Lower Jurassic-Lower Cretaceous belemnite biogeography and the development of the Mesozoic Boreal Realm

1987 ◽  
Vol 61 ◽  
pp. 237-254 ◽  
Author(s):  
Peter Doyle
1986 ◽  
Vol 5 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Nigel R. Ainsworth ◽  
Nicola F. Horton

Abstract. The geology, biostratigraphy and palaeoecology of exploration well Elf 55/30–1 in the Fastnet Basin are summarised. The biostratigraphical and ecological distribution of the foraminifera and Ostracoda from the late Triassic, the Lower Jurassic and the Lower Cretaceous are reviewed with reference to microfaunas elsewhere in Europe. Selected microfossil taxa are illustrated.


2020 ◽  
Author(s):  
Costantino Zuccari ◽  
Angelo Cipriani ◽  
Massimo Santantonio

<p>A geological mapping project was performed on the 1:10,000 scale in the northern Amerini Mts. (Narni–Amelia Ridge, Central Apennines), coupled with facies analysis and multidisciplinary outcrop characterisation. This project was focused on the Jurassic-Lower Cretaceous succession, in order to reconstruct the Mesozoic palaeogeography and tectono-sedimentary evolution of the study area. This sector of the Apenninic Chain (i.e. Umbria-Marche-Sabina palaeogeographic domain) experienced the Early Jurassic rifting phase, which dismembered the vast Calcare Massiccio carbonate platform. The development of a rugged submarine topography, coupled with drowning of the benthic factories, were the main effects of this normal faulting. The complex submarine physiography, made of structural highs and lows, is highlighted by facies and thickness variations of the Jurassic and Lower Cretaceous deposits. The hangingwall blocks hosted thick (hundreds of metres) pelagic successions, with variable volumes of admixed gravity-flow deposits. These successions onlapped the horst blocks along escarpments, rooted in the rift faults, where the pre-rift Calcare Massiccio was exposed. The tops of footwall blocks (Pelagic Carbonate Platforms or PCPs) were capped by thin (few tens of metres or less), fossil-rich and chert-free, condensed pelagic successions. This rift architecture was evened out at a domain scale in the Early Cretaceous. Successively, Miocene orogenic and Plio-Pleistocene extensional faulting caused uplift and exhumation of the Mesozoic rocks.</p><p>In the study area, geothematic mapping associated with the analysis of basin-margin unconformities and successions revealed a narrow and elongated Jurassic structural high (Mt. Croce di Serra - Mt. Alsicci structural high), surrounded by Jurassic basinal pelagites. The PCP-top condensed succession is not preserved. The chert-rich basinal units rest on the horst-block Calcare Massiccio through unconformity surfaces (palaeoescarpments), as marked by the silicification of the (otherwise chert-free) shallow-water limestone. The onlap successions embed megablocks of Calcare Massiccio (hundreds of metres across), detached from their parent palaeoescarpments. Very thin, condensed deposits form discontinuous veneers on the olistoliths of Calcare Massiccio (epi-olistolith deposits) and are onlapped by younger basin-fill pelagites. The beds surrounding the olistoliths are characteristically bent due to differential compaction, as their (newly acquired) strikes mimic the outline of the stiff objects they were burying.</p><p>Indirect evidence for a Toarcian, post-rift, tectonic pulse can be locally mapped, and is documented by angular unconformities between the Pliensbachian and Toarcian pelagites, as well as by mass-transport deposits found in the Rosso Ammonitico (Toarcian).</p><p>The same goes for millimetric to centimetric neptunian dykes made of Maiolica pelagites cross-cutting the Corniola Fm. (Sinemurian-Pliensbachian). These dykes, coupled with the occurrence of unconformities between Aptian-Albian pelagites (Marne a Fucoidi Fm.) and Lower Jurassic rocks (Calcare Massiccio and Corniola formations), provide evidence for a further Early Cretaceous tectonic phase, recently reported from the southern sectors of Narni-Amelia ridge.</p>


1996 ◽  
Vol 43 ◽  
pp. 133-142
Author(s):  
H. I. Petersen ◽  
J. A. Bojesen Koefoed ◽  
H. P. Nytoft

