نتایج جستجو برای: breccia

تعداد نتایج: 715  

Journal: :Geological Magazine 2021

Abstract Enrichment of the heavy rare earth elements (HREE) in carbonatites is as carbonatite petrogenesis favours light (L)REE. We describe HREE enrichment fenitized phonolite breccia, focusing on small satellite occurrences 1–2 km from Songwe Hill carbonatite, Malawi. Within breccia groundmass, a HREE-bearing mineral assemblage comprises xenotime, zircon, anatase/rutile and minor huttonite/th...

2010
REGINALD P. BRIGGS

The Figuera Lava, the oldest stratigraphic unit now recognized in northeastern Puerto Rico, and the overlying Fajardo Formation are redescribed and the name Figuera redefined and reinstated for formal use. Previously, lower Tertiary strata some distance from the type areas of the Figuera and Fajardo were correlated with the units by reconnaissance. Recent detailed mapping and paleontology now p...

Journal: :Science 2012
S W Squyres R E Arvidson J F Bell F Calef B C Clark B A Cohen L A Crumpler P A de Souza W H Farrand R Gellert J Grant K E Herkenhoff J A Hurowitz J R Johnson B L Jolliff A H Knoll R Li S M McLennan D W Ming D W Mittlefehldt T J Parker G Paulsen M S Rice S W Ruff C Schröder A S Yen K Zacny

The rover Opportunity has investigated the rim of Endeavour Crater, a large ancient impact crater on Mars. Basaltic breccias produced by the impact form the rim deposits, with stratigraphy similar to that observed at similar-sized craters on Earth. Highly localized zinc enrichments in some breccia materials suggest hydrothermal alteration of rim deposits. Gypsum-rich veins cut sedimentary rocks...

Journal: :KnE Social Sciences 2022

Landslides are caused by changes in the structure of subsurface materials on steep slopes due to weathered rock conditions and soil pores saturated conditions. This study used geoelectric resistivity method identify type landslide-susceptible areas Pacet-Trawas road corridor, Pacet District, Mojokerto Regency. The research location was an area with undulating mountainous morphology. geoelectric...

Journal: :Canadian Journal of Earth Sciences 2021

The Midcontinent Rift System of North America is a ?1.1 Ga large igneous province comprising mainly flood basalts and intrusive rocks. We present new data for the Pillar Lake Volcanics Inspiration Sill from northern edge in northwestern Nipigon Embayment. comprise ?20–40 m thick, flat-lying sequence mafic pillowed massive flows, flow breccia, hyaloclastite breccia. They are characterized by SiO...

Journal: :Mongolian geoscientist 2022

The Shand Cu-Mo deposit is located in the Orkhon-Selenge depression, Northern Mongolia. It lies near Erdenetiin Ovoo porphyry deposit, which together define one of Mongolian’s most economically significant metallogenic belts. In (Au?) several ore related breccia types are associated with porphyritic granodiorite intrusions, and they contain pre-, synand post-mineralized stocks, magmatic-hydroth...

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