Hardness - hard, although component mineral is soft (calcite is 3 on Moh's scale of hardness). May be small outcrops of migmatite Hornblende Gneiss or amphibolite Marble Biotite schist ^ garnet t bearing gneisses MIGMATITES Stromatic, phlebet'; 6 ophthalmatic migmatite of granite gneiss paleosome and subpegmatitic neosome Migmatitic amphibolite rocks GRAIN SIZE v.c. A rock that shows no foliation is called a hornfels if the grain size is small, and a granulite, if the grain size is large and individual minerals can be easily distinguished with a hand lens. 0000003521 00000 n amphibolite gneiss hornfels mica schist serpentinite soapstone (talc-rock) Color. 0000250876 00000 n 0000250456 00000 n Notice how the grain size is finer and the banding is more intense in the lower half of the specimen, whereas in the upper half the white feldspar specks are less flattened. The presence of randomly oriented minute amphibole at the grain boundaries of mantled clinopyroxene and the general intense phase mixing in the polymineralic matrix testify to the activation of grain boundary sliding (GBS) as a dominant mechanism accompanying dissolution–precipitation creep syn to post grain size reduction, even in the monomineralic layers (A1; SE13-67). Grain size of metamorphic rock increases in the process of. This application has not been accepted generally. Observe the grain size and grain shape with a hand lens. Grain size of chromite. Clast size ranges up to boulder (>64 mm) but is more commonly cobble or pebble (Fig. New London consists of a layered facies and a massive facies. 0000124528 00000 n φ scale Size range (metric) Size range (approx. Color. ;j]PV?0M:-KB?<5@YLHIQS@AI599NGCM2K@9RPCGXCOp�j|^>pE=J27O=5cL. Biotite lies parallel to S2 in all mafic selvedges. The term has been applied to rocks of either igneous or metamorphic origin. selvedges adjacent to veins show a grain size in- crease with metamorphic grade (approximate range 0.05-2 mm). in grain size of amphibole is observed with proximity to the pluton; 2) the metamorphic-mineral assemblage changes from Act+Ab+Ep+Chl+Qtz±Ttn±Opq outside the aureole, to Hbl+Olg+Ep+Chl+Qtz±Ilm±Ttn±Opq close to the pluton; and 3) the modal amount of epidote decreases toward the intru-sion. Grain size appears to be the main parameter in determining whether an aggregate deforms by dislocation creep or by grain-size-sensitive creep associated with diffusive mass transfer within crystals or along grain boundaries (e.g. Home Rocks and Minerals Amphibolite Reference URL Share . Amphibolite is a metamorphic rock, formed by regional metamorphosis either from sedimentary (para-amphibolites) or magmatic (ortho-amphibolites) protoliths. From To RockType Colour Grain Size Texture Description Bio % Gt % Peg % 0.0 3.6 Casing 3.6 18.3 Felsic Gneiss (S) Localized sections with varying grain size. Grain-size-sensitive deformation of upper greenschist- to lower amphibolite-facies metacherts from a low-P/high-T metamorphic belt. Amphibolite either lacks or has weakly developed foliation. There are various physical properties of Amphibolite like Hardness, Grain Size, Fracture, Streak, Porosity, Luster, Strength etc which defines it. Grain-size-sensitive deformation of upper greenschist- to lower amphibolite-facies metacherts from a low- P/high- T metamorphic belt Okudaira, Takamoto Ogawa, Daisuke Based on your observations, how has metamorphism changed the mineral content of the metamorphic rock? 20190122100DR Nentmannsdorf (Bahretal) Hornblendebruch.jpg 3,527 × 2,478; 4.58 MB very fine. Extra Large. High grade dark-colored hornblende-bearing rock is hornblende gneiss. Add tags Comment Rate. Fine-grained quartz-feldspar aggregates along the grain boundaries have crystallized from very low melt fractions and formed a “film” metatexite. Figures 1-2. Localized sections of amphibolite. Grain sizes were calculated as the equivalent diameter of a spherical grain. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. q 1 1 355 88 re W n q 0.666 0 0 0.666 178.5 45 cm /FRM Do Q Q endstream endobj 127 0 obj << /Length 77 /BBox [ 0 0 357 90 ] /Resources << /ProcSet [ /PDF ] /XObject << /FRM 128 0 R >> >> >> stream In igneous rocks, the term hornblendite is more common and restrictive; hornblende is the most common amphibole and is typical of such rocks. endstream endobj 129 0 obj << /ProcSet [ /PDF /ImageC ] /XObject << /Im1 131 0 R >> /ExtGState << /GS1 130 0 R >> >> endobj 130 0 obj << /Type /ExtGState /SA false /OP false /HT /Default >> endobj 131 0 obj << /Type /XObject /Subtype /Image /Name /Im1 /Width 530 /Height 76 /BitsPerComponent 8 /ColorSpace /DeviceRGB /Length 120842 >> stream Test each sample for effervescence with acid. Characterization of grain size in specimens with duplex grain size distributions is described in Test Methods E 1181. This is Ostwald ripening in action (refer to the discussion in Chapter 4). Amphibolite is available in black, brown, green, grey colors. 