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Earth Science Frontiers, Vol. 17, Special Issue, Aug. 2010 ISSN 1005-2321 Nepal and almost exclusive of other taxa (very few Pseudowaagenia, Physodoceras, Nebrodites, and Mesosimoceras). Of Early Tithonian age are also beds and faunas previously dated as Late Tithonian. First, the Virgatosphinctes and Aulacosphinctoides Beds and Fauna, a homogeneous fauna, the more so as there is some doubt that some elements belong to that fauna, because they are known in upperlying beds and fauna. Then, the Malagasites and Hildoglochiceras Beds and Faunas, of which the new genus Malagasites (= "Virgatosphinctes" gr. denseplicatus) is well-known in the Indo-Malagasian embayment and Antarctica. Hildoglochiceras perhaps would be characteristic of a peculiar fauna (and horizon) with numerous Oppeliids (Hildoglochiceras, Metauhligites). Although there is some doubt on the genus assignment, ?"Semiformi- ceras" aenigmaticum n. sp. is a clue datum for dating the fauna as uppermost Early Tithonian. Late Tithonian (pars). Ammonite bearing-beds of Late Tithonian age are not well developed in Nepal, being cut at top by terrigenous arrivals of the Chuck Formation (or Unit). The Blanfordiceras Beds and faunas are characterized by an almost exclusively monogeneric fauna, with supposition that a few other genera (Physodoceras, Corongoceras, Himalayites) belong to that fauna. The last ammonite assemblage, the Blanfordiceras and Umiaites Fauna, is known in only one outcrop, in the uppermost ammonite-bearing deposits, already invaded by silty arrival. Some dubiousness remains and proposed equi- valences with the European Tethyan zonal standard are close estimates, already at the stage level, still more concerning zones. The faunal succession achieved in Nepal is the reference used to revise correlations, first 142 with the Himalayan belt, in Pakistan, Indian Himalaya (Spiti, Kumaon) and southern Tibet; then towards east and more widely along the Indo-SW Pacific Province, Australasia (Sula Islands, Misol and Buru, Irian-Jaya and Papua-New Guinea), New Zealand, Antarctica and Magallanes Basin; at last towards west in the Indo-Malagasian embayment, in Kachcch (India), Malagasy, eastern Africa (Tanzania, Kenya, Ethiopia, Somaliland) and Yemen. Studied faunas are often dominated by one single genus or little number of genera within a same taxonomic group. Those point out some endemism of the Himalayan faunas which is also traced in the Indo-SW Pacific faunas along the perigondwanan margin (Sula Islands, Papua-New Guinea, New Zea- land) as far as Antarctica and Magallanes Basin. These faunas strongly contrast with the faunas which inhabited the Indo-Malagasian embayment (Kachchh, Malagasy, eastern Africa, Yemen) more diverse, including a greater frequency of forms identified or closely related to Submediterranean Tethyan taxa. It is assumed that the Indo-Malagasian faunas were related to relatively shallower environmental conditions on the proximal platform, a picture which is consistent with evidences of shallowing of the Spiti Shales in the Malagasites Beds and the uppermost Blanfordiceras and Umiaites Beds. The low diversity of the Indo-SW Pacific Province was already interpreted as resulting from origination of an Austral fauna and Realm (or Subrealm) during Late Jurassic time. Key words: Ammonite, Late Jurassic, Biostrati- graphy, Nepal Himalaya.
