In suspect terrane? Provenance of the late Archean Phantom Lake metamorphic suite, Sierra Madre, Wyoming

2006 ◽  
Vol 43 (10) ◽  
pp. 1557-1577 ◽  
Author(s):  
A Kate Souders ◽  
Carol D Frost
Keyword(s):  
Crustal Growth ◽  
Important Process ◽  
Light Rare Earth ◽  
Nd Isotope ◽  
Eu Anomaly ◽  
Sierra Madre ◽  
Wyoming Province ◽  
Metaigneous Rocks ◽  
Ree Patterns ◽  
Rattlesnake Hills

The 2.68 Ga Phantom Lake metamorphic suite of the Sierra Madre is a volcanogenic, volcaniclastic, and siliciclastic sequence that may have been deposited on or near the margin of the Wyoming Province or, alternatively, it may represent part of an exotic block accreted onto the southern margin of the Wyoming Province. The metamorphosed supracrustal rocks of the Phantom Lake metamorphic suite, along with quartzofeldspathic gneisses and granitoids of similar age, have light rare-earth element (LREE) – enriched REE patterns with little to no Eu-anomaly. These patterns are comparable to those of modern oceanic arc rocks and sediments. Both supracrustal and metaigneous rocks have radiogenic initial εNd from +4.5 to –2.5 and Nd crustal residence ages between 2.7 and 3.0 Ga. It is proposed that these juvenile rocks were part of an intra-oceanic arc system formed beyond the influence of detritus from the Wyoming Province and subsequently were accreted onto the southern Wyoming Province following intrusion of granitic gneisses in the Sierra Madre at ca. 2.64 Ga. The younger 2.43 Ga Baggot Rocks granite has less radiogenic εNd of –3.9 suggesting that the rocks of the Sierra Madre had accreted to the Wyoming Province by 2.43 Ga. The supracrustal sequences at South Pass, Bradley Peak, and the Rattlesnake Hills have similar, radiogenic initial Nd isotope compositions. Together with the Phantom Lake metamorphic suite, they represent juvenile additions to existing continental crust and provide evidence that lateral accretion of oceanic terranes was an important process of late Archean crustal growth in the Wyoming Province.

Early Archean to Mesoproterozoic evolution of the Wyoming Province: Archean origins to modern lithospheric architecture

2003 ◽  
Vol 40 (10) ◽  
pp. 1357-1374 ◽  
Author(s):  
Kevin R Chamberlain ◽  
Carol D Frost ◽  
B Ronald Frost
Keyword(s):  
Black Hills ◽  
Arc Magmatism ◽  
Crustal Growth ◽  
Crustal Layer ◽  
Oregon Trail ◽  
Sierra Madre ◽  
Cumulative Processes ◽  
Wyoming Province ◽  
Lower Crustal ◽  
East West

Local preservation of 3.6–3.0 Ga gneisses and widespread isotopic evidence for crust of this age incorporated into younger plutons indicates that the Wyoming Province was a [Formula: see text] 100 000 km2 middle Archean craton, which was modified by late Archean magmatism and tectonism and Proterozoic extension and rifting. On the basis of differences in late Archean histories, the Wyoming Province is subdivided into five subprovinces: three in the Archean core, (1) the Montana metasedimentary province, (2) the Bighorn subprovince, and (3) the Sweetwater subprovince, and two Archean terrains that may be allochthonous to the 3.0 Ga craton, (4) the Sierra Madre – Medicine Bow block, and (5) the Black Hills – Hartville block. A thick, fast lower crustal layer, imaged by Deep Probe, corresponds geographically with the Bighorn subprovince and may be an underplate associated with ca. 2.70 Ga mafic magmatism. The Sweetwater subprovince is characterized by an east–west tectonic grain that was established by three or more temporally related, late Archean, pulses of basin development, shortening, and arc magmatism. This tectonic grain, including the 2.62 Ga Oregon Trail structure, controlled the locations and orientations of Proterozoic rifting and Laramide uplifts. The present-day lithospheric architecture of the Wyoming Province is the result of cumulative processes of crustal growth and tectonic modification; lithospheric contrasts have apparently persisted for billions of years. If there has been any net crustal growth of the Wyoming Province since 3.0 Ga, it has involved a combination of mafic underplating and arc magmatism.

