The Paraná magmatism (Brazil) as the villain regarding the remagnetization of the Paleozoic sediments in the basin – half-truth!

2021 ◽  
Author(s):  
M. Irene B. Raposo ◽  
Marcia Ernesto ◽  
Daniele Brandt ◽  
Daniel Ribeiro Franco
Keyword(s):  
Early Cretaceous ◽  
Clay Content ◽  
Time Interval ◽  
Magnetic Mineralogy ◽  
Geomagnetic Reversal ◽  
Sedimentary Sequences ◽  
The North ◽  
Intrusive Rocks ◽  
Western Portion ◽  
North Western

<p>The sedimentation in the Paraná Basin started during the Ordovician and ended with the Early Cretaceous magmatic event. Thick lava pilescovered the entire basin, and voluminous dikes and sills occur in the sedimentary sequences, mainly in the northeastern border of the basin. Despite the thermal effect, some Paleozoic sedimentary formations preserved their primary magnetization. The paleomagnetic results from the glacial Aquidauana Formation, an equivalent to the Itararé group in the north-western portion of the basin, indicated that the magnetization is compatible with the Middle-Late Permian age assigned in literature. A detailed investigation of the magnetic mineralogy and the magnetization of other Paleozoic sedimentary rocks led to the conclusion that the intrusive rocks were more effective than the lavas in disturbing the primary magnetization, especially in the low-clay content rocks. The secondary magnetizations identified in the different areas of the basin are not always compatible with the Early Cretaceous magnetization imprinted by the Paraná magmatism. This component prevails in the northeastern area, while a Permo-Triassic magnetization was identified in other areas. The results obtained so far are coherent with the geomagnetic reversal scale for the considered time interval, and the paleomagnetic poles agree with the APWP for South America.</p>

Further Discoveries of Flint Implements in the Brown Boulder Clay of North-West Norfolk

1932 ◽  
Vol 6 (4) ◽  
pp. 306-315 ◽  
Author(s):  
J. Reid Moir
Keyword(s):  
Sea Level ◽  
Geological Survey ◽  
Prehistoric Archaeology ◽  
East Anglia ◽  
North West ◽  
Terminal Moraine ◽  
The North ◽  
Boulder Clay ◽  
Western Portion ◽  
North Western

Since my original paper on the flint implements found in the Brown Boulder Clay of north-west Norfolk, I have continued my researches in that region, and now wish to give some account of these, and of the further specimens which have been discovered in this most recent boulder clay of East Anglia. I would take this opportunity of thanking the Trustees of the Percy Sladen Fund for their kindness in supporting this research with a money grant, and so enabling me to continue my examination of an era of much interest and importance to prehistoric archæology. I am also very grateful to my friends, Mr. J. B. Calkin, Mr. Guy Maynard, and Mr. J. S. Fisher, for the valuable help they have given me in carrying out the investigation of the Brown Boulder Clay.As is now widely known, this deposit, so far as Norfolk is concerned, is confined to the north-western portion of that county, and many years ago was examined and reported upon by the Geological Survey in two of their memoırs. The Brown Boulder Clay occurs approximately at sea-level at Hunstanton, while at Brancaster, as reported by Mr. Clement Reid, the deposit is exposed at low water upon the foreshore, underlying the ‘submerged forest’ which he saw there. At other places, such as Holkham brickfield, and the remarkable formation (probably a terminal moraine) in Hunstanton Park, the boulder clay rests at about 50 ft, above O.D.

scholarly journals Local seismic response studies in the north-western portion of the August 24th, 2016 Mw 6.0 earthquake affected area. The case of Visso village (central Apennines)

2016 ◽  
Vol 59 ◽  
Author(s):  
Iolanda Gaudiosi ◽  
Gianluca Vignaroli ◽  
Pietro Sirianni ◽  
Silvia Giallini ◽  
Federico Mori ◽  
...  
Keyword(s):  
Time History ◽  
Ground Level ◽  
Central Apennines ◽  
The North ◽  
Local Seismic Response ◽  
Buildings Vulnerability ◽  
Geological Units ◽  
Soil Behaviour ◽  
Western Portion ◽  
North Western