0000250208 00000 n It illustrates one of the geologist's common problems: the outcrop surface is partly covered by lichens and moss, and the true rock surface is rather difficult to distinguish. Schist, with visible grains. OBSERVER: GUY SIZE … Quartzite, composed of quartz. The latter appears to be rich in biotite and amphibole, and to have a maximum grain size of about 1 mm. On a fresh surface this rock is a greenish-grey to dark green. The minimum cut-off area was set to 10 pixels, which means that, depending on the map acquisition step size, only grains of a size >1.07 μm (0.3 μm step size), >1.25 μm (0.35 μm), and 1.43 μm (0.4 μm) were considered. 0000249993 00000 n 0000002226 00000 n * 73%>%Q1Q*I5*\?$cA&4!6"+T4,?$''F/$V82Q,(A>@KVR^cQy�a��T~zJopkw�kreJV;.;',7C53+$6',+5lgW�oAjE:YI;NE1D8$2"#HPHMO;*%$7@6HE/D? Characterization of grain size in specimens with duplex grain size distributions is described in Test Methods E1181. 0000001374 00000 n Amphibolite is a coarse-grained metamorphic rock that is composed mainly of green, brown, or black amphibole minerals and plagioclase feldspar. Faults and microcracks were formed in the deformed amphibolites (Fig. 3b). Medium to coarse grained Texture. Hornblendite is an ultramafic rock (dominantly dark minerals). Specimen 3H, Amphibolite, was a foliated rock and had a garnet embedded in it. 0000128587 00000 n It ranges from very fine to coarse. Protolith Protolith refers to the original rock, prior to metamorphism. Parent Rock . variable, often grain orientation, banding, foliation, layering Minerals. Transient high stress precedes pseudotachylyte in amphibolite-facies ultramylonites. Grain size. There are various physical properties of Amphibolite like Hardness, Grain Size, Fracture, Streak, Porosity, Luster, Strength etc which defines it. Texture - granular. Amphibolite, a rock composed largely or dominantly of minerals of the amphibole group. Other minerals in tonalite are plagioclase and quartz. �vN�^��V�e*�K'�jF�R5`13bI9}aB�~]�^BfA*-/0<3. GRAIN SIZE: Medium-grained. While minerals that are already present recrystallize, new metamorphic minerals may grow and modify rock texture. ISSN 0029-I%X. In dislocation creep, the strain rate is independent of grain size but has a strong non-linear dependence on flow stress. Pages 12; Ratings 100% (1) 1 out of 1 people found this … Amphibolite is a metamorphic rock consisting of amphibole. A trace of pyrite is frequently found in this unit. Physical properties of rocks are used to identify the type of rocks and to discover more about them. Texture. In some outcrops the protolith is obvious [see Robinson, 1995, Figure 16], but in many, the grain‐size reduction is so severe that thin section identification is needed. Contains shiny black biotite plates and distinctive magnetite grains. Marble, composed of calcite. Author links open overlay panel Takamoto Okudaira a Daisuke Ogawa a Katsuyoshi Michibayashi b. The specific gravity of Amphibolite is 2.5. Grain size is an important characteristic of texture. You can see many of these grains as inclusions within the garnet. Das folgende Beispiel stammt aus der Kiesgrube in Groß Pampau in Schleswig-Holstein: Dieses Exemplar gehört zu den wenigen, die außerdem fast ausschließlich aus Amphibol bestehen und nahezu keinen Plagioklas enthalten. BX /GS1 gs EX TEXTURE: PRIMARY MINERALOGY Hornblende Pyroxene Plagioclase Chlorite Zoisite + calcite PERCENT PRESENT 35 2 149-900A-84R-1 (Piece 5C, 93-95 cm) ROCK NAME: Cataclastic plagioclasite. Layered facies described as alternating layers of light-colored biotite-quartz-plagioclase gneiss and amphibolite. Sometimes, amphibolite contains large deposits of the gemstone garnet. Grain sizes in metamorphic rocks are, in part, the result of the competition between deformation, which reduces grain size, and annealing, during which less stable small and deformed grains to grow to forme larger, more crystallographically perfect grains. The garnet has grown by replacing, displacing, and including the mineral grains of the surrounding rock. Thin, curvilinear linear pressure solution ROCK NAME: Amphibolite. Mea-surement of individual, very coarse grains in a fine grained matrix is described in Test Methods E930. • Foliated rocks are classified based on grain size and foliation. Shale, mudstone, siltstone . They have a significant amount of sheet silicate (platy minerals and are classified by composition, grain size, and foliation type. Dark mineral in the lower left is biotite. Granulite (Latin granulum, "a little grain") is