DOCSLIB.ORG

Pdf/91/11 Part II/2290/3433969/I0016-7606-91-11-2290.Pdf by Guest on 29 September 2021 P ----___

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pdf/91/11 Part II/2290/3433969/I0016-7606-91-11-2290.Pdf by Guest on 29 September 2021 P ----___ Geology and petrology of Volc5n Ceboruco, Nayarit, Mexico STEPHEN A. NELSON Departirieitt of Geology and Geophysics, University of California. Berkelea. Cnlifornia 94720 'Preserit nddress: Department of Geology, Ticllane University, New Orleans' Louisiana 701 18 Geological Society of Arriericd Bullctiii, Part II, v. 91, p. 2290-2431, 19 figs., 11 tables, Nove$t.r, 1980, Doc. no. M01102 - __ __ - These dacites contain xenoliths 0.f ABSTRACT high-"1, ba,salt that were apparentl'y Volch C(,boruch is a modc:atcly partially rnoltcm'at the time of their sized stratovolcanc located in the ir.clusion, sul:pc-is t.ing that the daci te northwestern ;:art 05 the ?:cxican magma iorred as R result of masma mixing Volcanic Belt. The bulk of the involving Ja1.a p;mice and basaltic magmas volcano consists of relatively The dacitc donic? later collapsed *to form alkali and incompatible element-poor the inner cal.dern, and Ceboruco again hypcrsthene andcsites erupted prior erupted andesi tcs. These postcaldera to the format.ion of two concentric andesites cont.nin both augite and hypersthene and arc enriched .in were' followed in tlic eruptive sequence alkalis antl incompntiblc clement4 by ;tie crupp'ior! 1,000 vr ago of a relative to tho precaldera andesikes. white $rliyo?i>cj t c' pumice, tcrmetl the . fin all.^, bc?twc,c!n 1870 and 1.875, Jala pumice. The eruption apparently rhyodacite 1.ava flows wre' eruptkd caused the> ' f.orma t: on of Ceborrico ' s during (:cboruco's only Iiistdc cuter ca1.dcra. !o!,--si lica dacite act-ivity. <J dome antl lav~flow were then erupted Crystal Fractionation models using anci partially fi lletl ttiis Caldera. ImtIi major and [:race elements' suggest 2290 Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 P ----___ . 21 - - - - - that the 1870 dacites and the Jala of the volcanoes in the belt have had pumice 'could have been derived from reported activity in historic times magma with postcaldera andesite compo- (Voosfr and otlic,rs. 1958), inclr~tling .- sition. To determine the o&gin of the Volca'n Ceboruccl, which erupted during Ceboruco andesites, trace-element the years 1870 tb 1875 (Caravantes, partial-melting models tested three 1870; 1,glesias and others, 1877). The possible sources: subducted oceanic belt has rccei.Ced little study by earth crust in the eclogite facies and the scientists, and its pdsition in'the amphibolite facies and mantle peridotite. global tectonic framework is little All models were found unreliable be- understood. Chcmical analyses of rocks . cause of the many assumptions involved. from the belt hnyc been reported by It is concluded that a cornplex process Burri (1930), Williams (1950) ,. Vilcdx involving partial nelting, fractional (1956), Gunn and Xooser (1971), crystalization, magma mixing, and, Negendank (1972), Bloomfield (1975), perhaps, crustal assimilation was and Pichler and Weyl (1976). These responsible for the generation of published studie:, reveal that the pre- the hdesites. Such a model cannot be dominant rock types are basaltic andesite , \ test'ed, however, because there are to andesite, with substantial quantities -.. at present no viable constraints that of olivine basn1-t and lesser quantities \ can be placed on this complex+equence of alkali basalt., dacite, and rhyolite. of events. The western part of the Mexican .Volcanic Belt overlaps onto an older INTRODUCTION Tertiary province of rhyolitic ash- Thc Yerican Volcanic Belt consists flow tuffs (Gastil 3nd others, 1979; of a chain of Yiocene to Holocene Gunn and >!ooser, 1971). Rhyolitic volcanoes that span Mexico from its vol.canism&s continued into rece'n-t Pac'ific coast to its gulf coast. Nine times ill tJie region of Guadalajara, I. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 .- . -- where compositions are peralkaline Ahuacatlin (Fig. 1.). It is built on (Maliood, 1978) (Fig. 1). the northern slopes of the valley of De Cserna (1961, 1965) suggested Ahuacatlsn and covers an area of about 3 that ci thrust-fault relation existed 80 Itm'. It rises to .an elevation of along the Middle America Trench along 2,200 m, or about 1,200 m above the the coast of Mexico, ahd Molnar and present valley floor, and is crowned Sykes (1969) showed that a Benioff by two concentric calderas, the older of zone exists lwncath Mexico, where which measures. 