<abstract xmlns="http://www.w3.org/1999/xhtml">

Cu-Ni-Co-PGE mineralization occurs at Haidbachgraben in the Early Palaeozoic, Subpenninic Hollersbach Complex of the Central Tauern Window, Austria. Massive sulfide ore formed from sulfide melt segregated from silicate melt during intrusion of pyroxenite into magmatic rocks formed in an MORB-type environment. Relics of magmatic minerals include chromian spinel and polyphase sulfide droplets composed of pyrrhotite, chalcopyrite and pentlandite preserved in recrystallized pyrite. Both ore and host rocks were multiply deformed and metamorphosed, leading to hornblendite carrying the ore, enveloped by chlorite-epidote schist. Conditions of – likely Variscan – amphibolite facies metamorphism are documented by relict pargasitic cores in hornblende and actinolite-tremolite, and by ternary sulfarsenide compositions in the Co-Ni-Fe solid solution series that are the most common accessory minerals found in the sulfide ore. Pyrrhotite, pentlandite, chalcopyrite and pyrite are the major sulfide minerals. Chalcopyrite is Cd-rich and retains a high-temperature magmatic signature. High Co/Sb and moderate Se/As ratios in pyrite also point to a magmatic environment of mineralization. The accessory mineral assemblage of small grain size (mostly &lt;10 µm) comprises native Au-Ag alloy and petzite as Au-Ag minerals, sperrylite, a variety of Pd tellurides and bismuthotellurides with elevated Sb, irarsite, and Re sulfides such as tarkianite and a Pb-Re sulfide. In addition, minor molybdenite, bournonite, scheelite and selenides have been identified. Two precious metal assemblages are present in individual samples: (1) hessite associated with Pd tellurides, often accompanied by sphalerite and chalcopyrite; (2) tarkianite forming euhedral inclusions in pyrite. Sperrylite and Au-Ag native alloys are present throughout and were also detected in silicate matrix. Most of the precious metal-bearing phases must have formed during recrystallization of base metal sulfides after the magmatic, and probably during later metamorphic events terminating in the Neoalpine Tauern crystallization.
</abstract>

Department of Civil Engineering and Natural Resources

Petrologia i Geologia Aplicada, Facultat de Ciènces de la Terra, Universitat de Barcelona

The Haidbach deposit in the Central Tauern Window, Eastern Alps, Austria: a metamorphosed orthomagmatic Ni-Cu-Co-PGE mineralization in the Polymetallic Ore District Venediger Nappe System – Hollersbach Complex

<abstract xmlns="http://www.w3.org/1999/xhtml">

For a long time, the 1.38 Ga old Dobra Gneiss (Type A) from the Lower Austrian Drosendorf Unit (Moldanubian Zone, Bohemian Massif) was considered the oldest rock of Austria. We now have dated zircons from a local mafic inlayer in the Dobra Gneiss Type A, termed Hauergraben Gneiss. This small-scale amphibole-bearing orthogneiss has a magmatic formation age of 1.40 Ga, and is, thus, to the present state of knowledge, the oldest rock of Austria. Based on geochemical investigations, the protolith of the Hauergraben Gneiss was a quartz-monzonite. It probably originated in a volcanic arc setting like the Dobra Gneiss, but shows distinctively higher transitional metal contents (especially Cr and Co), higher Ba and Sr, and higher light rare earth element contents, which hint at a lithospheric mantle input. This 1.40 Ga old mafic arc material was then incorporated into the 1.38 Ga old intrusive protolith of the Dobra Gneiss, probably in the form of enclaves. Considering the model that the Drosendorf Unit was part of Amazonia until the late Neoproterozoic, we propose that both, Dobra Gneiss Type A and Hauergraben Gneiss, originated at the western margin of the Columbia super-continent, where several long-lived Mesoproterozoic volcanic arcs existed and accreted over time. During the Variscan orogeny, the Hauergraben Gneiss experienced peak metamorphic temperatures of ~620 °C at pressures of ~6 kbar, as can be deduced from amphibole thermobarometry. This is in line with published peak-<italic>PT</italic> estimates from other parts of the Drosendorf Unit. Formation of secondary low-Al magnesiohornblende at the expense of the earlier edenitic/pargasitic peak amphibole indicates a subsequent retrograde overprint.
</abstract>