Earth Science Frontiers, Vol. 17, Special Issue, Aug. 2010 ISSN 1005-2321 Jurassic Spora-Pollen Assemblages and Paleoclamate in Innermongolia, Gansu, Qinghai, China Cunfeng Yan, Jianying Yuan Northwest Branch, Research Institute of Petroleum Exploration and Development, PetroChina, Lanzhou 730020, China (E-mail:ycf3708@sina.com) A larger part of Gansu, the west of Innermongolia and the northeast of Qinghai, in the centre part of north- western China, consists of Alashan, Beiqilian- Hexizoulang, Zhongqilian and Qaidam stratigraphical divisions. In this region the widely well-developed Jurassic sediments are rich in coal and oil natural resources. Based on fully studied Jurassic spores and pollen in this area, with preceding achievement, seven spora-pollen assemblages have been established. The low Jurassic includes three assemblages: Protoconi- ferus-Taeniaesporites, Osmundacidites-Chasmato- sporites-Disaccites and Classopollis-Cyathidites- Cycadopites. The middle Jurassic includes three assemblages: Cyathidites-Quadraeculina-Cycadopites, Cyathidites-Callialasporites-Pinuspollenites and Clas- sopollis-Cyathidites-Inaperturopllenites. The upper Jurassic is only represented by Classopollis assemblage. (1) Protoconiferus-Taeniaesporites assemblage: This spora-pollen assemblage is from lower Huxishan formation in Qaidam basin. Gymnosperm pollen (66.4%-100%, averaged 93.3%) are dominant and Pteridophytic spores (0-33.6%,averaged 6.4%) are much less. Among Gemnosperm pollen, nonstriata bisaccate pollen are dominant, consist of Paleoconi- ferus, Protoconiferus,Pseudopicea,Pseudopinus, Piceites,Piceaepollenites, Abietineaepollenites,Pinu- spollenites,Podocarpidites etc, with a small amount of monocolplate pollen Cycadopites Chasmatosporites. In addition, there are some other elements such as Taeniaesporites of the striate and ridged bisaccate pollen and Chordasporites, Riccisporites convolutes, Rhaetipollis germanicus,Ovalipollis breviformis in small quantities which usually appear in the Triassic. Among pteridophytic spores, apiculati azonotrilete spores are dominant, such as Baculatisporites, Osmun- dacidites, Lophotriletes, Apiculatisporites, Granulati- sporites. A small quantity of the laevigati azonotriletes spores occurs. This assemblage is Early Jurassic, may be Hettangian stage. (2) Osmundacidites-Chasmatosporites-Disaccites assemblage: This spora-pollen assemblage is from upper Huxishan to the first member of Dameigou formation in Qaidam basin, the lower-middle Tan- donggou formatin in Yaojie, Daxigou formatin in Aganzheng, Jijigou formation in Chaoshui and Yabulai basin. Gymnosperm pollen (averaged 88.5%) are dominant and pteridophytic spores are few. Among Gemnosperm pollen, bisaccate pollen are very abundant. The second is the monocolpate pollen mainly containing Cycadopites, Chasmatosporites. In addition, there are a little Chordasporites, Taeniae- sporites, Lueckisporites. Among the Pterodophytic spores, the genus Osmundacidites is of the highest percentage. Dictyophyllidites, Calamospora, Assereto- spora, Concavisporites, Crassitudispora are common. This assemblage is Early Jurassic, may be Pliensba- chian stage. (3) Classopollis-Cyathidites-Cycadopites assemblage: This spora-pollen assemblage is from the second-third member of Dameigou formation, upper Tandonggou formatin in Yaojie. The Gymnosperm pollen are much more abundant than pterodophytic spores. Among the Gymnosperm pollen, the quantity of Classopollis (13.7%-44.8%) overwhelms the bisaccate pollen of the Osmundacidites-Chasmatosporites- Dis- accites assemblage, with higher content of Cycadopites, and few bisaccate pollen. Among the pteridophytic spores, Cyathidites, Deltoidspora appear commonly. In addition, there are some genera in small quantities such as Dictyophyllidites, Calamospora, Asseretospora, Concavisporites, Crassitudispora, Chordasporites, Taeniaesporites, Lueckisporites. This assemblage is referred to Early Jurassic, may be Toarcian stage. (4) Cyathidites-Quadraeculina-Cycadopites assemblage: This spora-pollen assemblage is from Longfengshan formation in Jingyuan, Yaojie formation in Minhe basin, Qintujing formation in Chaoshui and Yabulai basins, the fourth and fifth member of Dameigou formation in Qaidam basin. Among the pteridophytic spores, Cyathidites (13%-23%) and Deltoidospra appear in a large quantity, with familiar species Neoraistrickia, Punctatisporites, Lycopodium- sporites, Cibotiumspoa, Undulatisporites, Bireti- sporites, Klukisporites, Lycopodiacidites, Converru- cosisporites, Crassitudisproa, Asseretospora, Glei- cheniidites, Osmundacidites, Todisprites, Steresporites. Gemnosperm pollen mainly consist of Cycadopites (7.3%-38.3%) and Quadraeculina (4%-8.3%), a few other elements such as Callialasporites, Cerebro- pollenites, Perinopollentes, Piceaepollenites, Euccom- miidites, Piceites, Pinuspollenites, Podocarpidites appear. This assemblage is Middle Jurassic, may be Aalenian- Bajocian stage. (5) Cyathidites-Callialasporites-Pinuspollenites assemblage: This spora-pollen assemblage is from lower Wangjiashan formation in Jinyuan, lower 143
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