U. A. Glasmacher

• Prof. Dr.
• Group Leader at Heidelberg University

Geochemical signatures of Miocene to Pleistocene sand deposits and potential source rocks including trace elements and REE were used to elucidate long-term changes in weathering and sediment transport in the northernmost part of the western branch of the East African Rift. Since the Pliocene, increased tectonic activity is reflected in deposited sa...

Fission-track and (U-Th-Sm)/He thermochronology on apatites are radiometric dating methods that refer to thermal histories of rocks within the temperature range of 40°-125 °C. Their introduction into geological research contributed to the development of new concepts to interpreting time-temperature constraints and substantially improved the underst...

The Chinese Continental Scientific Drilling (CCSD) project, part of the International Continental Drilling Program (ICDP), has completed drilling a 5158 m hole in the eastern part of the Dabie–Sulu ultrahigh-pressure metamorphic belt. This study reports on an apatite fission track analysis of core samples from 0 to 4000 m depth in the CCSD main hol...

Crystallographically oriented sections of natural gemstone quality cordierite single-crystals have been irradiated with swift heavy ions of GeV energy and various fluences. Irradiation effects on the crystal lattice were investigated by means of Raman spectroscopy. Raman line scans along the trajectory of the ions reveal a close correlation of beam...

This study reports on a fission track analysis of core samples from 0 to 5000m depth in the main hole (MH) and 0-1000m depth in the pilot PP2 of the Chinese Continental Scientific Drilling (CCSD) project. We determined the fission track ages of 59 apatite samples from different depths. The ages range between 79. 5 ±5. 1 and 50. 4 ±6. 2Ma for PP2 an...

Static elasticity measurements at high pressures were carried out on oriented fluorapatite single crystals, some of which contained oriented amorphous ion tracks (ITs) implanted with relativistic Au ions (2.2GeV) from the UNILAC linear accelerator at GSI, Darmstadt. High-pressure experiments on irradiated and non-irradiated crystal sections were ca...

In the western prolongation of the Pyrenees, the substratum of the Cantabrian Mountains consists of an E-W crustal section of the Gondwana continental margin involved in the Variscan collision. In Mesozoic times, the region was modified by rifting and the opening of the Atlantic and the Bay of Biscay, while in Paleogene-Neogene times it was affecte...

IntroductionBasin and Carbonate-Platform DevelopmentMethods and DatabaseResultsDiscussionConclusions AcknowledgementsReferences

The Rwenzori Mountains, situated SW of Lake Albert, form a striking feature within the Albertine Rift of the East African Rift System (EARS). They follow along the border of the Democratic Republic of Congo and Uganda, and extend about 120 km NS and 50 km NW. The Rwenzoris are built up by a dissected Precambrian metamorphic basement block that has...

Since the early 1990's the Paleozoic Uralide Orogen of Russia has been the target of a significant research initiative as part of EUROPROBE and GEODE, both European Science Foundation programmes. One of the main objectives of these research programmes was the determination of the tectonic processes that went into the formation of the orogen. In thi...

Natural cordierite crystals were irradiated with Xe ions of 1.465 GeV kinetic energy and fluences ranging from 108 to 1012 ions/cm2. Raman spectra of the surface and line scans along the trajectory of the ions have been recorded. At a fluence of 1012 ions/cm2 the colour of the originally blue sample changed to yellow and the Raman spectrum shows di...

Durango apatite was irradiated with energetic U ions of 2.64 GeV and Kr ions of 2.1 GeV, with and without simultaneous exposure to a pressure of 10.5 GPa. Analysis by confocal Raman spectroscopy gives evidence of vibrational changes being marginal for fluences below 5x10(11) ions/cm(2) but becoming dominant when increasing the fluence to 8x10(12) i...

A fission track analysis was carried out on the core samples from 0 ∼ 4000m in main hole of the Chinese Continental Scientific Drilling (CCSD). Fission track ages of 38 apatite samples from different depthes were dated. The distribution of them is between 98.6 ∼ 3.2Ma, and the values reduce gradually with depth increasing. The fission track age of...

In many solids, heavy ions of high kinetic energy (MeV-GeV) produce long cylindrical damage trails with diameters of order 10 nm. Up to now, no information was available how solids cope with the simultaneous exposure to these energetic projectiles and to high pressure. We report the first experiments where relativistic uranium and gold ions from th...

Within the framework of the International Continental Drilling Program (ICDP) we propose a comprehensive initiative to drill the continental crust bordering modern and ancient convergent and collisional plate boundaries. These zones host the vast majority of modern megacities and industrial installations on Planet Earth, and at the same time are lo...

A novel luminescence methodology for dating surfaces of granitoid rocks is presented, with encouraging results for archaeological stone structures. It is based on the zeroing of the latent signal of optically stimulated luminescence (OSL) in feldspar and quartz grains of the stone surface during exposure to daylight. When after bleaching the surfac...

