14 research outputs found
Early carboniferous brachiopod faunas from the Baoshan block, west Yunnan, southwest China
38 brachiopod species in 27 genera and subgenera are described from the Yudong Formation in the Shidian-Baoshan area, west Yunnan, southwest China. New taxa include two new subgenera: Unispirifer (Septimispirifer) and Brachythyrina (Longathyrina), and seven new species: Eomarginifera yunnanensis, Marginatia cylindrica, Unispirifer (Unispirifer) xiangshanensis, Unispirifer (Septimispirifer) wafangjieensis, Brachythyrina (Brachythyrina) transversa, Brachythyrina (Longathyrina) baoshanensis, and Girtyella wafangjieensis. Based on the described material and constraints from associated coral and conodont faunas, the age of the brachiopod fauna from the Yudon Formation is considered late Tournaisian (Early Carboniferous), with a possibility extending into earlyViseacutean.<br /
Palynology and correlation of the Upper Pennsylvanian Tobra Formation from Zaluch Nala, Salt Range, Pakistan
Samples from the upper 84 m of a 125 m thick section of the Tobra Formation at Zaluch Nala, western Salt Range,
Pakistan yielded palynomorph taxa including the spores Horriditriletes sp. and Microbaculispora tentula, abundant
monosaccate pollen including Barakarites cf. rotatus, Cannanoropollis janakii and Plicatipollenites malabarensis, and
rare taeniate and non-taeniate bisaccate pollen. Converrucosisporites grandegranulatus, Cycadopites cymbatus,
Horriditriletes ramosus, Horriditriletes tereteangulatus and Microbaculispora tentula indicate the South Oman 2165B
Biozone (Late Pennsylvanian), suggesting that the Tobra Formation in Zaluch Nala is equivalent to the middle part
of the Al Khlata Formation of South Oman (Petroleum Development Oman (PDO) Al Khlata production unit AK
P5). Brevitriletes leptoacaina, Brevitriletes parmatus, Horriditriletes ramosus and Microbaculispora tentula indicate
the lower part of the Oman and Saudi Arabia Palynological Zone 2 (OSPZ2). The Tobra Formation assemblages are
also correlated with those from Stage 2 and the eastern Australian Microbaculispora tentula Oppel-zone, based on
the occurrence of Brevitriletes cornutus, Brevitriletes parmatus, Cycadopites cymbatus, Horriditriletes ramosus,
Horriditriletes tereteangulatus and Microbaculispora tentula. The Tobra Formation in Zaluch Nala lacks the
deglaciation sequence that is present in several other palaeogeographically nearby basins such as those of south
Arabia and Western Australia. This is an indication of either non-deposition during the deglaciation period or
erosion associated with the unconformity between the Tobra Formation and the overlying Warchha Formation