Department of Chemistry and Physics of Materials

In search of the oldest rock of Austria: The Hauergraben Gneiss, a 1.40 Ga old mafic quartz-monzonitic inlayer in the Dobra Gneiss (Drosendorf Unit, Bohemian Massif) as a new candidate

<abstract xmlns="http://www.w3.org/1999/xhtml">

The Grazer Bergland is a mountainous region at the eastern end of the Alps that escaped glacial erosion in the Pleistocene and thus preserves low-relief landforms that are relics of the earlier uplift history. These relic landforms may reflect a Piedmonttreppe that formed during a series of stages of a wide-reaching Pliocene uplift event that interacts with the landscape evolution, but this model is not uniquely accepted for the region. In order to test this model and for a future better correlation of the paleosurfaces with those mapped in other regions, it is important to benchmark these relic landforms. We do so by presenting a geomorphic map of the Bergland region over some 600 km2. We describe the well-known levels Stadelberg/Zahrerberg- (at 540 – 700 m a.s.l.), Kalkleiten/Hochstraden- (at 700 – 850 m a.s.l.), Trahütten- (at 950 – 1100 m a.s.l.), Hubenhalt- (at 1200 m a.s.l.), as well as Wolschenegg- and Kor- (at 1200-1720 m a.s.l.) levels and correlate their distribution in space and time. Fluvial channels between segments of the relic surfaces have knickpoints that correlate with the planation surfaces, which is in strong support of the Piedmonttreppe model. Our analysis results in a model that interprets the course of the Mur river to be the product of a river piracy event near Peggau at the time of the planation of the Trahütten level (about 4 Ma), diverting the paleo-Mur from an eastwards course along the Mürz valley in direction Vienna, towards Graz. Thereafter, the Mur remained antecedent with respect to the uplift of the surrounding massifs resulting in massive base level drop for many tributaries, like the Mixnitzbach or Rötschbach. The resulting knickpoints have since migrated upstream to cause successive minor river capture events, for example the Rötschbach capture at Kesselfall. We also show that the presence of lower levels in the Passail Basin is best interpreted in terms of the more efficient erosion of basin sediments that filled a Miocene half graben north of the Schöckl ridge and analyze the two major drainages of the region, the Raab and the Weizbach.
</abstract>

The Relic Landscapes of the Grazer Bergland: Revisiting the Piedmonttreppen Debate

<abstract xmlns="http://www.w3.org/1999/xhtml">

The conditions in ancient evaporative environments conducive to authigenic carbonate (especially dolomite [CaMg(CO3)2]) formation are still insufficiently understood. Insights from microfacies analysis can help to constrain the conditions in these environments. We provide a brief overview of the microfacies association and carbon and oxygen isotope compositions of dolomite beds intercalated in a claystone-rich succession from the Norian Arnstadt Formation in Thuringia and Lower Saxony (Germany) in order to gain further insight into the depositional conditions and processes leading to the formation of authigenic Mg/Ca-carbonates in the Germanic Basin. The studied intervals are ascribed to lacustrine, partially evaporitic conditions, while the sedimentary structures were not obliterated by recrystallization. The microfacies of the dolomites is diverse, showing homogeneous micrite, mudclasts, lamination, and peloidal structures, and reflects a shallow to deeper water (below wave base) and episodically evaporative environment. The dolomites exhibit oxygen isotope values (δ18O) in the range from −5.21 to −0.36‰ VPDB and, hence, only represent a weak meteoric influence, suggesting that the authigenic carbonate generally formed under evaporative conditions. Carbon isotope values (δ13C) in the range of −4.28 to 1.39‰ VPDB indicate a small contribution of remineralized organic carbon, mainly in sediments that were presumably deposited in deeper water or under brackish conditions. Sedimentary structures, such as lamination with graded silt layers, reworked mudclasts embedded in a fine dolomicrite matrix, and peloids showing plastic deformation, indicate that the sediment was still unlithified. These observations would be consistent with an authigenic formation of Mg/Ca-carbonates directly from the lake water, and their deposition under variable conditions in a large playa-lake/perennial lake system.
</abstract>

Microfacies and C/O-isotopes in lacustrine dolomites reflect variable environmental conditions in the Germanic Basin (Arnstadt Formation, Upper Triassic)

