Redox conditions during sedimentation of the Middle Jurassic (Upper Bajocian–Bathonian) clays of the Polish Jura (south-central Poland)

Facies ◽  
2008 ◽  
Vol 55 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Michał Zatoń ◽  
Leszek Marynowski ◽  
Patrycja Szczepanik ◽  
David P. G. Bond ◽  
Paul B. Wignall
Keyword(s):  
Middle Jurassic ◽  
Redox Conditions ◽  
Central Poland ◽  
South Central ◽  
Upper Bajocian

Signs of predation in the Middle Jurassic of south-central Poland: evidence from echinoderm taphonomy

Lethaia ◽  
2007 ◽  
Vol 40 (2) ◽  
pp. 139-151 ◽  
Author(s):  
MICHAŁ ZATOŃ ◽  
LOÏC VILLIER ◽  
MARIUSZ A. SALAMON
Keyword(s):  
Middle Jurassic ◽  
Central Poland ◽  
South Central

Charcoals from three Neolithic settlements in the loess area of south-central Poland

1992 ◽  
Vol 139 (2-4) ◽  
pp. 373-382 ◽  
Author(s):  
Krystyna Wasylikowa ◽  
Irena Gluza ◽  
Maria Litynska-Zajac ◽  
Zofia Tomczynska
Keyword(s):  
Loess Area ◽  
Central Poland ◽  
South Central

Provenance of Jurassic sedimentary rocks of south-central Quesnellia, British Columbia: implications for paleogeography

2004 ◽  
Vol 41 (1) ◽  
pp. 103-125 ◽  
Author(s):  
Nathan T Petersen ◽  
Paul L Smith ◽  
James K Mortensen ◽  
Robert A Creaser ◽  
Howard W Tipper
Keyword(s):  
Detrital Zircon ◽  
Middle Jurassic ◽  
Sedimentary Rocks ◽  
Source Area ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Nd Isotopes ◽  
South Central ◽  
History Of

Jurassic sedimentary rocks of southern to central Quesnellia record the history of the Quesnellian magmatic arc and reflect increasing continental influence throughout the Jurassic history of the terrane. Standard petrographic point counts, geochemistry, Sm–Nd isotopes and detrital zircon geochronology, were employed to study provenance of rocks obtained from three areas of the terrane. Lower Jurassic sedimentary rocks, classified by inferred proximity to their source areas as proximal or proximal basin are derived from an arc source area. Sandstones of this age are immature. The rocks are geochemically and isotopically primitive. Detrital zircon populations, based on a limited number of analyses, have homogeneous Late Triassic or Early Jurassic ages, reflecting local derivation from Quesnellian arc sources. Middle Jurassic proximal and proximal basin sedimentary rocks show a trend toward more evolved mature sediments and evolved geochemical characteristics. The sandstones show a change to more mature grain components when compared with Lower Jurassic sedimentary rocks. There is a decrease in εNdT values of the sedimentary rocks and Proterozoic detrital zircon grains are present. This change is probably due to a combination of two factors: (1) pre-Middle Jurassic erosion of the Late Triassic – Early Jurassic arc of Quesnellia, making it a less dominant source, and (2) the increase in importance of the eastern parts of Quesnellia and the pericratonic terranes, such as Kootenay Terrane, both with characteristically more evolved isotopic values. Basin shale environments throughout the Jurassic show continental influence that is reflected in the evolved geochemistry and Sm–Nd isotopes of the sedimentary rocks. The data suggest southern Quesnellia received material from the North American continent throughout the Jurassic but that this continental influence was diluted by proximal arc sources in the rocks of proximal derivation. The presence of continent-derived material in the distal sedimentary rocks of this study suggests that southern Quesnellia is comparable to known pericratonic terranes.

scholarly journals First record of an erymid lobster (Crustacea, Decapoda) from the upper Bajocian of Northwest Bulgaria

2021 ◽  
Vol 50 (2) ◽  
pp. 69-74
Author(s):  
Lubomir Metodiev ◽  
Docho Dochev ◽  
Svetlozar Seferinov ◽  
Silviya Petrova
Keyword(s):  
Eastern Europe ◽  
Middle Jurassic ◽  
First Record ◽  
Upper Bajocian ◽  
Single Locality

Fossil chela of an erymid lobster from a single locality of the upper Bajocian in the Western Fore-Balkan Mts (NW Bulgaria) was studied. Two segments of the thoracic appendages, probably belonging to one individual, were described: 1) P1 propodus with partially preserved pollex and dactylus; and 2) P1 carpus and P1 merus attached. These elements of the first pair of pereiopods of a lobster were identified as Eryma compressum (Eudes-Deslongchamps, 1842). Eryma compressum a is well-known taxon from numerous Jurassic localities in Europe but has not been recorded in Bulgaria to date. Therefore, albeit being an isolated finding with only a few elements, the Bulgarian example contributes to the overall record of European erymid faunas from the Middle Jurassic, and especially in Eastern Europe, from where only a few erymids have been reported.

Les olistholites du Riou d'Entraix et leur signification paleostructurale

1966 ◽  
Vol S7-VIII (3) ◽  
pp. 401-404
Author(s):  
Philippe Artru
Keyword(s):  
Middle Jurassic ◽  
Deep Basin ◽  
Upper Bajocian

Abstract The upper Bajocian (middle Jurassic) heterogeneous polygene breccias of the Riou d'Entraix (southeast France) are interpreted as olistostromes formed by gravity sliding along a paleoscarp. The scarp was to the east, in the area presently covered by overthrusts, and separated a euxinic deep basin from a well-oxygenated shallow shelf. Similar deposits in the Barcelonette window and the semi-window at Embrun are probably of the same origin.

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