Le Neocomien de la region du Bas-Verdon

1966 ◽  
Vol S7-VIII (6) ◽  
pp. 802-806
Author(s):  
Jean Michel Belleville ◽  
Jean Chevalier
Keyword(s):  
Deep Water ◽  
Lower Cretaceous ◽  
Lacustrine Sediments ◽  
The West ◽  
Southern France ◽  
Marine Deposits ◽  
Continental Deposits ◽  
Facies Change ◽  
Marly Limestone

Abstract The Neocomian (lower Cretaceous) of the lower Verdon region (Basses-Alpes, southern France) represents a transition facies between deep-water marine deposits to the northwest and continental deposits to the southeast. The facies change between the marly limestone series of the flexure zone to the west and the white limestone series of the platform to the southeast can be traced. Fluctuations of the ancient shoreline resulted in alternations of bioclastic marine limestones and lacustrine sediments.

Etude stratigraphique et tectonique de la region du lac de Santa Croce (Alpes meridionales, province de Belluno, Italie)

1963 ◽  
Vol S7-V (5) ◽  
pp. 798-802
Author(s):  
Charles Fadat
Keyword(s):  
Deep Water ◽  
Lower Triassic ◽  
Southern Alps ◽  
The West ◽  
Structural Orientation ◽  
Terrigenous Sediments ◽  
Lake Region ◽  
Santa Croce ◽  
Facies Change

Abstract The rocks of the Santa Croce lake region belong to the calcareous southern Alps formed from a lower Triassic sequence. The sediments show a facies change between the reefal series of the Friuli zone to the east and the deep water Belluno zone to the west. The entirely marine series may be divided into two groups: the Liassic to Oligocene beds characterized by the absence of terrigenous sediments with thick limestones; and Eocene to Oligocene terrigenous flysch deposits. The area is part of the Venetian Prealps with east to west structural orientation.

Apercu geologique sur les collines de Boutenac (Aude)

1962 ◽  
Vol S7-IV (3) ◽  
pp. 362-379
Author(s):  
Alain Combes
Keyword(s):  
Upper Cretaceous ◽  
Upper Triassic ◽  
Normal Faulting ◽  
The West ◽  
Southern France ◽  
Sandy Limestone

Abstract The Boutenac hills in the northeastern Corbieres region of southern France, are part of the autochthonous foreland of the eastern Corbieres nappe. They are an isolated massif between the Paleozoic formations of the Alaric mountain on the west, and the Jurassic and Cretaceous formations of the Fontfroide chain on the east, entirely surrounded by alluvium. Structurally, they comprise Mesozoic formations on the east thrust over the Eocene on the west, on a fault that is the prolongation of the Saint Chinian frontal fault to the northeast. The Mesozoic formations comprise upper (?) Triassic shale and dolomite, sandy limestone, dolomite, and limestone; Jurassic red sandstones and shales; and upper Cretaceous transgressive clastics. The Eocene is limestone and marl overlain by continental conglomerate and molasse, transgressive on the west upon the Alaric Paleozoics. Folding and thrust and normal faulting are important in the structure.

scholarly journals Evidence of Unknown Paleo-Tsunami Events along the Alas Strait, West Sumbawa, Indonesia

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 46
Author(s):  
Bachtiar W. Mutaqin ◽  
Franck Lavigne ◽  
Patrick Wassmer ◽  
Martine Trautmann ◽  
Puncak Joyontono ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Pyroclastic Flows ◽  
Western Coast ◽  
Eastern Shore ◽  
Tsunami Deposits ◽  
The West ◽  
Marine Deposits ◽  
Sedimentary Records ◽  
The North ◽  
Large Earthquakes

