Page 1. Small-volume U�Pb zircon geochronology by laser ablation- multicollector-ICP-MS ... Keywords: U�Pb geochronology Zircon LA-ICP-MS ...

... Accession Number : ADA515753. Title : Small-Volume U-Pb Zircon Geochronology by Laser Ablation-Multicollector-ICP-MS. ...

Refractory oxide fibers of zirconia and zircon are now being produced in the form of wools and batts. The fibers may be laminated and impregnated, and they are useful for reinforcing ablation materials and for use as thermal insulation. The properties of the fibers are described, and the types of fibers available are outlined. (D.L.C.)

Trace element abundances in igneous zircons, as determined by electron microprobe and laser-ablation microprobe ICPMS analysis, are shown to be sensitive to source rock type and crystallisation environment. The concentrations of 26 trace elements have been determined for zircons from a wide range of different rock types and reveal ...

Cathodoluminescence (CL) images are routinely used as a guide to locate analysis points in ion probe or laser ablation ICP-MS U-Pb age and trace element analysis of zircon. However, because CL imaging�s clear signals are micron-scale, it cannot reveal depth dependent variation. This is important because typical ion microprobe and laser ...

A new U-Pb zircon dating protocol for small (10�50 ?m) zircons has been developed using an automated searching method to locate zircon grains in a polished rock mount. The scanning electron microscope-energy-dispersive X ray spectrum-based automated searching method can routinely find in situ zircon grains larger ...

youngest unit of the Chugach accretionary complex in southeastern Alaska. Using laser-ablation inductively coupled plasma mass spectroscopy, we obtained 492 detrital-zircon ages on...

In recent times antiferroelectric thin-film material compositions have been identified as one of the most significant thin films for development of devices such as high charge storage, charge couplers/decouplers, and high strain microelectromechanical systems. Thus, understanding the dielectric and electrical properties under an ac signal drive in these antiferroelectric thin-film compositions, ...

-Pb Laser Ablation ICP-MS Zircon Dating using Matrix-Matched Calibration Samples with a Frequency Quadrupled of laser ablation (LA) ICP-MS to the in situ analysis of 207Pb/206Pb and 206Pb/238U isotopic ratios analyses, LA-ICP-MS results on reference materials (UQ-Z1 and G91500) indicated individual precisions

of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to investigate the chemical or exposure to sunlight. 5.2.1 LA-ICP-MS The concentrations of many trace elements in the zircon samples were determined by single-grain analyses using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS

A laser ablation-inductively coupled plasma-mass spectrometric (LA-ICPMS) technique utilizing a titanium-sapphire (TiS) femtosecond laser (fs-laser) has been developed for elemental and isotopic analysis. The signal intensity profile, depth of the ablation pit and level of elemental fractionation were investigated in order to evaluate the analytical ...

Detrital zircons from all major clastic units in the Jack Hills and Mount Narryer metasedimentary belts, Western Australia, were analyzed for morphology, internal zoning, inclusion mineralogy, age, and trace element concentrations (latter two obtained by laser-ablation microprobe ICPMS). The results show that zircons were derived from ...

To test existing models for the formation of the Amerasian Basin, detrital zircon suites from 12 samples of Triassic sandstone from the circum-Arctic region were dated by laser ablation-inductively coupled plasma-mass spectrometry (ICP-MS). The northern Verkhoyansk (NE Russia) has Permo-Carboniferous (265-320 Ma) and Cambro-Silurian (410-505 Ma) ...

Zircon is arguably the most studied accessory mineral in geochronological studies and has been lauded for its mechanical and chemical robustness for decades. However, detailed understanding of growth and modification are still emerging from, particularly from in-situ studies combining petrography and internal texture studies with trace element geochemical analyses and U-Pb ...

The most popular mineral for uranium-lead geochronology is zircon (ZrSiO4) but for many rocks of interest, particularly those with basic to ultrabasic compositions, zircon is not present and baddeleyite (ZrO2) is the main alternative. Microbeam analyses by laser ablation-inductively coupled plasma mass spectrometry (LA- ICPMS) are ...

The combination of hafnium (Hf) isotopes, trace element contents, and U/Pb ages in the same zircon domains, provides new information on the creation, evolution, and fluid alteration of Kiruna-type iron oxide-apatite deposits in the Lyon Mountain granite, Adirondack Mountains, New York. The Lyon Mountain granite is host to numerous zircon-bearing iron ...

A new laser ablation technique combined with a chemical evaporation reaction has been developed for elemental ratio analysis of solid samples using an inductively coupled plasma mass spectrometer (ICPMS). Using a chemically assisted laser ablation (CIA) technique developed in this study, analytical repeatability of the elemental ratio measurement was ...

In-situ Hf isotope analyses and U Pb dates were obtained by laser ablation-MC-ICP-MS for a zircon-bearing mantle eclogite xenolith from the diamondiferous Jericho kimberlite located within the Archean Slave Province (Nunavut), Canada. The U Pb zircon results yield a wide range of ages (�2.0 to 0.8 Ga) indicating a complex geological ...