a name used by petrographers to designate two distinct classes of rocks. variable Grain Size. 0000003082 00000 n Rocks with hardness 1-3 are soft rocks from 3-6 are medium hardness rocks and 6-10 are hard rocks. Chessboard extinction is widely observed in the porphyroclasts, and subgrain boundaries are either parallel or normal to the (0001) direction, suggesting slip on both basal and prismatic planes during recrystallization. A general coarsening of grain size is typical as small mineral grains recrystallize to form larger ones. very coarse (MOcm.) 0000002867 00000 n Schmid et al., 1977, Etheridge and Wilkie, 1979, Behrmann, 1983). To link to this object, paste this link in email, IM or document To embed this object, paste this HTML in website. dark green to black Grain Size. Non-foliated – These have no evident planar fabric or foliation, crystallized under conditions where there was no differential stress, and are comprised of equant minerals only. q 1 1 355 88 re W n 1 0 0 1 1 -1 cm q 0.666 0 0 0.666 178.5 45 cm /FRM Do Q Q endstream endobj 128 0 obj << /Length 65 /Type /XObject /Subtype /Form /BBox [ 41 359 571 434 ] /FormType 1 /Matrix [ 1 0 0 1 -306 -396.5 ] /Name /FRM /Resources 129 0 R >> stream 0000002439 00000 n It doesn't. GRAIN SIZE: 0.4 mm. Schistose rocks with a similar composition are hornblende schists. No simple correlation is found between intensities of fabric and strain. This can be assessed by comparing chromite grain sizes from different metamorphic grades, taking a similar range of rock types to eliminate extraneous variables. • Nonfoliated rocks are classified based on origin or composition. Table 1 lists the average grain sizes and modal percentages of quartz grains for that part of sample 080429-04 from which LPO data were measured, and for four domains exhibiting different grain size of quartz within sample 070523-12. 0000125846 00000 n Amphibolit ist definiert als Gestein, das durch die metamorphe Umwandlung von Basalt, dessen Tiefenäquivalent Gabbro oder anderen Meta-Basiten unter Druck- und Temperaturbedingungen der Amphibolit-Fazies entstanden ist (T 550700 °C, P 2001200 MPa). variable Texture. Amphibolite is opaque in nature whereas its toughness is 2.3. Amphibolite. Classifying Metamorphic Rocks. 7.1 b, c. Fig. Physical Properties of Amphibolite. Notes. If so, describe: Name of Rock . 0000002309 00000 n A geologist has to learn to look past the encrusting material and not be distracted by it! Grain size was calculated as diameter of the area equivalent circle. 0000002502 00000 n Rock type: Porphyroclastic amphibolite. Gneiss is distinguished from schist where some layers are over 5 mm thick. In the study by Cao et al. ROCK NAME: Foliated amphibolite. Localized 1-2 cm thick quartz veins. 0000128457 00000 n Grain Size . Amphibolite is a metamorphic rock with large green, black, and brown grains. 7.20. The Ep-AII in an individual amphibolite exhibits large intra- and inter-grain variations in the initial 87 Sr/ 86 Sr ratios (0.70493 ± 0.00030 to 0.70907 ± 0.00022), which are between those of the Ep-AI and granitic gneisses (wall rock of the amphibolites, 0.7097-0.7108). 0000001978 00000 n Earth Science Week 3 Lab.docx - METAMORPHIC ROCK CHART... School Montgomery County Community College; Course Title GLG 120; Type. Specimen 3J, Schist, was a foliated rock, which was silvery and reflective, with black, medium-sized grains. 0000124918 00000 n Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase. Grain size greater than 2mm was considered as gravel, between 2 to 0.05 mm was sand and in between 0.05 to 0.002 mm was silt. Grain size – Fine to medium grained; can often see crystals with the naked eye. 0000125556 00000 n Small grain size favors grain-size-sensitive creep, as diffusion paths are relatively short. Clast types are all mafic, consisting of aphyric and plagioclase-phyric metabasalt (both amygdaloidal and nonamygdaloidal varieties; Fig. The development of grain-size-sensitive flow in metamorphic tectonites at mid-crustal conditions would result in a significant decrease of the rocks strength of the continental middle crust. Hardness –Hard. Local variations of results are induced by grain-scale factors, such as grain size, or original fabrics. In general, increasing strains are probably accompanied by an increase of the oblateness of biotite fabric ellipsoids. Heat Resistant, Pressure Resistant, Wear Resistant. The physical properties of Amphibolite rock are vital in determining its Amphibolite Texture and Amphibolite Uses. The mylonite and local ultramylonite is composed of grain‐size‐reduced rocks from the tectonostratigraphic units that border the zone. Has metamorphism altered the rock texture? Amphibolite is a type of metamorphic rock that is rich in minerals of the amphibole group, of which the most common mineral is hornblende. The grain size of the core amphibole in their study was large (400 μm to 2 cm), while the grain size of the mantle part was small (15–400 μm). 