Professor William Bill Compston is a renowned geophysicist who began his research career fingerprinting and dating rocks at the University of Western Australia before moving to the Research School of Earth Sciences at the Australian National University. Bill, you were born in in Western Australia, a state founded on its mineral wealth, and your mother came from the WA goldfields. But I believe your connection to geology and minerals goes back even further. They both arrived in the same year, , and got off the ship at Portland. Oh, lots of them. My schooling was a happy time for me. But during the Second World War we had to go to Toodyay, which is about 50 or 60 miles — in the old measure — from Perth, to get away from the military preparations all round Fremantle. Then we had a holiday visiting relatives in Melbourne. Ah yes. I started learning the piano when I was about seven or eight, still living at my original home.
Such a sophisticated ion probe, which can attain a high sensitivity at a high mass resolution, based on a double focusing high mass-resolution spectrometer, designed by Matsuda , was constructed at the Australian National University. Since its installation, our focus has been on the in-situ U—Pb dating of the mineral apatite, as well as zircon, which is a more common U-bearing mineral.
In this paper, we review the methodology associated with in-situ apatite dating and our contribution to Earth and Planetary Science over the past 16 years. Since the monumental studies reported in , 1 an enormous amount of work related to the Pb—Pb dating of meteorites has been reported via the use of TIMS Thermal Ionization Mass Spectrometry. After this, following cleaning with ethanol, to minimize surface contaminating Pb, the thin section was gold-coated to prevent a charge from developing on the sample surface during SHRIMP analyses.
azites of known age (Palaeoproterozoic, Mesoproterozoic and Early Devonian), determined by isotopic SHRIMP and. TIMS dating (Fig. 1). The method was then.
It is an indisputable fact that geochronology plays a vital role in geosciences. However, the application and relevant research of experimental results were constrained because traditional dating methods required dissolving samples in chemical reagent, which made it hard for researchers to obtain all information of the structurally-complex zircon. With an irreplaceable advantage in testing ages of zircon, SHRIMP II ushered in a new age of micro-area and in situ analysis of zircon chronology, producing far-reaching influence worldwide.
Following the principle of emphasizing key points, strengthening integration, optimizing allocation and scientific utilization, Beijing SHRIMP Center is the service lab featuring on open research established to meet the demand of the development of geoscience China. Under the Institute of Geology, Chinese Academy of Geological Sciences, the center engages in research on geochronology, cosmochronology, especially the microanalytical techniques of uranium and thorium, geological time scale, especially the formation of solar system and globe and the structural evolution of main orogenic belt system, ,metallogenic epoch of ore deposits andmicroanalyticaltechniques of rare earth.
This has laid a solid technology and operation basis for the establishment of a national virtual center of large instruments featured by the method of remote sharing, improving the efficiency and quality of major scientific equipment and accelerating the development of relevant research and platform building. So far, the virtual lab has provided remote experiment support for such subjects as earth science, material science, life science, medicine, nanotechnology through connecting micro-beam instrument sporadically distributed all around the country.
Foreign peer institutions also acclaimed the center as a world famous geochronology platform and one of the most outstanding geochronology lab in the world. Introduction of platform Contact us History Background of Platform.
The Jinjiang basic-intermediate dike swarms from southeast Fujian are further divided into two groups. The early-stage dike consist of hornblende diabases. Two groups of dike intruded always along joints of the late Mesozoic granitic gneiss. Geochemically, they are calc-alkaline series of basalt to andesite compositions with MgO varying from 5.
The Jinjiang basic-intermediate dike rocks have limited ranges of I sr values from 0. The overall elemental and Sr-Nd isotopic characteristics of the Jinjiang basic-intermediate dike swarms are similar to those of mafic dikes from Chinmen and Liehyu islands, and are further consistent with those of the late Mesozoic basic igneous rocks gabbros and basalts in SE Fujian.
Geochemistry, U-Pb SHRIMP zircon dating and Hf isotopes of the from representative of the samples preparation and analytical methods samples of the Río.
A Nature Research Journal. Although the quest for Earth’s oldest rock is of great importance, identifying the youngest exposed pluton on Earth is also of interest.
Thus, SIMS method is well-suited for the analysis of complex minerals, as often found in metamorphic terrains, some igneous rocks , and for relatively rapid analysis of statistical valid sets of detrital minerals from sedimentary rocks. The most common application of the instrument is in uranium-thorium-lead geochronology , although the SHRIMP can be used to measure some other isotope ratio measurements e. Bill Compston ,  trying to build an ion microprobe at the Research School of Earth Sciences of the Australian National University that exceeded the sensitivity and resolution of ion probes available at the time in order to analyse individual mineral grains.
