scholarly journals Basic data for three lacustrine clay deposits in the southern part of the San Joaquin Valley, California

Author(s):  
M.G. Croft
1971 ◽  
Vol 8 (12) ◽  
pp. 1525-1541 ◽  
Author(s):  
Gérard Ballivy ◽  
Gaston Pouliot ◽  
André Loiselle

The clay deposits of Northwestern Quebec (from Matagami to Rupert House) were formed during the retreat of the Laurentian ice sheet. The oldest deposits are varved clays formed when the region was submerged by glacial Lake Barlow – Ojibway; the varved clays have been traced northward to Rupert House. A minor glacial surge (Cochrane stadial) extending southward to Matagami, partly covered and reworked the lacustrine clays; evidences of this glacial readvance were observed on the left bank of Rupert River near Rupert House. Following this glacial stage, the land was invaded by sea water (Tyrrell Sea) from which were deposited the silty clay that underlies much of the Hudson Bay Lowlands.The mineralogical composition of the marine clay differs from that of the lacustrine clay by its carbonate content: 30% against 2% or less for the lacustrine clay. The clay fraction of the two types of clays is made up of similar minerals which, in order of decreasing importance are: illite, chlorite, vermiculite, and kaolinite. The marine clay is coarser grained than the lacustrine clay and, locally, gives rise to important flow-slides. The slides are subcircular in shape and have a typical bottle-neck opening; they have never been observed to develop in the varved clays. Their occurrence in the marine clays would seem to depend principally on the microstructure of the material, a silty clay that is fissured at the surface. The flow-slides occur specially during the spring thaw when the ground is oversaturated with water.


1973 ◽  
Vol 10 (3) ◽  
pp. 363-391 ◽  
Author(s):  
O. Dascal ◽  
G. S. Larocque ◽  
J.-P. Tournier

A test embankment was built in the James Bay region to establish the behavior of the lacustrine clay in the area with respect to the prediction settlement under earth and/or rockfill structures.The clay deposits are characterized by high sensibility (7–25), low shear strength (Cu = 400 p.s.f. (0.2 kg/cm2)), high compressibility (Cc/(1 + e0) = 0.6–0.9) and geological belong, to the normally consolidated type of the material. Nevertheless these clays exhibit an important 'quasipreconsolidation' behavior due to the phenomenon of delayed consolidation.The results of post construction surveys and observations taken during a period of 8 months have confirmed the characteristics already established by laboratory tests and particularly the high compressibility and the 'quasipreconsolidation pressure' of these clays.The measured settlements to date (18 in. (45 cm)) can be attributed in the following proportions, 70% to secondary consolidation, 22% to elastoplastic creep, and 6% to lateral creep.In the above mentioned period, practically no pore pressure dissipation was observed and consequently no settlement due to primary consolidation was considered.The results gathered seem to confirm the applicability of the settlement calculation method of the Bjerrum soil model, however, the rate of settlement computation using the classical method is very difficult if not impossible to calculate. The simultaneous developments of primary and secondary consolidation and the greater contribution of the latter to the total value of settlement does not permit the use of the classical method based on the pore pressure dissipation.The method proposed lately by Garlanger needs more development to permit the analysis of a multi-layered foundation with different compressive and preconsolidation characteristics.The stress and strain computation using the finite element method considering the foundation as an isotropic elasto-plastic medium seems to give satisfactory results at least for the range of stresses and the direction of deformation considered.


1975 ◽  
Vol 12 (4) ◽  
pp. 498-509 ◽  
Author(s):  
G. Ballivy ◽  
A. A. Loiselle ◽  
G. Pouliot

The marine and lacustrine clay deposits of the James Bay area in Northwestern Quebec are described as a function of their origin, modes of deposition, and identifying characteristics. The stratigraphic and geotechnical parameters of the Fort Rupert marine clays are given in view of elaborating on case histories of regional slides. Based on these parameters and on the results of a laboratory experiment on four samples, the effect of pore pressure buildup on the triggering of a slide and on the progressive development of failure is described.


Author(s):  
Umi Halimatus Saidah ◽  
Aang Fatihul Islam

The scenes in the trailer shown are all sorts of interesting and prominent scenesto attract the attention of potential viewers and be able to describe the entire contents of the movie without giving too much information. The trailer was created to promote theatrical release of the movie and the movie trailer was a clip containing all the parts of the advertised movie, shown before other movie screenings in the cinema, and aimed for the audience to come to watch. The best way to teach English is to use interesting material, appropriate teaching methods, the use of technology that can be one of the important and effective support tools. Meta-analysis is essentially a synthesis of a topic taken from several research reports. Based on the synthesis is drawn conclusions about the topic under study. This research uses some similar research results as basic data in conducting studies and conclusions. From the same five studies, it is concluded that Movie Trailer is effective as a learning medium because it can improve understanding in English learning.


2017 ◽  
Vol 94 (3) ◽  
pp. 37-61
Author(s):  
Douglas R. Littlefield

Some histories of California describe nineteenth-century efforts to reclaim the extensive swamplands and shallow lakes in the southern part of California's San Joaquin Valley – then the largest natural wetlands habitat west of the Mississippi River – as a herculean venture to tame a boggy wilderness and turn the region into an agricultural paradise. Yet an 1850s proposition for draining those marshes and lakes primarily was a scheme to improve the state's transportation. Swampland reclamation was a secondary goal. Transport around the time of statehood in 1850 was severely lacking in California. Only a handful of steamboats plied a few of the state's larger rivers, and compared to the eastern United States, roads and railroads were nearly non-existent. Few of these modes of transportation reached into the isolated San Joaquin Valley. As a result, in 1857 the California legislature granted an exclusive franchise to the Tulare Canal and Land Company (sometimes known as the Montgomery franchise, after two of the firm's founders). The company's purpose was to connect navigable canals from the southern San Joaquin Valley to the San Joaquin River, which entered from the Sierra Nevada about half way up the valley. That stream, in turn, joined with San Francisco Bay, and thus the canals would open the entire San Joaquin Valley to world-wide commerce. In exchange for building the canals, the Montgomery franchise could collect tolls for twenty years and sell half the drained swamplands (the other half was to be sold by the state). Land sales were contingent upon the Montgomery franchise reclaiming the marshes. Wetlands in the mid-nineteenth century were not viewed as they are today as fragile wildlife habitats but instead as impediments to advancing American ideals and homesteads across the continent. Moreover, marshy areas were seen as major health menaces, with the prevailing view being that swampy regions’ air carried infectious diseases.


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