In this work, we investigate the possible causes of the differential damaging observed in Visso village (central Apennines, about 28 km north from the August 24th, 2016 Mw 6.0 earthquake epicenter). Following insights from the available geological cartography at 1:10.000 scale, a preliminary geophysical survey has been performed in the damaged area in order to constrain geometries and extent of the subsoil lithotypes. Then, these results have been used to retrieve a Vs profile close to the most heavily damaged buildings. This latter has been used as input for a numerical analysis aimed at deriving the motion at the ground level in the study area. In particular, a linear equivalent simulation has been performed by means of EERA code and the waveform has been obtained convolving the time history recorded during the August 24th, 2016 mainshock at Spoleto Monteluco (SPM) site. Our preliminary results indicate a possible correlation of damaging to the thickness and shape of the geological units. Nevertheless, further analyses are necessary to highlight any 2D basin and / non - linear soil behaviour effects in order to compare them to the intrinsic buildings vulnerability, according to the EMS98 guidelines.

scholarly journals Bombus (Pyrobombus) jonellus (Kirby, 1802) in the north-western Russian Plain: its distribution and ecology

2020 ◽  
Vol 20 (1) ◽  
pp. 1-9
Author(s):  
GS Potapov ◽  
YuS Kolosova
Keyword(s):  
Russian Plain ◽  
The North ◽  
Northern Border ◽  
Wide Range ◽  
The Family ◽  
Distribution And Ecology ◽  
Northern Russia ◽  
Surrounding Areas ◽  
Western Portion ◽  
North Western

The fauna and ecology of bumblebees in the European North are quite well-studied. However, there is a scarcity of information about the distribution and ecology of certain species of bumblebees, especially for the territory of Northern Russia. In this study, we summarised materials concerning Bombus (Pyrobombus) jonellus (Kirby, 1802), which is typical bumblebee species for the north-western portion of the Russian Plain and surrounding areas. The studied territory includes the Arkhangelsk Region and the western part of the Nenets Autonomous District, i.e. a wide strip from taiga to tundra ecosystems. Due to the studies of materials that were collected over a period 17 years, we established that B. jonellus is widely distributed and the northern border of its range within the studied region reaches the northern part of the Kanin Peninsula. In the north-western Russian Plain, B. jonellus has been found in various types of habitats, the most common being coniferous and birch forests, secondary meadows and ruderal patches. In the Solovetsky Islands, White Sea, Russia, B. jonellus is typical on coastal heathlands. In the northern part of the studied region, B. jonellus has a tendency to forage in open habitats and visits a wide range of entomophilous plants, mostly of the family Ericaceae. Our findings highlight that the territory of the north-western Russian Plain and surrounding areas is where B. jonellus is widely distributed and abundant, being recorded in different types of habitats.

scholarly journals XXXIX. The lignites and clays of Bovey Tracey, Devonshire

1862 ◽  
Vol 152 ◽  
pp. 1019-1038 ◽  
Keyword(s):  
Far East ◽  
Left Bank ◽  
The South ◽  
North East ◽  
The North ◽  
South West ◽  
North Eastern ◽  
The Village ◽  
Western Portion ◽  
North Western

The little town or village of Bovey Tracey, in Devonshire, nestles at the foot of Dartmoor, very near its north-eastern extremity; it is situated on the left bank of the river Bovey, about two miles and a half above the point at which it falls into the Teign, and is about eleven miles from each of the towns Exeter, Torquay, and Totnes*,—bearing south-westerly from the first, north-westerly from the second, and northerly from the last. A considerable plain stretches away from it in a south-easterly direction, having a length of six miles from a point about a mile west of Bovey to another nearly as far east of Newton; its greatest breadth, from Chudleigh Bridge on the north-east to Blackpool on the south-west, is four miles. It forms a lake-like expansion of the valleys of the Teign and Bovey rivers, especially the latter, whose course it may be said to follow in the higher part, where it is most fully developed; whilst the Teign constitutes its axis below the junction of the two streams. Its upper, or north-western portion, immediately adjacent to the village, is known as “Bovey Heathfield,” and measures about 700 acres.

