Record details

    Causes of compositional diversity in a lobe of the Half Dome granodiorite, Tuolumne Batholith, Central Sierra Nevada, California
    Economos, Rita
    Erdmann, Saskia
    Memeti, Valbone
    Miller, Jonathan
    Paterson, Scott
    Žák, Jiří
Publication type
    článek v periodiku
Source title - serial
    Earth and Environmental Science Transactions of the Royal Society of Edinburgh
    Roč. 100, č. spec. issue 1-2
Thesaurus term
    fractional crystallisation, magmatic processes, plutons
Abstract (in english)
   The causes of compositional diversity in the Tuolumne Batholith, whether source heterogeneity, magma mixing, or fractional crystallisation, is a matter of longstanding debate. This paper presents data from detailed mapping and a microstructural and major element, trace element and isotopic study of an elongate lobe of the Half Dome granodiorite that protrudes from the southern end of the batholith. The lobe is normally zoned from quartz diorite along the outer margin to high-silica leucogranite in the core. Contacts are steep and gradational, except for the central leucogranite contact, which is locally sharp: magmatic fabrics overprint contacts. A striking feature of the lobe is the 18 wt SiO2 range comparable to that observed for the entire Tuolumne Batholith. Feldspar-compatible elements (Sr and Ba) decrease towards the centre, while Rb increases. Light and middle REEs show a smooth decrease towards the centre of the lobe. Calculated initial isotopic ratios of 87Sr/86Sr(i) and
    Česká geologická služba
Contributor code
    ČGS (RIV)
Source format
Import date
    15. 10. 2014