Sequence stratigraphy of the Upper Jurassic mixed siliciclastic-carbonate deposits in the North German Basin (Lower Saxony, Hildesheimer Wald)

2020 ◽  
Vol 109 (3) ◽  
pp. 893-910
Author(s):  
Huaqing Bai ◽  
Christian Betzler ◽  
Wenhui Huang ◽  
Fanfan Zuo ◽  
Feng Wu
Keyword(s):  
Sequence Stratigraphy ◽  
Upper Jurassic ◽  
North German Basin ◽  
Lower Saxony ◽  
The North ◽  
Carbonate Deposits ◽  
German Basin

Sequence stratigraphy of Upper Jurassic deposits in the North German Basin (Lower Saxony, Süntel Mountains)

Facies ◽  
2017 ◽  
Vol 63 (3) ◽  
Author(s):  
Hua-Qing Bai ◽  
Christian Betzler ◽  
Jochen Erbacher ◽  
Jesús Reolid ◽  
Fanfan Zuo
Keyword(s):  
Sequence Stratigraphy ◽  
Upper Jurassic ◽  
North German Basin ◽  
Lower Saxony ◽  
The North ◽  
German Basin

scholarly journals REY and Trace Element Chemistry of Fluorite from Post-Variscan Hydrothermal Veins in Paleozoic Units of the North German Basin

Geosciences ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 283 ◽  
Author(s):  
Patrick Nadoll ◽  
Meike Rehm ◽  
Florian Duschl ◽  
Reiner Klemd ◽  
Dennis Kraemer ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Geochemical Data ◽  
North German Basin ◽  
Lower Saxony ◽  
Rock Interaction ◽  
The North ◽  
Adsorption Processes ◽  
Growth Zones ◽  
Compositional Variations ◽  
German Basin

Hydrothermal fluorites from Paleozoic sedimentary rocks and volcanic units in the North German Basin (NGB) have been investigated to create a petrographic and geochemical inventory—with particular focus on strategic elements such as rare earth elements (REE)—and to uncover possible links between the post-Variscan hydrothermal mineralization in the NGB and bordering areas such as the Harz Mountains and Flechtingen Calvörde Block (FCB). Fluorites from ten localities underwent a detailed petrographic examination, including SEM-BSE/CL imagery, and were compositionally analysed using LA-ICP-MS. Overall, REY concentrations are comparatively low in fluorite from all investigated areas—the median sum of REY ranges from 0.3 to 176 ppm. EuropiumCN anomalies are slightly negative or absent, indicating that either the formation fluid experienced temperatures above 250 °C or that fluid-rock interactions and REE enrichment was likely controlled by the source rock (i.e., volcanic) composition and complexation processes. Fluorites from the Altmark-Brandenburg Basin (ABB) and the Lower Saxony Basin (LSB) display distinctly different REYCN signatures, suggesting that fluid compositions and genetic processes such as fluid-rock interaction differed significantly between the two areas. Complex growth zones and REYCN signatures in fluorite from the ABB and the FCB reflect geochemical variability due to adsorption processes and intrinsic crystallographic controls and imply that they are genetically related. Two petrographically and geochemically distinct generations are observed: Fluorite I—light SEM shades, relatively enriched in LREE; Fluorite II—darker SEM shades, comparatively depleted LREE, slightly higher HREE concentrations. These fluorite generations represent zoned (or cyclical) growth within a single progressive hydrothermal event and do not reflect a secondary remobilization process. We demonstrate that increasing Tb/La ratios and decreasing La/Ho ratios can be the result of continuous zoned growth during a single mineralizing event, with significant compositional variations on a micron-scale. This has implications for the interpretation of such trends and hence the inferred genetic evolution of fluorite that displays such geochemical patterns. The complex micro-scale intergrowth of these generations stresses the need for detailed petrographic investigations when geochemical data are collected and interpreted for mineral exploration.

scholarly journals A comprehensive model of seismic velocities for the Bay of Mecklenburg (Baltic Sea) at the North German Basin margin: implications for basin development