Planktonic foraminiferal biostratigraphy of the Limboto Limestone, Gorontalo Province, Indonesia

2020 ◽  
Vol 48 (1) ◽  
Author(s):  
Aang P. Permana ◽  
◽  
Subagyo Pramumijoyo ◽  
Akmaluddin Akmaluddin ◽  
Didit H. Barianto ◽  
...  
Keyword(s):  
Planktonic Foraminifera ◽  
Time Interval ◽  
Relative Age ◽  
The North ◽  
North Western ◽  
Foraminiferal Biostratigraphy

The limestone research within the Limboto Basin of Gorontalo Province becomes a new challenge, particularly for the study of planktonic foraminiferal biostratigraphy. This study uses the data obtained from the measured section in the north-western part of Limboto Lake. The purpose of this study is to determine the planktonic foraminiferal biozonation and the relative age of Limboto limestones. The analyzed planktonic foraminiferal fossils can be classified as well to moderately preserved of various species, in the context of abundance, categorized as frequent to abundant. There are three recognized planktonic foraminiferal biozones, i.e., two biozones for Miocene age (M13b and M14) and one biozone for Pliocene age (PL1). The Miocene biozones are named as Globorotalia plesiotumida partial range zone (M13b) and Pulleniatina primalis-Globoquadrina dehiscens concurrent range zone (M14), while the name of Pliocene biozone is Globorotalia acostaensis partial range zone (PL1). The results of this study can be a reference to propose an age of Limboto Limestone Formation. Identification and demarcation of the Limboto Limestone Formation are based on the time interval and relative age of the formation based on planktonic foraminifera.

scholarly journals A Romano-British House near Bedmore Barn, Ham Hill, Somerset

1913 ◽  
Vol 3 ◽  
pp. 127-133
Author(s):  
I. Hamilton Beattie ◽  
W. J. Phythian-Adams
Keyword(s):  
The South ◽  
The North ◽  
The Hill ◽  
Western Portion ◽  
North Western

Ham Hill forms the north-western and highest part of an irregular upland overlooking the lowlands of Somerset, some five miles west of Yeovil. The hill is famous for its earthworks, and for many antiquities of the Stone, Bronze, Late Celtic, and Roman periods which have been found upon it. Most of these seem to belong to its western portion, but the south-east corner near Bedmore, or Batemoor, Barn in the parish of Montacute has yielded interesting finds.

scholarly journals Evolution of the Late Mesozoic Magmatism of the Omulevka Terrane of the North Part of the Verkhoyansk–Kolyma Orogenic Region

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1208
Author(s):  
Vera A. Trunilina
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Active Continental Margin ◽  
Alkali Feldspar ◽  
Research Area ◽  
Total Alkalinity ◽  
Late Mesozoic ◽  
The North ◽  
Intrusive Rocks ◽  
North Part

This article presents the results of a study of Late Mesozoic intrusive formations of the Omulevka terrane of the Verkhoyansk–Kolyma orogenic region. The research area covers the Selennyakh block of the Omulevka terrane and the territory adjacent to the south. The compositions of rock-forming, accessory and restitic minerals and geochemical features of intrusive rocks are considered. The methods of optical microscopy, microprobe, silicate and spectral analyses were used. There are the following several stages in the evolution of magmatism: (1) the Late Jurassic supra-subduction (gabbro, dolerites), (2) the beginning of the Early Cretaceous-transitional from supra-subduction to marginal-continental (gabbro-diorites, diorites, granodiorites), (3) the Early Cretaceous of active continental margin (granodiorites, granites), (4) the Late Cretaceous postorogenic or continental-riftogenic (alkali-feldspar granites of A-type), (5) the Late Cretaceous continental riftogenic (subalkaline gabbroids and basaltoids). In the process of evolution from stage one to stage four, there was an increase in the silicic acid content, total alkalinity and ferruginousity of rocks with the movement of magmogeneration levels to higher and higher horizons of the lithosphere (calculated pressure from 1.6–1.4 GPa to 0.6–0.9 GPa). At the same time, the preservation of high temperatures of magmogeneration (1000–1150 °C) and crystallization implies the supply of additional heat from an external (deep) source during the formation of granitoid melts. The magmatic activity is completed by the intrusion of subalkaline derivatives of a deep hearth, formed by metasomatized lherzolites. All the studied igneous rocks are either direct mantle fusions, or bear signs of the participation of mantle matter in the generation of parent melts in crustal substrates: the presence of tschermakite in gabbroids, nonequilibrium structures, the composition of early generations of biotites corresponding to biotites of mantle and crust-mantle derivatives, the presence of pyroxenes and accessory minerals characteristic of mantle magmas in granitoids. In the diagram Al-Na-K-2Ca–Fe + Ti + Mg, the composition points of the studied intrusive rocks tend to the mixing trend. In general, the research results suggest that the evolution of the Late Mesozoic intrusive magmatism of the studied territory and the specific matter of rock compositions were caused by the crust-mantle interaction as a result of the rise of mantle diapirs in the crust from a long-existing deep hearth of the main melt.

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