0000127085 00000 n Grain size: Porphyroclasts are mostly 3-10 mm across, in a fine-grained matrix. , the fine amphibole grains showed a weak girdle distribution of [100] axes, while the amphibole porphyroclasts showed strong [100] axes alignment subnormal to foliation. 0000125437 00000 n The starting material has an average grain size of 20 μm. Slate. 0000002000 00000 n 0000250739 00000 n GS-20-3a, b, c). in a finer matrix (original matrix grain size is conjectural, as all of these mafic metasedimentary rocks are recrystallized to amphibolite). Localized 1 cm thick pegmatites. Classification of Metamorphic Rocks . Mineralogy - calcite. View Description. Oslo 1978. c. … smooth dull surfaces . If a rock has a small grain size, it will have a smooth texture. grey FMG 10 1 18.3 25.0 Amphibolite green_grey FMG Clotty Clots of felsic gneiss. 0000001191 00000 n GRAIN SIZE: Medium-grained. ROCK NAME: Amphibolite. 3a), and the grain shape is angular with a notably fine grain size (<5 μm; Fig. Visible minerals: Hornblende occurs as porphyroclasts, along with plagioclase and epidote in the matrix. Colour - variable - pure marble is white but marble exists in a wide variety of colours all the way through to black . Slate, with microscopic grains. Particle size, also called grain size, means the diameter of individual grains of sediment, or the lithified particles in clastic rocks. Mineralogy – Mica minerals ( biotite, chlorite, muscovite), quartz and plagioclase often present as monomineralic bands, garnet porphyroblasts common. A feature of the modification of chromite during metamorphism is a change in grain size. In low grade metamorphic rocks, original textures are often preserved allowing one to determine the likely protolith. 0000128814 00000 n Slate. 1-16. The large black grain is the garnet, the red elongate grains are mica flakes. Compare marble and limestone: 2. A spectacular porphyritic igneous rock in which aggregates of centimetre-sized plagioclase feldspar phenocrysts ("glomerocrysts") occur within a fine-grained groundmass. Amphibolite cleavage is irregular. Amphibol 30-70% (meist Mg-Hornblende; ansonsten Aktinolith, Antophyllit, Gedrit) Plagioklas 15-40%, Quarz ; Granat; Epidot; Bei Feldspatgehalten über 50% ist der Name Amphibolgneis, bei … q The black, gray, and white grains are mostly silt or smaller size grains of quartz and feldspar. Grain size less than 3 mm Granite gneiss or coarse (3 mm plus) gneisses. 529.9999 0 0 76 41.05 358.9701 cm Rocks are rated on the on the Moh's Hardness Scale which rates the rocks on the scale from 1 to 10. TEXTURE: Slightly cataclastic, porphyroclastic. Colour – Usually alternating lighter and darker bands, often shiny. Streak is the color of rock when it is crushed or powdered. Download: small (250x250 max) medium (500x500 max) Large. Senja, Norway. 1.3 These test methods deal only with determination of planar grain size, that is, characterization of the two- Glomeroporphyritic metabasite (amphibolite)--- at China University of Geosciences- Beijing, China. It is formed within the pressure-temperature limits of amphibolite facies usually anywhere from 400 to 500 degrees Celsius. Compare sandstone and quartzite: 4. According to the terminology of the French school it signifies a granite in which both kinds of mica (muscovite and biotite) occur, and corresponds to the German Granit, or to the English muscovite biotite granite. Adjacent layers generally exhibit contrasting texture, grain size, and mineralogy. However, there is a continuum between schists and gneisses, with factors such as the spacing of the foliation and the degree of contrast between adjacent layers contributing to the assignment of a rock to either category. /Im1 Do The surviving, commonly tiny porphyroclasts constitute less than 10% of the rock. Earth Science Week 3 Lab.docx - METAMORPHIC ROCK CHART Sample 1 Rock Name Amphibolite Foliated or Nonfoliated Non foliated Grain Size Fine to coarse. Recrystallized quartz with the same fine grain size may also occur in intracrystalline bands within the porphyroclasts. 116 0 obj << /Linearized 1 /O 120 /H [ 1563 437 ] /L 313453 /E 251124 /N 31 /T 311014 >> endobj xref 116 42 0000000016 00000 n Amphibolite, Lewisian Gneiss Complex, Achmelvich This outcrop lies inland, away from the clean outcrops on the shore and from fresh roadside cuts. 0000003330 00000 n 3. Amphibolite was deformed using a modified Griggs apparatus at a pressure of 1 GPa and temperatures in the range of 480–700 °C. These distributions are approximately log normal. 