Abstract Details
(2020) Popocatepetl’s Plinian Versus Vulcanian Behavior: Melt Inclusions Hold Clues to Fundamental Differences in Eruption Dynamics
Angeles De La Torre CA, Roberge J, Mercer CN & Wallace PJ
https://doi.org/10.46427/gold2020.66
The author has not provided any additional details.
05d: Room 2, Friday 26th June 22:39 - 22:42
Carlos A. Angeles-De la Torre
Julie Roberge View abstracts at 5 conferences in series
Celestine N. Mercer View all 3 abstracts at Goldschmidt2020
Paul J. Wallace View all 3 abstracts at Goldschmidt2020
Julie Roberge View abstracts at 5 conferences in series
Celestine N. Mercer View all 3 abstracts at Goldschmidt2020
Paul J. Wallace View all 3 abstracts at Goldschmidt2020
Listed below are questions that have been submitted by the community that the author will try and cover in their presentation. To submit a question, ensure you are signed in to the website. Authors or session conveners approve questions before they are displayed here.
Submitted by Chiara Maria Petrone on Friday 26th June 15:29
HI Carlos Antonio, interesting work. Popocatepetl is characterised by remarkable homogenous rock compositions from > 23.5ka for both Plinian and effusive (see Mangler et al 2019, Volcanica). I have a couple of questions. 1) The MI are very evolved compared with the WR for white pumice and pink pumice that are both high-silica andesite (Mangler et al., 2019), but the T are quite high compare to literature data (Sosa-Ceballos et al., 2012). What is you view on this?; 2) Your data cover two Plinian eruptions which are quite distant in time. In addition, the white pumice occurred at the end of the Ventorillo period, so technically before modern Popo. How do your data represent the entire Popo system?; 3) I'm very intrigued by the data on olivine for the present-day activity particularly by the very unusual trachytic composition, which is not typical of Popo rocks. How do you explain it? And have you looked at MI in px for the present-day activity? It would be interesting to see if they replicate the olivine or the px pattern. Thank you.
Dear Chiara, Thank you for your interest in my work. Yes, Popocatepetl’s composition has been remarkably homogeneous over > 23, 5 ka (Schaaf et al., 2005, Witter et al., 2006, Siebe et al., 20017, Angeles de la Torre et al., 2018, AGU, Mangler et al., 2019). To answer your questions: 1) We think that this compositional difference between Whole rock and MI is due to the magma mixing processes that occur under the volcano, this is supported by some petrological textures that we find in thin sections (sieve, Melt channels), and was also recognized by other authors (Schaaf et al., 2005, Witter et al., 2006, Roberge et al, 2009, Sosa Ceballos et al., 2014), where a more mafic component is injected into an evolved (rhyolitic) reservoir. You are right that the temperature is higher, but remember it was calculated experimentally and for a Whole Rock composition. Here we are using the Putirka 2008 thermometer for the OPX-Liquid pair that we believe is more accurate since the MI are hosted in these crystals. However, we are aware that statistically more data is needed to restricted better the temperature range (probe time canceled because of the virus!). 2) Yes you are right that the White Pumice was produced by the eruption that destroyed the previous edifice called Ventorillo (or also referred to as paleo-Popo) but is still considered to be Popocatepetl (see for example Schaaf et al., 2005, Siebe et al., 2017). We chose the White Pumice because we wanted the largest timespan and because its geochemistry has been well established by Siebe et al. (2017). As for the Pink Pumice, it was chosen for being the most recent plinian, and because preliminary worked (Flores del Rio et al., 2017, IAVCEI) and unpublished data by Roberge and Siebe suggest that it may have been one of the largest of Popocatepetl’s plinian eruptions of the last 23,500 years. 3) The olivine-hosted melt inclusions are from Roberge et al. (2009). This signature is not necessarily unusual, other authors have had trachi- andesite values as well (see Witter et al., 2006). We are working on getting data from Px-hosted inclusions from the recent eruption, we just need the labs to re open so we can run probe! But our data are chemically consistent with Atlas et al. (2005) and Witter et al. (2006). thanks again for the questions, Carlos
HI Carlos Antonio, interesting work. Popocatepetl is characterised by remarkable homogenous rock compositions from > 23.5ka for both Plinian and effusive (see Mangler et al 2019, Volcanica). I have a couple of questions. 1) The MI are very evolved compared with the WR for white pumice and pink pumice that are both high-silica andesite (Mangler et al., 2019), but the T are quite high compare to literature data (Sosa-Ceballos et al., 2012). What is you view on this?; 2) Your data cover two Plinian eruptions which are quite distant in time. In addition, the white pumice occurred at the end of the Ventorillo period, so technically before modern Popo. How do your data represent the entire Popo system?; 3) I'm very intrigued by the data on olivine for the present-day activity particularly by the very unusual trachytic composition, which is not typical of Popo rocks. How do you explain it? And have you looked at MI in px for the present-day activity? It would be interesting to see if they replicate the olivine or the px pattern. Thank you.
