Petrology of the 1998–2000 products of Volcán de Colima, México

Mora, Juan Carlos; Macías, José Luis; Saucedo, R.; Orlando, Andrea; Manetti, Piero; Vaselli, Orlando

doi:10.1016/s0377-0273(02)00244-5

Cited by 35 publications

(25 citation statements)

References 26 publications

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“…Over the last 400 years, the volcano has experienced ∼100 year cycles of effusive to explosive events. Throughout this period the lavas have been consistently andesitic (Luhr and Carmichael, 1980;Mora et al, 2002) with minor mafic excursions (relating to fresh mafic magma influx) that seem to dictate the cycle-ending (sub-)Plinian eruptions, the last one occurring in 1913 (Luhr, 2002). The crystal assemblage is predominantly plagioclase, with lesser amounts of orthopyroxene, clinopyroxene, and irontitanium oxides set in interstitial glass (Luhr and Carmichael, 1980).…”

Section: Historic Activity At Volcán De Colimamentioning

confidence: 97%

Blowing Off Steam: Tuffisite Formation As a Regulator for Lava Dome Eruptions

et al. 2016

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Tuffisites are veins of variably sintered, pyroclastic particles that form in conduits and lava domes as a result of localized fragmentation events during gas-and-ash explosions. Those observed in-situ on the active 2012 lava dome of Volcán de Colima range from voids with intra-clasts showing little movement and interpreted to be failure-nuclei, to sub-parallel lenses of sintered granular aggregate interpreted as fragmentation horizons, through to infilled fractures with evidence of viscous remobilization. All tuffisites show evidence of sintering. Further examination of the complex fracture-and-channel patterns reveals viscous backfill by surrounding magma, suggesting that lava fragmentation was followed by stress relaxation and continued viscous deformation as the tuffisites formed. The natural tuffisites are more permeable than the host andesite, and have a wide range of porosity and permeability compared to a narrower window for the host rock, and gaging from their significant distribution across the dome, we posit that the tuffisite veins may act as important outgassing pathways. To investigate tuffisite formation we crushed and sieved andesite from the lava dome and sintered it at magmatic temperatures for different times. We then assessed the healing and sealing ability by measuring porosity and permeability, showing that sintering reduces both over time. During sintering the porosity-permeability reduction occurs due to the formation of viscous necks between adjacent grains, a process described by the neck-formation model of Frenkel (1945). This process leads the granular starting material to a porosity-permeability regime anticipated for effusive lavas, and which describes the natural host lava as well as the most impervious of natural tuffisites. This suggests that tuffisite formation at Volcán de Colima constructed a permeable network that enabled gas to bleed passively from the magma. We postulate that this progressively reduced the lava dome's ability to seal and build pressure that drives explosions. Indeed, the time interval between explosions during 2007-2011 gradually increased before the onset of a period of quiescence starting in June 2011. We suggest that the permeability evolution during tuffisite formation has important consequences for modeling of gas-and-ash explosions, common at dome-forming volcanoes.

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Section: Historic Activity At Volcán De Colimamentioning

confidence: 97%

Blowing Off Steam: Tuffisite Formation As a Regulator for Lava Dome Eruptions

et al. 2016

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“…These scoria samples may, however, not be representative for the entire 1913 tephra fallout sequence, and tephra of this eruption has not yet been analysed at distal sites. The recent 1998-2000 Colima tephras, for instance, reveal an additional rhyolitic matrix glass (Mora et al 2002) that resembles the TAL2 tephra (Fig. 4, Table 2).…”

Section: Origin Of the Tephrasmentioning

confidence: 98%

First lacustrine varve chronologies from Mexico: impact of droughts, ENSO and human activity since AD 1840 as recorded in maar sediments from Valle de Santiago

et al. 2009

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We present varve chronologies for sediments from two maar lakes in the Valle de Santiago region (Central Mexico): Hoya La Alberca (AD 1852(AD -1973 and Hoya Rincón de Parangueo (AD 1839(AD -1943. These are the first varve chronologies for Mexican lakes. The varved sections were anchored with tephras from Colima (1913) and Paricutín (1943Paricutín ( /1944 and 210 Pb ages. We compare the sequences using the thickness of seasonal laminae and element counts (Al, Si, S, Cl, K, Ti, Mn, Fe, and Sr) determined by micro X-ray fluorescence spectrometry. The formation of the varve sublaminae is attributed to the strongly seasonal climate regime. Limited rainfall and high evaporation rates in winter and spring induce precipitation of carbonates (high Ca, Sr) enriched in 13 C and 18 O, whereas rainfall in summer increases organic and clastic input (plagioclase, quartz) with high counts of lithogenic elements (K, Al, Ti, and Si). Eolian input of Ti occurs also in the dry season. Moving correlations (5-yr windows) of the Ca and Ti counts show similar development in both sequences until the 1930s. Positive correlations indicate mixing of allochthonous Ti and autochthonous Ca, while negative correlations indicate their separation in sublaminae. Negative excursions in the correlations correspond with historic and reconstructed droughts, El Niño events, and This paper is dedicated to our colleague and friend Jim Luhr,

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“…4.3. Petrology and geochemistry of the 1998^1999 lavas (Luhr, 2002;Mora et al, 2002) The block lavas erupted in 1998^1999 are andesites with 59.5^61.3 wt% SiO 2 and 2.6^3.8 wt% MgO (normalized anhydrous with all Fe as FeO). They have minor amounts ( 6 0.5 vol%) of brown hornblende with reaction rims accompanying the dominant minerals plagioclase, orthopyroxene, clinopyroxene and Fe^Ti oxides (mostly titanomagnetite), surrounded by a microcrystalline to glassy groundmass.…”

Section: Emplacement Of Pyroclastic £Owsmentioning

confidence: 99%

“…This trend appeared to indicate a shift toward ma¢c magma compositions similar to that erupted explosively in 1913. Since then, however, andesitic lavas became progressively richer in SiO 2 during the 1991 eruption and the 1998^99 eruption, although Mora et al (2002) argued for mixing of hotter ma¢c andesitic magma as a trigger to the 1998^1999 eruption.…”

Section: Emplacement Of Pyroclastic £Owsmentioning

confidence: 99%