An Extended Rheological Map of Pāhoehoe—‘A‘ā Transition

Fiore, Fabrizio Di; Vona, Alessandro; Kolzenburg, Stephan; Mollo, Silvio; Romano, Claudia

doi:10.1029/2021jb022035

Cited by 14 publications

(23 citation statements)

References 96 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most commonly proposed mechanism for transition between pāhoehoe and 'a'ā lava flows is a viscous rupture of the crust under high shear stress exceeding the yield strength within lavas (Peterson and Tilling 1980;Di Fiore et al 2021). The vesicle data results in the present study indicate that the crust for F5 cooled (and solidified) at a relatively low-stress regime.…”

Section: Inferences On the Nature Of Transition In Cfb Rubbly Pāhoehoe Flowssupporting

confidence: 47%

“…vesicle distribution and textural variations) need to be collected to analyse whether this hypothesis applies to all rubbly pāhoehoe lavas. These datasets can also be used to study the effect of strain rate on the crust, which together with temperature, is believed to be one of the primary drivers of transition from pāhoehoe to 'a'ā lavas (Peterson and Tilling 1980;Di Fiore et al 2021).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cooling history and emplacement dynamics within rubbly lava flows, southern Deccan Traps: insights from textural variations and crystal size distributions

et al. 2021

View full text Add to dashboard Cite

We analyse two representative rubbly pāhoehoe lavas (F3 and F5) from drill cores at Tural-Rajwadi, southwest of Koyna, in the southern Deccan Traps. Low vesicle deformation (0.1 to 0.4) indicates that both lavas ultimately cooled under a lowstress regime. The crystal size distributions (CSDs) of most samples from F5 (especially those from within the core) are not linear but instead show kinks. These kinks are attributed to a rise in plagioclase nucleation due to degassing following the brecciation of the crust. Since it is difficult to constrain cooling time for ancient lava flows, we used the products of nucleation rates (Jt, 1.64 × 10 -8 to 1.45 × 10 -5 μm −3 ) and growth rates (Gt, 2.1 to 156 μm) with time. When compared with natural analogues as well as experimental results for basalt crystallisation, these values suggest a much faster lava cooling rate (~ 1 to 7℃/hr) than a conductive cooling model (≤ 0.1 ℃/hr). The CSDs for F3 fan with depth suggesting that the lava flow might represent local accumulation (ponding?) in a transitional lava flow field. CSDs for F5 show little variation with depth, with the exception of kinks for samples from the lower crust and core. The relatively higher number density of plagioclase microcrysts in our rubbly pāhoehoe (F5) and their CSD patterns are similar to those measured for transitional lavas from Hawaii. The vesicle data and CSDs indicate that brittle deformation was the primary mode of transition within these lavas. Identifying occurrence of thick ponded lavas within vertical stacks of rubbly pāhoehoe flows in the upper stratigraphic levels of the Deccan Traps are critically important as they demonstrate complex cooling styles, crystallisation histories, and emplacement dynamics. Transitional lavas such as rubbly pāhoehoe are important components of large CFB provinces such as the Deccan Traps and constitute nearly 46 to 85% of all lava types. Modelling of continental flood basalt provinces should therefore account for these diversities within lavas, and any oversimplified version using end-member morphotypes is unrealistic and untenable.

show abstract

Section: Inferences On the Nature Of Transition In Cfb Rubbly Pāhoehoe Flowssupporting

confidence: 47%

Section: Introductionmentioning

confidence: 99%

Cooling history and emplacement dynamics within rubbly lava flows, southern Deccan Traps: insights from textural variations and crystal size distributions

