Results 121 to 130 of about 394,950 (321)

Conjunctive K-Ca and Rb-Sr dating of glauconies

, 2008
The glaucony series (of which glauconitic mica is the K-rich end member) is one of the few widely occurring minerals in the sedimentary record. So their isotopic ages determined mainly by the K-Ar method represent a major database for the geologic time ...
Gopalan, K.
core   +1 more source

A Low‐Power Radioisotope XRF Spectrometer for Detection of Light Elements on Planetary Missions

X-Ray Spectrometry, EarlyView.
ABSTRACT Current X‐ray spectrometers for in situ geochemical analysis on planetary missions typically rely either on X‐ray tubes, which demand electrical power and add mass and thermal complexity, or on alpha particle X‐ray spectrometers (APXS) that use rare 244Cm$$ {}^{244}\mathrm{Cm} $$ sources, and come with severe concerns on radiation safety and ...
Leandro Silveri, Artem Knyazev, Hashem Alaidaros, Maryam Manzoor Amanullah, Zach Ioannou, Tengiz Ibrayev, Danish Khan, Sara Leardini, Laura Manenti, Simi Maria Emilia Mangani, Safa Naseem, Sandhya Sharma, Sara Trevisan, Alia Zino, Francesco Arneodo   +14 more
wiley   +1 more source

The Rb/Sr geochronology of the Archean Chibougamau pluton, Quebec

, 1980
The U–Pb zircon age for the Chibougamau pluton is some 200 Ma older than the published Rb–Sr total-rock age. However, application of sample rejection techniques based on petrography, volatile content, and major-element chemistry to published and new Rb ...
C. Brooks
core   +1 more source

Multielemental Analysis in Rice Grains by Total Reflection X‐Ray Fluorescence

X-Ray Spectrometry, EarlyView.
ABSTRACT Rice (Oryza sativa) is a staple food cultivated worldwide and represents a significant source of essential nutrients for humans. However, this cereal may also contain potentially toxic elements including chromium, arsenic, and lead typically present at trace concentrations (ng.g−1).
F. T. S. Tsuyama, R. G. Leitão, C. G. L. Canellas, G. C. Ferreira, J. L. Pereira, R. S. Santos, J. T. Assis, D. F. Oliveira, M. J. Anjos   +8 more
wiley   +1 more source

ORIGEM, SIGNIFICADO PETROGENÉTICO E IDADE DOS ORTOGNAISSES TERRA NOVA: REGISTRO DE MAGMATISMO ALCALINO EXTENSIONAL NEOPROTEROZOICO NO DOMÍNIO DA ZONA TRANSVERSAL DA PROVÍNCIA BORBOREMA [PDF]

Geochimica Brasiliensis, 2016
Os ortognaisses sieníticos de Terra Nova ocorrem encaixados na Faixa Feira Nova do Complexo Vertentes, no extremo leste do terreno Rio Capibaribe da Província Borborema, Nordeste do Brasil.
Haroldo Monteiro Lima, Valderez Pinto Ferreira, Edilton José dos Santos, Marcio Martins Pimentel, Lauro Montefalco de Lira Santos   +4 more
doaj  

Rb-Sr constraints on the age of Moon formation

Icarus
Determining the age of the Moon, which is commonly considered as the termination of Earth accretion has been a complex challenge for geochronology. A number of methods have been used to delineate the age of the Moon based either on absolute chronology of lunar rocks or have relied on more indirect methods using short-lived nuclides such as 182Hf that ...
Yobregat, Elsa, Fitoussi, Caroline, Bourdon, Bernard   +2 more
openaire   +3 more sources

Alkaline‐Earth Metal Complexes Based on Tridentate β‐Diketiminate Ligands Bearing a Tethered Secondary Amine: Synthesis and Characterization

Zeitschrift für anorganische und allgemeine Chemie, EarlyView.
Deprotonotion of a β‐diketiminate ligand with a tethered secondary amine resulted in highly stable heteroleptic complexes, but the formation of the dianionic ligand could not be achieved. The alkaline‐earth (Ae) metal chemistry of a β‐diketiminate (BDI) ligand with a bulky Ar‐substituent and a pendant amine arm was investigated. The ligand precursor HC[
Bastian Rösch, Jefferson Guzmán, Heiko Bauer, Jürgen Pahl, Michael Wiesinger, Ana Escalona, Sjoerd Harder   +6 more
wiley   +1 more source

ILGIN SAHASI (KONYA) BİTÜMLÜ KİLTAŞI ÇÖKELİMİ HAVZASINDA PALEO-HİDROTERMAL ÇÖKELME KOŞULLARI, PALEO-HİDRODİNAMİK OLAYLAR VE PALEO-İKLİM İNCELEMELERİ

Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi
Hidrotermal akışkan faaliyetleri kiltaşı ve şeyl gibi bitümlü sedimanter kayaçlardaki Mo, U, Cu, Ni ve Zn gibi iz elementlerin zenginleşmesinin yanı sıra organik maddenin korunma derecesini de önemli ölçüde etkiler. İncelenen örneklerinin Fe/Ti (ort: 126,
Fuat Erol, Kamal Ismayılzada, Ali Sarı, Elif Akıska   +3 more
doaj   +1 more source

Crystal Structure of [Sr(SeC2H)2(NH3)2], Solved and Refined From Powder X‐Ray Diffraction Data

Zeitschrift für anorganische und allgemeine Chemie, EarlyView.
The synthesis and crystal structure of [Sr(SeC2H)2(NH3)2] are described, the first alkaline earth metal compound with the recently discovered –SeC2H anion. The title compound releases NH3 even under ambient conditions, so its crystal structure had to be determined from moderately resolved X‐ray powder diffraction data.
Lisa Körtgen, Tim Mattick, Uwe Ruschewitz   +2 more
wiley   +1 more source

Strontium–Neodymium isotopic compositions of eighteen geological Chinese reference materials measured on TIMS and MC-ICP-MS

Solid Earth Sciences
This study presents radiogenic Sr–Nd isotopic compositions of eighteen geological Chinese reference materials (RMs) measured on TIMS and MC-ICP-MS independently.
Wenke Wang, Jiaojiao Wu, Fang Liu, Xin Li, Yajun An, Zhaofeng Zhang   +5 more
doaj   +1 more source