Volume 14, numéro 2, august 1978

EN :

A quandary as to the role of storms in initiating barrier island morphological change in the Gulf of St. Lawrence has been posed by recent research. Although major changes are evident from historical documentation, none of the processes responsible hoe been witnessed since 1970. Detailed calculations of the nearshore wave power climate have been used in conjunction with historical evidence and short term profile measurements between 1970-1978 to resolve this problem in Kouchibouguac Bay, New Brunswick. Although the individual effects of seasonal storms are random along these barrier islands, the additive effects do reflect the overall nearshore wave climate. Greatest change has been wrought in those areas having highest wave power components normal and parallel to shore. If barrier segments susceptible to modification can be predicted for Kouchibouguac Bay, definition of nearshore wave climates could be used to determine such changes elsewhere in the Gulf.

the nearshore wave climate will be established using wave refraction, shoaling and bottom frictional attenuation theory for shallow water. Then relative variations in wave power normal and parallel to shore will be calculated near the breaker point for the various components making up this nearshore wave climate. Finally, correlations of longshore variation in wave power will be evaluated with: (1) longshore changes in barrier morphology over the last 150 years, and (2) measured dune cliff and ocean beach profile changes since 1970.

EN :

Ice-push ridges and kaimoos are depositional features formed by iae on Tahusintac Beach, Hew Brunswick. These features are transformed into ridge-and-runnel systems when subjected to wave processes. Kaimoo and ice-push ridges I) protect the beach from storms for a few-week period, 2) induce deposition of sand at the upper beachface and 3) leave a lag deposit of cobble which may be a significant source of cobble transported across the beachfaoe during summer storms.

EN :

Intense human activity in the coastal zone has resulted in widespread deformation of coastal features. Vehicular and pedestrian traffic are the primary means of creating anthropical structures. While the long-term preservation potential for these structures is generally quite low, geologic investigations have shown that a large number of modern environments contain deformed layers in their sedimentary records.

EN :

The tests of 18 benthonic and one planktonic species of modern Foraminiferida from 8 bottom samples recovered from the eastern Canadian shelf fall into two, or perhaps three groups with respect to mean mole percent MgCO„, as follows: Group I - 0 to 2.5 % MgCO ; Group 2 - 2 to 5 % MgC02; and Group 3 - 5 to 9 % MgCO . The watermass characteristics and depth of each population are: Upper Water-mass, -I to Z or 5 C, 33 o/oo salinity, 62 m and 73 m: Intermediate Watermass, 0 C, 34 o/oo salinity, 99m; and Deep WatennasB, 4 to o C, 35 o/oo salinity, 263_ n, 431 m, 47S m, 479 m and 509 m.

In the samples examined low magnesium forms (Group I) occur in all three water-masses and in a late-glacial beach sample. The intermediate magnesium form Ephidiella arctica (Group 2) and the high magnesium forms (Group 3) Quinqueloculina arctica and 0. seminulum occur in the Upper Watermass. Populations of the low magnesium species Buccella inusitata, Islandiella helenae and Nonionellina labradorica are each found in both Upper and Deep Watermasses. The low magnesium Value of Quinqueloculina stalkeri may indicate that the form should be placed in another genus.