High-grade Terrains Research Articles

Petrology and geochemistry of the Neoproterozoic Guaxupégranulite facies terrain, southeastern Brazil

Geochemical and oxygen isotopic data on the Neoproterozoic granulite facies rocks (enderbites, charnockite and charnokitic augen gneisses) of Guaxupé, Brazil are assembled. Geochemical discrimination function calculations show an igneous origin for majority of the rock types in the area. Major and trace element data, especially REE, are similar to tonalite and granodiorite. Oxygen isotope composition for charnockitic gneisses and mafic granulites yield δ 18O values in the range of +8.8 to +11‰ and fall in the range of quartzofeldspathic rocks of medium- to high-grade terrains elsewhere. A small-scale variation of δ 18O values, compatible with the chemical data, imply the preservation of pre-metamorphic oxygen isotope compositions. Minimum peak pressure-temperature conditions are 8.5 kbar and 850°C. The high-grade metamorphism did not appear to have altered significantly the geochemical and oxygen isotope compositions of the protoliths. Approximately 2.5 kbar of pressure decrease accompanied by 200°C cooling has been recorded for a portion of the cooling path. The P–T path is consistent with a single event, namely the formation and uplift of the Guaxupénappe in the Neoproterozoic Brasiliano cycle.

Stable Isotopic Evidence for the Involvement of Mantle-Derived Fluids in Wynad Gold Mineralization, South India

Major gold deposits of the world are often associated with carbonate alteration halos and -rich fluid inclusions. The source and transfer mechanisms of the fluids that concentrate gold within quartz vein systems are topics of debate. Here we investigate the C, O, and S stable isotopic composition of -rich fluid inclusions, and quartz, calcite, and sulphide minerals associated with the gold-quartz veins from the Wynad Gold Field, emplaced within the Proterozoic Moyar-Bhavani transcrustal shear system in the granulite facies terrain of southern India. Optical and microthermometric studies of fluid inclusions in auriferous quartz veins reveal that the dominant fluid is , with high (0.7-1.0) and low salinity (ca. 4-5 wt % NaCl equiv.). The carbon isotopie composition of extracted from fluid inclusions by crushing shows a remarkably narrow range of values, -4.1 to . Oxygen isotopie composition of the quartz veins range from +9.2 to . The (-9.1 to ) and (+ 7.6 to ) values of calcite from carbonate veins also define a distinctly uniform range. Sulphur isotopie values in pyrite, chalcopyrite, and pyrrhotite associated with gold display a range of +1.4 to . The carbon isotopie composition of fluid inclusions and carbonates from Wynad are identical to those reported for low-temperature carbonate alterations in high-grade terrains induced by mantle-derived . The narrow spread in isotopie values associated with veins traversing compositionally variable host rocks is consistent with a model involving derivation of by degassing of underplated mantle-derived magmas and transfer of juvenile to higher crustal levels through felsic magmatic conduits. We envisage a common link between Proterozoic influx and incipient charnockite formation, carbonate alteration, and gold mineralization in this terrain.

The negative Eu anomaly in Archean sedimentary rocks: Implications for decomposition, age and importance of their granitic sources

