Results 1 to 10 of about 501 (102)

The Eastern Shore Spessartite Dykes, Nova Scotia, Canada: A Glimpse Into the Subcontinental Lithospheric Mantle Under the Meguma Terrane

Atlantic Geoscience
The ca. 370 Ma Eastern Shore dykes include six single or multiple (two or three) parallel spessartite dykes that trend NNW in the Sheet Harbour area of eastern mainland Nova Scotia. Spessartite is a variety of calc-alkaline lamprophyre that characteristically occurs in dykes associated with granitoid rocks and gold mineralization in orogenic belts ...
Sandra Barr, Chris E White, Shae J Nickerson   +2 more
exaly   +5 more sources

Study of Petrography and petrogenesis of Monavvar area Spessartite dykes (East Azerbaijan Province) [PDF]

پترولوژی, 2023
Many lamprophyric dykes' outcrops are found in Azerbaijan (in the northwest of Iran). These dykes which were the subject of many studies are including camptonite dykes in Misho Mountain, kersantite dykes of Goye-Poshti Mountain of Maragheh, camptonite ...
Mohsen Moayyed, Mahdy Ghaderi, Zahra gharechahi, Jamshid Ahmadian   +3 more
doaj   +4 more sources

GEOCHEMICAL AND PETROLOGICAL STUDIES OF A CARBONATISED METALAMPROPHYRE AT KALAGALLA - EVIDENCE FOR SHOSHONITIC CALC-ALKALINE MAGMATISM WITHIN AURIFEROUS RAMAGIRI-PENAKACHERLA SCHIST BELT (2.5 Ga), EASTERN DHARWAR CRATON, SOUTHERN INDIA

Geochimica Brasiliensis, 2020
Geochemical and petrological characteristics of a lamprophyre dyke at Kalagalla intruded into the auriferous schistose rocks of the Ramagiri-Penakacherla Schist Belt, Anantapur district, Andhra Pradesh, India are presented here. The Kalagalla lamprophyre
Rameshchandra Phani Pothuri, Raúl Lira, María José Espeche, Ananda Reddy Rokalla   +3 more
doaj   +5 more sources

Petrology and dating of the Permian lamprophyres from the Malá Fatra Mts. (Western Carpathians, Slovakia)

Geologica Carpathica, 2018
Calc–alkaline lamprophyres are known from several localities in the Malá Fatra Mountains. They form dykes (0.5–3 m) of varying degree of alteration that have intruded the surrounding granitoid rocks which are often incorporated xenoliths. Clinopyroxenes (
Spišiak Ján, Vetráková Lucia, Chew David, Ferenc Štefan, Mikuš Tomáš, Šimonová Viera, Bačík Peter   +6 more
doaj   +3 more sources

Astérisme inhabituel sur un brut de grenat spessartite/almandin du brésil

Gemmes
Un brut de grenat spessartite/almandin présente un effet optique analogue à un multi-astérisme, mais formé de douze étoiles grossières à 4 branches. Cependant, le mouvement des étoiles lors de la rotation du cristal sous une source de lumière ponctuelle est opposé à celui observé sur des cabochons de pierres astériées.
Jean-Pierre Gauthier, Marine Bouvier, Nicolas Stephant, Jacques Ferreire   +3 more
semanticscholar   +3 more sources

Spessartite in the Cambrian Manganese Ore of Merionethshire [PDF]

Geological Magazine, 1935
A. W. Woodland
exaly   +3 more sources

In situ U–Pb age determination of apatite from carbonatite and kimberlite in the Batain Basin, eastern Oman

Frontiers in Earth Science, 2023
Northeastern Oman is characterized by carbonatite and kimberlite complexes, which are the ideal samples for studying the relationship between carbonatite and kimberlite. However, the ages of the Oman kimberlite and carbonatite complexes are still unknown,
Jing Sun, Jing Sun, Leiyin Jiang, Jiaxuan Sun   +3 more
doaj   +2 more sources

The chemical composition and age of monazite and kularite from titanium ore of Pizhemskoye and Yarega deposits (Middle and Southern Timan)

Georesursy, 2020
A study on the typomorphic characteristics and age of the monazite the two giant titanium deposits of the Timan – Pizhemskoye and Yarega, which revealed differences in morphology in the species composition of the inclusions, the grain size, distribution ...
Alexander B. Makeyev, Sergey E. Borisovsky, Anna O. Krasotkina   +2 more
doaj   +2 more sources

Petrogenetic processes, crystallization conditions and nature of the Lower-Oligocene calc-alkaline spessartitic lamprophyres from Kal-e-kafi area (East of Anarak, Isfahan province)

Journal of Economic Geology, 2017
Introduction Lamprophyres are mesocratic to melanocratic igneous rocks, usually hypabyssal, with a panidiomorphic texture and abundant mafic phenocrysts of dark mica or amphibole (or both) with or without pyroxene, with or without olivine, set in a ...
Gholam Hossain Nazari , Ghodrat Torabi
doaj   +2 more sources

Subarc magmatic and hydration processes inferred from a hornblende peridotite xenolith in spessartite from Kyoto, Japan

Journal of Mineralogical and Petrological Sciences, 2009
Hornblende peridotite xenolith in the spessartite dike in the Tamba belt, northern Kyoto city, is mainly composed of olivine with high Fo and NiO contents (Fo87−94 and 0.22-0.51 wt%). The olivine encloses chromian spinels with a high Cr/(Cr + Al) atomic ratio, 0.66-0.80, partly replaced and digested by hornblendes with a low Mg/(Mg + total Fe) atomic ...
ISHIMARU, Satoko, ARAI, Shoji, TAMURA, Akihiro, TAKEUCHI, Miyuki, KIJI, Michio   +4 more
openaire   +3 more sources