A c. 1 m thick carbonaceous claystone from the type locality of the Lower Cretaceous Skyttegård Member (Rabekke Formation), Bornholm, has been investigated by organic pétrographie and organic geochemical methods in order to assess the depositional environment of the claystone and the thermal maturity of the organic matter. The claystone was deposited in a low-energy, anoxic lake which occasionally was marine influenced. The organic matter is terrestrial and can be classified as kerogen type III and lib. Detrital organic matter and cutinite are characteristic components. The organic matter is allochthonous but the transport distance was short, and the plant material was probably mainly derived from plants growing at the edge of, or nearto, the lake. Source-specific biomarkers such as norisopimarane suggest that the plant litter was derived from a gymnospermous, low-diversity vegetation. Evidence for early angiospermous plants cannot be demonstrated with any certainty. A huminite reflectance value of 0.24%Rm and several geochemical parameters indicate that the organic matter is highly immature. It has only experienced coalification corresponding to the peat stage. Estimates show that, prior to uplift, the claystone was buried to a maximum of approximately 260 m. Reflectance data further suggest that a maximum c. 550 m thick sediment package was removed by erosion prior to deposition of the ?uppermost Jurassic-Lower Cretaceous sediments on Lower Jurassic strata.


2020 ◽  
Vol 3 (1) ◽  
pp. 054-058
Author(s):  
HAICHUN ZHANG

The Ephialtitidae is an extinct family of wasps, with 29 genera reported from the Lower Jurassic-Lower Cretaceous in Kyrgyzstan, Kazakhstan, China, Mongolia, Russia, Spain, Germany and Brazil, and flourished in the Middle–Late Jurassic (Meunier, 1903; Rasnitsyn, 1975, 1977, 1990, 1999, 2008a, b; Zessin, 1981, 1985; Zhang, 1986; Darling & Sharkey, 1990; Rasnitsyn & Ansorge, 2000; Rasnitsyn & Martínez-Delclòs, 2000; Zhang et al., 2002; Rasnitsyn et al., 2003; Rasnitsyn & Zhang, 2004, 2010; Zhang et al., 2010; Ding et al., 2013, 2016; Li et al., 2013, 2014, 2015; Zhang et al., 2014). It is considered to be the most basal group of the Apocrita, one of two suborders of the order Hymenoptera (Rasnitsyn & Zhang, 2010).


2013 ◽  
Vol 151 (5) ◽  
pp. 798-815 ◽  
Author(s):  
MICHAEL ANENBURG ◽  
OR M. BIALIK ◽  
YEVGENY VAPNIK ◽  
HAZEL J. CHAPMAN ◽  
GILAD ANTLER ◽  
...  

AbstractSpectacular celestine geodes occur in a Jurassic peri-evaporitic sequence (Ardon Formation) exposed in Makhtesh Ramon, southern Israel. The geodes are found only in one specific location: adjacent to an intrusive contact with a Lower Cretaceous basaltic dyke. Celestine, well known in sedimentary associations worldwide and considered as a low temperature mineral, may therefore be associated with magmatic-induced hydrothermal activity. Abundant fluid inclusions in celestine provide valuable information on its origin: gas-rich inclusions in celestine interiors homogenized at T≥200°C whereas smaller liquid-rich inclusions record the growth of celestine rims at T≤200°C. Near 0°C melting temperatures of some fluid inclusions and the occurrence of hydrous Ca-sulphate solid crystals in other inclusions indicate that celestine precipitated from variably concentrated Ca-sulphate aqueous solutions of meteoric origin. Celestine crystallized from meteoric water heated by the cooling basaltic dyke at shallow levels (c. 160 m) during a Lower Cretaceous thermal perturbation recorded by regional uplift and magmatism. The 87Sr/86Sr ratio of geode celestine, 0.7074, is similar to that measured in the dolostones of the host Jurassic sequence, but differs markedly from the non-radiogenic ratio of the dyke. Strontium in celestine was derived from dolostones preserving the 87Sr/86Sr of Lower Jurassic seawater, while sulphur (δ34S = 19.9‰) was provided by in situ dissolution of precursor marine gypsum (δ34S = 16.8‰) indicated by relict anhydrite inclusions in celestine. Low-temperature meteoric fluid flow during the Campanian caused alteration of the dyke into secondary clays and alteration of geodal celestine into quartz, calcite and iron oxides.