A negative correlation between Eu anomaly (Eu/Eu * and chemical index of weathering (CIW) is found for Archean pelites in both greenstone belts and high-grade terrains from southern Africa, western Greenland, North America, Western Australia and China. A similar negative correlation betweenEu/Eu * and chemical index of alteration (CIA) is also found for worldwide young deep-sea sediments from various tectonic settings. The increase in the indices of weathering and alteration coincide with both shifts in mineral composition and mineral decomposition from plagioclase/K-feldspar to mica/kaolinite and from amphibole to chlorite/smectite. Juvenile crustal materials from local sources are only slightly decomposed due to little or no transport. They are characterized by low CIW/CIA and negligible Eu anomalies. In contrast, crustal materials from large provenance areas have usually suffered long transport and recycling, which results in decomposition of high-temperature minerals and large CIW/CIA values that are negatively correlated with significant negative Eu anomalies. Thus, the observed trends are interpreted as mainly reflecting increasing contributions of recycled and decomposed materials from large provenances relative to juvenile crustal additions through arc magmatism at local sources. In this context, there is no obvious distinction between Archean greenstone and high-grade metasediments and young deep-sea sediments. The large provenance areas have contained a significant proportion of granitic and rhyolitic materials, which, in part, have not resisted decomposition and erosion due to their occurrence in shallow crustal layers. Granites received their distinctive negative Eu anomaly from equilibration with a feldspar-rich residuum. The negative Eu anomaly of Archean metaclastic sediments apparently increased with decreasing age. Trends of minimum and averageEu/Eu * values of metaclastic sediments evolving with time are calculated for the Archean and lead us to infer that the negative Eu anormaly (Eu/Eu *< 0.9) of the upper continental crust might have appeared before 3.8 Ga. Thus, the first granite responsible for intracrustal fractionation originated very early. The negative Eu anomaly had been a common feature at least for a time span of ca. 3.2 Ga. At 2.5 Ga, the upper continental crust and clastic sediments had almost acquired their present Eu signature (solEu/Eu *∼ 0.65). The Archean-Proterozoic transition is not a boundary in the evolution of the composition of the continental crust.

Tectonic evolution of greenstone belts

Abstract Granite-greenstone terrains represent the main process by which continental crust was formed in the Archaean; the same process has continued since, at a diminishing rate. Granite plutonism added a layer about ten kilometres thick under the greenstones. From Early Archaean to Late Proterozoic, there was a progressive change in the volcanics; komatiites decreased from the Early Archaean, while the proportion of andesites and felsic volcanics increased. Continent-derived sediments, rare or absent from the Early Archaean, increased through time. Tectonic deformation in the greenstone belts is separable into pre-diapiric, diapiric and post-diapiric. The first deformations were translational, mainly flat thrusts, the second compressional without crustal shortening, the third involved crustal shortening. Only the diapiric structures are an essential element of greenstone belt evolution but the others are generally important. The pre-diapiric and diapiric structures are related to subduction; the post-diapiric structures may be accretionary or collisional. Granite-greenstone terrains show only minor crustal thickening. Some adjacent high-grade terrains were intensely deformed, and the crust greatly thickened, by continent-continent collision.

The origin of the foliations and tectonic style in the charnockitic gneisses, Eastern Hebei, China

Geological and microstructural studies have identified six types of foliations in the charnockitic gneisses in the Archaean high grade terrain, eastern Hebei province, China. The foliations are believed to result from décollement or ductile shearing under granulite facies metamorphism in the lower crust and subsequent folding. The charnockitic gneisses and supracrustal enclaves can be regarded as tectonic units formed in the lower level of the crust, which are marked by “décollement layers” or “tectonic cakes”. The tectonic style represents a pattern of regional fold interference over the “décollement layers”. A qualitative pattern has been established as follows: (1) detachment deformation of the charnockite and enclaves under granulite facies in the lower levels of the crust, yielding “décollement layers” or “tectonic cakes”; (2) tight folding of the “décollement layers” with a nearly vertical axial plane striking north-south; and (3) superposition of the later open folds with east-west striking axial planes, forming domes or oval structures in the region.

Geochemistry and single zircon geochronology of Archaean TTG gneisses in the Taihua high-grade terrain, Lushan area, central China

Gneisses of tonalite-trondhjemite-granodiorite (TTG) composition, typical rocks found in Archaean terrains all over the world, also occur in the Taihua high-grade terrain of the Lushan area, central China. These rocks underwent high-amphibolite to granulite facies metamorphism and intense deformation. Their petrology, geochemistry and single zircon geochronology suggests that they are derived from granitoid plutons which were emplaced 2806 ± 7 Ma, and 2841 ± 6 Ma, respectively. Geochemically, the gneisses show the calc-alkaline trend and have strongly fractionated rare earth element (REE) patterns. We suggest that the original granitoids formed through partial melting of garnet-granulite which is now represented by inclusions within the gneisses.

