Geochemistry of the Coastal Sonora batholith, Northwestern Mexico

2003 ◽  
Vol 40 (6) ◽  
pp. 819-831 ◽  
Author(s):  
M Valencia-Moreno ◽  
J Ruiz ◽  
L Ochoa-Landín ◽  
R Martínez-Serrano ◽  
P Vargas-Navarro
Keyword(s):  
Granitic Rocks ◽  
Magma Source ◽  
Arc Magmatism ◽  
American Continent ◽  
Geochemical Composition ◽  
Isotopic Signatures ◽  
Magmatic Arc ◽  
North American Continent ◽  
The North ◽  
Northwestern Mexico

New major- and trace-element and radiogenic Sr and Nd data from granitic rocks help to characterize the geochemical composition of the Coastal Sonora batholith, which represents the westernmost portion of the Laramide Magmatic arc (~80–40 Ma) in Mexico. Compared with more inland-located regions of the arc in central and eastern Sonora (Inner Granites), the plutons within the coastal batholith have higher MgO, FeO, and CaO and lower K2O contents, and tend to be more depleted in Nb, U, and to a lesser extent Rb, but relatively enriched in Sr. These rocks display flatter slopes of rare-earth elements, with La abundances around 80 to 200 times chondrite values and smaller but well-developed negative Eu anomalies. Initial 87Sr/86Sr ratios and εNd values from a few studied samples of the Coastal Sonora batholith range from 0.70586 to 0.70679 and from –2.3 to –4.7, respectively. These isotopic signatures allow recognition of a more mantle-related magma source for this batholith as compared with the Inner Granites, which have higher Sr and lower Nd ratios. In a more regional context, the compositions of the Coastal Sonora batholith rocks resemble those of the eastern portion of the Peninsular Ranges batholith to the northwest. Based on our observations, we propose that partial melting of a crust thickened by overlapping periods of Jurassic through Cretaceous arc magmatism along the southwestern edge of the North American continent may account for the geochemical and isotopic characteristics displayed by the Coastal Sonora batholith granitic rocks.

scholarly journals Q fever in South Australia: an outbreak in a meat-works

1962 ◽  
Vol 60 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Margaret D. Beech ◽  
A. E. Duxbury ◽  
Peter Warner
Keyword(s):  
Q Fever ◽  
South Australia ◽  
Meteorological Conditions ◽  
American Continent ◽  
North American Continent ◽  
The Past ◽  
The North ◽  
Epidemiological Features ◽  
Very High ◽  
Abattoir Workers

This paper consists of an epidemiological study of 52 cases of Q fever occurring in metropolitan Adelaide in 1957 and also a description of the results of a survey of 516 sera obtained from abattoir workers.The only case occurring outside the abattoirs was a dairy farmer who probably became infected while visiting the abattoirs. If this were so the incubation period (35 days) of his disease would have been exceptionally long.The general features of the outbreak, which lasted several months, differed from those on the North American continent in that the latter occurred explosively within a few days with very high attack rates. The situation in the Adelaide abattoirs is similar to that in Brisbane, where the disease appears to be endemic. However, unlike in Adelaide, cases are commonly recognized outside the abattoirs in Brisbane.In the abattoirs the disease affected mainly inspectors, those working on killing beef, and those working on offal. Mutton workers were not so severely affected. However, all these groups had similar incidences of low titre antibodies suggesting that in the past Q fever spread equally in all killing departments. In departments not directly associated with slaughtering the incidence both of cases in 1957 and low titre antibodies was relatively small.It was suggested that the epidemiological features of Q fever in Adelaide could be explained by the irregular appearance of animals from infected herds situated perhaps in Queensland—a known endemic area. Perhaps the appearance of such animals in the Adelaide abattoirs might be governed by meteorological conditions such that they were prevented from going to the ordinarily most convenient slaughterhouse.

Francisco de Miranda in Russia

1950 ◽  
Vol 6 (04) ◽  
pp. 431-449 ◽  
Author(s):  
Joseph O. Baylen ◽  
Dorothy Woodward
Keyword(s):  
North American ◽  
American Continent ◽  
Grand Tour ◽  
North American Continent ◽  
The North ◽  
Austrian Minister

On September 26, 1786, Don Francisco de Miranda, adventurer and patriot, secured a passport from the Austrian Minister in Constantinople which enabled him to continue his “grand tour” to Russia. The nature of Miranda’s subsequent visit, and the extent to which his reception at the court of Catherine II influenced Spanish and Russian policy, assumes significance in the light of events on the North American continent immediately preceding and during his stay in Russia.

scholarly journals Identification of a Marine Green Alga Percursaria percursa from Hypersaline Springs in the Middle of the North American Continent

2005 ◽  
Vol 119 (1) ◽  
pp. 82 ◽  
Author(s):  
Kathleen L. Londry ◽  
Pascal H. Badiou ◽  
Stephen E. Grasby
Keyword(s):  
Green Alga ◽  
Microbial Mat ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Western Shore ◽  
Dominant Member ◽  
Hypersaline Springs ◽  
First Time ◽  
North Western

The chlorophycean alga Percursaria percursa (Ulvaceae, Ulvales, Chlorophyceae), typical of marine inter-tidal zones, is reported for the first time from hypersaline springs located along the north-western shore of Lake Winnipegosis in Manitoba. Although not usually found inland, P. percursa is the dominant member of microbial mat communities that thrive in shallow pools at the outlets of hypersaline springs.

The Life History and Dispersal of the Bruce Spanworm, Operophtera bruceata (Hulst), (Lepidoptera: Geometridae)

1962 ◽  
Vol 94 (10) ◽  
pp. 1103-1107 ◽  
Author(s):  
C. E. Brown
Keyword(s):  
United States ◽  
Life History ◽  
The United States ◽  
American Continent ◽  
Forest Insect ◽  
North American Continent ◽  
The Third ◽  
The North ◽  
Insect Survey ◽  
Bruce Spanworm

The Bruce spanworrn, Operophtera bruceata (Hulst), is most common in the mid latitudes of the North American Continent; in Canada it occurs from Newfoundland to the interior of British Columbia (Prentice, In Press) and has been reported from Vermont and Wisconsin in the United States (Craighead, 1950.) Three outbreaks of this insect have been recorded in Alberta. The first occurred in 1903 (de Gryse, 1925) and was apparently of short duration. The second reported by Wolley Dod (1913) occurred in 1913 and denuded hundreds of acres of aspen poplar. Heavy defoliation in the third outbreak became evident in 1957 (Brown, 1957) but an examination of Forest Insect Survey records revealed that population buildup began about 1951. The outbreak continued to expand until 1958 and began to decline in 1959; by 1961 populations were again low except for one or two isolated areas where moderate to low populations persisted. At the peak of the outbreak in 1958 approximately 50,000 square miies were moderately or heavily infested and many more lightly infested.

The genus Crepidotus in Hawaii

1973 ◽  
Vol 51 (6) ◽  
pp. 1251-1254 ◽  
Author(s):  
Robert Ueki ◽  
Clifford W. Smith
Keyword(s):  
New Species ◽  
North American ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
One New Species

Ten species of the genus Crepidotus are described from Hawaii. They are Crepidotus alabamensis, C. amygdalosporus, C. appalachianensis, C. applanatus var. globigera, C. avellaneus, C. citrinus, C. mollis, C. nephrodes, and C. rhizomorphus. One new species, C. bakerae, is proposed. Keys and distinctive characters of each species are provided. It is suggested that most of the species came from the North American continent.

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