Petrology and textural classification of the Jericho kimberlite, northern Slave Province, Nunavut, Canada

2008 ◽  
Vol 45 (6) ◽  
pp. 701-723 ◽  
Author(s):  
Maya G. Kopylova ◽  
Patrick Hayman

The paper presents data on petrology, bulk rock and mineral compositions, and textural classification of the Middle Jurassic Jericho kimberlite (Slave craton, Canada). The kimberlite was emplaced as three steep-sided pipes in granite that was overlain by limestones and minor soft sediments. The pipes are infilled with hypabyssal and pyroclastic kimberlites and connected to a satellite pipe by a dyke. The Jericho kimberlite is classified as a Group Ia, lacking groundmass tetraferriphlogopite and containing monticellite pseudomorphs. The kimberlite formed during several consecutive emplacement events of compositionally different batches of kimberlite magma. Core-logging and thin-section observations identified at least two phases of hypabyssal kimberlites and three phases of pyroclastic kimberlites. Hypabyssal kimberlites intruded as a main dyke (HK1) and as late small-volume aphanitic and vesicular dykes. Massive pyroclastic kimberlite (MPK1) predominantly filled the northern and southern lobes of the pipe and formed from magma different from the HK1 magma. The MPK1 magma crystallized Ti-, Fe-, and Cr-rich phlogopite without rims of barian phlogopite, and clinopyroxene and spinel without atoll structures. MPK1 textures, superficially reminiscent of tuffisitic kimberlite, are caused by pervasive contamination by granite xenoliths. The next explosive events filled the central lobe with two varieties of pyroclastic kimberlite: (1) massive and (2) weakly bedded, normally graded pyroclastic kimberlite. The geology of the Jericho pipe differs from the geology of South African or the Prairie kimberlites, but may resemble Lac de Gras pipes, in which deeper erosion removed upper facies of resedimented kimberlites.

Koedoe ◽  
1995 ◽  
Vol 38 (1) ◽  
Author(s):  
G.J. Bredenkamp ◽  
H. Bezuidenhout

A procedure for the effective classification of large phytosociological data sets, and the combination of many data sets from various parts of the South African grasslands is demonstrated. The procedure suggests a region by region or project by project treatment of the data. The analyses are performed step by step to effectively bring together all releves of similar or related plant communities. The first step involves a separate numerical classification of each subset (region), and subsequent refinement by Braun- Blanquet procedures. The resulting plant communities are summarised in a single synoptic table, by calculating a synoptic value for each species in each community. In the second step all communities in the synoptic table are classified by numerical analysis, to bring related communities from different regions or studies together in a single cluster. After refinement of these clusters by Braun-Blanquet procedures, broad vegetation types are identified. As a third step phytosociological tables are compiled for each iden- tified broad vegetation type, and a comprehensive abstract hierarchy constructed.


2005 ◽  
Vol 221 (3-4) ◽  
pp. 520-528 ◽  
Author(s):  
André de Villiers ◽  
Pavel Majek ◽  
Frederic Lynen ◽  
Andrew Crouch ◽  
Henk Lauer ◽  
...  

2017 ◽  
Vol 9 (1) ◽  
pp. 228-243
Author(s):  
Shené Steenkamp ◽  
Rudie Nel

The classification of income from cloud computing activities, according to the substance-over-form doctrine, is fundamental to the application of the correct taxation source test. The designation of IaaS, PaaS and SaaS, the three main cloud computing service models, clearly denotes the form of cloud computing activities as that of a service. However, the nature of cloud computing inherently raises the question of whether or not cloud computing income should not rather be classified as income from leasing activities or the imparting of know-how. In fact, the findings of this study suggest the classification would not necessarily always be that of a service. The possible classification as lease income can be either income from the lease of tangible computer hardware and/or of intellectual property (royalty income). The aim of this study was to formulate guidelines to assist in the correct classification of income from cloud computing activities. This was achieved by performing doctrinal research based on the South African and international literature.


2018 ◽  
Vol 14 (3) ◽  
pp. 120-133 ◽  
Author(s):  
Said Fathalla

Due to the ubiquitous availability of the information on the web, there is a great need for a standardized representation of this information. Therefore, developing an efficient algorithm for retrieving information from knowledge graphs is a key challenge for many semantic web applications. This article presents spreading activation over ontology (SAOO) approach in order to detect the relatedness between two human diseases by applying spreading activation algorithm based on bidirectional search technique. The proposed approach detects two diseases relatedness by considering semantic domain knowledge. The methodology of the proposed work is divided into two phases: Semantic Matching and Diseases Relatedness Detection. In semantic matching, diseases within the user-submitted query are semantically identified in the ontology graph. In diseases relatedness detection, the relatedness between the two diseases is detected by using bidirectional-based spreading activation on the ontology graph. The classification of these diseases is provided as well.


2010 ◽  
Vol 47 (4) ◽  
pp. 369-388 ◽  
Author(s):  
Larry M. Heaman ◽  
D. Graham Pearson

A review of the ages determined for mantle material (xenoliths and xenocrysts entrained in kimberlite) derived from the Slave Province continental lithospheric mantle (CLM) indicates that a portion of the central Slave lithosphere may be ancient (3.5–3.3 Ga) harzburgite, but the majority of this lithosphere is much younger (2.9–2.0 Ga). Relying on the most robust chronometers, the majority of Slave lithosphere peridotite formed in the Neoarchean (peak at 2.75 Ga), whereas the majority of eclogite formed in the Paleoproterozoic (2.2–2.0 Ga). The northern Slave lithosphere contains evidence of peridotite xenolith ages that young with depth. The Paleoproterozoic eclogites may have multiple origins including remnants of subducted oceanic crust and mafic–ultramafic magmas that crystallized at great depth (100–200 km). Re–Os studies of sulfide inclusions in diamond indicate that some diamonds currently mined are ancient (∼3.5 Ga), but many Slave diamonds could be considerably younger. Most eclogitic diamonds recovered from the Slave craton are interpreted to be related to the formation of Paleoproterozoic eclogite. There is abundant evidence for Mesoproterozoic modification of the Slave lithosphere (e.g., heating by magma emplacement at great depth and metasomatism) and possible new addition to the lithosphere at that time. The Canadian Slave and African Kaapvaal lithospheres have similar peaks in cratonic peridotite formation ages at about 2.8 Ga, indicating that a large portion of the CLM in these two cratons formed and stabilized in the Neoarchean. One difference is that the Slave peridotites are much less enriched in SiO2, possibly reflecting the more metasomatized nature of the Kaapvaal CLM. The dominance of Paleoproterozoic formation ages for Slave mantle eclogites contrasts with the dominance of Neoarchean formation ages for Kaapvaal mantle eclogites.


1894 ◽  
Vol 185 ◽  
pp. 1029-1041 ◽  

The South African fossils with broad, flat, tuberculate tooth-crowns of mammalian type all from the eastern part of Cape Colony. Some of the most interesting are known from fragments, which indicate nothing but the middle region of the sail. They are apparently extremely rare. Two species, with teeth well preserved, found ten years ago by Dr. Kannemeyer, at Wonderboom, and presented to South African Museum, Cape Town, where they were brought under my notice by Peringuey. Others were found in a fragmentary condition by Mr. Alfred of Aliwal North, to the west of that town, in a bed which appeared to me be reconstructed. There is no doubt that the fossils are from the upper part of te Karroo formation, probably of Permian age, and below the Stormberg beds, in Saurischian fossils are found allied to those of the Trias of Europe. If the teeth had occurred isolated, without the means of demonstrating their rsemblance to Theriodonts, by comparison of what remains of the skull, it would have legitimate to have referred them to Mammals. There is no evidence of affinity Accept resemblances to Theriodonts, which show that the skull had pre-frontal and frontal bones, and therefore may be inferred to have had the lower jaw composite. The teeth are such as might be expected, perhaps, in a Monotreme Mammal, their interest is therefore the greater that there is no ground for suspecting them be mammalian, other than a general resemblance of the crown to the crowns of true teeth of Ornithorhynchus. That teeth of this type should occur in a group animals in which the shoulder-girdle and pelvis have monotreme characters, and in hich the principal limb bones are intermediate in character between Monotremes Marsupials, is evidence of a closer approximation between Mammals and Pep tiles has been manifest. And so far as I am aware the only Theriodont characters remaining to distinguish these animals from Mammals are the composite lower which is covered externally by the dentary bone along its whole length, and the resence of the pre-frontal, post-frontal, and transverse bones in the skull.


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