caa a22 4500 477062490 CHVBK 20180405111404.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/s004450050135 doi (NATIONALLICENCE)springer-10.1007/s004450050135 Higgins Michael D. Sciences de la Terre, Université du Québec à Chicoutimi, Chicoutimi, G7H 2B1, Canada, CA aut Crystal size distributions and other quantitative textural measurements in lavas and tuff from Egmont volcano (Mt. Taranaki), New Zealand [Elektronische Daten] [Michael D. Higgins]  The size, shape and orientation of plagioclase crystals have been quantified in a tuff and series of andesite lavas from the active Egmont volcano (Mt. Taranaki), New Zealand. Linear crystal size distributions (CSDs) show that if the magma had several components, then only one provided the crystals. The slope of the CSD indicates that the earliest lavas measured had a residence time of ∼50 years in the magma chamber for a growth rate of 10-11 cm/s. Subsequent lavas had slightly longer residence times (50-75 years), but the following series returned to 50-year residence times. The youngest magmas, from both Egmont summit and the parasitic Fantham's Peak, have the shortest residence times of ∼30 years. Variations in residence time may reflect changes in the magma chamber shape or depth, or the temperature of the surrounding rocks. Crystal shapes and zonation suggest that crystallization occurred in a bottle-shape magma chamber, and not in a narrow conduit. If future eruptions use the same magma chamber as the most recent eruptions, then a delay of approximately 30 years can be expected between refilling and eruption. Springer-Verlag Berlin Heidelberg, 1996 Key words CSD nationallicence Residence time nationallicence Egmont volcano nationallicence Mt. Taranaki nationallicence Crystal shape nationallicence Crystal orientation nationallicence Magma chamber nationallicence https://doi.org/10.1007/s004450050135 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s004450050135 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Higgins Michael D. Sciences de la Terre, Université du Québec à Chicoutimi, Chicoutimi, G7H 2B1, Canada, CA aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer