A GEOPHYSICAL CASE HISTORY OF THE LAKESHORE ORE BODY

Geophysics ◽  
1971 ◽  
Vol 36 (6) ◽  
pp. 1232-1249 ◽  
Author(s):  
Philip G. Hallof ◽  
Emil Winniski

The Lakeshore ore body is in Pinal County, Arizona about 30 miles south of Casa Grande. In February, 1969 when the latest figures were published, the ore reserves were reported at 241 million tons of disseminated sulfide ore (0.7 percent copper) and 24 million tons of concentrated metallic ore (1.69 percent copper). Sulfide copper ore was first intersected in July, 1967 in Hole P‐3. The magnetite‐pyrite‐chalco‐pyrite mineralization occurred in a banded tactite at a depth of 1147 ft. Hole P‐3 was the fourth of several holes that were drilled to determine the source of an induced polarization anomaly that had been outlined, at depth, to the west of the old Lakeshore pit. The successful conclusion of this exploration program by El Paso Natural Gas Company is an excellent example of an integrated exploration approach. The application of regional geological planning, geophysical methods, and detailed geological reasoning resulted in the discovery of a major copper ore body. Due to the depth of the ore zone and the disseminated character of most of the ore, the only geophysical technique that was useful in the direct detection of the ore mineralization was the induced polarization method. Field measurements were made sporadically between August, 1966 and July, 1968. Variable‐frequency induced‐polarization measurements, made using the dipole‐dipole electrode configuration and electrode intervals from 300 ft to 1000 ft, successfully indicated the presence of the metallic mineralization at depth and gave some indication of its extent. Comparisons of the induced polarization data and the appropriate geological sections give information concerning the usefulness of the method.

Author(s):  
L.M. Kryvosheieva ◽  
V.I. Chuchvaha ◽  
N.M. Kandyba

Aim. Based on the results of multi-year research into the flax gene pool, to form a flax training collection to provide breeding scientific organizations and educational institutions with collection samples as well as with information about the bast crop gene pool. Results and Discussion. The studies were conducted in the crop rotation fields for breeding and seed production of the Institute of Bast Crops of the NAAS (Hlukhiv, Sumska Oblast) in 1992-2018. The field measurements and laboratory analyses were carried out in accordance with conventional methods of field and laboratory studies of collection flax samples.The article presents the results on the formation of a training collection of flax at the Institute of Bast Crops of the NAAS, which has 117 accessions (11 botanical species and three varieties) from 22 countries. In addition to species diversity, the collection includes accessions with different levels of expression of valuable economic and biological characteristics. It also includes accessions selected by phenotypic variability of individual characters or their combinations. The multi-year research into the flax collection accessions resulted in identification of sources of highly-expressed valuable economic traits, which are of interest for the plant breeding course. The history of flax breeding in Ukraine is shown, where breeding varieties that are most widespread or were significant breeding achievements in solving certain problems, are presented. The collection can be used as a visual aid for the plant breeding course in educational programs; in addition, it can provide starting material for scientific and educational institutions. The collection is registered with the National Center for Plant Genetic Resources of Ukraine (certificate No. 00273 dated 04/11/2019). Conclusions. The studies of accessions from the national flax collection allowed us to build up a training collection and register it with the NCPGRU. The collection represents a wide range of biological and economic features of the gene pool of this crop. The collection can be used in the educational process of educational agricultural and biological institutions. The multi-year research into the national flax collection resulted in identification of sources of highly-expressed valuable economic traits, which are of interest to the plant breeding course. The history of flax breeding in Ukraine got covered, and breeding varieties that are most widespread or were significant breeding achievements in solving certain problems are presented.


Author(s):  
Bahram Mashhoon

A postulate of locality permeates through the special and general theories of relativity. First, Lorentz invariance is extended in a pointwise manner to actual, namely, accelerated observers in Minkowski spacetime. This hypothesis of locality is then employed crucially in Einstein’s local principle of equivalence to render observers pointwise inertial in a gravitational field. Field measurements are intrinsically nonlocal, however. To go beyond the locality postulate in Minkowski spacetime, the past history of the accelerated observer must be taken into account in accordance with the Bohr-Rosenfeld principle. The observer in general carries the memory of its past acceleration. The deep connection between inertia and gravitation suggests that gravity could be nonlocal as well and in nonlocal gravity the fading gravitational memory of past events must then be taken into account. Along this line of thought, a classical nonlocal generalization of Einstein’s theory of gravitation has recently been developed. In this nonlocal gravity (NLG) theory, the gravitational field is local, but satisfies a partial integro-differential field equation. A significant observational consequence of this theory is that the nonlocal aspect of gravity appears to simulate dark matter. The implications of NLG are explored in this book for gravitational lensing, gravitational radiation, the gravitational physics of the Solar System and the internal dynamics of nearby galaxies as well as clusters of galaxies. This approach is extended to nonlocal Newtonian cosmology, where the attraction of gravity fades with the expansion of the universe. Thus far only some of the consequences of NLG have been compared with observation.


2020 ◽  
Vol 68 (6) ◽  
pp. 1196-1198
Author(s):  
Christina G Bracamontes ◽  
Thelma Carrillo ◽  
Jane Montealegre ◽  
Leonid Fradkin ◽  
Michele Follen ◽  
...  

Women with an abnormal Pap smear are often referred to colposcopy, a procedure during which endocervical curettage (ECC) may be performed. ECC is a scraping of the endocervical canal lining. Our goal was to compare the performance of a naïve Poisson (NP) regression model with that of a zero-inflated Poisson (ZIP) model when identifying predictors of the number of distress/pain vocalizations made by women undergoing ECC. Data on women seen in the colposcopy clinic at a medical school in El Paso, Texas, were analyzed. The outcome was the number of pain vocalizations made by the patient during ECC. Six dichotomous predictors were evaluated. Initially, NP regression was used to model the data. A high proportion of patients did not make any vocalizations, and hence a ZIP model was also fit and relative rates (RRs) and 95% CIs were calculated. AIC was used to identify the best model (NP or ZIP). Of the 210 women, 154 (73.3%) had a value of 0 for the number of ECC vocalizations. NP identified three statistically significant predictors (language preference of the subject, sexual abuse history and length of the colposcopy), while ZIP identified one: history of sexual abuse (yes vs no; adjusted RR=2.70, 95% CI 1.47 to 4.97). ZIP was preferred over NP. ZIP performed better than NP regression. Clinicians and epidemiologists should consider using the ZIP model (or the zero-inflated negative binomial model) for zero-inflated count data.


2021 ◽  
pp. 1-17
Author(s):  
Behnam Shafiei Bafti ◽  
István Dunkl ◽  
Saeed Madanipour

Abstract The recently developed fluorite (U–Th)/He thermochronology (FHe) technique was applied to date fluorite mineralization and elucidate the exhumation history of the Mazandaran Fluorspar Mining District (MFMD) located in the east Central Alborz Mountains, Iran. A total of 32 fluorite single-crystal samples from four Middle Triassic carbonate-hosted fluorite deposits were dated. The presented FHe ages range between c. 85 Ma (age of fluorite mineralization) and c. 20 Ma (erosional cooling during the exhumation of the Alborz Mountains). The Late Cretaceous FHe ages (i.e. 84.5 ± 3.6, 78.8 ± 4.4 and 72.3 ± 3.5 Ma) are interpreted as the age of mineralization and confirm an epigenetic origin for ore mineralization in the MFMD, likely a result of prolonged hydrothermal circulation of basinal brines through potential source rocks. Most FHe ages scatter around the Eocene Epoch (55.4 ± 3.9 to 33.1 ± 1.7 Ma), recording an important cooling event after heating by regional magmatism in an extensional tectonic regime. Cooling of the heated fluorites, as a result of thermal relaxation in response to geothermal gradient re-equilibration after the end of magmatism, or exhumation cooling during extensional tectonics characterized by lower amount of erosion are most probably the causes of the recorded Eocene FHe cooling ages. Oligocene–Miocene FHe ages (i.e. 27.6 ± 1.4 to 19.5 ± 1.1 Ma) are related to the accelerated uplift of the whole Alborz Mountains, possibly as a result of the initial collision between the Afro-Arabian and Eurasian plates further to the south.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Partha Konar ◽  
Ananya Mukherjee ◽  
Abhijit Kumar Saha ◽  
Sudipta Show

Abstract We propose an appealing alternative scenario of leptogenesis assisted by dark sector which leads to the baryon asymmetry of the Universe satisfying all theoretical and experimental constraints. The dark sector carries a non minimal set up of singlet doublet fermionic dark matter extended with copies of a real singlet scalar field. A small Majorana mass term for the singlet dark fermion, in addition to the typical Dirac term, provides the more favourable dark matter of pseudo-Dirac type, capable of escaping the direct search. Such a construction also offers a formidable scope to radiative generation of active neutrino masses. In the presence of a (non)standard thermal history of the Universe, we perform the detailed dark matter phenomenology adopting the suitable benchmark scenarios, consistent with direct detection and neutrino oscillations data. Besides, we have demonstrated that the singlet scalars can go through CP-violating out of equilibrium decay, producing an ample amount of lepton asymmetry. Such an asymmetry then gets converted into the observed baryon asymmetry of the Universe through the non-perturbative sphaleron processes owing to the presence of the alternative cosmological background considered here. Unconventional thermal history of the Universe can thus aspire to lend a critical role both in the context of dark matter as well as in realizing baryogenesis.