3.7. km in diameter and earthquake.foci are reported to a depth the younger 1.5 km in diameter. of 150 km. Although the zone is not Caravantes (1870), Iglesias and. well defined, the active region ap- others (1877), and OrdoGez (1897) re- -. ?arently ends bcneath, or slightly ported ofl the 1870 eruption of Cebo&. oceanward of, the existing volcanic .l.r'aitz (1920) discussed the possibility front. , Focal mechanism studies re- that Cebo-ruco produced a nu6e ardente ported by the above authors are con- during that eriiption: Barrera (1931) sistent with the postulate that sub- discussed the 1870 eruption and some duction is takinj; place along the geologic featurcs of Ceboruco in his Middle America TrLnch off the investigation of the geology along the southern coast of Mexico. railroad route linking Guadalajara with Volcsn Ceboruco lies in the the Pacific coast. Segerstrom (1950) northwestern part of the Mexican reported on the erosion that has taken Volcanic Belt , where no signjficant place since the 1870 event. Thorpe earthquake activity is currently and Ffancis (1975) have prese'nted a observed (Mol nar and Sykes , 1969). photogeologic map and eight chemical, The volcano IS located at lat 21' 7' analyses of rocks from Ceboruco. 30" N, long 104" 20'61 in a broad basin Volcsn Ceboruco rests in a broad comprising thc, valleys of Jala and valley whose northern margin is marked Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 2295 =.. \G \G \. BAWIA GUADALAJARA Of LAS BAhOfRAS COLIMA 105’W. 104’ 103’ I I Figure 1,. ?lap of western Xcxico showing maj0.r volcanic centers: 1, Volcsn Tequila; 2, Volciin San Pedro; 3, Volcsn Tepetiltic; 4j’Santa Maria del Oro caldera; 5, Vo ca’n Sanganguey; 6, La Laguna del Tesoro caldera. Inset shqws map area and locations of & historically artive volcanoes of Mexico. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 . 2 by an escarpmcnt trending S6Oo15, from several of Ceboruco’ s flank cinder rising about 300 m above the gently cones. slopin; valley floor. The walls of The growth of Cebdruco has altered this escarpment are composed of and blocked the drainage system in the rhyolitic ash-flow tuffs, probably of valley of Ahuacatlsn. Tributaries to TerFiary age. The, escarpment fades to the Rio Ahuacatlsn, such as the Arroyo the east, where similar ash-flow tuffs Jala (Fig. 2) have steep gradients near slope gently down to the valley floor <heir headwaters, changing to nearly and d i s appear.ben e’a t h rkc en t a 11 uv i- um . flat gradients upon reaching the valley. tJ ’ Basaltic rocks are found along the Features suggestive of the steep head- southern valley margins and are oyer- water regions of such‘ tributaries are lain by ash-flow tuffs, which form a present in the cliffs norfh of the volcano. I xountain range termed the Sierra These drainage systems have been cut Guamuchil. parther south, these ash- off by the growth of Ceboruco and now ffow tuffs that compose_ the Sierra give the cliffs a scalloped appearance. Guamuchil Overlie gran.$t ic and The relatively- gentle gradients of ”’ gabbroic rocks that%lhave been dated streams flowing in.the valley of < at 61 and 87 m.y. old, respectively hhuacatlsn have res’uf ted from the growth (Gastil and others, 1976). of the volcano, causing the Rio It thus seems likely that the bedrock Ahuaca t lsn to continually grade itself concealed beneath Ceboruco is also .to the rising level of vglcanic material composed of rhyolitic ash-flow. tuffs expelled into the valley. similar. to those found in both vaLley Projecting the steep gradients of walls. Deeper levels beneath tribu;aries such a$ the Arroyo Jala Ceboruco must he composed in part of beneath the alluvial fill of the valley grani tic material, because xenoli ths suggests that the’valley of Ahuacatlsn of such rock are found in boxbs erupted was at least 500 m dee?er prior to the Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 2295 Figure -21: Geologic map of VolcLn Ceboruco and surrounding area. Figure 2 appears on 'the follow@g frames. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 2296 Figure 2. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 2297 Alluvium 1870 Daclte Caldera fill El Ceboruco Andeslte Andesite El Mo'lcajete Coapan [-I Andesite El Centro Andesite Dome rjCopales Dacite Dos Equis Dacite Dome Marquesado . Ash Flow Cerro Pedregoso Rhyodacite . La Picha,ncha El Cajon Andesite Cerro Pochelero Rhyolite Dome rjDestiladero Rhyodaci te Ceboruquilo Andcsite Pre Caldera II-Andesite Pre Ceboruco ' U Ash flow'tuffs Contacts -- - - dashed where Inferred A Cinder Cones Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11_Part_II/2290/3433969/i0016-7606-91-11-2290.pdf by guest on 29 September 2021 commencement of volcanism.
