The Inishdawros meta-peridotite, Callow, Ballyconneely, Connemara, Western Ireland

1978 ◽  
Vol 42 (321) ◽  
pp. 69-74 ◽  
Author(s):  
A. A. Ahmed ◽  
B. E. Leake
Keyword(s):  
The Body ◽  
Chemical Analyses ◽  
Previous Suggestion ◽  
Modal Variation ◽  
Igneous Origin ◽  
Western Ireland ◽  
Differentiation Trend

SummaryThe chemistry and petrography of a meta-ultrabasic lens containing peridotite with poikilitic pyroxenes and hornblende, both of probable igneous origin, are given. The body also contains feldspathic-bearing hornblende meta-gabbros and is a tectonic fragment in hornblende-plagioclase rock belonging to the same Errismore intrusion. Chemical analyses fail to discern any appreciable systematic differentiation trend across the body despite modal variation to hornblende plagioclase layers. The high Niggli mg near the structural bottom of the intrusion suggests that this part of the Errismore intrusion is right way up, contrary to a previous suggestion.

XII.—Petrology and Petrogenesis of some Garnetiferous Peridotites

1963 ◽  
Vol 65 (12) ◽  
pp. 251-314 ◽  
Author(s):  
M. J. O'Hara ◽  
F. H. Stewart
Keyword(s):  
South Africa ◽  
Crystalline Rocks ◽  
Chemical Analyses ◽  
X Ray ◽  
Metamorphic History ◽  
Igneous Origin ◽  
Mineral Assemblages ◽  
History Of ◽  
Reliable Interpretation ◽  
Recent Experimental Work

SynopsisGarnetiferous peridotite masses which occur among gneisses in the Tafjord district of Norway are cold intrusions emplaced as crystalline rocks late in the metamorphic history of the region. No relationship other than similarity of mineral facies can be established between the peridotites and the eclogite bodies in the surrounding gneiss. Chemical analyses of twelve olivines, fourteen orthopyroxenes, nine chrome diopsides, nine garnets, three amphiboles and two rocks are presented, representing material from the Tafjord and Almklovdalen districts of Norway, a garnetiferous peridotite mass near Bellinzona, Switzerland, and the garnet-peridotite inclusions in the kimberlite pipes of South Africa. Optical and X-ray data for the analyzed and some unanalyzed assemblages are also presented. The mineral assemblages of these rocks are compared with each other, and with data from the peridotites of layered tholeiitic intrusions, alpine-type peridotites and the peridotite nodules in basalts. The garnet-peridotites of Norway, Switzerland and South Africa are believed to be little altered fragments of the mantle, whereas the peridotite nodules in basalts and the alpine-type peridotites are believed to be of igneous origin. Examination of the distribution of cations between the coexisting phases suggests that there are too many variables to permit a reliable interpretation of the results.The orthopyroxenes from the garnetiferous peridotites are not rich in A1203, contrary to expectations based upon recent experimental work.

The petrogenesis and origin of the analcime in the volcanic rocks of the Crowsnest Formation, Alberta

1978 ◽  
Vol 15 (1) ◽  
pp. 69-77 ◽  
Author(s):  
L. J. Ferguson ◽  
A. D. Edgar
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Volcanic Rocks ◽  
Crustal Material ◽  
Igneous Origin ◽  
Partial Fusion ◽  
Extensive Exchange ◽  
Inclusion Trails ◽  
Convincing Data ◽  
Differentiation Trend

The Crowsnest Formation consists of trachytes, analcime phonolites and blairmorites, metamorphosed to zeolite facies. The latter rocks contain large analcime phenocrysts variously suggested as being of primary igneous origin or due to transformation from original leucite by reaction of Na-rich fluids. Although neither field relationships or petrography provide convincing data favouring either hypothesis, the presence of primary undisrupted inclusion trails in the analcime tend to support the former hypothesis. Compositions of the analcimes differ from that of an analcime formed by transformation from leucite. The chemistry of the rocks and their constituent pyroxenes are consistent with a sodic rather than a potassic differentiation trend; feldspar and garnet analyses support this conclusion. Oxygen isotope values for the pyroxenes indicate no extensive exchange with a low temperature fluid. Thus it seems unlikely that leucite was ever a constituent of the Crowsnest suite as necessitated by the hypothesis of transformation from leucite. Geochemistry and known experimental data indicate that the analcime phonolites and blairmorites differentiated from a trachytic magma under restricted conditions at depths greater than 25 km by early sanidine and later analcime fractionation. The parental trachyte may be produced by partial fusion of crustal material at depths greater than 35 km.

scholarly journals Metasomatic zonation of an ultramafic lens at Ikátoq, near Færingehavn, southern West Greenland

1980 ◽  
Vol 135 ◽  
pp. 1-32
Author(s):  
M.R Sharpe
Keyword(s):  
Carbonate Rock ◽  
The Body ◽  
Chemical Analyses ◽  
Ion Migration ◽  
West Greenland ◽  
Mineral Reaction ◽  
Parent Rocks ◽  
Reaction Stoichiometry ◽  
Common Parent ◽  
Host Rocks

The Ikátoq zoned ultramafic lens occurs as an elliptical body in Archaean gneisses and amphibolites to the south of Færingehavn, southern West Greenland. From the unaltered serpentinite core to the contact with the surrounding gneisses five zones were distinguished: serpentinite (5), talc-carbonate rock (4), tale (3), amphibole (2) and chlorite (1): their interrelationships are discussed in the light of the theory of zoning. It is shown that these five main lithological types developed from a common parent rock under the inf1uence of low temperature metamorphism as a process of steatisation – the outer chlorite zone representing altered host rocks, whilst the inner tale, tale-carbonate and serpentinite shells represent changed serpentine core. The original junction between the two parent rocks lies in the amphibole zone. The growth process of the zones is discussed and evidence concerning these mechanisms is presented. Estimates of bulk transport and ion migration during the alteration are developed from the chemical analyses, based on whole-rock formulas and equivalent volumes, using ideal-mineral reaction stoichiometry. The system was open to migrating components, and it is shown that the body lost Mg to the gneisses, which in turn supplied some Ca and K to the reacting system. It is likely that CO2 and H2O were permanently in excess. A volume contraction of approximately 6 per cent during the steatisation process is postulated.

THE EFFECTS OF PELAGIC HYDROCARBONS ON THE ROCKY INTERTIDAL FLORA AND FAUNA OF BERMUDA

1977 ◽  
Vol 1977 (1) ◽  
pp. 499-503
Author(s):  
Nancy G. Maynard ◽  
Conrad D. Gebelein ◽  
Adam Zsolnay
Keyword(s):  
Intertidal Zone ◽  
Reproductive Potential ◽  
The Body ◽  
Rocky Intertidal ◽  
Body Tissue ◽  
Splash Zone ◽  
Chemical Analyses ◽  
The Past ◽  
Hydrocarbon Content ◽  
Heavy Tar

ABSTRACT Over the past decade, the islands of Bermuda have been exposed to an increasing influx of floating pelagic hydrocarbons (“tar balls”). Large quantities of the pelagic tar become stranded on the rocks in the intertidal zone. Tar coverage on the rocks is controlled by the slope of the shore, with the maximum amount accumulating on gently sloping or flat shores. The tar is deposited almost exclusively in the splash zone, and, therefore, the only animals directly affected by the attached tar are those who inhabit and/or feed in this zone. Chemical analyses show that the snails, Nodilittorina tuberculatus and Tectarius muricatus, which live in the splash zone, have the highest hydrocarbon content in body tissue of all animals analyzed. In contrast, all animals sampled from immediately adjacent tide pools contained no petrogenic hydrocarbons. The most abundant life in the intertidal zone is concentrated below this splash zone area of tar accumulation. With few exceptions, the animals from this zone have demonstrated low or zero levels of petrogenic hydrocarbons in the body tissue. The presence of tar on the rocks does not appear to adversely affect reproductive potential, size frequency or abundance of the animals in this intertidal region below the splash zone. The microscopic and macroscopic algae produce very large amounts of biogenic hydrocarbon material. In addition, however, some algal samples from sites of heavy tar accumulation contained high levels of petrogenic hydrocarbons.

