Cryptic layering
WebCryptic layering. Not visible to naked eye, chemical variations. Mg content in mafic phases and Ca content in plag decrease going upward. Rhythmic layering. Layers repeat … http://www.alexstrekeisen.it/english/pluto/cumulate.php
Cryptic layering
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WebJan 1, 1996 · Layering is a common, almost ubiquitous, feature of gabbroic and syenitic intrusions. Individual layers, or layered sequences, however, vary greatly in such features as thickness and length, the nature of layer boundaries, internal vertical and lateral variations within layers, and the relationships to other nearby layers. WebCryptic layering tends to span even larger sequences, up to the entire body. Rhythmic layering occurs on the scale of just a few layers , whereas phase layering generally occurs on the scale of several tens of layers . Cryptic layering tends to span even larger sequences , up to the entire body . 11.
WebThis cryptic change is more pronounced in the northern half of the complex where rocks are darker, fresh, and the rhythmic layering is also more conspicuous. Within the white … WebRhythmic layering is believed to result from gravitational settling of mafics and plagioclase from magmatic currents at a differential rate. "Turbulence layering" is developed in rocks …
WebLayering is a common feature in mafic and ultramafic layered intrusions and generally consists of a succession of layers characterized by contrasted mineral modes and/or mineral textures, ... Cryptic layering Skaergaard, Greenland Troctolite-gabbro ... WebSome chemical trends in the rocks indicate that cryptic layering is present but is the reverse of that found in most mafic layered intrusions. The anomalous position of highly …
WebAfter the Second World War this “Skaergaard memoir” quickly became the “avant garde” of much igneous petrologic thinking, and the study of layered intrusions, the cumulates they contain, and the rhythmic and cryptic layering they exhibit, became a major field of research. A follow-up expedition to E Greenland was not possible until 1953.
WebJan 1, 2000 · Modal layering of silicates and magnetite is well developed in the mafic rocks as is modal and cryptic (precious metals) layering of the sulfides in the Precious Metals … jobs with us marshalsWeb3. cryptic layering: systematic variations in the chemical composition of certain minerals with stratigraphic height in a layered sequence what is rhythmic (2 types) and intermittent layering in terms of regularity of layering rhythmic: layering systematically repeated, two types: microrhythmic: few cm thick, macrorhythmic: several m thick intech trailers websitehttp://www.minsocam.org/msa/OpenAccess_publications/MSA_SP_1/MSA_SP1_108-115.pdf intech trailers facebookintech trailers infoWebLayering (or stratification)Layering (or stratification) 2) Phase layering:2) Phase layering: the appearance or disappearancethe appearance or disappearance of minerals in the crystallization sequenceof minerals in the crystallization sequence developed in modal layersdeveloped in modal layers Phase layeringPhase layering … intech trailers contact numberWebThe anomalous position of highly calcic plagioclase near the top of the intrusion, inferred from field relations, coupled with possible reverse cryptic layering suggests a separation of anorthosite by flotation or rafting of plagioclase. © 1975 Geological Society of America. jobs with usps near meWebJan 1, 1996 · Layering is a common, almost ubiquitous, feature of gabbroic and syenitic intrusions. Individual layers, or layered sequences, however, vary greatly in such … intech trailers discovery