Forebulge dynamics and sedimentary response of an initial Variscan foreland basin; the Upper Devonian of the southern Cantabrian Mountains, N Spain

2020 ◽  
Vol 171 (3) ◽  
pp. 249-276
Author(s):  
Gerard B. S. van Loevezijn
Keyword(s):  
Foreland Basin ◽  
Upper Devonian ◽  
Cantabrian Mountains

An enigmatic blastozoan echinoderm fauna from central kentucky

2009 ◽  
Vol 83 (5) ◽  
pp. 739-749 ◽  
Author(s):  
Colin D. Sumrall ◽  
Carlton E. Brett ◽  
Troy A. Dexter ◽  
Alexander Bartholomew
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Middle Devonian ◽  
Fossil Record ◽  
Foreland Basin ◽  
Late Ordovician ◽  
Upper Devonian ◽  
Range Extension ◽  
First Report ◽  
Appalachian Foreland

A series of small road cuts of lower Boyle Formation (Middle Devonian: Givetian) near Waco, Kentucky, has produced numerous specimens of three blastozoan clades, including both “anachronistic” diploporan and rhombiferan “cystoids” and relatively advanced Granatocrinid blastoids. This unusual assemblage occurs within a basal grainstone unit of the Boyle Limestone, apparently recording a local shoal deposit. Diploporans, the most abundant articulated echinoderms, are represented by a new protocrinitid species, Tristomiocystis globosus n. gen. and sp. Glyptocystitoid rhombiferans are represented by isolated thecal plates assignable to Callocystitidae. Three species of blastoids, all previously undescribed, include numerous thecae of the schizoblastid Hydroblastus hendyi n. gen. and sp., the rare nucleocrinid Nucleocrinus bosei n. sp., and an enigmatic troosticrinid radial. The blastoid Nucleocrinus is typical for the age; however, the callocystitid, schizoblastid, and protocrinitid are not. Hydroblastus is the oldest known schizoblastid. Middle and Upper Devonian callocystitids have been previously reported only from Iowa and Michigan USA with unpublished reports from Missouri USA and the Northwest Territories, Canada. This occurrence is thus the first report of a Middle Devonian rhombiferan from the Appalachian foreland basin. Tristomiocystis is the first known protocrinitid in North America and the only protocrinitid younger than Late Ordovician. This occurrence thus represents a range extension of nearly 50 million years for protocrinids. This extraordinary sample of echinoderms in a Middle Devonian limestone from a well-studied area of North America highlights the incompleteness of the known fossil record, at least in fragile organisms such as echinoderms.

scholarly journals Famennian ostracods from the Istanbul zone (Gebze, Kocaeli, NW Turkey) and their paleogeographical relations

2012 ◽  
Vol 63 (5) ◽  
pp. 355-363 ◽  
Author(s):  
Atike Nazik ◽  
Șenol Çapkinoğlu ◽  
Emine Șeker
Keyword(s):  
North Africa ◽  
Upper Devonian ◽  
Late Devonian ◽  
Rhenish Massif ◽  
Cantabrian Mountains ◽  
Holy Cross Mountains ◽  
Thin Walls ◽  
Nw Turkey ◽  
Conodont Zonation ◽  
First Time

Abstract Famennian (Late Devonian) ostracods of the Thuringian Mega-Assemblage were recovered for the first time from three incomplete sections of the Ayineburnu Member of the Büyükada Formation in the Denizliköy area (Gebze, NW Turkey), which were sampled for conodonts. Conodont faunas define an interval extending from the Upper rhomboidea? or Lower marginifera Zone into the Middle expansa Zone of the standard Upper Devonian conodont zonation. The ostracod faunas found here consist of species mainly with thin-walls, long spines and often smooth surfaces such as Rectonaria, Tricornina, Orthonaria, Triplacera, Beckerhealdia, Timorhealdia, Bohemina, Paraberounella and Acratia. These taxa indicate faunal relationship with Thuringia and the Rhenish Massif in Germany, the Cantabrian Mountains and Pyrenees in Spain, Holy Cross Mountains in Poland, North Africa and China.

Tectonostratigraphy and provenance analysis to define the edge and evolution of the eastern Wuyi-Yunkai orogen, South China

2017 ◽  
Vol 156 (1) ◽  
pp. 83-98 ◽  
Author(s):  
WEIHUA YAO ◽  
ZHENG-XIANG LI
Keyword(s):  
South China ◽  
Foreland Basin ◽  
Early Carboniferous ◽  
Upper Devonian ◽  
Provenance Analysis ◽  
Upper Ordovician ◽  
Rift Basins ◽  
Lower Silurian ◽  
Thrust Zone ◽  
Topographic High