Indonesia is exposed to earthquakes, volcanic activities, and associated tsunamis. This is particularly the case for Lombok and Sumbawa Islands in West Nusa Tenggara, where evidence of tsunamis is frequently observed in its coastal sedimentary record. If the 1815 CE Tambora eruption on Sumbawa Island generated a tsunami with well-identified traces on the surrounding islands, little is known about the consequences of the 1257 CE tremendous eruption of Samalas on the neighboring islands, and especially about the possible tsunamis generated in reason of a paucity of research on coastal sedimentary records in this area. However, on Lombok Island, the eruption of the Samalas volcano produced significant volumes of pyroclastic flows that entered the sea in the North and East of the island. These phenomena must have produced a tsunami that left their traces, especially on Sumbawa Island, whose western coastline is only 14 km away from Lombok’s eastern shore. Therefore, the main goal of this study is to investigate, find evidence, and determine the age of marine-origin sediments along the shore of the Alas Strait, Indonesia. We collected and analyzed samples of coral and seashells from marine deposits identified along the west coast of Sumbawa, i.e., in Belang Island and abandoned fishponds in Kiantar Village, in order to identify the sources and the occurrence period of these deposits events. Based on the radiocarbon dating of coral and seashell samples, we concluded that none of the identified marine deposits along the western coast of Sumbawa could be related chronologically to the 1257 CE eruption of Samalas. However, possible tsunami deposits located in Belang Island and abandoned fishponds in Kiantar Village yielded 4th century CE, 9th century CE, and 17th century CE. We also conclude that past large earthquakes triggered these tsunamis since no known volcanic eruption occurred near the Alas Strait at that time that may have triggered a tsunami.

scholarly journals 14C in the Deep Water of the East Atlantic

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 391-396 ◽  
Author(s):  
Reiner Schlitzer
Keyword(s):  
Deep Water ◽  
Large Scale ◽  
Bottom Water ◽  
Source Parameters ◽  
Potential Temperature ◽  
Source Terms ◽  
East Atlantic ◽  
The West ◽  
Model Calculations ◽  
Inflowing Water

The renewal of east Atlantic deep water and its large-scale circulation and mixing have been studied in observed distributions of temperature, silicate, ΣCO2, and 14C. 14C variations in northeast Atlantic deep water below 3500m depth are small. Δ14C values range from − 100‰ to −125‰. 14C bottom water concentrations decrease from Δ14C =−117‰ in the Sierra Leone Basin to Δ14C = − 123‰ in the Iberian Basin and are consistent with a mean northward bottom water flow. The characteristic of the water that flows from the west Atlantic through the Romanche Trench into the east Atlantic was determined by inspection of θ/Δ14C and θ/SiO2 diagrams. A mean potential temperature of θ = 1.50 ± .05°C was found for the inflowing water. A multi-box model including circulation, mixing, and chemical source terms in the deep water has been formulated. Linear programing and least-squares techniques have been used to obtain the transport and source parameters of the model from the observed tracer fields. Model calculations reveal an inflow through the Romanche Trench from the west Atlantic, which predominates over any other inflow, of (5 ± 2) Sv (potential temperature 1.50°C), a convective turnover of (150 ± 50) years and a vertical apparent diffusivity of (4 ± 1) cm2/s. Chemical source terms are in the expected ranges.

scholarly journals Types of river sources of the thin-grained aluminosilicaclastics for the Jurassic and lower cretaceous deposits of the West Siberian megabasin

2021 ◽  
Vol 63 (4) ◽  
pp. 52-61
Author(s):  
A. V. Maslov
Keyword(s):  
Lower Cretaceous ◽  
The Urals ◽  
River Systems ◽  
The West ◽  
Rock Composition ◽  
Fine Grained ◽  
The North ◽  
Catchment Areas ◽  
Cretaceous Deposits ◽  
West Siberian Basin

Background. The lithogeochemical features of fine-grained detrital rocks (mudstones, shales, and fine-grained siltstones) allow, with a certain degree of success, the main parameters of the formation of sedimentary sequences to be reconstructed. These parameters include (primarily in terms of their REE and Th systematics) the types of river systems supplying thin terrigenous suspension in the sedimentation area: the rivers of the 1st category – large rivers with a catchment area of more than 100,000 km2; 2nd category – rivers feeding on the products of erosion of sedimentary deposits; 3rd category – rivers draining mainly igneous and metamorphic rocks; and 4th category – rivers carrying erosion products of volcanic associations.Aim. To reveal, based on the analysis of interrelationships between such parameters as (La/Yb)N, Eu/Eu* and the Th content, the types of river systems that fed the Jurassic and Lower Cretaceous deposits of the Shaim oil and gas region (OGR) (Sherkalinsky, Tyumen, Abalak and Mulymya formations) and the region of the North Pokachevsky field of the Shirotnoe Priobye region (Sherkalinsky, Tyumen and Bazhenov formations, Lower Cretaceous deposits).Materials and methods. The ICP MS data for almost 100 samples of mudstones and fine-grained clayey siltstones were used to analyse the features of distribution of lanthanides and Th in the Jurassic and Lower Cretaceous clayey rocks of the Shaim OGR and the area of the North Pokachevsky deposits. Individual and average composition points for formations, members and layers were plotted on the (La/Yb)N-Eu/Eu*, (La/Yb)N–Th diagrams developed by us with classification areas of the composition of fine suspended material of modern rivers of different categories.Results and conclusion. The results presented in the article showed that during the formation of the deposits of the Shaim OGR in the Early and Middle Jurassic, erosion affected either mainly sedimentary formations or paleo-catchment areas that were very variegated in their rock composition. In the Late Jurassic, the source area was, most likely, a volcanic province, composed mainly of igneous rocks of the basic composition, and located within the Urals. This conclusion suggested that the transfer of clastic material from the Urals to the Urals part of the West Siberian basin “revived” much earlier than the Hauterivian. The Jurassic-Lower Cretaceous section of the vicinity of the North Pokachevsky field was almost entirely composed of thin aluminosilicaclastics formed due to the erosion of volcanic formations. These volcanic formations were located, as followed from the materials of earlier performed paleogeographic reconstructions, probably within the Altai-Sayan region or Northern Kazakhstan. Thus, the supply of detrital material in the considered territories of the West Siberian basin had a number of significant differences in the Jurassic and early Cretaceous.