<abstract xmlns="http://www.w3.org/1999/xhtml">

In the course of field investigations and formalisation of Quaternary deposits in the Lake Neusiedl/Seewinkel and Hanság area the Osli Formation is designated as new formal lithostratigraphic unit. It covers an area of ~200 square kilometres and, in historic times, wetlands such as swamps and peat bogs extended from Waasen in the south-eastern Seewinkel Plain to the Hanság (Kisalföld). Due to missing stratigraphic data this formation cannot be formally divided into two members but into a lower and upper section instead. The lower section of the Osli Formation was cored in the Seewinkel Plain and consists of lacustrine deposits of up to 10 metres in thickness that were presumably deposited during Preboreal. Despite the draining of the Hanság over centuries and decades of peat mining, the upper section of the Osli Formation nowadays still consists of an at least one-meter-thick succession of peat intercalated with fluvio-lacustrine deposits. The investigated peat layers at Tétényi-Hany (~5 km north of Osli) were 14C-dated, ranging in age from ~2,400 BC to 1,500 AD. 14C ages of peat profiles at Osli-Tőzegbánya (Fövenyes-tó), located ~2,5 km northeast of Osli, even date back to ~4,000 BC. Hence the 10 to 12 m thick Osli Formation can be dated as Holocene. It is underlain by Quaternary deposits of the Illmitz Formation.
</abstract>

Vienna Environmental Research Accelerator (VERA)-Laboratory, Faculty of Physics, Isotope Physics

The Osli Formation – a Holocene lithostratigraphic unit in the Danube/Kisalföld Basin, eastern Austria and northwestern Hungary

AHEAD OF PRINT

Volume 117 (2024): Issue 1 (January 2024)

Volume 116 (2023): Issue 1 (January 2023)

Volume 115 (2022): Issue 1 (January 2022)

Volume 114 (2021): Issue 1 (January 2021)

Volume 113 (2020): Issue 2 (June 2020)

Volume 113 (2020): Issue 1 (January 2020)

Volume 112 (2019): Issue 2 (December 2019)

Volume 112 (2019): Issue 1 (June 2019)

Volume 111 (2018): Issue 2 (December 2018)

Volume 111 (2018): Issue 1 (September 2018)

Austrian Journal of Earth Sciences

 AUSTRIAN JOURNAL OF EARTH SCIENCES is the official journal of the Austrian Geological (ÖGG), Mineralogical (ÖMG), Palaeontological (ÖPG) and Hydrogeological (ÖVH) Societies, hosted by a country that is famous for its spectacular mountains, sedimentary basins and classical fossil sites that were and are the birthplace for many geoscientific concepts in modern Earth science. Further information on the journal may also be obtained from the local website at: www.ajes.at     AUSTRIAN JOURNAL OF EARTH SCIENCE focuses on all aspects relevant to the geosciences of the Alpine realm including the Bohemian Massif, the surrounding sedimentary basins and related regions in Central Europe, for example the Tethyan and Paratethyan realms. As such, we invite contributions from the fields of mineralogy, geology, geophysics, petrology or hydrogeology, as well as all aspects of palaeontology, palaeobiogeography and biostratigraphy that are of relevance to the greater Alpine orogen and its surrounding oceans. Contributions on other regions are welcome if they embed their findings into a conceptual framework that relates the contribution to Alpine-type orogens and Alpine regions in general and are thus relevant to an international audience. Contributions are subject to peer review and editorial control according to SCI guidelines to ensure that the required standard of scientific excellence is maintained.     AUSTRIAN JOURNAL OF EARTH SCIENCES is a peer reviewed journal.   Why subscribe and read   The journal of the Austrian Geological Society is published for more than 100 years, starting in 1908 as ‘Mitteilungen der Geologischen Gesellschaft in Wien’. Traditionally, the main focus of the journal is on Alpine and Austrian geology and applied geosciences but contributions to all aspects of Earth Sciences are welcome. Austrian Journal of Earth Sciences is an Open Access Journal hosted as of 2018 by SCIENDO. For earlier back issues go to the Archive section at: ajes.at/index.php/archive   Why submit   The journal of the Austrian Geological Society is published for more than 100 years, starting in 1908 as ‘Mitteilungen der Geologischen Gesellschaft in Wien’. Traditionally, the main focus of the journal is on Alpine and Austrian geology and applied geosciences but contributions to all aspects of Earth Sciences are welcome. Austrian Journal of Earth Sciences is an Open Access Journal hosted as of 2018 by SCIENDO. As of 2021, AJES represents all Austrian Earth Science societies. For earlier back issues go to the Archive section at: ajes.at/index.php/archive     Archiving   Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.   Plagiarism Policy   The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 