AbstractWe report three Palaeozoic sedimentary successions in northeastern South China that display markedly different tectonostratigraphic characteristics: the Jiangshan section exhibits an angular unconformity between the Upper Ordovician and Carboniferous stratra; the Shuangming section exhibits a disconformity between the lower Silurian and Upper Devonian strata; and the Xinqiao section exhibits a disconformity between the upper Silurian and Upper Devonian strata. The Shuangming and Xinqiao sections are interpreted to represent the remnant Nanhua foreland basin, whereas the Jiangshan section is in the fold-and-thrust zone of the Wuyi-Yunkai orogen. The Lizhu-Changshan thrust fault in between is interpreted to be the frontal thrust and the boundary of the orogen. Detrital provenance analysis of the Ordovician–Devonian sandstones from the Shuangming and Xinqiao sections shows that the Ordovician–Silurian, mid- to late-orogenic sandstones contain dominantly 860–780 Ma zircon populations and subordinate 2.5 Ga, 1.89–1.78 Ga, 980–950 Ma, 630–540 Ma and 430 Ma populations, indicating nearby sources including the early Neoproterozoic Sibao orogen, inverted Neoproterozoic rift basins and related plutons, recycled Ediacaran–Cambrian strata and, increasing with time, exposed Cathaysia basement and minor syn- to late-orogenic plutonic intrusions. The Devonian post-orogenic sandstones exhibit a dominant 440 Ma population with minor 2.5 Ga, 1.89–1.78 Ga, 860–780 Ma and 630–540 Ma populations, suggesting a dominant contribution from now widely exposed, mid- to late-orogenic plutonic intrusions (with or without contributions from rare volcanism of similar ages) in a residual topographic high SE of the Lizhu-Changshan fault. This residual topographic high of the Wuyi-Yunkai orogen had completely perished by early Carboniferous time, c. 60Myr after the end of the orogenic event.

scholarly journals Alpine tectonic wedging and crustal delamination in the Cantabrian Mountains (NW Spain)

Solid Earth ◽  
2016 ◽  
Vol 7 (4) ◽  
pp. 1043-1057 ◽  
Author(s):  
Jorge Gallastegui ◽  
Javier A. Pulgar ◽  
Josep Gallart
Keyword(s):  
Cross Section ◽  
Foreland Basin ◽  
Seismic Reflection Profile ◽  
Cantabrian Mountains ◽  
Seismic Modelling ◽  
The North ◽  
Geological Cross Section ◽  
Deformation Event ◽  
Southern Border ◽  
Detailed Interpretation

Abstract. The Cantabrian Mountains have been interpreted as a Paleozoic basement block uplifted during an Alpine deformation event that led to the partial closure of the Bay of Biscay and the building of the Pyrenean range in the Cenozoic. A detailed interpretation of deep seismic reflection profile ESCIN-2 and the two-dimensional seismic modelling of the data allowed us to construct a N–S geological cross section along the southern border of the Cantabrian Mountains and the transition to the Duero Cenozoic foreland basin, highlighting the Alpine structure. The proposed geological cross section has been constrained by all geophysical data available, including a 2-D gravity model constructed for this study as well as refraction and magnetotelluric models from previous studies. A set of south-vergent thrusts dipping 30 to 36° to the north, cut the upper crust with a ramp geometry and sole in the boundary with the middle crust. These thrusts are responsible for the uplift and the main Alpine deformation in the Cantabrian Mountains. A conspicuous reflective Moho shows that the crust thickens northwards from the Duero basin, where subhorizontal Moho is 32 km deep, to 47 km in the northernmost end of ESCIN-2, where Moho dips to the north beneath the Cantabrian Mountains. Further north, out of the profile, Moho reaches a maximum depth of 55 km, according to wide-angle/refraction data. ESCIN-2 indicates the presence of a tectonic wedge of the crust of the Cantabrian margin beneath the Cantabrian Mountains, which is indented from north to south into the delaminated Iberian crust, forcing its northward subduction.

scholarly journals Alpine tectonic wedging and crustal delamination in the Cantabrian Mountains (NW Spain)

2016 ◽  
Author(s):  
Jorge Gallastegui ◽  
Javier A. Pulgar ◽  
Josep Gallart
Keyword(s):  
Cross Section ◽  
Foreland Basin ◽  
Seismic Reflection Profile ◽  
Cantabrian Mountains ◽  
Seismic Modelling ◽  
The North ◽  
Geological Cross Section ◽  
Deformation Event ◽  
Southern Border ◽  
Detailed Interpretation

Abstract. The Cantabrian Mountains have been interpreted as a Paleozoic basement block uplifted during an Alpine deformation event that led to the partial closure of the Bay of Biscay and the building of the Pyrenean range in the Cenozoic. A detailed interpretation of deep seismic reflection profile ESCIN-2 and the two-dimensional seismic modelling of the data allowed us to construct a N-S geological cross-section along the southern border of the Cantabrian Mountains and the transition to the Duero Cenozoic foreland basin, highlighting the Alpine structure. The proposed geological cross-section has been constrained by all geophysical data available, including a 2-D gravity model constructed for this study as well as refraction and MT models from previous studies. A set of thrusts vergent to the S, dipping 30° to 36°, cut the upper crust and are responsible for the uplift and the main Alpine deformation in the Cantabrian Mountains. A conspicuous reflection Moho shows that the crust thickens northwards from the Duero basin, where subhorizontal Moho is 32 km deep, to 47 km in the northernmost end of ESCIN-2 where it is dipping to the north beneath the Cantabrian Mountains. Further north, out of the profile, Moho reaches a maximum depth of 55 km according to wide-angle/refraction data. ESCIN-2 indicates the presence of a tectonic wedge of the crust of the Cantabrian margin beneath the Cantabrian Mountains, which is indented from north to south into the delaminated Iberian crust, forcing its northwards subduction

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