Autobrecciation and fusing of mafic magma preceding explosive eruptions

نویسندگان

چکیده

Abstract Bubble and crystal textures evolve during magma ascent, altering properties that control ascent such as permeability viscosity. Eruption style results from feedbacks between bubble nucleation growth, microlite crystallization, gas loss, all processes recorded in pyroclasts. We show pyroclasts of the mafic Curacautín ignimbrite Llaima volcano, Chile, record a history repeated autobrecciation, fusing, crystallization. identified with domains heterogeneous vesicle sharp contact one another are overprinted by extensive Broken crystals long axes (l) >10 μm fragmentation events eruption. A second population unbroken microlites l ≤10 overprint sutures fused domains, suggesting highly crystalline groundmass formed at shallow depths after autobrecciation fusing. Nearly contain plutonic ancestral lithics inclusions, implying fusing occurs few kilometers depth to surface. propose autobrecciated proto-pyroclasts remained melt rich enough fuse together. Lithics conduit margins were entrained into before Autobrecciation broke existing phenocrysts microlites; rapid post-fusing crystallization then generated groundmass. This proposed process has implications for interpreting products explosive eruptions.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Explosive volcanic eruptions on Mercury: Eruption conditions, magma volatile content, and implications for interior volatile abundances

a Geological Sciences Department, Brown University, 324 Brook Street, Box 1846, Providence, RI 02912, USA b Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, N.W., Washington, DC 20015, USA c The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA d Environmental Science Department, Lancaster Univers...

متن کامل

Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments

The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions of Kīlauea volcano, Hawaii. Incomplete e...

متن کامل

Depth of origin of magma in eruptions

Many volcanic hazard factors--such as the likelihood and duration of an eruption, the eruption style, and the probability of its triggering large landslides or caldera collapses--relate to the depth of the magma source. Yet, the magma source depths are commonly poorly known, even in frequently erupting volcanoes such as Hekla in Iceland and Etna in Italy. Here we show how the length-thickness r...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Geology

سال: 2022

ISSN: ['0091-7613', '1943-2682']

DOI: https://doi.org/10.1130/g50180.1