Scholarship_Directory1-Afro-American-Canadian-Carribean
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Scholarship_Directory1-Afro-American-Canadian-Carribean
Scholarship_Directory1-Afro-American-Canadian-Carribean
1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribean implications for the mid-Cretaceous4Juan Pedro Rodriguez-Lopez1, Carlos L. Liesa2, Gonzalo Pardo3, Nieves SMelendez4,5, Ana R. Soria3, Ian Skilling1^School of Applied Sciences. Faculty of Computing, Engineering and Sciences. University of South Wales. 7UK. Glyntaf, Pontypridd, Rhonda Cynon Taff, CF Scholarship_Directory1-Afro-American-Canadian-Carribean37 4AT. iuanp.rodrlauez&souihwales.ac.uk, 8lan.skllllng@southwales.ac.uk&Grupo Geotransfer (DGA), Departamento de Clenclas de la Tierra, Facultad de CScholarship_Directory1-Afro-American-Canadian-Carribean
lencias, Universldad lOde Zaragoza, C/ Pedro Cerbuna 12, 50009, Zaragoza, Spain, carluls@unizar.esiPGrupo de Andlisis de Cuencas Sedimentarias Contine1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeangpardo@unicar.es. asoria@unizar.es14* Institute de Geoclenclas (IGEO) (CS1C).l5sGrupo de Análisis de Cuencas (UCM). Departamento de Estratigrafia (UCM), Facultad de Ciencias IGGeolõglcas, Institute de GeoCiendas (1GEO UCM-CSIC) Ciudad Unlversiterta, 28040 Madrid. Spain. i7nievesml@ucm.es1819Correspo Scholarship_Directory1-Afro-American-Canadian-Carribeannding author: Dr. Juan Pedro Rodriguez-LopezZOSchool of Applied Sciences. Faculty of Computing, Engineering and Sciences. University of South Viales,Scholarship_Directory1-Afro-American-Canadian-Carribean
21 UK. Glyntef, Pontypridd, Rhonda Cynon Taff. CF37 4AT. luani). rodriauez@southwales.ac.uk2223Short title: Glacial dropstones in western Tethys.24Key1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribean period is commonly considered the only cold snap in 28Earth history without any direct evidence of polar ice. A newly discovered dropstone-29bearing interval from the subtropical Iberian Basin (western Tethys) is described and 30provides evidence of contemporaneous polar glaciation. This interval i Scholarship_Directory1-Afro-American-Canadian-Carribeanscorrelated Bilaterally for 4.8 km andcontains a boulder and two cobble-sized quartzite dropstones 32that are encased in mid-Cretaceous fissile blackScholarship_Directory1-Afro-American-Canadian-Carribean
shales and fine-grained sandstones. 33Based on previously published dimensions of similar large clasts, only glacial 34dropstones and impact ejecta bl1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeantransport and abrasion in a subglacial setting which closely 37resemble the features observed in recent glacial boulders exposed near the snouts of 38glaciers in Iceland. These Late Aptian dropstones from Spain correlate with many other 39similar erratics in the northern and southern palaeohemispher Scholarship_Directory1-Afro-American-Canadian-Carribeanes, and suggest that ice 40sheets formed around the palaeo-North Pole during certain periods of the early 41Cretaceous. Our results and associated eviScholarship_Directory1-Afro-American-Canadian-Carribean
dence such as the occurrence of glendonites, 42tillites, moderate- to high-amplitude sea-level oscillations worldwide, minimum pco2 43concentrations, 1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeanre 45periods of ice growth and decay that influenced the palaeotemperature, palaeoecology 46and sedimentology of the marine realm. Thenew data from Iberia also coincides with 47recent results from Arctic Canada that indicate cool shelves and a mid-Cretaceous cold 48snap that developed for Myr betwee Scholarship_Directory1-Afro-American-Canadian-Carribeann 118 and 112 Ma. The late Aptian dropstones 49reported in eastern Iberiawere likely transported from high northern latitudes towards 50subtropical onScholarship_Directory1-Afro-American-Canadian-Carribean