scholarly journals Quaternary deposits between the Sukkertoppen ice cap and Nordre Strømfjord

1970 ◽  
Vol 28 ◽  
pp. 23-25
Author(s):  
A Weidick ◽  
N.W Ten Brink
Keyword(s):  
Land Area ◽  
The West ◽  
Quaternary Deposits ◽  
Sea Levels ◽  
West Greenland ◽  
Marine Deposits ◽  
Ice Cap

The area investigated during 1969 is located approximate1y between 66° 10' and 67° 30' N, and 50° and 52° W, the eastem half of the West Greenland ice-free land area transected by Søndre Strømfjord. The principal objectives of the work were to map and describe the glacial and emerged marine deposits for a Quatemary map at 1:500 000 scale, and to collect material for establishing a radiometric chronology of former ice-margin positions and sea levels. In order to study as large an area as possible, the investigations north of Søndre Strømfjord and Sondrestrom Airbase were conducted by A. Weidick, the area south of this by N. W. Ten Brink.

Deep-Water Contourite Drifts in the West of North-China Platform

2013 ◽  
Vol 318 ◽  
pp. 447-452
Author(s):  
Shun She Luo ◽  
Zhen Zhong Gao ◽  
You Bin He ◽  
Qi Qi Lv ◽  
Ying Meng
Keyword(s):  
Deep Water ◽  
North China ◽  
The West ◽  
North China Platform ◽  
Middle Ordovician ◽  
Contourite Drifts

The middle Ordovician of Pingliang area on the west margin of North-China platform is represented by a succession of deep-water sediments in which contourites are well-developed. Contour current deposits are well-developed. The contourites can be classified into:calcarenitic contourite, calcisiltitic contourite and calcilutitic contourite. Three typical contourite successions are recognized: complete contourite succession, incomplete contourite succession and contourite successions consisting only of calcarenitic contourites. According to the palaeocorrent and the palaeogeographic format analyse,carbonate contourite drift in the study area is unfolded crossing northwest-southeast, forwarding from southeast to northwest along the slope, and compared with other contourite drifts, it has some characteristics of coarser-grained sediment, thicker individual layers, and highly developed calcarenitic contourites and so on.

Spectrum Analysis of Deep Water Ambient Noise in the West Pacific

2021 ◽  
Author(s):  
Jiahua Zhu ◽  
Wei Guo ◽  
Bingbing Zhang ◽  
Yanxin Ma ◽  
Yangyang Chen ◽  
...  
Keyword(s):  
Deep Water ◽  
Spectrum Analysis ◽  
Ambient Noise ◽  
The West ◽  
West Pacific

Geologie de la region de Bar-le-Duc (Meuse)

1959 ◽  
Vol S7-I (8) ◽  
pp. 803-808
Author(s):  
Vladimir Stchepinsky
Keyword(s):  
Lower Cretaceous ◽  
Upper Jurassic ◽  
The West ◽  
Solid Block ◽  
East West

Abstract Upper Jurassic (Kimeridgian and Portlandian) and lower Cretaceous formations crop out in the area south of Bar-le-Duc, France. In contrast to the fractured area to the west, this area is a solid block. The relatively unimportant Veel-Combles fault is related to the Marne double fault, despite its isolation. An east-west fault, 20 kilometers long with a southward throw of 10 meters, can also be traced. The paleogeographic evolution of the area during the Mesozoic is outlined.

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