The Toarcian extinction event was therefore a protracted crisis associated with the diachronous onset of oxygen-poor deposition in marine settings.