Crustal studies in the La Malbaie Region, Quebec

1980 ◽  
Vol 17 (4) ◽  
pp. 478-490 ◽  
Author(s):  
J. A. Lyons ◽  
D. A. Forsyth ◽  
J. A. Mair
Keyword(s):  
Deep Structure ◽  
Numerical Models ◽  
Moho Depth ◽  
The North ◽  
Crustal Velocity ◽  
Time Distance ◽  
Microseismic Activity ◽  
A Minor ◽  
North And South ◽  
St Lawrence River

The results of three seismological investigations of the crust in the seismically active La Malbaie Region are reported. First arrivals from a reversed reflection–refraction profile within the Charlevoix structure indicate a uniform Pg velocity of 6.08 ± 0.04 km/s. Secondary arrivals forming discontinuous, sometimes arcuate segments on the record sections are interpreted as subcritical reflections from structural contortions related to impact of the Charlevoix meteorite. A coherent event at 14 s may signal reflection from the M-discontinuity near 45 km depth.Analysis of travel times from calibration shots recorded by a network of stations spanning the St. Lawrence River in terms of time–distance profiles, travel time residuals, and numerical models provides excellent support for a model of the Precambrian–Paleozoic contact striking along the north shore and dipping to the southeast about 20° beneath the wedge of 5.5 km/s sediments.Unreversed profiles obtained by recording timed Thetford Mines blasts across a similar network suggests a comparable deep structure beneath the north and south shores, with average crustal velocities of 6.8 and 6.7 km/s, respectively. A minor mid-crustal discontinuity is suggested, and Moho depth is estimated at 42–43 km.The 6.2 km/s upper crustal velocity found for the crater and immediately surrounding area is anomalously low compared to the 6.4–6.5 km/s reported for the eastern shield region. Structural lineations gleaned from satellite imagery suggest an elongated area of impact-related disruption much larger than previously recognized. This expanded area of crustal weakening encompasses and may partially explain the zone of continuing microseismic activity, as well as the low upper crustal velocity of the La Malbaie Region.

Peromyscus populations and their Cuterebra parasites display congruent phylogeographical structure

Parasitology ◽  
2005 ◽  
Vol 131 (2) ◽  
pp. 237-245 ◽  
Author(s):  
S. NOËL ◽  
B. ANGERS ◽  
F.-J. LAPOINTE
Keyword(s):  
Parasite Species ◽  
Isolation By Distance ◽  
Deer Mouse ◽  
Genetic Distances ◽  
Limited Sample ◽  
The North ◽  
Mitochondrial Sequences ◽  
North And South ◽  
White Footed Mouse ◽  
St Lawrence River

The relationships between populations of the Deer Mouse (Peromyscus maniculatus) and the White-footed Mouse (P. leucopus) and their respective Cuterebra parasites were examined. Population genetic structure of hosts and parasites was inferred using cytochrome oxidase mitochondrial sequences of specimens from 7 populations. Genetic analyses revealed that isolation-by-distance applies for P. maniculatus and its associated parasite (C. grisea). A significant correlation was also observed between the genetic distances of these host and parasite species. Furthermore, populations of P. maniculatus and C. grisea from the North and South shores of the St Lawrence River were found to be significantly different. This structure may be explained by the St Lawrence River being a dispersal barrier for both species. A robust analysis of the other species pair (P. leucopus and C. fontinella) could not be performed because of limited sample sizes.

The Central Brae Field, Blocks 16/07a, 16/07b, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Keith J. Fletcher
Keyword(s):  
Upper Jurassic ◽  
Western Boundary ◽  
The South ◽  
Submarine Fan ◽  
Water Contact ◽  
The North ◽  
Oil Water ◽  
Clay Formation ◽  
A Minor ◽  
North And South

abstractThe Central Brae Oilfield is the smallest of three Upper Jurassic fields being developed in UK, Block 16/07a. The field was discovered in 1976 and commended production in September 1989 through a sub-sea template tied back to the Brae 'A' platform in the South Brae Oilfield. The field Stooip is 244 MMBBLs, and by May 1999 cumulative exports of oil and NGL reached 44 MMBBLs.The Central Brae reservoir is a proximal submarine fan sequence, comprising dominantly sand-matrix conglomerate and sanstone with a minor mudstone units. The sediments were shed eastwards off the Fladen Ground Spur and were deposited as a relatively small and steep fan at the margin of the South Viking Graben. Mudstone facies border the submarine fan deposits to the north and south, forming stratigraphic seals. The structure is a faulted anticline developed during the latest Jurassic and early Cretaceous, initially formed as a hangingwall anticline during extension but subsequently tightened during compressional phases. The western boundary of the field is formed by a sealing fault, whilst to the east, there is an oil-water contact at 13426 ft TVDss. The overlying seal is the Kimmeridge Clay Formation, which also interdigitates with the coarser facies basinwards and provides the source of the hydrocarbons.