Load more

Recommended publications
  • Mantle Peridotite Xenoliths
    Earth and Planetary Science Letters 260 (2007) 37–55 www.elsevier.com/locate/epsl Mantle peridotite xenoliths in andesite lava at El Peñon, central Mexican Volcanic Belt: Isotopic and trace element evidence for melting and metasomatism in the mantle wedge beneath an active arc ⁎ Samuel B. Mukasa a, , Dawnika L. Blatter b, Alexandre V. Andronikov a a Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109-1005, USA b Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA Received 6 July 2006; received in revised form 3 May 2007; accepted 7 May 2007 Available online 13 May 2007 Editor: R.W. Carlson Abstract Peridotites in the mantle wedge and components added to them from the subducting slab are thought to be the source of most arc magmas. However, direct sampling of these materials, which provides a glimpse into the upper mantle beneath an active margin, is exceedingly rare. In the few arc localities where found, peridotite xenoliths are usually brought to the surface by basaltic magmas. Remarkably, the hornblende-bearing ultramafic xenoliths and clinopyroxene megaxenocrysts from El Peñon in the central Mexican Volcanic Belt were brought to the surface by a Quaternary high-Mg siliceous andesite, a rock type usually considered too evolved to be a direct product of mantle melting. The xenoliths and megaxenocrysts from El Peñon represent lithospheric mantle affected by significant subduction of oceanic lithosphere since as early as the Permian. Trace element and radiogenic isotope data we report here on these materials suggest a history of depletion by melt extraction, metasomatism involving a fluid phase, and finally, limited reaction between the ultramafic materials and the host andesite, probably during transport.
    [Show full text]
  • Chemical and Isotopic Studies of Monogenetic Volcanic Fields: Implications for Petrogenesis and Mantle Source Heterogeneity
    MIAMI UNIVERSITY The Graduate School Certificate for Approving the Dissertation We hereby approve the Dissertation of Christine Rasoazanamparany Candidate for the Degree DOCTOR OF PHILOSOPHY ______________________________________ Elisabeth Widom, Director ______________________________________ William K. Hart, Reader ______________________________________ Mike R. Brudzinski, Reader ______________________________________ Marie-Noelle Guilbaud, Reader ______________________________________ Hong Wang, Graduate School Representative ABSTRACT CHEMICAL AND ISOTOPIC STUDIES OF MONOGENETIC VOLCANIC FIELDS: IMPLICATIONS FOR PETROGENESIS AND MANTLE SOURCE HETEROGENEITY by Christine Rasoazanamparany The primary goal of this dissertation was to investigate the petrogenetic processes operating in young, monogenetic volcanic systems in diverse tectonic settings, through detailed field studies, elemental analysis, and Sr-Nd-Pb-Hf-Os-O isotopic compositions. The targeted study areas include the Lunar Crater Volcanic Field, Nevada, an area of relatively recent volcanism within the Basin and Range province; and the Michoacán and Sierra Chichinautzin Volcanic Fields in the Trans-Mexican Volcanic Belt, which are linked to modern subduction. In these studies, key questions include (1) the role of crustal assimilation vs. mantle source enrichment in producing chemical and isotopic heterogeneity in the eruptive products, (2) the origin of the mantle heterogeneity, and (3) the cause of spatial-temporal variability in the sources of magmatism. In all three studies it was shown that there is significant compositional variability within individual volcanoes and/or across the volcanic field that cannot be attributed to assimilation of crust during magmatic differentiation, but instead is attributed to mantle source heterogeneity. In the first study, which focused on the Lunar Crater Volcanic Field, it was further shown that the mantle heterogeneity is formed by ancient crustal recycling plus contribution from hydrous fluid related to subsequent subduction.