Mg-Al yttrian zirconolite in a partially melted sapphirine granulite, Vestfold Hills, East Antarctica

AbstractA new compositional variety of zirconolite characterized by high Mg, Al, Y2O3 and REE, and low Fe is described from a sapphirine granulite xenolith entrained in an intrusive norite body which was emplaced into the late Archaean (2520–2480 Ma) Vestfold Hills high-grade terrain during the early Proterozoic. The zirconolite, and similarly Mg-Al rich perrierite-(Ce), formed as a result of sanidinite facies partial melting of the particularly magnesian and aluminous sapphirine granulite xenolith during its incorporation into the c. 1170°C basic magma at c. 2240 Ma. The high REE compared to Al cations require that a previously unrecognized coupled substitution:occurs in this zirconolite. Full chemical analyses are presented for zirconolite and perrierite from this unique occurrence.

Origin of vein graphite in high-grade metamorphic terrains

The role of CO2 in the creation of a refractory base of granulite by metamorphism has received increasing attention by geologists investigating sub-crustal phenomena. A voluminous source of mantle-derived CO2 has been postulated for the phenomenon of granulite formation. Recent studies on the granulite terrain of Sri Lanka has clearly shown that it is only an upper crustal section and that it had been subjected to a much smaller influx of CO2 than hitherto envisaged. The close association of graphite with the granulites and the recent discovery of grain-boundary graphite in the lower crust implies graphite as a major source of CO2. Recent reports on the discovery of alluvial diamonds within the granulite belt of the Highland Complex of Sri Lanka where graphite is abundant possibly indicates penetration of the graphite-diamond inversion line.

Crustal Evolution in South India: Constraints from Nd Isotopes

Nd-isotope analyses from a range of lithologies, including charnockites, metasediments, and granitoids that comprise the high-grade terrain of South India define contrasting age provinces. North of the Palghat-Cauvery shear zone, the Karnataka Craton and the granulite blocks of Nilgiri and Madras are characterized by model Nd ages from 3.4 to 2.4 Ga with significant crustal growth during the Late Archean. South of the Palghat-Cauvery shear zone a Pan-African granulite-facies event resulted in Sm/Nd fractionation, as observed in several incipient charnockite localities. Model Nd age calculations that allow for Sm/Nd fractionation at 550 Ma yield ages in the range of 2.9 to 1.3 Ga. This range compares closely with published model Nd ages from the high-grade terrain of Sri Lanka. Mid-Proterozoic crustal growth (~1.1 Ga) observed in the Vijayan Complex of Sri Lanka may have provided source material for metasediments characterized by young model Nd ages in southern Peninsular India. The Palghat-Cauvery shear zone therefore represents a boundary between southern terranes that are characterized by crustal reworking and high-grade metamorphism during the Pan-African tectonothermal event and an Archean craton to the north where no Pan-African overprint has been detected. Charnockite formation is identified both with the period of Late Archean crustal growth and with the period of Pan-African metamorphism, as can be observed not only in southern India, but also in the proximal Gondwanan fragments of East Antarctica and Madagascar.