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The estimation of the cooling rate (q c ) embedded in volcanic glasses is pivotal for the reconstruction of their petrogenesis (Wilding et al 1995(Wilding et al , 1996a(Wilding et al , b, 2000(Wilding et al , 2004Dingwell 2001a, b, 2002;Gottsmann et al 2004;Potuzak et al 2008;Nickols et al 2009;Kueppers et al 2012;Helo et al 2013;Lavallée et al 2015;Hui et al 2018). Indeed, the q c experienced by the magma controls the texture of volcanic rocks via the modulation of crystal and bubble growth with time, as well as the timescale of post-depositional processes such as sintering, welding, agglutination, rheomorphism, degassing, and crystallization (Quane et al 2009;Shea et al 2010;Gonnermann and Manga 2012;Di Genova et al 2013;Vasseur et al 2013;Vetere et al 2015;Iezzi et al 2017;Wadsworth et al 2019;Cashman 2020;Giuliani et al 2020;Di Fiore et al 2021).…”

Section: Motivation and Aimsmentioning

confidence: 99%

Determination of cooling rates of glasses over four orders of magnitude

Scarani

Vona

Genova

et al. 2022

Contrib Mineral Petrol

View full text Add to dashboard Cite

Volcanic materials can experience up to eleven orders of magnitude of cooling rate (qc) starting from 10–5 K s−1. The glassy component of volcanic material is routinely measured via differential scanning calorimeter (DSC) to obtain qc through the determination of the glass fictive temperature (Tf). Conventional DSC (C-DSC), which has been employed for decades, can only access a relatively small range of qc (from ~ 10–2 to ~ 1 K s−1). Therefore, extrapolations up to six orders of magnitude of C-DSC data are necessary to derive qc of glasses quenched both at extremely low and high qc. Here, we test the reliability of such extrapolations by combining C-DSC with the recently introduced flash calorimetry (F-DSC). F-DSC enables to extend the qc exploration up to 104 K s−1. We use three synthetic glasses as analogs of volcanic melts. We first apply a normalization procedure of heat flow data for both C-DSC and F-DSC to derive Tf as a function of experimental qc, following the “unified area-matching” approach. The obtained Tf–qc relationship shows that Arrhenius models, widely adopted in previous studies, are only valid for qc determination within the calibration range. In contrast, a non-Arrhenius model better captures qc values, especially when a significant extrapolation is required. We, therefore, present a practical “how-to” protocol for estimating qc using DSC.

show abstract

“…The rheological behavior of magma is controlled not only by temperature, pressure, and chemical composition, but also by the presence of crystals and bubbles 3 – 7 . The effect of crystals is especially influential, and the volume of crystals increases with cooling and/or degassing 8 , 9 .…”

Section: Introductionmentioning

confidence: 99%

Aging in magma rheology

Kurokawa

Miwa

Ishibashi

2022

Sci Rep

View full text Add to dashboard Cite

Aging, change in property depending on the elapsed time from preparation, is known to affect the rheological behavior of various materials. Therefore, whether magma ages must be examined to characterize potentially widespread volcanic phenomena related to the transition from rest to flow. To achieve this, we performed rheological measurements and microstructural analyses on basaltic andesite lava from the 1986 Izu-Oshima eruption. The rheology shows an initial overshoot of shear stress during start-up flow that correlates with the duration and the shear rate of a pre-rest time. This indicates that the yield stress of magma and lava increases with aging. The microstructure shows that original aggregates of crystals, which may grow during crystallization, coalesce during the pre-rest period to form clusters without changing the crystal volume fraction. We conclude that the clusters are broken by shear in the start-up flow, which induces the stress overshoot. Thus, aging in magma rheology will impact the understanding of dynamic flow.

show abstract

An Extended Rheological Map of Pāhoehoe—‘A‘ā Transition

Abstract: One of the main challenges in volcanology and petrology is to define and quantify the interdependence and timescales of processes acting during magma ascent through the crust as well as during eruption and em-

Cited by 14 publications

References 96 publications

Cooling history and emplacement dynamics within rubbly lava flows, southern Deccan Traps: insights from textural variations and crystal size distributions

Cooling history and emplacement dynamics within rubbly lava flows, southern Deccan Traps: insights from textural variations and crystal size distributions

Determination of cooling rates of glasses over four orders of magnitude

Aging in magma rheology

Contact Info

Product

Resources

About