    [Show full text]
  • Geology and Petrology of Volcán Ceboruco, Nayarit, Mexico: Summary
    Geology and petrology of Volcán Ceboruco, Nayarit, Mexico: Summary STEPHEN A. NELSON* Department of Geology and Geophysics, University of California, Berkeley, California 94720 INTRODUCTION 1870; Iglesias and others, 1877). The volcano is in the northwest- ern part of the Mexican Volcanic Belt at lat 2 I °7'.W'N, 104°30'W. Volcan Ceboruco is one of nine of Mexico's historically active It is crowned by two concentric calderas and rises to an elevation of volcanoes (Mooser and others, 1958), with a single documented 2,200 m, or about 1,100 m above the surrounding valley of historical eruption during the period 1870—1875 (Caravantes, Ahuacatlan. Tertiary rhyolitic ash-flow tuffs crop out on both sides of the valley of Ahuacatlan and probably underlie Volcan * Present address: Department of Geology, Tulane University, New Or- Ceboruco. leans, Louisiana 701 18. The complete article, of which this is a summary, appears in Part II of the Bulletin, no. 1 1, p. 2290 —2431. Geological Society of America Bulletin, Part I, v. 91, p. 639-643, 3 figs., November 1980, Doc. no. S01 102. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11/639/3429689/i0016-7606-91-11-639.pdf by guest on 29 September 2021 Figure 1. Geologic map of Volcán Ceboruco and surrounding area. Inset shows loca- tion of Ceboruco relative to the other active volcanoes of Mexico (from west to east: Col- ima, Paricutin, Jorullo, Xitli, Popocateptl, Orizaba, and San Martin. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/91/11/639/3429689/i0016-7606-91-11-639.pdf by guest on 29 September 2021 VOLCÁN CEBORUCO, MEXICO: SUMMARY 641 Figure 2.
    [Show full text]
  • Some Isotopic and Geochemical Anomalies Observed in Mexico Prior to Large Scale Earthquakes and Volcanic Eruptions
    41 SOME ISOTOPIC AND GEOCHEMICAL ANOMALIES 2) OBSERVED IN MEXICO PRIOR TO LARGE SCALE EARTHQUAKES AND VOLCANIC... s nucleare s investigacione e d l naciona o institut INSTITUTO NACIONAL DE INVESTIGACIONES NUCLEARES DIRECCIÓN DE INVESTIGACIÓN Y DESARROLLO SOME ISOTOPIC AND GEOCHEMICAL ANOMALIES OBSERVED IN MEXICO PRIOR TO LARGE SCALE EARTHQUAKES AND VOLCANIC ERUPTIONS. GERENCIA DE INVESTIGACIÓN APLICADA INFORME TÉCNICO IA-92-1 3 MAYO DE 1992. SOME ISOTOPIC AND GEOCHEMICAL ANOMALIES OBSERVED IN MEXICO PRIOR TO LARGE SCALE EARTHQUAKES AND VOLCANIC ERUPTIONS. S. de la CjDi2=a@ynaf, M.A. Amienta*, y N. Segovia A. Gerencia de Investigación Aplicada Dirección de Investigación y Desarrollo Instituto Nacional de Investigaciones Nucleares * Instituto de Geofísica de la U.N.A.M. GERENCIA DE INVESTIGACIÓN APLICADA INFORME TÉCNICO IA-92-13 MAYO DE 1992. SOME ISOTOPIC AND GEOCHEMICAL ANOMALIES OBSERVED IN MEXICO PRIOR TO LARGE SCALE EARTHQUAKES AND VOLCANIC ERUPTIONS Servando De la Cruz-Reyna1'3, M.Aurora Armienta H.1, Nuria Segovia2 1 Instituto de Geofisica, UNAM, Ciudad Universitaria, Mexico 04 510 D. F., (Mexico). 