Transitional granulite-eclogite facies metamorphism of basic supracrustal rocks in a shear zone complex in the Precambrian shield of south India

AbstractThe phase petrology of two bodies of basic granulites occurring in association with supracrustal sequences within a dextral oblique-slip shear complex in the high-grade terrain of south India, have been studied. Some metabasites are characterized by garnet + clinopyroxene assemblages such as Grt + Cpx + PI ± Hbl ± Opx ± Qtz + Fe-Ti oxide(s) which are high-pressure granulites (garnet-clinopyroxene subfacies) transitional between the intermediate-pressure granulites (orthopyroxene-plagioclase subfacies) and eclogite. Mineralogical characteristics suggest that metamorphic conditions did not reach the eclogite facies but certainly approached that level. Close spatial association of the garnetiferous varieties with garnet-free assemblages (Opx + Hbl + Pl ± Cpx) and intimate juxtaposition of anhydrous and hydrous assemblages indicate a complex interplay of variable μH2O and bulk composition, especially αSiO2. Due to variable and low closure temperature of Fe-Mg exchange reactions between coexisting pyroxene and garnet, reliable estimation of peak temperatures during this near eclogite-facies metamorphism is problematic. A combination of a garnet-clinopyroxene barometer and various temperature estimates suggests P-T conditions of 875 ± 25°C and 8 ± 1 kbar for the Mettuppalaiyam samples and 900 ± 50°C and 14 ± 2 kbar for the Kanjamalai samples. Bulk rock chemical differences in terms of SiO2-content can account for the development of similar mineral assemblages along a near adiabatic metamorphic gradient between these two localities. These assemblages represent some of the highest grade granulite facies rocks in south India. The high-pressure granulites are not in situ samples of ancient lower continental crust, but low-pressure protoliths buried at depth. Textural features suggest that the high-pressure garnet-clinopyroxene subfacies rocks evolved from an amphibolitic assemblage by formation of garnet at the expense of hornblende and plagioclase and this high-pressure assemblage underwent an isothermal decompression indicating a clockwise P-T-t path resulting from crustal thickening and exhumation. A later isobaric cooling, possibly accompanying shearing and high H2O influx (aH2O≈0.78) gave rise to the coexisting orthopyroxeneplagioclase subfacies rocks (intermediate pressure granulites).

A new occurrence of musgravite, a rare beryllium oxide, in the Caledonides of North-East Greenland

AbstractMusgravite, Be(MgFeZn)2Al6O12, is associated with norbergite and minor chlorite in a Precambrian calcite marble within the gneissic basement in an internal part of the Caledonian mobile belt in Dove Bugt, North-East Greenland. It commonly occurs as vitreous black, idioblastic crystals (&lt;7 mm in size) with combined rhombohedral and basal pinacoid forms. XRD data show that its space group is R3m and its unit cell dimensions are a 5.687 ± 0.002 Å and c 41.16 ± 0.02 Å. Electron microprobe and ICP-MS analyses have yielded BeO 5.51 wt.% and ranges in abundance (wt.%): Al2O368.74-70.63; Tot, Fe as FeO 6.76-7.89; MgO 12.17-13.98; and ZnO 3.22-4.47. ICP-MS analysis also revealed significant trace amounts of V 249 ppm, Cr 740 ppm and Ga 178 ppm. The crystallographic parameters and composition are broadly in accord with those of musgravite from the two other recorded occurrences, in Precambrian high-grade terrains in Australia and Antarctica, although mineral and rock associations in these localities differ from those in Dove Bugt. The source of beryllium in each of the musgravite occurrences is uncertain, although a metasomatic source related to granite emplacement is favoured for the occurrence in North-East Greenland.

Mineralogical and petrochemical characteristics and genesis of Laoniugou gneiss in Jiapigou gold mine, Jilin Province

Detailed mineralogical and petrochemical studies show that the Laoniugou gneiss of the Jiapigou gold mine is composed mainly of plagioclase gneiss and irregular to lentiform plagioclase amphibolite melanic enclaves. The major element contents show an obvious bimodal and trondhjemitic series evolutional trend. This situation is significantly different from that encountered in bimodal calc-alkalic volcanic rocks in the rift-type Archaean greenstone belt. The contents of Rb, Sr and Ba are 7–21 ppm, 153–363 ppm and 201–1451 ppm respectively, close to those of common Archaean grey gneisses. AU the samples of plagioclase gneisses show positive Eu anomalies (even up to 4.6). The protoliths of the plagioclase gneiss are high-Al2O3 trondhjemitic series rocks, belonging to typical TTG of Archaean high-grade metamorphic terrain. The gneiss is quite similar to the B-type Amitsoq gneiss of W. Greenland. The authors believe that the plagioclase amphibolite enclaves are the relics of ancient oceanic crust while the plagioclase gneiss is the TTG ancient intrusive rock resulting from partial melting of the oceanic crust.

