Results 31 to 40 of about 20,254 (256)

Geologic history of Martian regolith breccia Northwest Africa 7034: Evidence for hydrothermal activity and lithologic diversity in the Martian crust [PDF]

, 2016
The timing and mode of deposition for Martian regolith breccia Northwest Africa (NWA) 7034 were determined by combining petrography, shape analysis, and thermochronology.
Adcock, Agee, Andersen, Aström, Bacon, Bagnold, Beck, Bellucci, Bibring, Bibring, Bish, Blake, Blott, Borg, Bradley, Brandon, Cannon, Carr, Cartwright, Chipera, Christensen, Claoué-Long, Collinet, Cooney, Dahl, Day, Domokos, Domokos, Downs, Dreibus, Dyar, Ehlmann, Ehlmann, Farley, Filiberto, Filiberto, Filiberto, Filiberto, Foland, Friedman, Gattacceca, Gellert, Gellert, Goderis, Golden, Greeley, Greenwood, Grimes, Grotzinger, Hartmann, Haskin, Heaman, Herd, Hiess, Hiess, Humayun, Hurowitz, Jerolmack, Jutzeler, Kaminski, Kekäläinen, Keller, Klingelhofer, Lee, Leroux, Liu, Lorand, Ludwig, Ludwig, Malin, Manga, Mattinson, McCanta, McCubbin, McCubbin, McCubbin, McCubbin, McCubbin, McEwen, McKay, McLennan, McLennan, McLennan, McLennan, McSween, McSween, McSween, McSween, McSween, McSween, Medard, Meldrum, Mezger, Monders, Monkawa, Morris, Morris, Moser, Murchie, Musselwhite, Muttik, Nekvasil, Nekvasil, Nemchin, Nyquist, Nyquist, Papike, Papike, Poulet, Santos, Sarbadhikari, Sautter, Sautter, Schmidt, Schmidt, Schoene, Schon, Sha, Sharp, Shearer, Shearer, Squyres, Squyres, Squyres, Stacey, Steele, Stolper, Szabó, Tartèse, Taylor, Taylor, Taylor, Terada, Terada, Thomson, Tosca, Treiman, Tuff, Udry, Usui, Vaniman, Vaniman, Wadhwa, Walker, Wang, Wang, Wiedenbeck, Wiedenbeck, Williams, Wingate, Wittmann, Yen   +151 more
core   +2 more sources

A study on the zircons from the pyroclastic volcanic rocks

The Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists, 1970
In this paper, the writers studied on the morphological characters of the zircon crystals from the pyroclastic volcanic rocks in Japan and obtained the following results; i) In the pyroclastic volcanic rocks, the zircons are contained in much smaller amount than in the granitic rocks and the grain sizes are mostly very minute ranging from 0.02×0.01mm ...
Kazuko Ushijima, Takashi Yamamoto
openaire   +3 more sources

Interpretation of Subsurface Structure Based on Magnetic Anomaly Analysis as Geothermal Manifestation in Lake Linting Deli Serdang

Jurnal Fisika Flux
- Research has been carried out with the aim of determining the type of subsurface lithology of the geothermal area in Lake Linting Deli Serdang, to determine the geological structure, as well as the type of rock that functions as a reservoir for ...
Yusril Padli Sitompul, Ratni Sirait, Ridwan Yusuf Lubis   +2 more
doaj   +1 more source

Holocene record of large explosive eruptions from Chaitén and Michinmahuida Volcanoes, Chile

Andean Geology, 2013
Tephra fall deposits and one large ignimbrite close to Chaitén and Michinmahuida Volcanoes were analyzed for chemistry and radiocarbon dated to correlate the eruptive units and establish the timing of eruptions.
Álvaro Amigo, Luis E. Lara, Victoria C. Smith   +2 more
doaj   +1 more source

Diagenetic processes controlled by volcanic detritus of the Lower‐Middle Permian Shanxi and Shihezi sandstone formations, North Ordos Basin, China

The Depositional Record, EarlyView.
Comparisons of Lower‐Middle Permian Shanxi and Lower Shihezi formations from the North Ordos Basin reveal that different types and percentages of volcanic detritus induced by active magmatic cycles can significantly change diagenetic evolution and favourable reservoirs.
Yuanlan Tang, Wei Jiang, Xianfeng Tan, Long Luo, Eduardo Garzanti, Jon Gluyas, Xueqi Yan, Jianping Liu, Tao Lei, Xuejiao Qu, Jia Wang, Xin Yu   +11 more
wiley   +1 more source

Numerical and experimental study on P‐wave propagation across a rock joint with different orientations

Deep Underground Science and Engineering, EarlyView.
Joint orientation significantly affects P‐wave velocity, with the highest velocity at zero‐degree angles, decreasing to 30° as the angle increases. The velocity increases slightly from 30 to 45 degrees but sharply decreases from 45 to 90 degrees. Abstract Determination of the required parameters in different science contexts using the ultrasonic wave ...
Yaghoob Zarei, Mojtaba D. fallahi, Ali Uromeihy, Mohammad R. Nikoodel, Mohammad Fathollahy   +4 more
wiley   +1 more source

"Hot and sticky" and "cold and damp" pyroclastic eruptions, and their relationship with topography: valley- and lake-filling ignimbrites, Ardnamurchan, NW Scotland

Volcanica
Pyroclastic density currents are complex mixtures of rock, ash and gas and represent significant hazards at many active volcanoes worldwide. Ignimbrites are the deposits of pyroclastic density currents and can be used to record the eruption dynamics and ...
David Brown, Ailsa Quirie, Peter Reynolds, Simon Drake   +3 more
doaj   +1 more source

Influence of Rock Properties in Estimating Rock Strength for Shallow Underground Structures in Weak Rocks

Indonesian Journal on Geoscience, 2018
DOI: 10.17014/ijog.5.2.93-105Two popular rock strength criteria, the linear Coulomb and non-linear Hoek-Brown, are widely used in underground designs. These two criteria may be applied differently depending on rock conditions.
Didi Supriadi Agustawijaya
doaj   +1 more source

Physical and mechanical characterization of the soft pyroclastic rocks forming the Orvieto cliff [PDF]

, 2002
The paper describes the results of laboratory and in situ investigations carried out on weak pyroclastic materials which could be encountered during engineering activities in volcanic regions.
RIBACCHI, Renato, ROTONDA, Tatiana, TOMMASI P   +2 more
core  

Preparation and Identification of Heavy Minerals for Archaeometrical Studies: Villa of Fiumana (FC), Italy

Journal of Raman Spectroscopy, EarlyView.
This paper presents a new protocol for the laboratory preparation of archaeological samples. Ceramics that have been hand‐crafted using different sediments as raw materials were collected in a Roman Villa sited in Fiumana (FC), Italy. This method aims at concentrating and analysing heavy minerals in the 15–250 μm grain size fraction, studying the ...
S. Andò, G. Vezzoli, M. Barbarano, L. Fornasini, L. Saviane, R. Villicich, D. Bersani   +6 more
wiley   +1 more source