2020 ◽  
Vol 7 (13) ◽  
Author(s):  
Javier Alfredo Fayad

En este artículo se propone valorar las formas, prácticas y propuestas que las comunidades indígenas han elaborado en función de sus proyectos de educación propia, como resultado de presiones y luchas ante el modelo de educación oficial. La historia de implementación de la educación en las comunidades indígenas ha sido la negación de sus idiomas y formas culturales a partir del modelo de educación evangelizadora, republicana y estandarizada. Los cambios en ese camino muestran el paso de la etnoeducación a la educación propia indígena, que se reconoce en Colombia gracias a la Constitución de 1991 y a las luchas de las comunidades por transformar el modelo institucionalizado de educación, al proponer una educación que reconozca los principios culturales, los idiomas, las lógicas otrasde los pueblos indígenas. Los aportes de los pueblos Nasa y Misak en el departamento del Cauca demuestran la riqueza de cómo se viene investigando, indagando y tratando de fortalecer una propuesta educativa desde las comunidades. THE PATH OF EDUCATION OF INDIGENOUS PEOPLES IN THE DEPARTMENT OF CAUCA, COLOMBIA:from ethnoeducation to own education ABSTRACTThe purpose of this article is to discuss the practices and proposals of education projects that indigenous communities have elaborated, against the official education model. The history of implementation of education in indigenous communities has been the negation of their languages and cultural forms based on the evangelizing, republican and standardized education model. The changes in this path show the passage from ethnoeducation to indigenous education itself, recognized in the 1991 Constitution. The contributions of the Nasa and Misak peoples in the department of Cauca demonstrate the way that they are trying to strengthen an educational proposal from the communities.Key-words: Ethnoeducation. Own education. Accompaniment. Recognition of differences. Knowledge relationships.  


Author(s):  
William O'Brien

The Iberian Peninsula is one the most mineralized parts of Europe, with a long history of metal mining from prehistoric and Roman to modern times. The earliest evidence for copper metallurgy dates to the fifth millennium BC; however, distinctive Chalcolithic metalworking traditions did not emerge in most regions until 3000 BC onwards. There are widespread occurrences of copper mineralization in Spain and Portugal, including many areas with deposits of lead, tin, silver, and gold. Copper deposits occur in the Galician and Cantabrian mountain ranges of northern Spain, extending east to the Pyrenees. They are also numerous in central Spain, in the provinces of Madrid, Avila, Salamanca, and Segovia in the Central Range, and also in the Toledo and Betic mountains of Cordoba. Farther south, there are major copper deposits in the so-called Pyrite Belt, extending from Seville to Huelva into southern Portugal, and also in the Penibetic range from Cartagena to Malaga crossing the sierras of Almeria (Rovira 2002: fig. 3c; see Delibes de Castro and Montero Ruiz 1999 for regional surveys of copper deposits and indications of early mining; also Gómez Ramos 1999; Hunt Ortiz 2003). The widespread availability of ore deposits was a significant factor in the establishment of copper metallurgy in Iberia. How early is contentious, as is the means by which the new technology first developed in different parts of the peninsula. The older explanation of metal-seeking colonists from the east Mediterranean introducing this technology to southern Spain was replaced in the 1960s by a model that emphasized autonomous development (Renfrew 1967, 1973; Montero Ruiz 1994). This was based on the apparent antiquity of copper mining and metallurgy in Iberia and the distinctive technological processes that developed there relative to other parts of Europe. The earliest indication of copper metallurgy in Iberia may come from the settlement of Cerro Virtud in Almeria, south-west Spain. A single sherd from a metallurgical crucible used to reduce oxidized copper ore was discovered in a layer dated to the early fifth millennium BC (Montero Ruiz and Ruíz Taboada 1996; Ruíz Taboada and Montero Ruiz 1999).


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