2 Instituto Nacional de Investigaciones Nucleares, Ap. Postal 18-1207, Mexico 11801, D.F. (Mexico). 3 consultant to CENAPRED (National Center for Disaster Prevention) Av. Delfin Madrigal 665, Mexico, D.F. (Mexico) SUMMARY A brief account of some experiences obtained in Mexico, related with the identification of geochemical precursors of volcanic eruptions and isotopic precursors of earthquakes and volcanic activity is given. The cases of three recent events of volcanic activity and one large earthquake are discussed in the context of an active geological environment. The positive results in the identification of some geochemical precursors that helped to evaluate the eruptive potential during two volcanic crises (Tacana 1986 and Colima 1991), and the significant radon-in-soil anomalies observed during a volcanic catastrophic eruption (El Chichón, 1982) and prior to a major earthquake (Michoacan, 1985) are critically analyzed.
    [Show full text]
  • A Pliocene Ignimbrite Flare-Up Along the Tepic-Zacoalco Rift: Evidence For
    A Pliocene ignimbrite fl are-up along the Tepic-Zacoalco rift: Evidence for the initial stages of rifting between the Jalisco block (Mexico) and North America Holli M. Frey† Rebecca A. Lange Chris M. Hall Department of Geological Sciences, 1100 N. University Ave., University of Michigan, Ann Arbor, Michigan 48109-1005, USA Hugo Delgado-Granados Instituto de Geofi sica, Universidad Nacional Autónoma de México (UNAM), Coyoacan 04510 DF, Mexico Ian S.E. Carmichael Department of Earth and Planetary Science, University of California, Berkeley, California 94720-4767, USA ABSTRACT prior to the transfer of Baja California from Farallon microplates, the Rivera plate, currently North America to the Pacifi c plate. subducts along the Middle America Trench The Tepic-Zacoalco rift, a NW-trending Additionally, new 40Ar/39Ar dates show that beneath western Mexico (Figs. 1 and 2). There corridor ~50 × ~250 km, is one arm of a tri- the Sierra Madre Occidental volcanic prov- has been considerable speculation as to its future ple-rift system in western Mexico. Together ince extends across the entire width of the fate and whether it will eventually suture to the with the Colima rift and the Middle America Tepic-Zacoalco rift and terminates abruptly Pacifi c plate. Luhr et al. (1985) proposed that Trench, it bounds the Jalisco block, a por- at the northern boundary of the Jalisco block if the Rivera plate does transfer to the Pacifi c, tion of western Mexico that may be moving near the Rio Ameca. In contrast, Paleocene- it is likely to bring a piece of western Mexico independently of North America.
