The skaergaard intrusion is a layered igneous intrusion in the kangerlussuaq area. Differentiation and compaction in the skaergaard intrusion article pdf available in journal of petrology 505 june 2009 with 175 reads how we measure reads. Chiara domeneghetti cation ordering of orthopyroxenes from. Four olivines separated from the rocks of the skaergaard intrusion, kangerdlugssuak, east greenland, have been analysed. 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. Those chapters on individual intrusions concentrate on factual information. Jul 15, 2001 read the differentiation trend of the skaergaard intrusion and the timing of magnetite crystallization. It is most apparent for tio 2 and p 2o 5 which are almost twice as high in the.
Olivines from the skaergaard intrusion, kangerdlugssuak, east. The first part of the book covers the general principles and processes which apply to all intrusions. Four olivines separated from the rocks of the skaergaard intrusion,l kangerdlugssuak, east greenland, have been analysed. Reexamination of textural and structural features of the skaergaard intrusion has clarified the process responsible for various forms of. The shape and volume of the skaergaard intrusion, greenland. Skaergaard intrusion photomicrographs these photomicrographs were taken of thin sections from samples i collected while on this trip. Crystallization and layer formation in the middle zone of. 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. New constraints on the origin of the skaergaard intrusion cu.
Introduction the skaergaard intrusion is the type example of a layered intrusion and displays a wide diversity of structures. The origin of the troughs and layering is contentious, attributed variously. Download pdf layered intrusions free online new books in. The proposal that a large mass of rhyolitic liquid occupied the upper levels of. Pdf a textural record of solidification and cooling in. At most localities the contact is sharp and the contact zone is little deformed, but on mellemo fig. Pdf the presence of fe and sirich liquids found as melt inclusions in apatite and olivine in. Trace element constraints on the differentiation and crystal.
The volume of the skaergaard intrusion is here estimated to be 280 23 km 3 c. The formation of lowvolume, hightenor magmatic pgeau sulfide mineralization in closed systems. The mechanisms of the formation of layering and the trend of differentiation revisited r. Differentiation and compaction in the skaergaard intrusion. Pdf crystallization of the skaergaard intrusion from an emulsion. Pdf developing a 3d model for the skaergaard intrusion. The early eocene skaergaard intrusion of greenland includes enormous numbers of rocks of both exotic and cognate origins. Cation ordering of orthopyroxenes from the skaergaard intrusion. A detailed full colour geological map of the skaergaard intrusion is also included. Sep 15, 2010 coexisting pyroxenes from skaergaard intrusion, greenland plotted in the pyroxene quadrilateral.
Reexamination of the skaergaard intrusion in the context of its regional setting, combined with new data from exploration drilling, has resulted in. Whatever game you are searching for, weve got it here. Brnnrb department of earth sciences, dartmouth college hanover, new hampshire 03755 abstract ilvaite, cafe. The explanation of map units is shown below the dark blue lines are the field excursions on land, described in the travel log pages. Pgm updated inferred mineral resource for the skaergaard project. All analyses recalculated to 100% volatile free and with all fe as feo. Pdf lateral reactive infiltration in avertical gabbroic. W crystallization and layer formation in the middle zone of the skaergaard intrusion. The skaergaard intrusion formed when tholeiitic magma was emplaced about 55 million years ago, during the initial opening of the north atlantic ocean. The hidden zone of the skaergaard intrusion revealed. 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. Reexamination of the skaergaard intrusion of east greenland has revealed that the model of differentiation based on an original liquid with the. Ch 12 layered mafic intrusionschapter 12 skaergaard.
Geologic map of the skaergaard intrusion, modified after mcbirney 1989. Except close to the olivine free horizon the amount of modal olivine in the average rock is. Atextural record of solidification and cooling in the skaergaard intrusion, east greenland marian b. The aim is to make the intrusion more accessible to researchers, teachers, and students as a resource of magmatic structures. Note that the cpx augite has less ca than dihd and that pigeonite and opx aka. Four olivines separated from the rocks of the skaergaard intrusion, kangerdlugssuak, east. 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. 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 body represents essentially a single pulse of magma, which crystallized from the bottom upward and the top downward. The photos here are generally representative, though doubtless my collection has gaps in mineralogy and textures. Use features like bookmarks, note taking and highlighting while reading intrusion.
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. Skaergaardite is the most common pgm mineral in the intrusion, making up over 90% of all the pgm observed. Although the size, shape and composition of this subzone have been debated, all subsequent works include it in their models. Pdf differentiation and compaction in the skaergaard intrusion. Mcbirney department of geological sciences, university of oregon, eugene, oregon 97403, u. Skaergaard intrusion photomicrographs union college. Sulfides, native silver, and associated trace minerals of the. Ilvaite, an alteration product replacing olivine in the. Lateral reactive infiltration in avertical gabbroic crystal mush, skaergaard intrusion, east greenland article pdf available in journal of petrology 545. The most mineralrich layer of the intrusion could contain over tons of skaergaardite. Shape and volume of the skaergaard intrusion, greenland. 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. 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. Atextural record of solidification and cooling in the.
Macrorhythmic layering and modallygraded layering in a 23. 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 skaergaard intrusion is the only known source of skaergaardite large enough to be mined. Skaergaard intrusion, sermersooq, greenland, denmark. Layered mafic intrusions chapter 12 skaergaard layered mafic intrusion greenland. 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. Pdf differentiation and compaction in the skaergaard. Download it once and read it on your kindle device, pc, phones or tablets.
Business, international hispanic americans mineral deposits greenland mineral industry mines and mineral resources mining industry palladium. The intrusion displays a succession of rocks evolving from troctolitic and gabbroic compositions to ferrodiorites with minor amounts of anorthosite and granophyre. Briefly, the skaergaard complex is a 55 ma brooks and gleadow84 1977. Reexamination of the skaergaard intrusion in the context of its regional setting. Intrusion 3 games play free games online gameslist. The bismuth contents of 19 rocks from the skaergaard intrusion, determined by a substoichiometric tracer isotope dilution method, range from 0. Play free online games includes funny, girl, boy, racing, shooting games and much more. The differentiation of the skaergaard intrusion springerlink. The geochemistry of bismuth in the skaergaard intrusion. The differentiation trend of the skaergaard intrusion and the. Apr 25, 2018 the upper parts of the floor cumulates of the skaergaard intrusion, east greenland, contain abundant features known as troughs. Ilvaite, an alteration product replacing olivine in the skaergaard intrusion h. All analyses recalculated to 100% volatile free and with all. The intrusion is related to the paleogene 86 rifting of greenland from eurasia nielsen 1975.
View ch 12 from geo 3041 at louisiana state university. 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. Evidence from precious and base metal geochemistry of the platinova reef, skaergaard intrusion, east greenland. Numerical calculation of silver mobility in a sulfide free system. The volume of the skaergaard intrusion has been estimated in. 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. The olivines occur in a layered gabbro intrusion which shows continuous crystallisationdifferentiation from a lower and earlier hyperstheneolivinegabbro to an upper and later fayalitequartzgabbro. Developing a 3d model for the skaergaard intrusion in east greenland. This site presents a compilation of material that is available on the skaergaard intrusion. A cartoon explaining many of the observations reported in this study. 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.
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