2018 ◽  
Vol 472 (472) ◽  
pp. 327-338
Author(s):  
Izabella Gryszkiewicz ◽  
Mariusz Socha

The thermal and mineralized waters in the subsurface of Sulejówek, Józefów, and Otwock towns of the Warsaw region have been analyzed. An initial assessment of the utilization of such waters based on deep boreholes and significance of these waters for development of the communities has been considered. The analysis shows that in the area of Sulejówek, Józefów and Otwock communes there are chloride and sodium waters in the aquifer of the Lower Cretaceous and the Jurassic of mineralization from about 10 to over 70 g/dm3, probably characterized by an increased content of specific components desirable in the case of waters used in balneotherapy – iodides (above 1 mg/dm3 in the lower cretaseous and lower jurassic) and divalent iron (over 10 mg/dm3 in the lower jurassic). The values of subsurface temperature in this area at a depth of 1000 m are about 35°C, at a depth of 2000 m the temperature exceeds 50°C. An optimist scenario includes a possibility of future development of touristic attractions in terms of therapeutic resorts in the Warsaw region.


2021 ◽  
pp. 1-23
Author(s):  
Songnan Liu ◽  
Yu Wang ◽  
Huimin Ma ◽  
Tao Qian

Abstract The theory of plate tectonics suggests that deformation occurs mainly along plate boundaries; however, compression can result in the formation of orogens and basins within intracontinental settings. During these two tectonic processes, the sedimentation and environmental changes occur in response to marginal and intracontinental deformation. Early Jurassic – Early Cretaceous deformation and basin formation along the Qinling orogenic belt and the northwestern Sichuan Basin in central–SW China are ideal for investigating a reactivated tectonic belt and basin formation. We studied the Lower Jurassic – Lower Cretaceous sedimentary sequences and structures along the northwestern margin of the Sichuan Basin, and obtained detrital zircon U–Pb ages for these rocks. The structures show that deformation migrated SE-wards and S-wards into the Sichuan Basin along the Longmen Shan, Micang Shan and Daba Shan tectonic belts during middle–late Mesozoic time. The Lower Jurassic oligomictic conglomerates have a smaller grain size and thicken towards the south, indicating protracted transport from a northern source. The conglomerates deposited near-source record post-orogenic south-vergent thrusting during the Late Triassic – Early Jurassic epochs. The Lower Cretaceous conglomerates and sandstones have multiple sources, which indicate that they were rapidly deposited near their source, synchronous with thrusting that occurred in response to coeval SE-wards and S-wards thrusting in the Longmen Shan and Daba Shan tectonic belts during the Late Jurassic – Early Cretaceous epochs. Detrital zircon grains from the Lower Jurassic – Lower Cretaceous sedimentary rocks yielded age peaks of 2600–2200, 1850–1600, 850–700, 540–400, 250–180 and 180–140 Ma. A comparison of these ages with those of surrounding exposed rocks indicates that the sediments in the northwestern Sichuan Basin were supplied from the Qinling orogenic belt, the northwestern Yangtze Block, the south margin of the North China Block and the Songpan–Garzê Terrane. The youngest peaks of detrital zircon U–Pb ages at 207 and 159 Ma constrain the two stages of intracontinental shortening and highlight the link between intracontinental deformation and sedimentation.


2019 ◽  
pp. 1350-1361
Author(s):  
Mohammed Sadi Fadhil ◽  
Ali M. Al-Rahim

Study of three dimensional seismic data of Merjan area-central Iraq has shown that the Jurassic – Cretaceous succession is affected by faulting system. Seven major normal faults were identified and mapped. Synthetic traces have been calculated by using sonic and density log data of the well Me-1.Two exploration wells were drilled in the area Me-1 and Wkf-1 wells, the distance between them is 15.82 km. Discussion about the effect of this system on the sedimentary package has been presented. The tight faults that couldn’t be distinguished it on seismic sections were determined using seismic attributes. They have different strike and limited in their vertical and horizontal extension. They are system facilitates the movement or migration of the fluid across the stratigraphic column in the study area. Faulting framework can be divided into two groups: the first affects the Jurassic and lower Cretaceous rocks and the second effect the upper Cretaceous and lower Tertiary rocks. The first group is associated with the post rift thermal sag, passive margin progradation and gravitational collapse (lower Jurassic – upper Cretaceous (Turonian) 022 – 93 Ma); approximately Sargelue – NahrUmr depositional time. The second group is few and is associated with the rifting creating the Euphrates graben (Late Turonian – Maastrichtian 90 – 70 Ma) approximately Tanuma shale / Sadi – Shiranish) depositional time.


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