    [Show full text]
  • Chapter 8 Volcanic Activity in Mexico During the Holocene
    Chapter 8 Volcanic Activity in Mexico During the Holocene José L. Macías and José L. Arce Abstract This chapter presents an overview of the volcanic eruptions that have occurred in Mexico during the Holocene. Although volcanic regions are distributed all over the country, Holocene eruptions are mainly concentrated in the southern half of the country and, in particular, in the Trans-Mexican Volcanic Belt. Here, we summarize the details of the eruptions from the stratovolcanoes and monogenetic volcanoes, which have been extensively documented in the volcanological litera- ture, and their radiometric or historical dates. Out of the 153 Holocene eruptions described so far, ~63.4% have occurred at active stratovolcanoes and calderas, while the remaining ~36.6% have occurred from vents within monogenetic volcanic fields. Surprisingly, it seems that volcanism increased through time from Early (~17.7%), Middle (~26.8%) to Late Holocene (~55.5%). These figures may be biased because younger deposits are better preserved than older ones, and the latter usually are eroded through time especially around active stratovolcanoes. Around 24 eruptions (~15.6%) have taken place in pre-Hispanic and historical time out of which 11 occurred during the Little Ice Age. These eruptions have posed a serious threat to the surrounding regions and their populations. Some stratovolcanoes have collapsed at least once, covering and destroying previous deposits and making it difficult to reconstruct past eruption records. Large, Plinian to sub-Plinian eruptions at stratovolcanoes are well recorded in the stratigraphy, but the small eruptions that did not produce widespread deposits are difficult to define. Eruptions from monoge- netic volcanic fields were fed from central vents and fissures and mostly dominated by Strombolian activity and lava flows.
    [Show full text]
  • The Eruptive History of the Mascota Volcanic Field, Western Mexico: Age
    Journal of Volcanology and Geothermal Research 177 (2008) 1077–1091 Contents lists available at ScienceDirect Journal of Volcanology and Geothermal Research journal homepage: www.elsevier.com/locate/jvolgeores The eruptive history of the Mascota volcanic field, western Mexico: Age and volume constraints on the origin of andesite among a diverse suite of lamprophyric and calc-alkaline lavas Steven E. Ownby, Rebecca A. Lange ⁎, Chris M. Hall Department of Geological Sciences, University of Michigan, Ann Arbor, MI, USA article info abstract Article history: The Mascota volcanic field is located in the Jalisco Block of western Mexico, where the Rivera Plate subducts Received 28 November 2007 beneath the North American Plate. It spans an area of ∼2000 km2 and contains ∼87 small cones and lava Accepted 7 August 2008 flows of minette, absarokite, basic hornblende lamprophyre, basaltic andesite, and andesite. There are no Available online 15 August 2008 contemporary dacite or rhyolite lavas. New 40Ar/39Ar ages are presented for 35 samples, which are combined with nine dates from the literature to document the eruptive history of this volcanic field. The oldest lavas Keywords: fi eruption rates (2.4 to 0.5 Ma) are found in the southern part of the eld area, whereas the youngest lavas (predominantly b fi geochronology 0.5 Ma) are found in the northern portion. On the basis of these ages, eld mapping, and the use of ortho 3 minette aerial photographs and digital elevation models, it is estimated that a combined volume of 6.8±3.1 km andesite erupted in the last 2.4 Myr, which leads to an average eruption rate of ∼0.003 km3/kyr, and an average Jalisco Block volume per eruptive unit of b0.1 km3.
    [Show full text]
  • May 15, 2020 Mary Gates Hall
    May 15, 2020 Mary Gates Hall boruco’s magmatic system before the event. Phase equilib- SESSION O-1I ria modelling suggests re-equilibration of orthopyroxenes ap- proximately in the upper 7 km during magma ascent. The LITHOSPHERE TO BIOSPHERE: compositional and textural variability indicate magma mix- ing, which is a common process leading to explosive activity VOLCANOES,GLACIERS,CLIMATE in other TMVB volcanoes such as Popocatepetl´ and Volcan´ CHANGE, AND INSECTS de Colima. Session Moderator: Kirsten Nicolaysen, Geology 11:00 AM to 12:30 PM * Note: Titles in order of presentation. Lavas, domes, and beetles: Probing the magmatic processes leading to the 1870-5 CE eruption of Ceboruco Volcano, Mexico. Gustavo Bejar Lopez, Senior, Geology, Whitman College Mentor: Kirsten Nicolaysen, Geology, Whitman College Mentor: Nick Varley, Universidad de Colima As one of the westernmost stratovolcanoes in the Trans- Mexican Volcanic Belt (TMVB), Ceboruco exhibits a wide range of compositions correlating to its variable eruption style. With around 55,000 people residing within 10 km to the vent, Ceboruco represents an important hazard. Magma- tism in the Ceboruco region is the consequence of both com- pressional and extensional tectonic regimes: the small Rivera plate subducts under North America, and regional crustal ex- tension promotes the formation of three intersecting grabens in western Mexico, one of which hosts Ceboruco. In this tec- tonic setting, compositions are variable, and types of eruption fluctuate between moderately-effusive ones, like Ceboruco’s 1870-5 CE event, to large Plinian activity, like its caldera- forming eruption 1,060 ± 55 yr BP. Historically documented, the 1870-5 CE eruption led to the formation of a 7.5 km long lava flow, a small plug dome, and a larger dome complex (El Escarabajo).