The voluminous (~390,000 km3) and prolonged (~18 myr) explosive silicic volcanism of the mid Tertiary Sierra Madre Occidental of Mexico is generally considered to have formed by fractional crystallisation from crustally contaminated andesitic parental magmas (AFC), with <20% crustal contributions. Evidence for larger crustal contributions has been constrained by the lack of isotopic variation ...

Detrital zircons from five Paleozoic and Mesozoic sandstones from the Brooks Range and North Slope of Alaska, and two Triassic sandstones from the Sverdrup Basin in northern Canada were dated using SHRIMP and laser ablation ICPMS geochronology. In Alaska, dated samples from allochthonous strata of the Brooks Range include the northern and southern ...

We compared the analytical performance of ultraviolet femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). The benefit of ultrafast lasers was evaluated regarding thermal-induced chemical fractionation, that is otherwise well known to limit LA-ICPMS. Both lasers had a Gaussian beam energy profile and were tested using the same ...

Laser ablation has been used to produce thin films of lanthanum- modified lead zirconate titanate or PLZT, as defined by Pb(1-x)La(x)(Zr(1-y) Ti(y)(1-x/4)O3). PLZT is an interesting class of materials having a wide range of compositionally dependent elect...

A geochronology and Hf isotope study, using laser ablation-ICP-MS analysis of zircon grains, has been conducted to date felsic volcanic rocks from the Portuguese sector of the Iberian Pyrite Belt and to establish possible sources for these rocks. The ages obtained range from the Famennian to the Tournaisian, with the oldest ages reported in the Belt so far ...

Zircon is a common accessory phase in clastic sedimentary rocks as well as one of the most stable minerals in sedimentary environments. Investigating the age spectra of detrital zircons is important for sedimentary provenance analysis to glean information regarding ancient source areas and major magmatic events, crucial for plate-tectonic and ...

The Graciosa Province comprises more than 20 A-type granitic and syenitic plutons in southern Brazil. This province was emplaced during a period of tectonic change, with A-type magmatism post-dating syntectonic I- and S-type magmatism to the east. Dating the age of magmatism has proven challenging, with current published results showing a wide range of ages (550-590 Ma), most of which with low ...

Detailed zircon analyses were carried out on samples from the B�lv�ny North section, which contains the Permian-Triassic boundary. A fine-grained sandstone bed within the "boundary shale" contains a significant amount of zircon crystals. Pupin morphological, scanning electron microscopy [secondary electron, back-scattered electron, cathodoluminescence ...

The Colorado River is a large, youthful, unequilibrated continental drainage system the base-level for which was established rather abruptly between 5 and 6 million years ago in conjunction with Gulf of California rifting and establishment of the modern river course through the western Grand Canyon and lower Colorado river region. New laser ablation ICPMS detrital ...

The composition, structure, spatial extent, and history of Archean crust buried beneath the Snake River Plain (SRP) are important for assessing the role of the lithosphere in regional igneous and tectonic activity. We report the U-Pb age and Hf isotope composition of Archean zircons from xenoliths entrained in Snake River Plain basalts. The xenoliths come from three ...

Lower crustal rocks, including AMCG suites, are widely exposed in the Oaxacan Complex of S Mexico and in the Novillo, Huiznopala, and Guichicovi gneisse of eastern and SE Mexico, also referred to as 'Oaxaquia' [1-4 and refs. therein]. To characterize the different basement exposures, we combined U-Pb dating by LA-MC- ICPMS and single-grain ID-TIMS with single-grain Lu-Hf analysis by solution ...

Dating of single zircon crystals by both the (U-Th)/He and U/Pb methods (He-Pb* double-dating) provides high-temperature (crystallization or high-grade metamorphism) and low-temperature ( �180 � C) ages. Advantages of He-Pb* double-dating of detrital zircons includes greatly improved resolution of source terrain provenance, as well as constraints on ...

In the North Atlantic region, Caledonian and Grenvillian terrains are exposed on Svalbard, Greenland, Great Britain, Canada and Scandinavia. Reconstructing the original configuration of these terrains depends partly on determining the age and provenance of the sedimentary rocks overlying the basement. Provenance investigations using detrital zircon U-Pb ages are a powerful ...

Vast (about 7 billions km2) almost wholly (98%) covered with ice continental mass of East Antarctica is the central fragment of ancient supercontinents of Rodinia and Gondwana. Any information on its geologic structure is of the greatest importance for solving the problems of formation and amalgamation of lithosphere of ancient continents, processes of intraplate activity, denudation and ...

Isotope studies have proved of enormous benefit in fingerprinting the source rocks of silicic magmas and tracing open system petrogenetic processes, such as crustal assimilation or magma mixing. Quantification of these processes, especially the role of mantle-derived magmas, is essential to formulating realistic models for the thermal regime and compositional evolution of the continental crust. ...

The Late Archean Abitibi greenstone belt, in SE Superior Province, is one of the largest contiguous greenstone belts on Earth. Geochronological data from upper crustal rocks indicate it was formed by volcanism and plutonism that spanned 2760 Ma through 2660 Ma. The classical model for the Abitibi belt is one of tectonic accretion and thrust stacking of magmatic arcs, and possibly plateau ...