Constraints on the composition of fluids involved in retrograde anthophyllite formation in the Limpopo Belt, South Africa

Orthoamphibole occurs widely in the metapelitic gneisses and other lithologies within the Southern Marginal Zone of the Limpopo Belt in southern Africa. Petrographic relations indicate that the orthoamphibole formed as a retrogressive replacement of the granulite facies minerals cordierite and orthopyroxene. The existence of a discrete retrograde orthoamphibole isograd that can be mapped for over 150 km has led previous workers to suggest that the orthoamphibole formed as a result of equilibrium high-temperature reactions which occurred in response to regional influx of fluids at the close of the Limpopo Orogeny, 2670 Ma ago. However, in order to substantiate this interpretation, it is necessary to show from phase equilibrium analysis that the metapelitic minerals and their retrograde products comprise assemblages stable at elevated pressure and temperatures, rather than disequilibrium assemblages formed at unspecified lower temperatures by monotropic reactions. Some of the properties of the infiltrating fluids may, in turn, be specified if the alteration products represent equilibrium assemblages. It is shown that the presence of anthophyllite and the absence of talc in two analysed metapelites from the retrograde isograd require an associated vapour phase to have been relatively low in water ( a H 2O ≤ 0.7) and temperatures to have been below 620°C when the anthophyllite developed from the orthopyroxene. The fast kinetics of formation of talc and the relatively sluggish kinetics of formation of anthophyllite in experimental systems make it highly unlikely that the orthoamphibole could have formed metastably at low temperatures and high water activities. A more general phase equilibrium analysis based on the coexistence of cordierite, garnet, biotite, enstatite, plagioclase and quartz with retrograde anthophyllite and kyanite indicates that this assemblage was in equilibrium at temperatures between 450 to 650°C for pressures of 5 to 7 kbars and water activities between 0.6 and 0.1. The temperatures, pressure and water activities are highly correlated, and lower pressures and water activities are required for equilibrium at lower temperatures. The reduced water activities calculated require that a substantial quantity of another volatile be present in the vapour phase; in the absence of stable scapolite or carbonates, this volatile cannot be confirmed to be CO 2. The required infiltration of late-orogenic fluids with reduced water activities is apparently a major feature of the Limpopo event, and may have parallels in other large Precambrian high grade terrains, in as much as orthoamphibole replacing orthopyroxene is a commonly observed mineral assemblage.

Field geology of high-grade gneiss terrains

Field geology of high-grade gneiss terrains

Isotopic contrasts, chronology of elemental transfers and high-grade metamorphism: the Sri Lanka Highland granulites, and the Lewisian (Scotland) and Nuk (SW Greenland) gneisses