2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Michael Schnabel ◽  
Vera Noack ◽  
Niklas Ahlrichs ◽  
Christian Hübscher
Keyword(s):  
Model Building ◽  
Sedimentary Basins ◽  
Lower Triassic ◽  
Upper Jurassic ◽  
Rock Properties ◽  
Seismic Velocities ◽  
North German Basin ◽  
Seismic Profiles ◽  
The North ◽  
German Basin

AbstractThe geometry of sedimentary basins is normally described by the interpretation of seismic reflectors. In addition to that, rock properties of the sedimentary successions between these reflectors give further insight into the subsurface geology. Here, we present a model for the Bay of Mecklenburg, situated at the northeastern margin of the North German Basin. The model consists of eight layers; it covers seismic velocities of sediments from the Neogene down to the base of the Permian Zechstein. We use eight seismic profiles for model building and apply seismic migration velocity analysis in combination with pre-stack depth migration. The results are interval velocities down to a depth of 5000 m. A further aim of the study is to investigate the sensitivity of these indirectly deduced velocities in comparison to direct measurements within drill holes. The velocities from this study are in good agreement with earlier results from vertical seismic profiling at a nearby well. Cenozoic and Mesozoic strata within the Bay of Mecklenburg show clear depth-dependent velocity trends. A comparison of these trends with predicted compaction trends shows that burial anomalies within Lower Triassic units are significantly higher than in Upper Cretaceous units. This finding could be explained by a greater amount of erosion during Upper Jurassic/Lower Cretaceous times than during Cenozoic times. The Zechstein layer shows a decreasing interval velocity with increasing thickness. Our study demonstrates that seismic velocities deduced from surface-based measurements are of high value in areas with sparse drilling coverage.

Seismic tomographic interpretation of Paleozoic sedimentary sequences in the southeastern North Sea

Geophysics ◽  
2005 ◽  
Vol 70 (4) ◽  
pp. R45-R56 ◽  
Author(s):  
Lars Nielsen ◽  
Hans Thybo ◽  
Martin Glendrup
Keyword(s):  
North Sea ◽  
Velocity Structure ◽  
Seismic Velocity ◽  
P Wave ◽  
Wide Angle ◽  
North German Basin ◽  
Sedimentary Sequences ◽  
The North ◽  
Crystalline Crust ◽  
German Basin

Seismic wide-angle data were recorded to more than 300-km offset from powerful airgun sources during the MONA LISA experiments in 1993 and 1995 to determine the seismic-velocity structure of the crust and uppermost mantle along three lines in the southeastern North Sea with a total length of 850 km. We use the first arrivals observed out to an offset of 90 km to obtain high-resolution models of the velocity structure of the sedimentary layers and the upper part of the crystalline crust. Seismic tomographic traveltime inversion reveals 2–8-km-thick Paleozoic sedimentary sequences with P-wave velocities of 4.5–5.2 km/s. These sedimentary rocks are situated below a Mesozoic-Cenozoic sequence with variable thickness: ∼2–3 km on the basement highs, ∼2–4 km in the Horn Graben and the North German Basin, and ∼6–7 km in the Central Graben. The thicknesses of the Paleozoic sedimentary sequences are ∼3–5 km in the Central Graben, more than 4 km in the Horn Graben, up to ∼4 km on the basement highs, and up to 8 km in the North German Basin. The Paleozoic strata are clearly separated from the shallower and younger sequences with velocities of ∼1.8–3.8 km/s and the deeper crystalline crust with velocities of more than 5.8–6.0 km/s in the tomographic P-wave velocity model. Resolution tests show that the existence of the Paleozoic sediments is well constrained by the data. Hence, our wide-angle seismic models document the presence of Paleozoic sediments throughout the southeastern North Sea, both in the graben structures and in deep basins on the basement highs.

Chemistry and isotopic composition of Rotliegend and Upper Carboniferous formation waters from the North German Basin

2010 ◽  
Vol 276 (3-4) ◽  
pp. 198-208 ◽  
Author(s):  
Volker Lüders ◽  
Birgit Plessen ◽  
Rolf L. Romer ◽  
Stephan M. Weise ◽  
David A. Banks ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
North German Basin ◽  
Upper Carboniferous ◽  
The North ◽  
German Basin
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