This paper describes the fundamentals of a technique that enables the assessment of the uranium and thorium dose-rate component from fission tracks induced by neutrons. Apart from analysing elemental contents as low as 10-9g/g, the microscopic distribution of the alpha and beta dose-rates within petrologic sections can be spatially resolved down to...

The Rosengarten and Latemar Middle Triassic carbonate platforms indicate similar subsidence patterns during equivalent times of platform evolution as calculated by numerical basin reverse modelling. In the case of Rosengarten and Latemar, thermo-tectonic subsidence is the most significant among all three subsidence components (thermo-tectonic s., f...

This work is motivated by heavy-ion irradiation of materials exposed to high hydrostatic pressures in a diamond anvil cell (DAC). Those studies require the complete passage of ions through one of the two anvils consisting of natural diamond. Due to typical anvil lengths of about 2–3 mm, ion energies of a few hundred MeV/u, as provided by the SIS he...

In the Montes de Toledo area, located in the axial part of the Central Hercynian zone, a long-term thermo-tectonic evolution can be deduced from apatite fission-track (AFT) data in conjunction with tight geological constraints derived from the knowledge of regional geology and other independent chronometers. The area is composed of two different bl...

The eastern margin of the East European Craton (EEC) has a long lasting geological record of Precambrian age. Archaean and Proterozoic strata are exposed in the western fold-and-thrust belt of the Uralides and are known from drill cores and geophysical data below the Palaeozoic cover in the Uralides and its western foredeep. In the southern Uralide...

Ion tracks in solids can be visualized by appropriate etching. During the etching procedure, size and depth of the etch pits grow linearly with time. Their shape is mainly controlled by the crystal structure. For example, in muscovite, ion tracks have a rhombic cross-section after HF etching, whereas in polycarbonate etch pits are circular after Na...

In the western fold-and-thrust belt of the southern Urals, the Kbler and rkai indices determined on shales, slates and phyllites record an increase from lower late diagenetic to epizonal grade from west to east. The metamorphic grade varies strongly within the different tectonic segments, which are separated by major thrusts. The increase of diagen...

Physikalische Datierungsverfahren basieren auf dem natürlichen Zerfall radioaktiver Mutternuklide in Tochternuklide. Für den Altersbereich seit dem Auftreten des Menschen (zwei bis drei Millionen Jahre) werden vor allem die K-Ar, die Lumineszenz, die Kernspaltspuren, die Uranreihen und die Radiokohlenstoffmethode angewandt. Ständige Weiterentwicklu...

Alpha-recoil tracks (ART) are lattice defects caused by the a-decay of 238 U, 235 U, 232 Th, and daughter products. Visualization of etched ARTs in dark mica by phase-contrast microscopy allows dating of Quaternary geological as well as archaeological materials. Visualization of etched ARTs by Nomarski-differential-interference-contrast mi-croscopy...

Alpha-recoil tracks (ARTs) created by the α-decay of U, Th, and their daughter nuclei, are used by a new dating method to determine the formation age of dark mica bearing Quaternary and Neogene volcanic rocks and the cooling age of plutonic and metamorphic rocks [Chem. Geol. 166 (2000) 127, Science 155 (1967) 1103]. The age equation combines the vo...

Major and trace elements and nitrogen were analysed in 59 Cambrian and Ordovician slates/phyllites of various lithostratigraphic levels within the Meguma Supergroup, 14 Ordovician slates/phyllites of The Ovens gold mineralisation, and 16 Ordovician slates/phyllites of the Eastville Pb–Zn–Cu mineralisation.The fixed nitrogen content and the normativ...

In the external Humber zone, the emplacement episodes of allochthonous nappes and related low-grade metamorphism are mainly based on paleontological ages from the St. Lawrence Lowlands. In fact, Late Ordovician flysches are affected by thrusting, and it is not clear if the nappe imbrication is the result of the Taconian or the Acadian deformation....

A fission-track (FT) study was carried out on apatite from Upper Proterozoic to Upper Carboniferous sedimentary and volcanic rocks in the Barrandian, Czech Republic. Apatite FT-ages vary between 324±8 Ma (Lower Carboniferous) and 196±14 Ma (Lower Jurassic). Mean confined track lengths range from 11.68±1.76 to 13.30±1.41 μm. The temperature–time pat...

Archaeochronometry uses luminescence dating to reveal ages of sediments and artefacts. Uncertainties in luminescence ages are partly related to the dating procedure, which uses grain separates. This is particularly true for stone surfaces, which require an imaging method for luminescence detection. Here we present the development of a novel lumines...

A new geological dating method uses alpha-recoil tracks (ART) created by the natural a-decay of U, Th, and their daughter products. When visualizing ART by optical microscopy, the age range is restricted to the last 10(6) a. Recording of etched ART by scanning force microscopy (SFM) enables the access to track densities beyond 10(8) cm(-2) and thus...

