نتایج جستجو برای: tholeiite
تعداد نتایج: 69 فیلتر نتایج به سال:
New high-precision ages, determined from palynomorph assemblages within intercalated sedimentary deposits, are presented for the Palaeogene lava fields (Skye, Mull and Antrim) of the British Province. These data reveal very rapid averaged eruption rates (1 m/200 years) and the non-synchronous formation of the lava fields. Eruption of the volumetrically dominant transitional to mildly alkaline l...
Microprobe analyses of Ca-rich pyroxenes crystallized in the melting ranges of a magnesian alkali basalt, a transitional basalt, an olivine tholeiite, a tholeiitic andesite, and an augite leucitite at pressures between 8 and 45 kb show complex variation. Ca-poor pyroxene precipitated only from the alkali basalt at pressures between 14 and 18 kb. Pyroxene falling near the Di-Hed join in the pyro...
Shallow water sedimentary units are generally considered scarce in Archean greenstone belts. We describe an unusual quartz arenite-subaerial andesite association within the Archean Hisovaara greenstone belt, a fragment of the Parandovo-Tikshozero belt within the Karelian craton of the Baltic Shield. The Hisovaara greenstone belt consists of several lithotectonic assemblages: (1) a komatiite-tho...
Abstract The Proterozoic Chotanagpur Granite Gneiss Complex (CGGC) at the northern boundary of Central Indian Tectonic Zone (CITZ) eastern shield preserves relics fossilized oceanic back-arc crust. We describe field, petrographical and geochemical characteristics mafic rocks comprising pillow basalts dolerites from Bathani area fringe CGGC, India. consist plagioclase feldspar, hornblende, opaqu...
The Azov Domain occurs as a part of larger Mesoarchean (3.2-3.0 Ga) craton, fragments which are preserved in the eastern Ukrainian Shield and block Kursk Magnetic Anomaly (KMA). In Neoarchean-Palaeoproterozoic time, it was fragmented into several tectonic blocks: Vovcha, Remivka, Huliaipole, Bilotserkivka, Saltych. northern Huliaipole Block is composed tonalite-trondhjemite-granodiorite (TTG) r...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید