Play free online games includes funny, girl, boy, racing, shooting games and much more. Our purpose here is to clarify the respective roles of dynamic and nondynamic processes in producing the structural features of layered igneous rocks, such as those of the skaergaard intrusion. Differentiation of the skaergaard intrusion nature. The troughs are gently plunging synformal structures comprising stacks of crescentic modally graded layers with a sharply defined mafic base that grades upward into plagioclaserich material. Shape and volume of the skaergaard intrusion, greenland. Ch 12 layered mafic intrusionschapter 12 skaergaard. Geologic map of the skaergaard intrusion, modified after mcbirney 1989. Those chapters on individual intrusions concentrate on factual information. The intrusion displays a succession of rocks evolving from troctolitic and gabbroic compositions to ferrodiorites with minor amounts of anorthosite and granophyre. Evidence from precious and base metal geochemistry of. Ilvaite, an alteration product replacing olivine in the skaergaard intrusion h.
Intrusion 3 games play free games online gameslist. The hidden zone of the skaergaard intrusion revealed. For the skaergaard intrusion, differentiation of the mush liquid was shown by the evolution of ti concentration in corerim profiles in plagioclase crystals humphreys, 2009, 2011. Farla abstract the skaergaard intrusion on the coast of east greenland is a prime example of a layered intrusion that has often been referred to since its discovery in 1932 by wager and. Use features like bookmarks, note taking and highlighting while reading intrusion. The most mineralrich layer of the intrusion could contain over tons of skaergaardite. The main problem of genetic interpretations of the skaergaard intrusion is a strong misbalance between the parental compositions followed from contact rocks and the results of geochemical thermometry and that of the whole di. Skaergaard intrusion photomicrographs these photomicrographs were taken of thin sections from samples i collected while on this trip. The end product of differentiation was not a large mass of rhyolite but an ironrich, silicapoor liquid not unlike that deduced by wager in 1960. The volume of the skaergaard intrusion has been estimated in.
Atextural record of solidification and cooling in the. Sep 15, 2010 coexisting pyroxenes from skaergaard intrusion, greenland plotted in the pyroxene quadrilateral. Olivine from the layered series ls, upper border series ubs, and marginal border series mbs of the skaergaard intrusion was analyzed. Trace element constraints on the differentiation and crystal. It is most apparent for tio 2 and p 2o 5 which are almost twice as high in the. Chiara domeneghetti cation ordering of orthopyroxenes from. The differentiation of the skaergaard intrusion springerlink. At most localities the contact is sharp and the contact zone is little deformed, but on mellemo fig. The formation of lowvolume, hightenor magmatic pgeau sulfide mineralization in closed systems. The intrusion is related to the paleogene 86 rifting of greenland from eurasia nielsen 1975. The aim is to make the intrusion more accessible to researchers, teachers, and students as a resource of magmatic structures.
Mcbirney department of geological sciences, university of oregon, eugene, oregon 97403, u. Skaergaard intrusion, sermersooq, greenland, denmark. Evidence from precious and base metal geochemistry of the platinova reef, skaergaard intrusion, east greenland. W crystallization and layer formation in the middle zone of the skaergaard intrusion. Abstract thanks to its magnificent exposures and extraordinarily complete sequence of strongly dif ferentiated rocks, the skaergaard intrusion has long served as a prime example of shallow magmatic differentiation and as. Four olivines separated from the rocks of the skaergaard intrusion,l kangerdlugssuak, east greenland, have been analysed. Lateral reactive infiltration in avertical gabbroic crystal mush, skaergaard intrusion, east greenland article pdf available in journal of petrology 545. New constraints on the origin of the skaergaard intrusion cu.
Pgm updated inferred mineral resource for the skaergaard project. Pdf differentiation and compaction in the skaergaard intrusion. A cartoon explaining many of the observations reported in this study. Cation ordering of orthopyroxenes from the skaergaard intrusion. We find no support for the claim that the skaergaard magma followed the trend of common tholeiitic volcanic magmas, such as those of iceland and the scottish tertiary. Reexamination of the skaergaard intrusion in the context of its regional setting. Reexamination of the skaergaard intrusion of east greenland has revealed that the model of differentiation based on an original liquid with the. Pdf developing a 3d model for the skaergaard intrusion. Differentiation and compaction in the skaergaard intrusion article pdf available in journal of petrology 505 june 2009 with 175 reads how we measure reads. Pdf differentiation and compaction in the skaergaard. View ch 12 from geo 3041 at louisiana state university. Skaergaard intrusion photomicrographs union college. Skaergaardite occurs as droplets, equant grains with rounded outlines, subhedral to euhedral crystals and as irregular grains that vary in size from 2 to 75 mm, averaging 22 mm.
Pdf crystallization of the skaergaard intrusion from an emulsion. The photos here are generally representative, though doubtless my collection has gaps in mineralogy and textures. Briefly, the skaergaard complex is a 55 ma brooks and gleadow84 1977. Ilvaite, an alteration product replacing olivine in the. The origin of the troughs and layering is contentious, attributed variously. Download pdf layered intrusions free online new books in. The bismuth contents of 19 rocks from the skaergaard intrusion, determined by a substoichiometric tracer isotope dilution method, range from 0. All analyses recalculated to 100% volatile free and with all fe as feo. Whatever game you are searching for, weve got it here. Layered mafic intrusions chapter 12 skaergaard layered mafic intrusion greenland. Differentiation and compaction in the skaergaard intrusion.
Pdf a textural record of solidification and cooling in. This site presents a compilation of material that is available on the skaergaard intrusion. All analyses recalculated to 100% volatile free and with all. Apr 25, 2018 the upper parts of the floor cumulates of the skaergaard intrusion, east greenland, contain abundant features known as troughs.
The shape and volume of the skaergaard intrusion, greenland. The explanation of map units is shown below the dark blue lines are the field excursions on land, described in the travel log pages. The skaergaard intrusion is the only known source of skaergaardite large enough to be mined. The skaergaard intrusion is a layered igneous intrusion in the kangerlussuaq area. A textural record of solidification and cooling in the skaergaard intrusion, east greenland article pdf available in journal of petrology 4812 october 2007 with 102 reads how we measure reads. The mechanisms of the formation of layering and the trend of differentiation revisited r. The lower parts of the marginal border series contain abundant fragments of feldspathic peridotite that are possibly autoliths, intermixed with occasional xenoliths of precambrian gneiss and metasomatized cretaceous paleocene sediments derived from adjoining country. Olivines from the skaergaard intrusion, kangerdlugssuak, east. Except close to the olivine free horizon the amount of modal olivine in the average rock is. Sulfides, native silver, and associated trace minerals of the.
The hidden zone of skaergaard was hypothesized by lr wager and coworkers as representing a large, unexposed, basal cumulate series rich in calcic plagioclase and with subordinate olivine and pyroxene. The proposal that a large mass of rhyolitic liquid occupied the upper levels of. Trace element variation in olivine in the skaergaard intrusion. Four olivines separated from the rocks of the skaergaard intrusion, kangerdlugssuak, east. A detailed full colour geological map of the skaergaard intrusion is also included. We find no support for the claim that the skaergaard magma followed the trend of common tholeiitic volcanic magmas, such as those of iceland and the scotti. Macrorhythmic layering and modallygraded layering in a 23. Download it once and read it on your kindle device, pc, phones or tablets. Skaergaardite is the most common pgm mineral in the intrusion, making up over 90% of all the pgm observed. Note that the cpx augite has less ca than dihd and that pigeonite and opx aka. The geochemistry of bismuth in the skaergaard intrusion. The body represents essentially a single pulse of magma, which crystallized from the bottom upward and the top downward. The early eocene skaergaard intrusion of greenland includes enormous numbers of rocks of both exotic and cognate origins. Pdf the presence of fe and sirich liquids found as melt inclusions in apatite and olivine in.
Reexamination of the skaergaard intrusion of east greenland has revealed that the model of differentiation based on an original liquid with the composition of the chilled margin and a large. Brnnrb department of earth sciences, dartmouth college hanover, new hampshire 03755 abstract ilvaite, cafe. Although the size, shape and composition of this subzone have been debated, all subsequent works include it in their models. The skaergaard intrusion formed when tholeiitic magma was emplaced about 55 million years ago, during the initial opening of the north atlantic ocean. Introduction the skaergaard intrusion is the type example of a layered intrusion and displays a wide diversity of structures. However, the use of mineral compositions to track melt differentiation relies on the assumption that elements are immobile after they have been entrapped in the. The application of hrxct to samples from the platinova reef in the skaergaard intrusion revealed the particular association between spherical droplets of cufe sulfide melt with bulk compositions very close to bornite, skaergaardite grains pdcu, aubearing alloys, feti oxides and silicates.
Jul 15, 2001 read the differentiation trend of the skaergaard intrusion and the timing of magnetite crystallization. Business, international hispanic americans mineral deposits greenland mineral industry mines and mineral resources mining industry palladium. The differentiation trend of the skaergaard intrusion and the. The first part of the book covers the general principles and processes which apply to all intrusions. The volume of the skaergaard intrusion is here estimated to be 280 23 km 3 c. Reexamination of textural and structural features of the skaergaard intrusion has clarified the process responsible for various forms of. Layering in the skaergaard intrusion has been divided into two general types, one produced by magmatic flow and another by processes resulting from variations of rates of nucleation and crystallization, and, in the case of the layered series, by compactionrelated processes. Reexamination of the skaergaard intrusion in the context of its regional setting, combined with new data from exploration drilling, has resulted in. The olivines occur in a layered gabbro intrusion which shows continuous crystallisationdifferentiation from a lower and earlier hyperstheneolivinegabbro to an upper and later fayalitequartzgabbro. Pdf lateral reactive infiltration in avertical gabbroic. Numerical calculation of silver mobility in a sulfide free system. Four olivines separated from the rocks of the skaergaard intrusion, kangerdlugssuak, east greenland, have been analysed.
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