The Uralides, a linear N-S trending Palaeozoic fold belt, reveals an intact, well-preserved orogen with a deep crustal root within a stable continental interior. In the western fold- and-thrust belt of the southern Uralides, Devonian to Carboniferous siliciclastic and carbonate rocks overlay Mesoproterozoic to Neoproterozoic sedimentary rocks. Defo...

Apatite fission track study of the Chaudiere and Motmorency transect indicates that at least 3000 m of cover have been eroded from the Precambrian basement since the Early Cretaceous. https://sociedadgeologica.org/publicaciones/geotemas/geo-temas-4/

A new dating technique uses alpha-recoil tracks (ART), formed by the natural alpha-decay of U, Th and their daughter products, to determine the formation age of Quaternary volcanic rocks (<10(6) a). Visualization of etched ART by scanning force microscopy (SFM) enables to access track densities beyond 10(8) cm(-2) arid thus extend the new ART-datin...

Apatite Fission Track data set limits for the timing in the evolution of the Laurentian Margin of Quebec and the development of the St Lawrence Rift System

Clay mineral crystallinity of Early Paleozoic shale and slate samples from five boreholes (G 14-1, K 5-1, H 2-1, Rügen 5, Loissin 1) across the Caledonian Deformation Front were determined to characterize the thermal grade. In general, the mineral composition of the samples as revealed by X-ray diffraction (XRD)-analysis of the < 63 μm size fractio...

Two contrasting provenance areas for Neoproterozoic sandstones can be distinguished in the southwestern Urals by light and heavy mineral analyses as well as by mineral chemistry. These reflect a dramatic change of geotectonic conditions at the eastern border of the Baltica protocontinent at around 610–620 Ma. Detritus from Riphean and Lower Vendian...

An integrated geological study of the tectono-metamorphic evolution of the metamorphic complex of Beloretzk (MCB) which is part of the eastern Bashkirian mega-anticlinorium (BMA), SW Urals, Russia shows that the main lithological units are Neoproterozoic (Riphean and Vendian age) siliciclastic to carbonate successions. Granitic, syenitic and mafic...

A combined optical and X-ray characterisation of fine-grained micas in granodioritic to tonalitic dikes and intrusions of the Eastardennes–Eifel nappe (Linksrheinisches Schiefergebirge, Germany–Belgium) was completed with K–Ar dating of separated size fractions from these rocks. In each sample, the K–Ar ages decrease with decreasing size fraction,...

From three Rügen boreholes (G14, Rügen 5, Loissin 1) across the Caledonian deformation front four Lower Palaeozoic slate samples and three detrital muscovite concentrates from associated sandstones have been analysed by ⁴⁰ Ar/ ³⁹ Ar analysis. Microprobe analysis of the detrital muscovites show homogeneous, but distinct chemical compositions for eac...

West of the Main Uralian fault, the main suture in the southern Urals, 40Ar/39Ar apparent ages of amphibole, muscovite and potassium feldspar are interpreted as cooling ages. A fast exhumation of the metamorphic complex of Kurtinsky during Upper Carboniferous time is indicated by the small age difference (15 Ma) between cogenetic amphibole and musc...

The Bashkirian anticlinorium of the southwestern Urals shows a much more complex structural architecture and tectonic evolution than previously known. Pre-Uralian Proterozoic extensional and compressional structures controlled significantly the Uralian tectonic convergence. A long-lasting Proterozoic rift process created extensional basement struct...

The low-temperature thermal history of Paleozoic and Precambrian shales and slates was studied in detail along a NW-SE transect between Ufa and Beloretzk in the western fold-and-thrust belt of the southern Urals, Russia. The aim of the investigations was to compare four thermal parameters, namely illite and chlorite crystallinity, vitrinite reflect...

A fission track investigation was carried out on apatite from Paleozoic sandstones along a NW-SE transect and the Hill-intrusion in the northern Linksrheinisches Schiefergebirge. The study included age determinations, confined track length and chemical analysis as well as computer modeling of the thermal history. Apatite fission track ages vary bet...

The mineral cordierite is a framework silicate with cor-ner-sharing six-membered rings of SiO 4 -tetrahedra, form-ing channels along the crystallographic c-axis. During crystal growth, these channels incorporate alkali atoms and various volatiles (e.g., Na, K, CO 2 , H 2 O, CH 4). Natural cordierite single crystals from Madagascar were oriented wit...

In geological minerals, tracks of fragments from spon-taneous fission of U nuclei accumulate over geological time scales and are widely used for fission-track dating and thermochronology [1, 2]. In our recent studies, we tackled the problem how solids exposed to energetic heavy ions cope with the simultaneous exposure of exter-nal pressure. This co...

"März 1991"--Cover. Thesis (doctoral)--Rheinisch-Westfälische Technische Hochschule Aachen, 1990. Includes bibliographical references (p. 330-351).