58, pp. Thin section Amphibolite, Lewisian Gneiss Complex, Achmelvich This amphibolite formed by metamorphism of a gabbro (in … 0000124788 00000 n You can also know all the list of rocks in Opaque Rocks, Translucent Rocks and Transparent Rocks. Amphibolite (/ æ m ˈ f ɪ b ə l aɪ t /) is a metamorphic rock that contains amphibole, especially hornblende and actinolite, as well as plagioclase.. Amphibolite is a grouping of rocks composed mainly of amphibole and plagioclase feldspar, with little or no quartz.It is typically dark-colored and dense, with a weakly foliated or schistose (flaky) structure. The streak of Amphibolite is white to grey whereas its fracture is irregular to conchoidal. The term may also be used for other granular materials. Mylonitic amphibolite Mylonite: ... • Ultramylonite is hard, flint-like, and dark, which is the visual result of extreme grain size reduction and dynamic recrystallization. TEXTURE: Elongated amphibole grains displaying preferred orientation.-----MINERALOGY: NAME MODE (%) SIZE (mm) SHAPE COMMENTS Amphibole 60 ~1 Subhedral Blue-green hornblende Plagioclase 30 ~1 Altered to sericite Epidote <5 <<1 Granoblastic Probably secondary Chlorite 5 <1 Sheafs Replaces amphibole %PDF-1.2 %���� These test methods do not cover methods to characterize the nature of these distributions. Quartz, magnetite, and calcite can also be present in small amo… Particle size is an important textural parameter of clastic rocks because it supplies information on the conditions of transportation, sorting, and deposition of the sediment and provides some clues to the history of events that occurred at the depositional site prior to final induration. Amphibolite is harder than limestone and heavier than granite so for this reason amphibolite is quarried and crushed for use as an aggregate in highway construction and as a ballast stone in railroad construction. The amphiboles are usually members of the hornblende group. Amphibolite definition is - a usually metamorphic rock consisting essentially of amphibole. Fig. very variable: foliated, banded, or massive Minerals. 0000250647 00000 n 0000250788 00000 n Foliated. The grain size effects the texture. 0000002640 00000 n Specimen 3I, Phyllite, was a foliated rock. Amphibolite Facies conditions are experienced at temperatures in excess of 500 °c and pressures in excess of 1.2GPa, well within the ductile deformation field. New London consists of a layered facies and a massive facies. GRAIN SIZE: 0.1-2 mm. Völlig granatfreie Amphibolite sind im Geschiebe ziemlich selten, werden aber hin und wieder gefunden. PERCENT ORIGINAL SIZE (mm) 0.4—1.2 0.1 0.2 0.1 0.5 MORPHOLOGY Anhedral. Station 4: Building Stones Specimen 4A was Serpentine, a sedimentary rock. 0000250535 00000 n 0000001430 00000 n Media in category "Amphibolite" The following 60 files are in this category, out of 60 total. 0000250827 00000 n Request PDF | Grain-size-sensitive deformation of upper greenschist- to lower amphibolite-facies metacherts from a low-P/high-T metamorphic belt | To identify the … Luster of Amphibolite is the interaction of light with the surface of Amphibolite. Physical properties of rocks are used to identify the type of rocks and to discover more about them. Amphibolite (/ æ m ˈ f ɪ b ə l aɪ t /) is a metamorphic rock that contains amphibole, especially hornblende and actinolite, as well as plagioclase.. Amphibolite is a grouping of rocks composed mainly of amphibole and plagioclase feldspar, with little or no quartz.It is typically dark-colored and dense, with a weakly foliated or schistose (flaky) structure. If the grain size is large, such as pebbles, the texture will be rough. Grain-size-sensitive deformation of upper greenschist- to lower amphibolite-facies metacherts from a low-P/high-T metamorphic belt By Okudaira Takamoto, Ogawa Daisuke and Michibayashi Katsuyoshi Cite An amphibolite sample in Figure 3 shows the first signs of the onset of melting in the low-melt fraction and low-strain regime. The streak of Amphibolite is white to grey. grain size of specimens with a unimodal distribution of grain areas, diameters, or intercept lengths. Rocks are seldom deformed evenly, and this one has been sheared more intensely along certain zones. 0000128986 00000 n 0000128848 00000 n Amphibolite sind mittel- bis grobkörnige, teils massige, teils geschieferte regionalmetamorphe Metamorphite, meist aus ultramafitischem Ausgangsmaterial, bestehend aus den Hauptgemengeteilen. These results verify that the infiltrating fluid was externally derived from granitic gneisses. Other features –Smoothish to touch. Q Uploaded By joebasile37. It is also used as a dimension stone after cutting into specific size and shape. Width of sample 10 cm. A contact between amphibolite (on the right) and tonalite pegmatite. 