Results 121 to 130 of about 72,388 (278)

Predicting Groundwater Hydrochemical Facies in Three Dimensions with Random Forest Classification, USA

Groundwater, EarlyView.
Random forest classification predictions of groundwater hydrochemical facies (HCFs) can be used for multiple purposes, including the mapping of salinity and other groundwater characteristics. Shown on the figure are predictions of HCFs at the water table across the conterminous United States.
Paul E. Stackelberg, Katherine J. Knierim, Kenneth Belitz, Charles A. Cravotta III, R. Blaine McCleskey, Courtney D. Killian   +5 more
wiley   +1 more source

Damage analysis of rocks with different properties under cyclic splitting action

Solid Earth Sciences
In underground construction operations, there are different types of rocks in repeated loading and unloading environments. For this reason, in this paper, two rock samples—slate and metamorphic sandstone, which contain different properties, were ...
ZhiYong Xu, WenQiang Ao, Yi Liu
doaj   +1 more source

Metamorphic Rocks, Ireland [PDF]

Nature, 1880
THERE appears to be confusion as to the times when metamorphic action occurred among the Irish rocks; my experience would point to the following:—
openaire   +1 more source

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

Journal 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, Martin Racek, Petr Jeřábek, Benjamin Paddon   +3 more
wiley   +1 more source

Structural characterization of the metamorphic basement from North Dobrogean Promontory (Romania) using geophysical well logging

E3S Web of Conferences, 2018
Metamorphic processes, leading to mineralogical and structural changes of the rocks in response to physical (pressure, temperature) and chemical conditions, can be associated with the development of sinmetamorphic or post-metamorphic fractures.
Ciupercă Constantin-Laurian, Niculescu Bogdan Mihai, Popina Bogdan Marian   +2 more
doaj   +1 more source

Variable Sr Diffusion and Implications for Rb–Sr Biotite Geochronology

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The rubidium–strontium (Rb–Sr) system has a long pedigree as a geochronological tool that relies on the application of an isochron approach. In particular, biotite contains strongly radiogenic Rb–Sr isotopes, and thus can yield meaningful crystallisation or cooling ages via this approach. However, the response of the Rb–Sr system in biotite to
Riley Rohrer, Christopher L. Kirkland, Hugo Olierook, Tim Johnson, Katy Evans   +4 more
wiley   +1 more source

P–T Modelling Constrains the Depth of Emplacement of the Porto Azzurro Pluton and Implies Minor Exhumation Caused by the Zuccale Fault (Island of Elba, Italy)

Journal of Metamorphic Geology, EarlyView.
ABSTRACT Understanding the pressure of emplacement of granitic intrusions is crucial to understanding the exhumation history of plutons and constraining the tectonic setting of magma emplacement. However, P–T and geochronological constraints from exhumed plutons are often characterized by large uncertainties, especially in shallow crustal settings with
Samuele Papeschi, Marco Bonini, Matteo Lupi, Chiara Del Ventisette, Domenico Montanari   +4 more
wiley   +1 more source

Distribution of Fenitized Crustal Xenoliths in Carbonatite Intrusions, West-Central Arkansas [PDF]

, 1981
Crustal xenoliths from carbonatite intrusions in the Morrilton-Perryville Arkansas area display a variety of mineralogical and textural features that suggest that they are fragments of basement crystalline rock that has undergone sodic metasomatism ...
Sharp, John
core   +2 more sources

Tracking Dehydration Reactions and Fossil Fluid Flux in Shear Zones Using Garnet Microstructures

Journal of Metamorphic Geology, EarlyView.
ABSTRACT Shear zones act as preferential fluid pathways during prograde and retrograde stages of metamorphism. Nonetheless, we still have limited knowledge of the drainage and permeability of natural settings. The preserved signature of fluid in exhumed rocks provides insights into fluid flow during burial and exhumation.
Alessandro Petroccia, Francesco Giuntoli, Alissa Kotowski, Gianmarco Buono, Alireza Chogani, Eric Hellebrand, Lucia Pappalardo, Ivan Callegari   +7 more
wiley   +1 more source

Determining impact angle from the spatial distribution of shock metamorphism: A case study of the Gosses Bluff (Tnorala) impact structure, Australia

Meteoritics &Planetary Science, EarlyView.
Abstract The majority of planetary impacts occur at oblique angles. Impact structures on Earth are commonly eroded or buried, rendering the identification of the direction and angle of impact—using methods such as asymmetries in ejecta distribution, surface topographic expression, central uplift structure, and geophysical anomalies—challenging. In this
Eloise E. Matthews, Auriol S. P. Rae, Thomas Kenkmann, Nicholas E. Timms, Aaron J. Cavosie, Marian B. Holness   +5 more
wiley   +1 more source