es in the western Tethys by an extreme iceberg drift similar to those52 67Rodríguez-Lopez et al.51occurring at the present day in the Atlantic Ocean. 1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeanmany years the Cretaceous has been considered a greenhouse period of 56about 79 Myrduration with no ice present at the poles. After Frakes (1979), Frakes and 57Francis (1988) and Frakes et al. (1995) that reported a 3 m diam.dropstone from 58Australia, the possibility of polar ice during the Cretace Scholarship_Directory1-Afro-American-Canadian-Carribeanous came under scientific 59discussion and remains a controversial topic.(Koch and Brenner, 2008). The GOinterpretation of Cretaceous large clasts asScholarship_Directory1-Afro-American-Canadian-Carribean
dropstones has been problematic due to the 61occurrence of these deposits in the standard model of an ice-free Cretaceous world 62(Frakes and Francis,1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeansited from 64driftwood (wood-rafting) in both lacustrine (e.g.. Doublet and Garcia, 2004) and marine 65settings (e.g., Noe-Nygaard. 1975).66 The present manuscript presents the occurrence of an isolated quartzite 67dropstone boulder (74x50x40 cm) in the late Aptian-early Aibian Escucha Formation in Scholarship_Directory1-Afro-American-Canadian-Carribean68an outcrop near Oliete (central-eastern Iberia), and two cobble-sized dropstones from 69the same stratigraphic interval in the Arifio sector (Fig. 1Scholarship_Directory1-Afro-American-Canadian-Carribean
A-D). These clasts represent 70the southernmost Cretaceous dropstones reported from the palaeo-Northern Hemisphere 7 land the largest is one of the bi1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeannalyze the morphological features of the dropstones, to compare them with other 74erratics from the Archean to Recent, to analyze their presence in a palaeogeographical 75context, to critically discuss the geological processes that could lead to their deposition89310Rodn'guez-López et al.76and (0 ou Scholarship_Directory1-Afro-American-Canadian-Carribeantline any palaeoclimate and palaeogeographic implications for the mid-77Cretaceous.782. Geological and palaeogeographical setting79 The studied outcroScholarship_Directory1-Afro-American-Canadian-Carribean
ps of the Lower Cretaceous Escucha Formation are located in 80the eastern central part of Iberia (Fig. 1A), in particular in the central sector of the1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeano the western 83European Rift system (Ziegler, 1988; Ziegler et al., 1998). Sedimentary basins 84developed in eastern Iberia during a period of Mesozoic crustal thinning with two main 85rifting episodes recognized, (Salas and Casas. 1993; Soria et al., 2000; Capote et al., 862002; Martin-Chivelet et Scholarship_Directory1-Afro-American-Canadian-Carribean al., 2002), during thelate Permian-Triassic and late Jurassic-87early Cretaceous. Early Cretaceous rifling was controlled by NW-SE and NE-SW 88basemeScholarship_Directory1-Afro-American-Canadian-Carribean
nt alignments that defined a mosaic of subsiding and non-subsiding blocks 89(Álvaro et al., 1979; Salas and Casas, 1993; Soria et al., 2000; Antolín-T1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeanence from fracture system (Liesa, 922000; Antolín-Tomás et al., 2007) and magnetic fabric (Garcia-Lasanta et al., 2015) 93analysis in the Maestrazgo basin.94 The Oliete sub-basin was a well-differentiated sub-basin formed in the North of 95the Maestrazgo basin during the second rifting episode, and Scholarship_Directory1-Afro-American-Canadian-Carribeanwhich triggered the 96fragmentation of the late Jurassic platforms (e.g., Salas and Casas, 1993; Soria et al., 972000). The sub-basin formed in the laScholarship_Directory1-Afro-American-Canadian-Carribean
te Hauterivian and existed until the early-middle 98Albian (Soria, 1997; Soria et al., 2000; Salas et al., 2001; Rodriguez-Lopez, 2008). Its 99structu1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographic Scholarship_Directory1-Afro-American-Canadian-Carribeanwhich suffered1Rodriguez-Lopez et al.1 Glacial dropstones in the western Tethys during the 2late Aptian-early Albian cold snap: palaeoclimate and 3palaeogeographicGọi ngay
Chat zalo
Facebook