scholarly journals Ammonoid soft tissue remains revealed by computed tomography

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
R. Hoffmann ◽  
D. Morón-Alfonso ◽  
C. Klug ◽  
K. Tanabe
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Soft Tissues ◽  
Tube Wall ◽  
Short Description ◽  
The Body ◽  
Chemical Analyses ◽  
Ne Germany ◽  
The Rich ◽  
Ct Data

AbstractFindings of ammonoid soft tissues are extremely rare compared to the rich fossil record of ammonoid conchs ranging from the Late Devonian to the Cretaceous/Paleogene boundary. Here, we apply the computed-tomography approach to detect ammonoid soft tissue remains in well-preserved fossils from the Early Cretaceous (early Albian) of NE-Germany of Proleymeriella. The ammonites were found in glauconitic–phosphatic sandstone boulders. Analyses of the high-resolution Ct-data revealed the presence of cameral sheets, the siphuncular tube wall, and the siphuncle itself. The siphuncle is a long, segmented soft tissue that begins at the rear end of the body chamber and comprises blood vessels. Chemical analyses using energy-dispersive spectroscopy (EDS) showed that all preserved soft tissues were phosphatized and are now composed of fluorapatite. The same holds true for preserved shell remains that locally show the nacreous microstructure. We provide a short description of these soft tissue remains and briefly discuss the taphonomic pathway.

scholarly journals MINERALIZAÇÃO DE Fe-Ti-V ASSOCIADA AO GABRO MARCOS DA COSTA (MIGUEL PEREIRA), ESTADO DO RIO DE JANEIRO

2018 ◽  
Author(s):  
Ronaldo Mello Pereira ◽  
Marcelo Salomão ◽  
Reiner Neumann ◽  
Paulo Guimarães ◽  
Enrico Pedroso
Keyword(s):  
Magnetic Susceptibility ◽  
Rio De Janeiro ◽  
The State ◽  
The Body ◽  
Total Weight ◽  
Chemical Analyses ◽  
Primary Flow ◽  
Basal Portion ◽  
Mineral Concentrations ◽  
Janeiro State

