Dinoflagellate cyst biostratigraphy of the Upper Miocene Deurne Sands (Diest Formation) of northern Belgium,southern North Sea Basin     

Stephen Louwye 《Geological Journal》2002,37(1):55-67

Diverse and well‐preserved palynomorph assemblages recovered from the Deurne Sands, a local member of the Upper Miocene Diest Formation near Antwerp, allow the recognition of dinoflagellate cyst biozones defined in the North Atlantic realm (East Coast, USA) and the North Sea region (Nieder Ochtenhausen well, northern Germany). Based on the dinoflagellate cyst assemblages and the calcareous microfossils, the deposition of the Deurne Sands took place at some time during middle to late Tortonian (Late Miocene). These sands can be correlated biostratigraphically with the Dessel Sands in the Campine area of northern Belgium. This correlation demonstrates the existence of two separate and contemporary depositional areas in northern Belgium during early Late Miocene times. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Waulsortian buildups of Waulsort,Belgium     

Johan A.E. Dehantschutter  Alan Lees 《Geological Journal》1996,31(2):123-142

The biostratigraphy and sedimentology of the late Tournaisian, Waulsortian buildups of the type area, at Waulsort (Belgium), are examined in detail. Four buildups are present. Overall, they span the stratigraphic interval from the base of the Ivorian stage to the lower part of the Moliniacian stage, ending just below the base of the Viséan. Petrographic study shows that all Waulsortian Phases are represented, the older buildups being of Phases A and B, whereas the youngest ranges through Phases A to D. The relatively crude Phase classification is refined by correspondence analysis, which shows that the grain types present in the Waulsortian and associated limestones conform closely to the relay (systematic shift of relative importance of grain types) described from other Waulsortian buildups in Belgium. A Relay Index, derived from the correspondence analysis and defining the position of each sample in the compositional relay, is plotted on stratigraphic logs of the sections studied to allow detailed comparison with other Waulsortian and peri-Waulsortian sections in the Dinant area for which similar curves already exist. The Waulsort buildups are found to fit closely into the depositional and palaeobathymetric patterns established or suspected in the area. Two shallowing upward sequences seem to be present, separated by an abrupt deepening. The earlier, relatively minor shallowing trend, in the Polygnathus communis carina Zone, is here recorded in buildup facies for the first time: previous evidence had come from the laterally equivalent facies. The other shallowing trend, which extends through the Scaliognathus anchoralis Zone and culminates near the base of the Moliniacian stage, is the regional, late Tournaisian regression which had a major influence on the biota of the Waulsortian banks in Belgium and was probably largely responsible for cessation of bank growth over most of the area.  相似文献   

Devonian graptolites from southwestern Europe: a review with new data     

A. C. Lenz  M. Robardet  J. C. Gutirrez-Marco  J. M. Piarra 《Geological Journal》1996,31(4):349-358

Lower Devonian graptolite faunas have been recognized in the Normandy and southeastern regions of the Armorican Massif, France; the Pyrenees and Catalonian Coastal Ranges regions and northern Minorca, Balearic Islands, Spain; the southern Hesperian Massif (Ossa Morena Zone) of the Iberian Peninsula; and from southeastern Sardinia, Italy. All but one the of the graptolite faunas collected throughout this large region are from Lochkovian age strata, representing the Monograptus uniformis, Monograptus praehercynicus, and Monograptus hercynicus biozones corresponding to the lower, middle and upper Lochkovian, respectively, and mostly represented by monospecific or low diversity assemblages. Although many individual sections contain representatives of two of the biozones, relatively few reveal all three. A single, poorly preserved faunule, collected in the Ossa Morena region of Spain from strata dated by brachiopods as Pragian–early Emsian may represent the only known graptoloid fauna of post-Lochkovian age. Almost all graptolites have been recovered from condensed successions of black shales and limestone nodules, similar to those of other proto-Tethyan (i.e. outer shelf, with dominantly pelagic faunas) regions such as Thuringia, Bohemia, the Carnic Alps and northwestern Africa. The two exceptions are an occurrence in a shallow-water, coarser clastic sequences at the Carteret locality in Normandy and in deep water turbidites on the island of Minorca. Graptolites are not known from any other thick, shallow water clastic sequences, although whether this is because of paleo environmental exclusion or simply lack of recovery to date is unknown. Other fossil evidence (e.g. chitinozoans), however, indicates continuous marine sedimentation from the Silurian to Devonian. © 1996 John Wiley & Sons, Ltd.  相似文献   

新疆柯坪大湾沟剖面柯坪塔格组中段底部笔石生物地层初步分析   总被引：6，自引：0，他引：6  

江大勇  皮学军  孙作玉  陈颖  吴飞翔  郝维城 《地层学杂志》2006,30(3):253-257

新疆塔里木盆地西北缘柯坪大湾沟剖面柯坪塔格组中段底部的泥岩夹白云岩地层中发现有较丰富的笔石、腕足类、三叶虫、双壳类等化石,其中笔石有4属8种及2个比较种和1个未定种,可能属笔石Coronograptuscyphus带至Coronograptusgregarius带。从笔石生物地层看,柯坪塔格组中段底部的时代很可能为志留纪兰多维列世鲁丹期末至埃隆期初。  相似文献   

Stratigraphical correlation of the Late Jurassic Lourinhã Formation in the Consolação Sub‐basin (Lusitanian Basin), Portugal     

Andrew M. Taylor  Stuart Gowland  Simon Leary  kevin j. Keogh  Allard W. Martinius 《Geological Journal》2014,49(2):143-162

The c. 700 m thick succession of continental–brackish‐marine deposits forming the Lourinhã Formation, cropping out along the coast of western Portugal between Baleal and Santa Cruz, has been correlated using laterally persistent shelly marker beds. Three shelly units record the episodic establishment of relatively short‐lived, brackish‐marine embayments, transgressing from the southwest, onto a low‐lying coastal plain. The succession displays systematic changes in facies types and stacking patterns reflecting differences in fluvial style, bedload character and palaeontological content. Based on these observations, four new members for the Lourinhã Formation are proposed: the Sáo Bernardino, Porto de Barças, Areia Branca and Ferrel members. New biostratigraphical data indicate that the Lourinhã Formation is Late Kimmeridgian to earliest Early Tithonian in age. This age has also been obtained from the underlying mixed carbonate and clastic deposits of the Abadia Formation at Consolação. As a result, these latter sediments are now re‐assigned to the Alcobaça Formation, a lithostratigraphical term currently in use in other areas of the Lusitanian Basin. Improved regional mapping of the Lourinhã Formation has established a new sub‐basin within the western parts of the Lusitanian Basin. This sub‐basin, now named the Consolação Sub‐basin, is bounded to the east by the Lourinhã–Caldas de Rainha (L–C) fault zone and to the west by the Berlengas Horst. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献