scholarly journals The origins and spread of stock-keeping: the role of cultural and environmental influences on early Neolithic animal exploitation in Europe

Antiquity ◽  
2013 ◽  
Vol 87 (338) ◽  
pp. 1046-1059 ◽  
Author(s):  
Katie Manning ◽  
Sean S. Downey ◽  
Sue Colledge ◽  
James Conolly ◽  
Barbara Stopp ◽  
...  
Keyword(s):  
Cultural Practices ◽  
Domestic Animal ◽  
Minor Role ◽  
Early Neolithic ◽  
Faunal Assemblages ◽  
The North ◽  
Animal Use ◽  
A Minor ◽  
North And South

It has long been recognised that the proportions of Neolithic domestic animal species—cattle, pig and sheep/goat—vary from region to region, but it has hitherto been unclear how much this variability is related to cultural practices or to environmental constraints. This study uses hundreds of faunal assemblages from across Neolithic Europe to reveal the distribution of animal use between north and south, east and west. The remarkable results present us with a geography of Neolithic animal society—from the rabbit-loving Mediterranean to the beef-eaters of the north and west. They also demonstrate that the choices made by early Neolithic herders were largely determined by their environments. Cultural links appear to have played only a minor role in the species composition of early Neolithic animal societies.

Preliminary results of the study on the reasons of the Hai Hau erosion phenomenon

2007 ◽  
Vol 29 (3) ◽  
pp. 415-426
Author(s):  
Pham Van Ninh ◽  
Phan Ngoc Vinh ◽  
Nguyen Manh Hung ◽  
Dinh Van Manh
Keyword(s):  
Mathematical Modeling ◽  
Historical Data ◽  
Middle Part ◽  
Red River ◽  
Erosion Process ◽  
Red River Delta ◽  
The North ◽  
Severe Erosion ◽  
North And South ◽  
Very High

Overall the evolution process of the Red River Delta based on the maps and historical data resulted in a fact that before the 20th century all the Nam Dinh coastline was attributed to accumulation. Then started the erosion process at Xuan Thuydistrict and from the period of 1935 - 1965 the most severe erosion was contributed in the stretch from Ha Lan to Hai Trieu, 1965 - 1990 in Hai Chinh - Hai Hoa, 1990 - 2005 in the middle part of Hai Chinh - Hai Thinh (Hai Hau district). The adjoining stretches were suffered from not severe erosion. At the same time, the Ba Lat mouth is advanced to the sea and to the North and South direction by the time with a very high rate.The first task of the mathematical modeling of coastal line evolution of Hai Hau is to evaluate this important historical marked periods e. g. to model the coastal line at the periods before 1900, 1935 - 1965; 1965 - 1990; 1990 - 2005. The tasks is very complicated and time and working labors consuming.In the paper, the primarily results of the above mentioned simulations (as waves, currents, sediments transports and bottom - coastal lines evolution) has been shown. Based on the obtained results, there is a strong correlation between the protrusion magnitude and the southward moving of the erosion areas.

Studies of Ptiliidae (Coleoptera) in the Spirit Collection of the Natural History Museum, London 2: New species and records from P. Hammond's visit to New Zealand in 1983–84

2018 ◽  
Vol 154 (3) ◽  
pp. 179-196
Author(s):  
Michael Darby
Keyword(s):  
New Species ◽  
New Zealand ◽  
Natural History ◽  
Natural History Museum ◽  
History Museum ◽  
The North ◽  
Three New Species ◽  
North And South

Some 2,000 Ptiliidae collected in the North and South Islands of New Zealand in 1983/1984 by Peter Hammond of the Natural History Museum, London, are determined to 34 species, four of which are new to the country. As there are very few previous records, most from the Auckland district of North Island, the Hammond collection provides much new distributional data. The three new species: Nellosana insperatus sp. n., Notoptenidium flavum sp. n., and Notoptenidium johnsoni sp. n., are described and figured; the genus Ptiliodes is moved from Acrotrichinae to Ptiliinae, and Ptenidium formicetorum Kraatz recorded as a new introduction. Information is provided to aid separation of the new species from those previously recorded.

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