O Gabro Marcos da Costa, localizado em Miguel Pereira, é mais um dos registros de rochas gabroides encontrados no estado do Rio de Janeiro. O corpo tem formato lenticular, 2,7 km2 de área aflorante, é estruturalmente isotrópico e sem presença visível de texturas primárias como a orientação por fluxo ou cumuláticas. Amostras do gabro foram submetidas a análises químicas e medidas de susceptibilidade magnética (SM). Possui caráter toleítico, com trend de enriquecimento em Fe. A ambientação tectônica é do tipo intraplaca e possível geração a partir de magma basáltico de alto-Ti (>3% TiO2). Os teores em TiO2 e V em rocha total são equiparáveis aos encontrados em gabros que encerram mineralizações em Fe-Ti-V. Ilmenita e magnetita, geralmente vanadinífera, são os principais minerais opacos e encontram-se disseminadas na rocha. A composição química da magnetita determinada em MEV-EDS varia de: 90,23% a 98,77% de FeOt, 0,07% a 0,42% de TiO2 e 0,59% a 2,13% de V2O5. Os valores de SM medidos em afloramentos estão entre -0.44 x10-4 a 89.4 x10-4 SI-emu. Em afloramento, por meio dessas medidas de SM, percebe-se a presença de níveis e bandas centimétricas aonde a concentração de minerais ferromagnéticos chega a até 22% em peso e interpretadas como estratificação magmática. As maiores concentrações de minerais ferromagnéticos ocorrem na parte setentrional do corpo aqui considerada como a porção basal da câmara magmática.Palavras Chave: mineralização de Fe-Ti-V, gabro, Rio de Janeiro, magnetita vanadiníferaAbstract:Fe-Ti-V MINERALIZATION ASSOCIATED WITH GABRO MARCOS DA COSTA (MIGUEL PEREIRA), RIO DE JANEIRO STATE. Marcos da Costa Gabbro, located in Miguel Pereira city, is one of the records of gabbroid rocks found in the state of Rio de Janeiro. The body is lenticular shape, with 2.7 km² outcrops, structurally isotropic and without visible presence of primary flow or cumulate textures. Gabbro samples were submitted to chemical analyses and magnetic susceptibility measurements (MS). Its character is toleithic, with trend of enrichment in Fe. The tectonic ambiance is intraplate type, with possible generation from basalt with high-Ti (> 3% TiO2). The TiO2 and V contents are comparable to those found in gabbros containing Fe-Ti-V mineralizations. Ilmenite and magnetite, usually vanadiniferous, are scattered in the rock. The magnetite contents determined in SEM-EDS vary from: 90.23% to 98.77% of FeOt, 0.07% to 0.42% of TiO2 and 0.59% to 2.13% of V2O5. MS values range from -0.44 x10-4 to 89.4 x10-4 SI-emu. Levels and centimeter bands with high MS exhibit ferromagnetic mineral concentrations of up to 22% of total weight and were interpreted as magmatic layering. The highest concentrations of ferromagnetic minerals occur in the northern part of the body here regarded as the basal portion of the magma chamber.Keywords: Fe-Ti-V mineralization, gabbro, Rio de Janeiro, vanadiferous magnetite

Mineralogical characteristic of mortars from the Temple of Hatshepsut at Deir el-Bahari: preliminary report

2016 ◽  
Vol XXIV (2) ◽  
pp. 93-111
Author(s):  
Teresa Dziedzic ◽  
Wojciech Bartz ◽  
Maria Gąsior
Keyword(s):  
Preliminary Report ◽  
The Body ◽  
Chemical Analyses ◽  
Body Of Knowledge ◽  
Physico Chemical ◽  
Mineralogical Characteristic ◽  
The Temple ◽  
Masonry Mortar

The article presents the results of physico-chemical analyses of a few masonry mortar and whitewash samples taken in the mid-1990s from the Temple of Hatshepsut in Deir el-Bahari. The mineralogical characteristic of the samples contributes to the body of knowledge on the composition of these masonry mortars and their structure, while at the same time encouraging further research on a greater number of samples.

scholarly journals THE MAINTENANCE OF BLOOD COLLOID: PASSAGE OF STORED GUM ACACIA FROM THE CELLS TO THE CIRCULATION AFTER PLASMAPHERESIS

1950 ◽  
Vol 92 (1) ◽  
pp. 77-83 ◽  
Author(s):  
R. E. Knutti ◽  
R. A. Warrick ◽  
J. B. Goetsch
Keyword(s):  
Blood Plasma ◽  
Blood Stream ◽  
The Body ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Previous Suggestion ◽  
Gum Acacia ◽  
Low Protein

Removal of blood plasma by plasmapheresis from dogs made hypoproteinemic by injections of gum acacia over long periods of time, has resulted in the removal of more gum acacia than was originally present in the plasma. Gum acacia injections had been discontinued previous to the start of the experiments, and hence it must be concluded that the excess amounts of acacia were derived from deposits in the various organs. These observations verify the previous suggestion that the increase in blood acacia in the hypoproteinemic dog on a low protein diet is due to the transfer of acacia to the blood from its sites of deposit in the body. The experiments further suggest that the colloid content of the blood stream is maintained at the expense of tissue colloids, and support the idea that colloidal substances may pass in and out of cells.

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