    [Show full text]
  • Geology and Eruptive History of Some Active Volcanoes of México
    spe422-06 50 pages Geological Society of America Special Paper 422 2007 Geology and eruptive history of some active volcanoes of México José Luis Macías* Departamento de Vulcanología, Instituto de Geofísica, Universidad Nacional Autónoma de México, Coyoacán 04510, México D.F. ABSTRACT Most of the largest volcanoes in México are located at the frontal part of the Trans-Mexican Volcanic Belt and in other isolated areas. This chapter considers some of these volcanoes: Colima, Nevado de Toluca, Popocatépetl, Pico de Orizaba (Citlaltépetl), and Tacaná. El Chichón volcano is also considered within this group because of its catastrophic eruption in 1982. The volcanic edifi ce of these volcanoes, or part of it, was constructed during the late Pleistocene or even during the Holo- cene: Colima 2500 yr ago, Pico de Orizaba (16,000 yr), Popocatépetl (23,000 yr), Tacaná (~26,000 yr), and Nevado de Toluca (>50,000). The modern cones of Colima, Popocatépetl, Pico de Orizaba, and Tacaná are built inside or beside the remains of older caldera structures left by the collapse of ancestral cones. Colima, Popocatépetl, and Pico de Orizaba represent the youngest volcanoes of nearly N-S volcanic chains. Despite the repetitive history of cone collapse of these volcanoes, only Pico de Orizaba has been subjected to hydrothermal alteration and slope stability studies crucial to understand future potential events of this nature. The magmas that feed these volcanoes have a general chemical composition that varies from andesitic (Colima and Tacaná), andesitic-dacitic (Nevado de Toluca, Popocatépetl, and Pico de Orizaba) to trachyandesitic (Chichón). These magmas are the result of several magmatic processes that include partial melting of the mantle, crustal assimilation, magma mixing, and fractional crystallization.
    [Show full text]
  • Neogene-Quaternary Volcanic Forms in the Carpathian-Pannonian Region: a Review
    Cent. Eur. J. Geosci. • 2(3) • 2010 • 207-270 DOI: 10.2478/v10085-010-0024-5 Central European Journal of Geosciences Neogene-Quaternary Volcanic forms in the Carpathian-Pannonian Region: a review Review Article Jaroslav Lexa1∗, Ioan Seghedi2, Károly Németh3, Alexandru Szakács24, Vlastimil Koneˇcný5, Zoltán Pécskay6, Alexandrina Fülöp7, Marinel Kovacs7 1 Geological Institute of the Slovak Academy of Sciences, Bratislava, Slovakia, 2 Institute of Geodynamics, Romanian Academy, Bucharest, Romania 3 Volcanic Risk Solutions CS-INR, Massey University, Palmerston North, NewZealand, 4 Sapientia University, Dept. of Environmental Sciences, Cluj-Napoca, Romania 5 State Geological Institute of D. Štúr, Bratislava, Slovakia 6 Institute of Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary 7 North University, Faculty of Mineral Resources, Baia Mare, Romania Received 27 May 2010; accepted 18 July 2010 207 Neogene-Quaternary Volcanic forms in the Carpathian-Pannonian Region: a review Abstract: Neogene to Quaternary volcanic/magmatic activity in the Carpathian-Pannonian Region (CPR) occurred be- tween 21 and 0.1 Ma with a distinct migration in time from west to east. It shows a diverse compositional variation in response to a complex interplay of subduction with roll-back, back-arc extension, collision, slab break-off, delamination, strike-slip tectonics and microplate rotations, as well as in response to further evo- lution of magmas in the crustal environment by processes of differentiation, crustal contamination, anatexis and magma mixing. Since most of the primary volcanic forms have been affected by erosion, especially in areas of post-volcanic uplift, based on the level of erosion we distinguish: (1) areas eroded to the basement level, where paleovolcanic reconstruction is not possible; (2) deeply eroded volcanic forms with secondary morphology and possible paleovolcanic reconstruction; (3) eroded volcanic forms with remnants of original morphology preserved; and (4) the least eroded volcanic forms with original morphology quite well preserved.