scholarly journals REE and Sr–Nd Isotope Characteristics of Cambrian–Ordovician Carbonate in Taebaek and Jeongseon Area, Korea

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 326
Author(s):  
Tae-Hyeon Kim ◽  
Seung-Gu Lee ◽  
Jae-Young Yu
Keyword(s):  
Depositional Environment ◽  
Sea Water ◽  
Geological Time ◽  
Nd Isotope ◽  
Diagenetic Processes ◽  
Platform Margin ◽  
Carbonate Formations ◽  
Diagenetic History ◽  
Cretaceous Period ◽  
Ree Patterns

Carbonate formations of the Cambro-Ordovician Period occur in the Taebaek and Jeongseon areas, located in the central–eastern part of the Korean Peninsula. This study analyzed the rare earth element (REE) contents and Sr–Nd isotope ratios in these carbonates to elucidate their depositional environment and diagenetic history. The CI chondrite-normalized REE patterns of the carbonates showed negative Eu anomalies (EuN/(SmN × GdN)1/2 = 0.50 to 0.81), but no Ce anomaly (Ce/Ce* = CeN/(LaN2 × NdN)1/3 = 1.01 ± 0.06). The plot of log (Ce/Ce*) against sea water depth indicates that the carbonates were deposited in a shallow-marine environment such as a platform margin. The 87Sr/86Sr ratios in both Taebaek and Jeongseon carbonates were higher than those in the seawater at the corresponding geological time. The 87Sr/86Sr ratios and the values of (La/Yb)N and (La/Sm)N suggest that the carbonates in the areas experienced diagenetic processes several times. Their 143Nd/144Nd ratios varied from 0.511841 to 0.511980. The low εNd values and high 87Sr/86Sr ratios in the carbonates may have resulted from the interaction with the hydrothermal fluid derived from the intrusive granite during the Cretaceous Period.

scholarly journals Geochemical Characteristics and Tectonic Setting of Amphibolites in Ifewara Area, Ife-Ilesha Schist Belt, Southwestern Nigeria

2016 ◽  
Vol 6 (1) ◽  
pp. 43 ◽  
Author(s):  
Anthony Temidayo Bolarinwa ◽  
Adebimpe Atinuke Adepoju
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Major Element ◽  
Tectonic Setting ◽  
Crustal Contamination ◽  
Geochemical Evolution ◽  
Schist Belt ◽  
Southwestern Nigeria ◽  
Eu Anomaly ◽  
Ree Patterns

Trace and Rare Earth Elements (REEs) data are used to constrain the geochemical evolution of the amphibolites from Ifewara in the Ife-Ilesha schist belt of southwestern Nigeria. The amphibolites can be grouped into banded and sheared amphibolites. Major element data show SiO2 (48.34%), Fe2O3 (11.03-17.88%), MgO (5.76-9.90%), CaO (7.76-18.6%) and TiO2 (0.44-1.77%) contents which are similar to amphibolites in other schist belts in Nigeria. The Al2O3 (2.85-15.55%) content is varied, with the higher values suggesting alkali basalt protolith. Trace and rare earth elements composition reveal Sr (160-1077ppm), Rb (0.5-22.9ppm), Ni (4.7-10.2ppm), Co (12.2-50.9 ppm) and Cr (2-7ppm). Chondrite-normalized REE patterns show that the banded amphibolites have HREE depletion and both negative and positive Eu anomalies while the sheared variety showed slight LREE enrichment with no apparent Eu anomaly. The study amphibolites plot in the Mid Oceanic Ridge Basalts (MORB) and within plate basalt fields on the Zr/Y vs Zr discriminatory diagrams. They are further classified as volcanic arc basalt and E-type MORB on the Th- Hf/3- Ta and the Zr-Nb-Y diagrams. The amphibolites precursor is considered a tholeiitic suite that suffered crustal contamination, during emplacement in a rifted crust.

scholarly journals PRE-ALPINE MIGMATITIC ROCKS AND ACID TO INTERMEDIATE ORTHOGNEISSES IN PENTELIKON MOUNTAIN (NE ATTICA, GREECE)