Crust formation ages inferred on the basis of Nd model age, U-Pb zircon and Pb-Pb data for granulites from central Sri Lanka, and the late Archean Lewisian (Scotland) and Nuk (south-western Greenland) high-grade gneisses are comparable, and in the range 2.2–3.0 Ga and 2.8–3.0 Ga respectively. The time interval between crust formation and high-grade metamorphism (with its attendant depletions of incompatible and heat-producing elements) is in the order of ∼ 2 Ga for the ∼ 0.6 Ga Highland granulites of Sri Lanka, but are less than ∼ 0.1–0.2 Ga for the Lewisian and Nuk gneisses. Severe depletions of U and Th produced the distinctive unradiogenic present-day Pb ratios of the Lewisian and Nuk gneisses. The Sri Lanka granulites, in contrast, preserve a record of an extended residence in a high U/Pb, high Th/Pb environment and display radiogenic »upper crustal« — like present-day isotope ratios. Relative to primitive mantle compositions, the Pb isotopes identify the Lewisian and Nuk terrains as crustal reservoirs depleted in Th and U (relative to Pb), whereas the Highland granulites are enriched. The global Pb isotope mass balance requires the existence of low U/Pb, low Th/Pb and high Th/U reservoir(s) for successful solutions, and the lower crust is a likely candidate for this reservoir. High-grade terrains like Sri Lanka show depletions of measured U and Th abundances relative to Pb, but do not show Pb isotope signatures of »model bulk lower crust«. Archean high-grade gneisses display the appropriate combination of retarded Th/Pb and U/Pb although their absolute compositions are much less radiogenic than those of »model bulk lower crust« predicted from simple mass balance calculations.

Geochemistry of Gneiss-Granulite transformation in the ?incipient charnockite? zones of southern India

Upper amphibolite facies gneisses in the southern Indian Shield show local transformation into veins, clots and patches of orthopyroxene-bearing dry granulites (“incipient charnockites”). Depending upon the protolith composition, these desiccated zones are classified into ortho- and para-charnockites and have developed within rocks of distinct mineralogy and chemistry at different time intervals through the structurally-controlled influx of carbon dioxide-rich fluids. Our geochemical investigations at five critical quarry sections indicate that the incipient charnockites have undepleted chemistry and very low K/Rb values. In the paracharnockite localities, where granulite formation is characterized by consumption of garnet, biotite and quartz to produce orthopyroxene, loss of Rb and Ba and enrichment of Ti are observed. In contrast, the orthocharnockite localities show marked LILE enrichment with gain of K, Rb and Ba and loss of CaO, suggesting extensive replacement of plagioclase in the gneisses by K-feldspar in the charnockite through K-Na-Ca exchange reactions with influxing carbonic fluids. The marked depletion in Fe, Mg, Ti and P in these rocks correlates with progressive dissolution of hornblende, biotite, magnetite and accessory apatite. Our study indicates that gneiss to granulite transformation, even if on a local scale, is not an isochemical phenomenon, but attended by distinct element mobilities, although they are contrastingly different from the geochemical trends in some regional high grade terrains.

Ductile reactivation of Proterozoic brittle fault rocks; an example from the Vestfold Hills, East Antarctica

Abstract Brittle fault rocks, usually in the form of minor pseudotachylyte veins have been reported from most high-grade metamorphic Archaean and Proterozoic terrains. In analyses of local crustal evolution such brittle structures are often ignored; brittle faults commonly reflect the very last phases of local deformation during final uplift of the basement to shallow crustal levels, and as such they are thought to be of minor or no importance in large-scale Archaean and Proterozoic tectonics. New data from Archaean and Proterozoic high grade terrains in Australia and Antarctica indicate that minor fault veins may in some cases represent significant early low-grade brittle events which have been overprinted and largely erased by subsequent phases of ductile deformation. This paper describes such a brittle event in the Vestfold Hills, East Antarctica, which may represent an important phase of mid-Proterozoic uplift and crustal extension.

Archaean gneisses, amphibolites and banded iron-formations from the Anshan area of Liaoning Province, NE China: Their geochemistry, metamorphism and petrogenesis

