Results 41 to 50 of about 7,254 (226)

Evidence for an impact-induced biosphere from the δ34S signature of sulphides in the Rochechouart impact structure, France [PDF]

open access: yes, 2017
The highly eroded 23 km diameter Rochechouart impact structure, France, has extensive evidence for post-impact hydrothermal alteration and sulphide mineralization.
Boyce, A.J.   +4 more
core   +1 more source

The Middle Jurassic Alpine Tethyan Unconformity and the Eastern Sardinia - Corsica Jurassic High: A sedimentary and regional analysis [PDF]

open access: yes, 2016
Investigations performed along the Middle Jurassic Alpine Tethyan unconformity surface of E Sardinia evidenced an elaborate surface that developed over older Late Paleozoic to Triassic rocks. This surface is covered by the Middle Jurassic Genna Selole Fm,
Costamagna, Luca Giacomo
core   +2 more sources

Reassessing the intrusive tempo and magma genesis of the late Variscan Aar batholith: U–Pb geochronology, trace element and initial Hf isotope composition of zircon

open access: yesSwiss Journal of Geosciences, 2022
The Variscan orogeny was responsible for the formation of a significant volume of igneous basement throughout present-day Europe. Detailed understanding of these rocks has, however, been obfuscated by significant overprinting during younger geologic ...
Mélissa Ruiz   +7 more
doaj   +1 more source

Jadeite in Continental Subduction: Its Preservation, Breakdown and Pseudomorphic Replacement in Erzgebirge UHP Gneisses

open access: yesJournal of Metamorphic Geology, EarlyView.
ABSTRACT The absence of jadeite in regions where subduction of continental crust has been documented by other high‐pressure (HP) or ultrahigh‐pressure (UHP) minerals is striking. This study presents only the second discovery of jadeite in the crystalline rocks of the Erzgebirge, a region known for its occurrences of microdiamond, coesite and omphacite ...
Ondrej Lexa   +3 more
wiley   +1 more source

Tectonostratigraphic terranes and zones juxtaposed along the Mid-Hungarian Line: their contrasting evolution and relationships [PDF]

open access: yes, 2010
The Mid-Hungarian (or Zagreb-Zemplin) Line of WSW–ENE strike divides the Pannonian basement into two mega-units, the Tisia Composite Terrane in the SE and the ALCAPA Composite Terrane in the NW. They became juxtaposed no earlier than the Middle Miocene
Brezsnyánszky, Károly   +4 more
core   +1 more source

The Muschelkalk aquifer of the Molasse basin in SW-Germany: implications on the origin and development of highly saline lithium-rich brines in calcareous hydrothermal reservoirs

open access: yesGeothermal Energy, 2023
Highly saline lithium-rich hydrothermal fluids (measured chloride concentration up to 44 g kg−1, lithium concentration up to 162 mg kg−1) occur in the deep calcareous Muschelkalk aquifer beneath the northern Alpine foreland (Molasse) basin.
Ingrid Stober   +2 more
doaj   +1 more source

Vertical profiling of shock attenuation at the Rochechouart impact structure, France

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Rochechouart, south‐west France, is a complex impact structure. Here, we present the first report of shock barometry of quartz from what are likely parautochthonous basement units at depth, based on samples from the 2017 C.I.R.I.R drilling campaign. The crystallographic orientations of 725 sets of PDFs in 512 quartz grains in samples from four
P. Struzynska   +4 more
wiley   +1 more source

Regional scale surface of the top of the Variscan basement in the central sector of Italy

open access: yesJournal of Maps, 2023
In this study, we combined regional geology and geostatistical analytical processing to model the top surface of the Variscan basement in Italy. This surface, which is overlain by the pre-Alpine sedimentary cycle (Upper Carboniferous – Permian) followed ...
Eugenio Trumpy   +2 more
doaj   +1 more source

Static recrystallization of shocked calcite in Ries impact breccias

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Calcite is prone to chemical and microstructural modifications, especially after having been strained at high stresses and strain rates, as during hypervelocity impact events. These modifications include precipitation from pore fluid as well as replacement of strained volumes by recrystallization. In calcite aggregates of a metagranite breccia
Claudia A. Trepmann   +8 more
wiley   +1 more source

A lead isotope perspective on urban development in ancient Naples [PDF]

open access: yes, 2016
The influence of a sophisticated water distribution system on urban development in Roman times is tested against the impact of Vesuvius volcanic activity, in particular the great eruption of AD 79, on all of the ancient cities of the Bay of Naples ...
Albarède, Francis   +6 more
core   +2 more sources

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