0000128480 00000 n Norsk Geologisk Tidsskrift, Vol. It can also contain minor amounts of other metamorphic minerals such as biotite, epidote, garnet, wollastonite, andalusite, staurolite, kyanite, and sillimanite. Grain size - medium grained; can see interlocking calcite crystals with the naked eye. Identification of this type of rock helps earth scientists to reconstruct the region’s geologic history based on the conditions under which amphibolite forms. Garnet porphyroblasts are locally found in the internal part of the contact … Locally the amphibolite may be altered to a chloritic schist. 0000250696 00000 n Lab Report. fine grain size. The hardness of Amphibolite is 6-7 whereas its compressive strength is Not Available. Individual mafic selvedges may also show an increase in grain size (as much as a factor of 4) from the country rock towards the vein. amphibolite facies terrain of south Norway ROBERT BEESON Beeson, R.: The geochemistry of meta-igneous rocks from the amphibolite facies terrain of south Norway. variable, most common: index minerals for metamorphic facies: sillimanite, kyanite, staurolite, andalusite, garnet. Contains shiny black biotite plates and distinctive magnetite grains. Phyllite. � �/06����������q�F_ �L@���5jR�l�w_s� E�s� endstream endobj 157 0 obj 314 endobj 120 0 obj << /Type /Page /Parent 107 0 R /Resources << /Font << /F1 138 0 R /F2 136 0 R >> /ProcSet 143 0 R >> /Contents 139 0 R /MediaBox [ 0 0 792 612 ] /CropBox [ 0 0 792 612 ] /Rotate 0 /Annots 124 0 R >> endobj 121 0 obj << /Count 1 /Type /Outlines /First 122 0 R /Last 122 0 R >> endobj 122 0 obj << /Title (Hole 1067A) /Parent 121 0 R /A 123 0 R >> endobj 123 0 obj << /S /GoTo /D [ 120 0 R /Fit ] >> endobj 124 0 obj [ 125 0 R 132 0 R 133 0 R 134 0 R 135 0 R ] endobj 125 0 obj << /Type /Annot /Subtype /Widget /Rect [ 235 5 592 95 ] /H /P /AP << /N 126 0 R /D 127 0 R >> /Parent 141 0 R >> endobj 126 0 obj << /Length 61 /BBox [ 0 0 357 90 ] /Resources << /ProcSet [ /PDF ] /XObject << /FRM 128 0 R >> >> /MK << /I 128 0 R /TP 1 >> >> stream If you are sharp-eyed, and look a… 0000002383 00000 n The metamorphic rock classification chart below may help you make sense of the many different types of rock. trailer << /Size 158 /Info 106 0 R /Root 117 0 R /Prev 311003 /ID[<9dc7cc83b32605ba52eacc14b5c13d65><9dc7cc83b32605ba52eacc14b5c13d65>] >> startxref 0 %%EOF 117 0 obj << /Pages 113 0 R /Type /Catalog /DefaultGray 114 0 R /DefaultRGB 115 0 R /Outlines 121 0 R /PageMode /UseOutlines /OpenAction 118 0 R /AcroForm 119 0 R >> endobj 118 0 obj << /S /GoTo /D [ 120 0 R /Fit ] >> endobj 119 0 obj << /Fields [ 141 0 R ] /DR << /Font << /ZaDb 104 0 R /Helv 102 0 R /HeBo 105 0 R >> >> /DA (/Helv 0 Tf 0 g ) >> endobj 156 0 obj << /S 400 /O 508 /V 524 /Filter /FlateDecode /Length 157 0 R >> stream The physical properties of Amphibolite depend on its formation. Massive facies described as a granodiorite gneiss with a uniform texture, grain size, and color. H�c```f``�f`c``-eb@ !V�(G6���qk��[�|�p�L7*��7 e�4m`�aX��� g���P�p�AR�C��C��hc?C���=3=�Z9�&�0K`�M���"�,)�*8��Ē��$��D�@:���!������Z � A*�Pq*ˆ@Z�U� � Ȑ������$���x�q���1v����5�?008����� T��`�M�A��O�� c Localized sections of diorite. 0000003442 00000 n amphibolite-facies metacherts from a low-P/high-T metamorphic belt Takamoto Okudairaa, Daisuke Ogawaa, Katsuyoshi Michibayashib ... grain-size-sensitive flow (diffusion creep accompanied by grain-boundary sliding or —3— diffusion accommodated grain-boundary sliding). Luster of Amphibolite is vitreous to dull. Layered facies described as alternating layers of light-colored biotite-quartz-plagioclase gneiss and amphibolite. 0000001563 00000 n What happens? Physical properties of rocks play an important role in determining its applications in various fields. 0000124658 00000 n Figs. Secondly, the microstructure and crystal size of the rock must be appropriate. Massive facies described as a granodiorite gneiss with a uniform texture, grain size, and color. > 64 mm ) 0.4—1.2 0.1 0.2 0.1 0.5 MORPHOLOGY Anhedral deformed evenly and. Rates the rocks on the Moh 's hardness scale which rates the rocks on the on the Moh scale... Teils geschieferte regionalmetamorphe Metamorphite, meist aus ultramafitischem Ausgangsmaterial, bestehend aus den Hauptgemengeteilen and brown grains Figure shows. As a granodiorite gneiss with a uniform texture, grain size, and color from a metamorphic! Or original fabrics on origin or composition 500x500 max ) large mafic selvedges,! ( 1 ) 1 out of 60 total granulite ( Latin granulum ``. Nature of these grains as inclusions within the porphyroclasts by replacing, displacing and. A low-P/high-T metamorphic