    [Show full text]
  • The Geology of the Tecolotlan Graben, Jalisco, Mexico
    The Geological Society of America Digital Map and Chart 22 2017 The Geology of the Tecolotlan Graben, Jalisco, Mexico Bart J. Kowallis Eric H. Christiansen Department of Geological Sciences, Brigham Young University, Provo, Utah 84602, USA Oscar Carranza-Castañeda Centro de Geociencias, Campus Juriquilla, Universidad Nacional Autónoma de México, 76230, Mexico Wade E. Miller Keryn T. Ross David G. Tingey Department of Geological Sciences, Brigham Young University, Provo, Utah 84602, USA ABSTRACT The Tecolotlan valley is a small graben ~110 km southwest of Guadalajara in the northeastern corner of the Jalisco block of west-central Mexico. The graben trends roughly north-south, is ~10 km wide and 20 km long, with ~500 m of topographic relief. It is bounded to the east by a horst of Cretaceous (Albian/Cenomanian) lime- stone and to the west by a block of Late Cretaceous volcaniclastic sedimentary rocks, lava fl ows, and ignimbrites (one is 77 Ma). These volcanic rocks have chemical and mineralogical affi nities with continental volcanic arc sequences and record a history of arc volcanism and sedimentation during the Late Cretaceous. The sequence (over 300 m thick) consists of rhyolitic ash-fl ow tuffs and trachytic lava fl ows (lacking pil- low structures) interbedded with volcanic debris fl ow deposits, arkosic fl uvial sand- stones, and volcanic conglomerates. This suggests that by the Late Cretaceous the continental arc was emergent, but probably still low-standing as it continued to accu- mulate sediment after the closure of the Arperos oceanic basin and accretion of the Guerrero arc terrane to Mexico. The Tecolotlan valley contains discontinuously deposited latest Miocene to Recent sediments that are important for their record of extension, magmatism, and diverse vertebrate fauna.
    [Show full text]
  • The Colima Volcanic Complex, Mexico
    Contributions to Contrib. Mineral. Petrol. 71, 343-372 (1980) Mineralogy and Petrology by Springer-Verlag 1980 The Colima Volcanic Complex, Mexico I. Post-Caldera Andesites From Volcfin Colima James F. Luhr and Ian S.E. Carmichael Dept. of Geology and Geophysics, University of California, Berkeley, California 94720, USA Abstract. Volcfin Colima is Mexico's most historically semblage of the olivine-andesite is calculated to equili- active andesitic composite volcano. It lies 150 km brate at 1,000 bars with 0.8% H20. north of the Middle America Trench at the western Orthopyroxenes and certain clinopyroxenes in all end of the Mexican Volcanic Belt, closer to the trench pre-1961 samples are reversely zoned, with relatively than any other composite volcano in Mexico. Since Mg-rich rims. The most pronounced Mg-rich rims its earliest reported eruption in 1576, V. Colima has occur in the olivine-andesites and are thought to re- evolved through three cycles of activity. Each cycle flect pre-eruptive magma mixing, involving a basic, culminated in a major ashflow eruption, halting activ- olivine +/- clinopyroxene-bearing magma. In addi- ity for 50 or more years. The last major ashflow tion to their normally zoned pyroxenes, the post- eruption occurred in 1913. Andesitic block lava erup- 1961, fourth cycle andesites display a number of other tions in 1961-1962 and 1975-1976 marked the incep- features which distinguish them from earlier post- tion of activity in a fourth historical cycle which may caldera hornblende-andesites of similar bulk composi- also terminate with a major ashflow eruption in the tion.
    [Show full text]