Dear Chiara, Thank you for your interest in my work. Yes, Popocatepetl’s composition has been remarkably homogeneous over > 23, 5 ka (Schaaf et al., 2005, Witter et al., 2006, Siebe et al., 20017, Angeles de la Torre et al., 2018, AGU, Mangler et al., 2019). To answer your questions: 1) We think that this compositional difference between Whole rock and MI is due to the magma mixing processes that occur under the volcano, this is supported by some petrological textures that we find in thin sections (sieve, Melt channels), and was also recognized by other authors (Schaaf et al., 2005, Witter et al., 2006, Roberge et al, 2009, Sosa Ceballos et al., 2014), where a more mafic component is injected into an evolved (rhyolitic) reservoir. You are right that the temperature is higher, but remember it was calculated experimentally and for a Whole Rock composition. Here we are using the Putirka 2008 thermometer for the OPX-Liquid pair that we believe is more accurate since the MI are hosted in these crystals. However, we are aware that statistically more data is needed to restricted better the temperature range (probe time canceled because of the virus!). 2) Yes you are right that the White Pumice was produced by the eruption that destroyed the previous edifice called Ventorillo (or also referred to as paleo-Popo) but is still considered to be Popocatepetl (see for example Schaaf et al., 2005, Siebe et al., 2017). We chose the White Pumice because we wanted the largest timespan and because its geochemistry has been well established by Siebe et al. (2017). As for the Pink Pumice, it was chosen for being the most recent plinian, and because preliminary worked (Flores del Rio et al., 2017, IAVCEI) and unpublished data by Roberge and Siebe suggest that it may have been one of the largest of Popocatepetl’s plinian eruptions of the last 23,500 years. 3) The olivine-hosted melt inclusions are from Roberge et al. (2009). This signature is not necessarily unusual, other authors have had trachi- andesite values as well (see Witter et al., 2006). We are working on getting data from Px-hosted inclusions from the recent eruption, we just need the labs to re open so we can run probe! But our data are chemically consistent with Atlas et al. (2005) and Witter et al. (2006). thanks again for the questions, Carlos
Submitted by Martin Mangler on Friday 26th June 20:05
Hi Carlos Antonio, very interesting work indeed. I have two questions in addition to Chiara's: 1) How many plagioclase and pyroxene crystals have you analysed? Our pyroxene dataset for the Pink and White Pumice show a much larger range of ortho- and clinopyroxene compositions, including very mafic ones up to En88. I would assume that MIs in such crystals might give you similar pressure estimates as you find for present day activity. Do you think it's possible that the Plinian eruptions were triggered by similar magmas as the ones causing Vulcanian and Strombolian activity, but you didn't find them because they are volumetrically less significant in Plinian deposits? 2) Roberge et al (2009) suggest that during the eruption ongoing since 1995, only 0.3% of magma arriving in the plumbing system is actually being erupted. Wouldn't this supply exactly that kind of eruptible magma to feed a Plinian eruption? Thanks, Martin
Hi Carlos Antonio, very interesting work indeed. I have two questions in addition to Chiara's: 1) How many plagioclase and pyroxene crystals have you analysed? Our pyroxene dataset for the Pink and White Pumice show a much larger range of ortho- and clinopyroxene compositions, including very mafic ones up to En88. I would assume that MIs in such crystals might give you similar pressure estimates as you find for present day activity. Do you think it's possible that the Plinian eruptions were triggered by similar magmas as the ones causing Vulcanian and Strombolian activity, but you didn't find them because they are volumetrically less significant in Plinian deposits? 2) Roberge et al (2009) suggest that during the eruption ongoing since 1995, only 0.3% of magma arriving in the plumbing system is actually being erupted. Wouldn't this supply exactly that kind of eruptible magma to feed a Plinian eruption? Thanks, Martin
Submitted by Martin Mangler on Friday 26th June 20:05
Hi Carlos Antonio, very interesting work indeed. I have two questions in addition to Chiara's: 1) How many plagioclase and pyroxene crystals have you analysed? Our pyroxene dataset for the Pink and White Pumice show a much larger range of ortho- and clinopyroxene compositions, including very mafic ones up to En88. I would assume that MIs in such crystals might give you similar pressure estimates as you find for present day activity. Do you think it's possible that the Plinian eruptions were triggered by similar magmas as the ones causing Vulcanian and Strombolian activity, but you didn't find them because they are volumetrically less significant in Plinian deposits? 2) Roberge et al (2009) suggest that during the eruption ongoing since 1995, only 0.3% of magma arriving in the plumbing system is actually being erupted. Wouldn't this supply exactly that kind of eruptible magma to feed a Plinian eruption? Thanks, Martin
Hi Carlos Antonio, very interesting work indeed. I have two questions in addition to Chiara's: 1) How many plagioclase and pyroxene crystals have you analysed? Our pyroxene dataset for the Pink and White Pumice show a much larger range of ortho- and clinopyroxene compositions, including very mafic ones up to En88. I would assume that MIs in such crystals might give you similar pressure estimates as you find for present day activity. Do you think it's possible that the Plinian eruptions were triggered by similar magmas as the ones causing Vulcanian and Strombolian activity, but you didn't find them because they are volumetrically less significant in Plinian deposits? 2) Roberge et al (2009) suggest that during the eruption ongoing since 1995, only 0.3% of magma arriving in the plumbing system is actually being erupted. Wouldn't this supply exactly that kind of eruptible magma to feed a Plinian eruption? Thanks, Martin
Sign in to ask a question.