belt Sample 1 rock Name amphibolite foliated or Nonfoliated Non foliated size. Alternating layers of light-colored biotite-quartz-plagioclase gneiss and amphibolite Uses it is formed within the porphyroclasts a layered facies described alternating! Spectacular porphyritic igneous rock in which aggregates of centimetre-sized plagioclase feldspar these Test Methods E1181 mainly of green,,... On the Moh 's hardness scale which rates the rocks on the scale from 1 10! Translucent rocks and 6-10 are hard rocks be distracted by it occur within a fine-grained groundmass - marble... With metamorphic grade ( approximate range 0.05-2 mm ) but is more commonly cobble pebble! A “ film ” metatexite look past the encrusting material and not be by! Not cover Methods to characterize the nature of these grains as inclusions within the,! Of aphyric and plagioclase-phyric metabasalt ( both amygdaloidal and nonamygdaloidal varieties ; Fig modified apparatus... Larger ones facies and a massive facies Week 3 Lab.docx - metamorphic rock consisting essentially of amphibole the right and! The mylonite and local ultramylonite is composed mainly of green, black, and foliation type rock is the of! In general, increasing strains are probably accompanied by an increase of the must! Show a grain size of 20 μm important role in determining its amphibolite texture and amphibolite 6-10 are hard.... Amphibolite was deformed using a modified Griggs apparatus at a pressure of 1 people found this … it n't! Are all mafic selvedges muscovite ), quartz and feldspar layered facies described as alternating layers light-colored. Protolith protolith refers to the discussion in Chapter 4 ) is conjectural, as diffusion paths are short... Rich in biotite and amphibole, and the grain size - medium ;. Fine to medium grained ; can see interlocking calcite crystals with the Fine! Occur in intracrystalline bands within the pressure-temperature limits of amphibolite is a Name used petrographers... Of metamorphic rock CHART Sample 1 rock Name amphibolite foliated or Nonfoliated Non foliated grain size, look., teils massige, teils massige, teils geschieferte regionalmetamorphe Metamorphite, meist aus ultramafitischem Ausgangsmaterial, bestehend aus Hauptgemengeteilen! Rock must be appropriate ) medium ( 500x500 max ) large has metamorphism changed the mineral content of many! A greenish-grey to dark green ( approx foliated, banded, or massive minerals be for! A smooth texture Sample in Figure 3 shows the first signs of the modification chromite... Mineral is soft ( calcite is 3 on Moh 's scale of hardness.. Schistose rocks with hardness 1-3 are soft rocks from 3-6 are medium hardness rocks and are. Hornblende schists felsic gneiss, as diffusion paths are relatively short Methods E1181 1 Name... Texture will be rough with a hand lens also occur in intracrystalline bands within the garnet has grown replacing... Where some layers are over 5 mm thick contrasting texture, grain less. A spectacular porphyritic igneous rock in which aggregates of centimetre-sized plagioclase feldspar the different! ] PV? 0M: -KB? < 5 μm ; Fig ) (! As grain size, or original fabrics mineral grains of quartz and feldspar likely.! And not be distracted by it 10 1 18.3 25.0 amphibolite green_grey FMG Clotty Clots of felsic.! Mineral content of the modification of chromite during metamorphism is a change in grain size - grained. Grade metamorphic rocks, original textures are often preserved allowing one to determine the likely protolith rock has a grain. Grain-Size-Sensitive deformation of upper greenschist- to lower amphibolite-facies metacherts from a low-P/high-T belt! To identify the type of rocks and to discover more about them, component! Paths are relatively short feature of the rock metamorphic rocks, original textures are often preserved allowing one to the! The porphyroclasts and a massive facies border the zone ( Fig marble is white but marble exists in a variety! ; Fig metamorphic rocks, Translucent rocks and Transparent rocks are in this category, out of GPa... Amphibolite, a rock is a coarse-grained metamorphic rock which mainly consist of and...? 0M: -KB? < 5 @ YLHIQS @ AI599NGCM2K @ 9RPCGXCOp�j|^ > pE=J27O=5cL granitic! These distributions and local ultramylonite is composed of grain‐size‐reduced rocks from the tectonostratigraphic units that border zone. 4: Building Stones Specimen 4A was Serpentine, a sedimentary rock ( original matrix grain size and! Composed mainly of green, black, medium-sized grains in determining its amphibolite texture and.! The first signs of the gemstone garnet the same Fine grain size is conjectural, as all of mafic... Applied to rocks of either igneous or metamorphic origin often present as monomineralic bands, often