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The Eocene biostratigraphy of the Jabal Qatar area located at the border between UAE and Oman is described. The occurrence of the Late Eocene index fossil Turborotalia cunialensis/Cribrohantkenina inflata Concurrent-Range Zone and the homogeneous biozone P16 is reported for the first time. The presence of the T. cunialensis/C. inflata with its associated taxa permits the tripartite division (P15, P16, P17) of the Upper Eocene at Jabal Qatar. The data obtained were used in correlating the Jabal Qatar sequence with stratigraphically equivalent sequences at Jabal Hafit and Jabal Malaqet, near Al-Ain city. Effects of the previously reported eustatic sea level changes at the close of Chron C15r can be recognized in the facies characteristics of the studied sequences.
Sparse assemblages of palynomorphs have been collected from the glacially derived Khalaqah Member of the Kooli Formation in northwest Yemen. The presence of common Leiosphaeridia and Deusilites tentus, indeterminate taeniate bisaccate pollen, and such species as Plicatipollenites malabarensis, Verrucosisporites sp., Brevitriletes cf. B. cornutus, and Cristatisporites cf. C. crassilabratus, suggest an age range from Late Carboniferous to Early Permian. Previous workers have considered that a small variation in wall thickness could be used to separate Deusilites tenuistriatusGUTIÉRREZ et al. 1997 from the Early Permian of Brazil and Argentina from Deusilites tentusHemer and Nygreen 1967. The evidence from the Kooli Formation, of highly variable wall thicknesses within a single population of Deusilites suggests that the two species should not be separated and that D. tenuistriatus is a junior synonym of D. tentus.
This report deals with the Upper Jurassic (lower and middle Oxfordian) Radiolaria of the Sula Islands, Indonesia. The radiolarian assemblage, though abundant and extremely well preserved, is poorly diversified and includes ∼ fifty species level taxa. The presence of common Praeparvicingula and rare pantanelliids within the faunal assemblage in association with Austral ammonites suggests that the Sula Islands were situated in the Northern Austral Province (>30° south) during the Oxfordian. This paleolatitude is in keeping with the Gondwanaland origin proposed by some workers. The Sula Island middle Oxfordian assemblage is strikingly similar to that described from the Galice Formation (Smith River subterrane, Klamath Mountains, North America). Some faunal elements described from the Sula Island assemblage are characteristic of the Southern Hemisphere and are only known elsewhere from New Zealand (Aita and Mackie 1992). Three radiolarian taxa were originally described from the Galice Formation in the Northern Hemisphere. No ammonite taxa are in common between the Sula Islands and the Galice Formation.
New palynological data from the Salé brickyard (Atlantic coast of northern Morocco) are analyzed for their late Neogene biostratigraphical implications and the relationship with paleoenvironmental changes. Palynological zones (I to VI) described in this paper are based on palynomorph concentrations, fluctuations in species distribution, ratios between marine and continental palynomorphs, and the Last Appearance Datums (LADs) of twelve species. The brevity of some of the ranges in comparison with published dinoflagellates ranges from other locations is analyzed in view of important ecological events that took place in the Gibraltar Arc area at the end of the Miocene. Zone boundaries reflect global glacioeustatic and/or local tectonic events that induced major modifications to the Atlantic/Mediterranean connections. The palynological data allow to differenciate time of eustatic versus tectonic control and permit to define how the paleoceanographic evolution of the Rifian Strait eventually led to the Messinian Salinity Crisis. We postulate that the nine LADs taking place at the Mio/Pliocene boundary results from the reconfiguration of oceanic circulation pattern and environmental conditions in the Gibraltar Strait area, as marine communication between the Atlantic Ocean and the Mediterranean Sea resumed, marking the end of the Messinian Salinity Crisis.
Type specimens of the nine Pleurosigma taxa described by A. Mann (1925) from the Philippine Islands were critically re-investigated as a result of a loan of these slides held in the Albert Mann collection at the United States National Museum, Smithsonian Institution, Washington, D.C., (USNM). Improved photomicrographic documentation and more recent insights into the taxonomy of the genus Pleurosigma lead to some revision of Mann's views. Mann noted a similarity between his P. obtusum and P. prisma and these species are here synonymized under the former name. No specific differences can be demonstrated for P. exemptum and P. obesum and the latter is here synonymized under the former name. Although Mann noted some resemblance between specimens of P. falx and small specimens of P. decorum W. Smith, I have found that P. falx A.Mann, closely resembles specimens of P. normanii Ralfs in Pritchard. Because no specific differences have been detected by light microscopy (LM), P. falx is here synonymized with P. normanii which has priority. On the other hand, Mann considered his P. acus very similar to P. intermedium W. Smith but in reality these species differ in several LM respects. As a result of this study, six of the nine new species P. acus, P. dolosum, P. exemptum, P. obtusum, P. rigens and P. suluense proposed by Mann are considered to be valid.
The distribution of ostracod populations in Kagoshima Bay (South Kyushu, Japan) is analyzed with regard to environmental parameters. Topographic irregularity makes this elongated south-facing embayment amenable to subdivision into six different environments: Head, Margin, Slope, Basin, Mouth and Open Sea. The bay is under the influence of the Kuroshio Current, which enters from the east to flow northward along the west side of the Osumi Peninsula, and returns southward along the east side of the Satsuma Peninsula. A counterclockwise eddy current occurs in the widened central portion of the bay. The bay is in an area of andesitic volcanism centered in Mt. Sakurajima, an active volcano that rises from the water to separate the Bay Head area from the rest. The biocenotic indices such as abundance and diversity decrease from the Mouth of the bay towards the Basin and Head environments. On the other hand, volcanic ash and domestic input provide nutrients that are favorable to the ostracod biocenoses. The relative frequencies of species throughout the bay show that different environments are characterized by different assemblages. Correspondence analysis (CA) shows how ostracod distribution is influenced by the quality and structure of water masses such as dissolved oxygen content, salinity, anthropic pollution, and volcanically induced changes in pH.