The Late Cretaceous Boulder batholith, southwestern MT, is composed of the Butte Granite and at least a dozen smaller granodiorite to syenogranite plutons. These plutons (81-73 Ma) were dated by zircon U-Pb geochronology using the SHRIMP. Typically for SIMS analysis of igneous zircon, the analytical spot is located midway between core and rim on an area ...

... 15. NUMBER OF PAGES 105 Calcium Zirconate, Barium Zirconate, Strontium Zirconate 16. ... 31 3.1.2 Barium Zirconate ..... 35 ...

Zircon was extracted from a sample of gabbroic anorthosite of the Duluth gabbro complex (1099.0 � 0.6 Ma) at Forest Center, MN. A previous collection from this site has been labeled FC-1 and has been used as a U-Pb age standard for SIMS analyses at the RSES of the ANU. Several other laboratories are also now evaluating FC-1 as a standard for ion probe (SIMS) and LA-ICP-MS ...

We present (1) a simple approach to correct the mass bias as well as isobaric interferences for Hf-Lu isotopic geochemistry of spiked and unspiked zircon samples, (2) new Lu and Nd isotopic data on the zircon standard 91500, and (3) a new 176Hf/177Hf reference value on the zircon standard 91500 specific for MC-ICP-MS instruments. The ...

Laser ablation (LA-)ICP-MS geochronology, principally of zircon, has become a routine procedure utilised by c.70 laboratories worldwide, providing access to key geochronological information for a wide community of geoscientists. Using this technique uncertainties of 1-1.5% 2SD on the final U-Pb ratio are now relatively routine. Sedimentary provenance ...

Accessory phase minerals with inherited cores surrounded by very thin (often <10?m) and irregular rims are common throughout the geologic record. Current in-situ U-Th-Pb analytical techniques (e.g. SIMS, LA-ICPMS) generally employ a static 'spot' analysis method which makes it difficult to confidently sample only the outer rim of such material. In addition, this approach has the potential to ...

Using laser ablation ICP-MS techniques, U-Pb ages are reported for 338 detrital zircons separated from four Franciscan metagraywacke samples from imbricate thrust sheets cropping out in the Pacheco Pass area, east central California Coast Ranges. Structurally higher slabs are clastic quartz � albite-bearing rocks typified by neoblastic lawsonite + ...

NW Turkey is a mosaic of several continental and oceanic units, that were amalgamated by collisional and strike-slip tectonics. One of the continental units is the ?stanbul terrane, the Palaeozoic strata of which comprise an Early Ordovician to Early Carboniferous transgressive sedimentary sequence. The basement to the Palaeozoic succession is exposed in the Bolu Massif and is represented by a ...

NW Turkey is a mosaic of several continental and oceanic units, that were amalgamated by collisional and strike-slip tectonics. One of the continental units is the ?stanbul terrane, the Palaeozoic strata of which comprise an Early Ordovician to Early Carboniferous transgressive sedimentary sequence. The basement to the Palaeozoic succession is exposed in the Bolu Massif and is represented by a ...

The Sitka Graywacke is the westernmost and youngest unit of the Chugach accretionary complex in southeastern Alaska. Using laser-ablation inductively coupled plasma mass spectroscopy, we obtained 492 detrital-zircon ages on seven typical samples of Sitka Graywacke turbidites, which were collected in a transect across much of the unit near Sitka, Alaska. ...

A number of U-Pb geochronological techniques are now available, each of which has pros and cons associated with spatial resolution, accuracy, precision and also operating cost and throughput. Zircon U-Pb age analyses using TIMS (Thermal Ionization Mass Spectrometry) can yield geological dates with uncertainties at or below the 1 permil level (precision and accuracy), but ...

The Solomon Islands chain is located in an area dominated by the Ontong Java Plateau (OJP). The island of Malaita formed at the obducted leading edge of the OJP and is geologically distinct from the islands to the west. Occurrences of pipe-like bodies of aln�ite outcrop within limestones and mudstones in northern Malaita and have been seismically imaged offshore within the OJP. The Malaita ...

... (Author). Descriptors : (*STRONTIUM COMPOUNDS, ZIRCONATES), (*ZIRCONATES, MECHANICAL PROPERTIES), (*CRYSTAL STRUCTURE ...

An article comprises a silicon-containing substrate and a zircon coating. The article can comprise a

The recently developed method of laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) allows the determination of 207 Pb/ 206 Pb ages of single zircon grains. The main advantages of the method are minimal sample preparation, low cost, and high throughput. In this work we present an analytical routine for geochronological analyses of ...

Inverted extensional basins with continental deposits of the Mitu Group straddle the Eastern Cordillera of Peru. The present study investigates the Mitu Group of south-east Peru (13-16�S), which consists of continental clastic sedimentary rocks and interbedded basaltic to andesitic lavas. There is a paucity of geochemical and geochronological data from the Mitu Group, and the interpretation of ...