The first successful geological applications occurred in Narryer in Western Australia  and then later at the nearby Jack Hills.
Methods recently advanced for discrimination on the genesis of metamorphic zircon, such as analysis of mineral inclusions and trace elements, provide us po.
Methods recently advanced for discrimination on the genesis of metamorphic zircon, such as analysis of mineral inclusions and trace elements, provide us powerful means to distinguish zircon overgrowth during high-pressure metamorphism. No inherited core was identified in the analyzed zircons by means of cathodoluminescence images. The occurrence of high-pressure metamorphic mineral inclusions in zircon, such as garnet, omphacite, rutile, and the flat HREE pattern in zircon indicate that the zircon formed at high-pressure metamorphic conditions.
Therefore, a weighted average U-Pb age of This is a preview of subscription content, log in to check access. Gebauer, D. Peucat, J. Earth Planet.
When you think of a laboratory, images of glass tubes, gurgling liquids, and scientists in white lab coats studiously taking notes may be some of the images which come to your mind. While it’s true that some of the time the lab work I was involved with did include gurgling liquids and white lab coats, my preconceived notions of what laboratory work is all about were quickly shattered. On my first day, I found myself put to work in a zircon picking lab where I would spend much of my first four months meticulously digging through small dishes of crushed rock material to find the best zircon crystals and set them aside to be used to determine the age of the rocks from which they formed in.
These tiny crystals, small enough to be dwarfed by my pin-tip sized tweezers, were the start of a long complicated procedure which helps provide geologists with some very powerful information. Zircon is a mineral that forms as small microscopic crystals in hot magma as it cools magma is molten rock, similar to lava, which is magma that has spilled out onto the surface of the Earth.
However, the application and relevant research of experimental results were constrained because traditional dating methods required dissolving samples in.
Always quote above citation when using data! You can download the citation in several formats below. High- to very-high-grade migmatitic basement rocks of the Wilson Hills area in northwestern Oates Land Antarctica form part of a low-pressure high-temperature belt located at the western inboard side of the Ross-orogenic Wilson Terrane. Zircon, and in part monazite, from four very-high grade migmatites migmatitic gneisses to diatexites and zircon from two undeformed granitic dykes from a central granulite-facies zone of the basement complex were dated by the SHRIMP U-Pb method in order to constrain the timing of metamorphic and related igneous processes and to identify possible age inheritance.
There is only minor evidence of age inheritance in zircons of these four samples. Zircon from two other samples metatexite, posttectonic granitic dyke gave scattered PbU ages. In the metatexite, a major detrital contribution from – Ma old source rocks can be identified. The new age data support the model that granulite- to high-amphibolite-facies metamorphism and related igneous processes in basement rocks of northwestern Oates Land were confined to a relatively short period of time of Late Cambrian to early Ordovican age.
An age of approximately Ma is estimated for the Ross-orogenic granulite-facies metamorphism from consistent ages of monazite from two migmatites and of the older zircon age population in one metatexite. The presence of inherited zircon components of latest Neoproterozoic to Cambrian age indicates that the high- to very-grade migmatitic basement in northwestern Oates Land originated from clastic series of Cambrian age and, therefore, may well represent the deeper-crustal equivalent of lower-grade metasedimentary series of the Wilson Terrane.
Median Latitude: Creative Commons Attribution 3. Blowaway, northern Oates Coast.
stratigraphy, the laser technique has certain advantages. Key words: MC-ICP-MS, SHRIMP, Faraday cups, Multi-ion Counting System, U-Pb in situ zircon dating.
For geological purposes, this is taken as one year. Another slideshare of expressing this is the half-life period given the symbol T. The half-life is the time it takes for half of the parent atoms to decay. The relationship between the two is: Many different radioactive isotopes and techniques are used for dating. All rely on the fact that certain elements particularly uranium and potassium contain a number of different isotopes whose half-life is exactly known and therefore the relative concentrations of these isotopes within a imaging or mineral can measure the deviantart.
For an element anu be useful for geochronology measuring geological time , the isotope must be reasonably abundant and produce spectrometry isotopes at a good rate. Either a whole rock or a single mineral grain can be dated. Some techniques place the sample in a nuclear reactor first to excite the isotopes present, then measure these isotopes using a mass spectrometer such as in the argon-argon scheme. Others place mineral grains under a high slideshare, firing a laser beam at the discordia which ionises the shrimp and releases the isotopes.