2004 ◽  
Vol 36 (1) ◽  
pp. 542
Author(s):  
I. Baziotis ◽  
E. Mposkos ◽  
V. Perdikatsis
Keyword(s):  
Broad Area ◽  
Magmatic Arc ◽  
Eu Anomaly ◽  
High K ◽  
Arc Setting ◽  
Ree Patterns

In the broad area of Pentelikon Mountain, which is part of the Attic-Cycladic crystalline belt, metamigmatites and orthogneisses occur as tectonic slices within the calc-schists or between calcschists and marbles. In the metamigmatites relic of migmatitic fabrics, comprising leucosomes and melanosomes, and cross-cutting aplitic and pegmatitic dykes are still preserved. The orthogneisses have dioritic to granitic composition. They are interpreted to be probably formed in a magmatic arc setting. Granitic orthogneisses show high-K contents and are enriched in LILEs and depleted in HFSEs. They also exhibit fractionated REE patterns with slight to strong negative Eu anomaly. The exceptionally high K2O contents (>7%) and the very low Na2Û contents (0.4-0.98 wt%) of certain phengite-orthogneisses with ultramylonitic textures are attributed to metasomatic processes that occurred during ultramylonitization.

Pyroclastic rocks from Kanchanaburi and Uthai Thani Province, Inthanon Zone, Western Thailand

2020 ◽  
Author(s):  
Suwijai Jatupohnkhongchai ◽  
Sirot Salyapongse ◽  
Burapha Phajuy ◽  
Daniela Gallhofer ◽  
Christoph Hauzenberger
Keyword(s):  
Volcanic Rocks ◽  
Potassium Feldspar ◽  
Geochronological Data ◽  
Rock Composition ◽  
Pyroclastic Rocks ◽  
Eu Anomaly ◽  
Geologic Map ◽  
Ree Patterns ◽  
First Time ◽  
Strong Depletion

<p>A series of pyroclastic rocks are mapped as a Silurian-Devonian unit in the Kanchanaburi-Uthai Thani area, Western Thailand, which belongs to the Inthanon Zone. These pyroclastic rocks were discovered and described for the first time in 1977 and mentioned in the 1:250,000 Suphanburi geologic map sheet and report. Since then these rocks were poorly investigated and their formation and geotectonic setting is unclear. As a result, we report petrographic, geochemical and geochronological data of these pyroclastic rocks. Petrographically, the pyroclastic rocks can be described as a meta-quartz-K-feldspar crystal tuff, a meta-quartz crystal tuff, and a meta-lithic tuff. They are made up of mm sized clasts in a finely grained matrix. The clasts consist of potassium feldspar, rounded quartz, embayed quartz, trachytic and metasedimentary rock clasts embedded in a highly altered devitrified fine-ash matrix containing sericite.</p><p>The whole-rock composition shows enrichments in SiO<sub>2</sub> and K<sub>2</sub>O and a strong depletion in CaO and Na<sub>2</sub>O which is related to late alteration of the volcanoclastic rocks. Based on the immobile element classification plot of Pearce 1996, the tuffs can be classified as trachyandesite, trachyte, dacite and rhyolite. Their chondrite-normalized REE patterns display light REE enrichment with nearly flat heavy REE and a negative Eu anomaly, typical for calcalkaline volcanic rocks. Most samples fall in the volcanic arc granites field in the granite discrimination diagrams of Pearce 1984.</p><p>Zircons extracted from the tuffs will be used to constrain their crystallization age by U-Pb LA-MCICPMS dating. This allows us to constrain the age of formation and to place this in context with the closure of the Paleotethys.</p>

Petrology of Tertiary lavas from the western Kangerdlugssuaq area, East Greenland

1982 ◽  
Vol 45 (337) ◽  
pp. 211-218 ◽  
Author(s):  
J. J. Fawcett ◽  
J. Gittins ◽  
J. C. Rucklidge ◽  
C. K. Brooks
Keyword(s):  
Rare Earth ◽  
Electron Microprobe ◽  
Minor Element ◽  
Flood Basalt ◽  
Light Rare Earth ◽  
Additional Material ◽  
East Greenland ◽  
Eu Anomaly ◽  
Light Rare Earth Elements ◽  
Basaltic Lavas