An investigation of the trace element geochemistry and geothermobarometry of amphibolites and banded iron-formations (BIF) of the Anshan Group, and of associated amphibolite-facies orthogneisses in the Anshan area of Liaoning Province of NE China has been carried out with a view to understanding the petrogenesis and evolution of this Archaean high-grade terrain which is unique for its abundance of BIF. The Anshan supracrustal group, which has a Sm-Nd isochron age of 2.79 Ga, comprises BIF, metavolcanic amphibolites, quartzites, phyllites and schists. The BIF (actinolite-cummingtonite-magnetite-quartz-stilpnomelane) occurs in kilometre-long beds up to 80 m thick, which contain very low contents of total REE, CO2, S, Cu, Pb, Zn, Mn, Ni, P, Ti, V and Cr; δS34 is near chondritic and δO18 approximates the calculated primary δO18 of SiO2 deposited from Archaean sea-water. The amphibolites (hornblende-plagioclase ± quartz ± epidote ± tourmaline) form beds up to 1 km thick, range from quartz- to olivine- and hyperthene-normative and have low Zr and Ti abundances and trace element patterns that are most similar to those of basalts derived from sub-continental mantle or to those of modern island-arc tholeiites. Metasediments are muscovite-tourmaline quartzites, quartz-muscovite-chlorite phyllites, quartz-biotite-muscovite-garnet-staurolite schists, quartz-garnet-biotite schists, quartz-garnet-cumming-tonite-gedite rocks and quartz-K-feldspar-plagioclase-biotite-sillimanite gneisses. The Tiejiashan orthogneisses, which have Rb-Sr and Pb-Pb isotopic ages of 2.83-2.86 Ga, probably represent basement to the Anshan Group. They range from granites to trondhjemites and consist of quartz, plagioclase, biotite and microcline. The Anshan orthogneisses have a Sm-Nd isochron age of 2.53 Ga and range in composition from granites to tonalites. They intruded the Anshan supracrustals with the result that the BIF and associated supracrustal rocks now form lenses of up to several kilometres in the gneisses. The most common assemblage is quartz-K-feldsparplagioclase-biotite. Both the Tiejiashan and Anshan gneisses have high Sr, Rb, and K/Sr and low Ca, and thus are similar to amphibolite-facies gneisses in many high-grade terrains, and to modern volcanic-arc granites. Geothermometry of metasediments suggests that T increased from 500–550°C in the south to 600°C in the north of the area. These temperatures are consistent with the presence of amphibolites, sillimanite in gneisses, and staurolite in schists. No assemblages are suitable for estimating pressure. Combined geological, geochronological and geochemical data suggest to us that the Anshan Group was deposited in a shallow-water basin on or against a continental margin or basement and close to a magmatic arc. During the accretion events associated with the 2.5 Ga Anshan orogeny, arc-driven granitic rocks intruded the basin and engulfed the supracrustal rocks, leaving the BIF, etc., as enclaves in ductile orthogneisses.

R. G. Park and J. Tarney, Eds. Evolution of the Lewisian and Comparable Precambrian High Grade Terrains. London (Geological Society: Special Publication No. 27) and Oxford (Blackwell Scientific Publications), 1987. viii + 315 pp. Price £39.50.

R. G. Park and J. Tarney, Eds. Evolution of the Lewisian and Comparable Precambrian High Grade Terrains. London (Geological Society: Special Publication No. 27) and Oxford (Blackwell Scientific Publications), 1987. viii + 315 pp. Price £39.50.

The evolution of the lewisian and comparable precambrian high‐grade terrains edited by R. G. Park and J. Tarney, Geological Society Special Publication no. 27, Blackwell Scientific Publications, Oxford, 1987. no. of pages: 315. price: £39.50 (hardback). isbn 0‐632‐01683‐3

Geological JournalVolume 23, Issue 4 p. 339-339 Book ReviewFree Access The evolution of the lewisian and comparable precambrian high-grade terrains edited by R. G. Park and J. Tarney, Geological Society Special Publication no. 27, Blackwell Scientific Publications, Oxford, 1987. no. of pages: 315. price: £39.50 (hardback). isbn 0-632-01683-3 G. T. R. Droop, G. T. R. DroopSearch for more papers by this author G. T. R. Droop, G. T. R. DroopSearch for more papers by this author First published: October/December 1988 https://doi.org/10.1002/gj.3350230405AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume23, Issue4October/December 1988Pages 339-339 RelatedInformation