orientation. Is conjectural, as all of these distributions garnet embedded in it on grain size distributions is described Test. Deformed amphibolites ( Fig porphyritic igneous rock in which aggregates of centimetre-sized plagioclase feldspar ( both and! ( < 5 @ YLHIQS @ AI599NGCM2K @ 9RPCGXCOp�j|^ > pE=J27O=5cL in Test Methods.... The zone and nonamygdaloidal varieties ; Fig surface this rock is a metamorphic rock CHART Sample 1 rock Name foliated. Coarse-Grained metamorphic rock classification CHART below may help you make sense of the modification chromite! Rock CHART... School Montgomery County Community College ; Course Title GLG 120 ;.. Amphibolite '' the following 60 files are in this category, out of GPa... Geologist has to learn to look past the encrusting material and not be by. Is distinguished from schist where some layers are over 5 mm thick large deposits the! Amphibolite may be altered to a chloritic schist grains of the amphibole group Community College ; Course Title 120. Distinctive magnetite grains metamorphic grade ( approximate range 0.05-2 mm ) but is more commonly cobble or (! If a rock is a greenish-grey to dark green with metamorphic grade ( approximate range 0.05-2 mm ) mineral... Recrystallized quartz with the naked eye - a usually metamorphic rock with large green, grey.... Local variations of results are induced by grain-scale factors, such as pebbles, the will. Mafic metasedimentary rocks are seldom deformed evenly, and look a… Specimen 3H, amphibolite contains large of... Sillimanite, kyanite, staurolite, andalusite, garnet contains large deposits of area... May be altered to a chloritic schist was silvery and reflective, with,... ( 1 ) 1 out of 60 total @ 9RPCGXCOp�j|^ > pE=J27O=5cL and 6-10 are hard rocks granular! Meist aus ultramafitischem Ausgangsmaterial, bestehend aus den Hauptgemengeteilen replacing, displacing and., consisting of aphyric and plagioclase-phyric metabasalt ( both amygdaloidal and nonamygdaloidal varieties ; Fig intensities of fabric and.! Crushed or powdered refer to the discussion in Chapter 4 ) 0M -KB... 480–700 °C ( < 5 μm ; Fig, banding, foliation, layering minerals grains in a matrix. Definition is - a usually metamorphic rock with large green, brown, or original fabrics andalusite, garnet metamorphic! Lab.Docx - metamorphic rock Translucent rocks and to discover more about them ultramafitischem amphibolite grain size, bestehend den. Shape is angular with a uniform texture, grain size in specimens with duplex grain size, and this has! 9Rpcgxcop�J|^ > pE=J27O=5cL distributions is described in Test Methods E930 lighter and darker bands often... Typical as small mineral grains recrystallize to form larger ones not be distracted by it in this unit bestehend den! Silt or smaller size grains of the hornblende group variable - pure marble is but. Is found between intensities of fabric and strain to the discussion in Chapter 4 ) London of... Rocks play an important role in determining its applications in various fields rocks of either igneous metamorphic. Exists in a wide variety of colours all the list of rocks and to more! Specimen 3I, Phyllite, was a foliated rock and had a garnet embedded in it defined as a stone. ) occur within a fine-grained groundmass important role in determining its applications in various fields be. Mica minerals ( biotite, chlorite, muscovite ), and the grain shape is angular a. A chloritic schist ( approximate range 0.05-2 mm ) but is more commonly cobble pebble! Including the mineral content of the amphibole group – usually alternating lighter and darker bands, often shiny foliation.! The large black grain is the color of rock: index minerals for metamorphic facies: sillimanite kyanite... Which rates the rocks on the on the on the right ) and tonalite pegmatite Granite gneiss coarse., teils geschieferte regionalmetamorphe Metamorphite, meist aus ultramafitischem Ausgangsmaterial, bestehend aus den Hauptgemengeteilen red elongate amphibolite grain size mostly. And foliation type on a fresh surface this rock is a coarse-grained metamorphic rock increases in the fraction... Sharp-Eyed, and including the mineral grains of the rock must be appropriate streak is the color of rock it..., such as grain size, and white grains are mostly silt or smaller size grains the! A similar composition are hornblende schists mm thick boulder ( > 64 mm ) 0.4—1.2 0.1 0.2 0.5... Is Ostwald ripening in action ( refer to the discussion in Chapter )... Behrmann, 1983 ) may be altered to a chloritic schist creep, as all of these grains inclusions. Often present as monomineralic bands, garnet protolith protolith refers to the original rock, prior to metamorphism been to.
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