AbstractWhole-rock, minor element, rare earth, and electron microprobe data are presented for basaltic lavas from the western Kangerdlugssuaq area of East Greenland. Samples were obtained from Professor W. A. Deer's 1936 collection at Triangular Nunataks and Gardiner Plateau, and additional material obtained by sampling moraines on the surface of Kangerdlugssuaq Glacier. Both undersaturated and tholeiitic lavas are present at the Triangular Nunatak locality but the glacier suite is dominantly tholeiitic. The tholeiitic suite is less evolved than tholeiites from the Scoresby Sund area. Undersaturated lavas show enrichment in light rare earth elements and tholeiitic lavas show fiat chondrite-normalized patterns. Tholeiites from the Gardiner Plateau show no Eu anomaly but others show a slight negative Eu anomaly. Chemical data and considerations of regional geology are consistent with Cox's (1980) model of flood basalt vulcanism.

Major-, trace-, and rare-earth-element geochemistry of the Archaean Maggo gneisses, southern Nain Province, Labrador

1991 ◽  
Vol 28 (1) ◽  
pp. 44-57 ◽  
Author(s):  
Gregory C. Finn
Keyword(s):  
North Atlantic ◽  
Earth Element ◽  
Parent Magma ◽  
High Field Strength ◽  
Element Geochemistry ◽  
Eu Anomaly ◽  
Ree Patterns ◽  
Continuous Range ◽  
The Eu ◽  
Grey Gneiss

The early middle Archaean Maggo gneisses of the southern Nain Province, Labrador, form the southwest portion of the once contiguous North Atlantic (Nutak) Craton (NAC). The gneisses and their late middle Archaean metamorphosed and migmatized equivalents are typical of grey gneiss terranes exposed worldwide. Geochemically the gneisses exhibit a continuous range of composition from 53.7 to 78.4 wt.% SiO2 and straddle the boundary between low- and high-Al trondhjemites. Major-element distributions are comparable to those of other Archaean-aged NAC gneisses (Amîtsoq, Uivak, and Nûk gneisses), however, the Na2O and K2O contents are scattered. The gneisses are depleted in K, Rb, and Ba, are enriched in Sr, and have high-field-strength-element distributions similar to those for NAC gneisses.Rare-earth-element (REE) patterns of Maggo gneisses can be subdivided, on the basis of the nature of the Eu anomaly, into two groups of samples: (i) with negative Eu anomalies and higher Σ REE contents and (ii) with positive to normal Eu anomalies and lower Σ REE contents. The subdivision reflects differentiation processes in the parent magma of the Maggo gneisses. REE patterns are similar to those reported for NAC grey gneiss complexes. On the basis of the (La/Yb)N and (Yb)N values, the Maggo gneisses parent magma is interpreted as being derived by partial-melting processes from preexisting, high-grade (granulite to amphibolite facies) sialic continental crust equivalent to the early Archaean lithologies preserved elsewhere in the NAC.

scholarly journals Supplemental Material: Apatite fingerprints on the magmatic-hydrothermal evolution of the Daheishan giant porphyry Mo deposit, NE China

2021 ◽  
Author(s):  
Pan Qu ◽  
Wubin Yang
Keyword(s):  
Wall Rock ◽  
Major And Trace Elements ◽  
Primitive Mantle ◽  
Ne China ◽  
Pb Isotope ◽  
Nd Isotope ◽  
Isotope Data ◽  
Porphyry Mo Deposit ◽  
Spider Diagrams ◽  
Ree Patterns

Figure S1: Harker diagrams illustrating major elemental variations of the porphyry and wall rock. QGP—Qiancuoluo granodioritic porphyry; QBG—Qiancuoluo biotite granodiorite; Figure S2: (a) Chondrite-normalized REE patterns and (b) primitive mantle (PM)-normalized spider diagrams of the porphyry and wall rock. Normalizing values are taken from S. Sun and McDonough (1989); Table S1: Whole-rock major and trace element compositions of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG) granites; Table S2: Whole-rock Sr-Nd compositions of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG); Table S3: Apatite major and trace elements (ppm) of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG); Table S4: Apatite Sr and Nd isotope data of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG); Table S5: Apatite U-Pb isotope data of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG).

Sign in / Sign up

Export Citation Format

Share Document