updated 08/18/2005 Todd Bowers updated 03/01/2105 Todd Bowers updated 02/14/2005 keith georef data 2002-055534 TI Late-Pleistocene to Precolumbian behind-the-arc mafic volcanism in the eastern Mexican volcanic belt; implications for future hazards. AU Siebert-Lee; Carrasco-Nunez-Gerardo AF Smithsonian Institution, Global Volcanism Program, Washington, DC, United States SO Journal of Volcanology and Geothermal Research. 115; 1-2, Pages 179-205. 2002. PB Elsevier. Amsterdam, Netherlands. 2002. CP Netherlands PY 2002 LA English AB An area of widespread alkaline-to-subalkaline volcanism lies at the northern end of the Cofre de Perote-Citlaltepetl Pico de Orizaba volcanic chain in the eastern Mexican Volcanic Belt MVB. Two principal areas were active. About a dozen latest-Pleistocene to precolumbian vents form the 11-km-wide, E-W-trending Cofre de Perote vent cluster CPVC at 2300-2800 m elevation on the flank of the largely Pleistocene Cofre de Perote shield volcano and produced an extensive lava field that covers >100 km super 2 . More widely dispersed vents form the Naolinco volcanic field NVF in the Sierra de Chiconquiaco north of the city of Jalapa Xalapa. Three generations of flows are delineated by cone and lava-flow morphology, degree of vegetation and cultivation, and radiocarbon dating. The flows lie in the behind-the-arc portion of the northeastern part of the MVB and show major- and trace-element chemical patterns transitional between intraplate and subduction zone environments. Flows of the oldest group originated from La Joya cinder cone radiocarbon ages approximately 42 000 yr BP at the eastern end of the CPVC. This cone fed an olivine-basaltic flow field of approximately 20 km super 2 that extends about 14 km southeast to underlie the heavily populated northern outskirts of Jalapa, the capital city of the state of Veracruz. The Central Cone Group CCG, of intermediate age, consists of four morphologically youthful cinder cones and associated vents that were the source of a lava field >27 km super 2 of late-Pleistocene or Holocene age. The youngest group includes the westernmost flow, from Cerro Colorado, and a lava flow approximately 2980 BP from the Rincon de Chapultepec scoria cone of the NVF. The latest eruption, from the compound El Volcancillo scoria cone, occurred about 870 radiocarbon years ago and produced two chemically and rheologically diverse lava flows that are among the youngest precolumbian flows in Mexico and resemble paired aa-pahoehoe flows from Mauna Loa volcano. The El Volcancillo eruption initially produced the high effusion rate, short-duration Toxtlacuaya alkaline aa lava flow from the southeastern crater. This 12-km-long hawaiite average 50.5% SiO sub 2 flow was followed by extrusion of the calc-alkaline Rio Naolinco lava flow from the northwestern crater. This large-volume approximately 1.3 km super 3 tube-fed basaltic pahoehoe flow average SiO sub 2 49% traveled 50 km. Inferred effusion rates suggest emplacement over a decade-long period. Flows of all three age groups are transected by Highway 140 and the railway that form major transportation arteries between Jalapa and Puebla. This area has not previously been considered to be at volcanic risk, but volcanism here has continued into precolumbian time. Future eruptions of similar magnitude and location to those documented here could pose significant hazards to transportation corridors and to densely populated areas in and to the north of Jalapa. Slight variations in vent locations could produce future flows down one or more of more than a half dozen drainages with widely varying population densities. DE alkali-basalts; basalts-; Cenozoic-; eruptions-; geologic-hazards; igneous-rocks; lava-flows; Mexican-volcanic-belt; Mexico-; Pico-de-Orizaba; Pleistocene-; Quaternary-; risk-assessment; upper-Pleistocene; volcanic-risk; volcanic-rocks; volcanism-; volcanoes- CC 24-Quaternary-geology DT Serial BL Analytic MC LAT| N190100; N190100; LONG: W0971600; W0971600. IL Refs 80; illus. incl. 5 tables, geol. sketch maps. RF GeoRef, Copyright 2002, American Geological Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands IS 0377-0273 CO JVGRDQ AN 2002-055534 UD 200218 Sample Data Item Alt_Sample_Name Location Rock_type Geologic_Age Geologic_Age_Prefix Age Age_Min Age_Max Age_Error TMVB_Episode Long Lat Dist. to trench Laboratory SiO2 TiO2 Al2O3 Fe2O3 Fe0 Fe2O3t FeOt Mn0 MgO CaO Na2O K2O P2O5 LOI H2O+ H2O- CO2 Tot. S calc DIFF 100-suma Li Be B Sc V Cr Co Ni Cu Zn Ga Rb Sr Y Zr Nb Mo Sn Sb Cs Ba La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Au Tl Pb Th U Rb87/Sr86 Sr87/Sr86 147Sm/144Nd Nd144/Nd143 epsilon Nd 206Pb/204Pb 207Pb/204Pb 208Pb/204Pb Delta 18 O Observaciones State Units MA MA MA DD DD KM WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% WT% PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM PPM Method 2 2 2 3 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 4 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 4 4 4 4 4 4 4 4 Sample Name CP-100 2262 La Joya, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 51.45 1.19 17.06 9.88 0.15 6.77 9.02 3.27 0.88 0.2 0.09 99.96 99.96 0 0.04 30.7 190 219 40 84 16 80 17.7 354 25.81 127 7.1 0.46 271 14.8 30.05 3.75 16.24 4.3 1.44 4.58 0.76 4.76 0.97 2.68 0.38 2.35 0.38 3.32 0.46 4.05 2.45 0.63 Veracruz CP-124 2263 Cerro Colorado, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 49.93 1.8 15.74 11.08 0.17 8.59 8.17 3.44 1.19 0.39 0.19 100.69 100.69 0 -0.69 27 204 357 42 163 12 88 23.4 501 26.19 174 13.6 0.84 303 18.85 39.93 5.04 22.34 5.73 1.84 5.59 0.89 5.21 1.01 2.71 0.36 2.18 0.34 4.23 0.93 5.16 2.81 0.98 Veracruz CP-127 2264 Dos Veredas, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 49.36 1.89 16.67 10.38 0.17 6.99 8.74 3.74 1.14 0.45 0.12 99.65 99.65 0 0.35 28.4 208 179 37 99 12 88 19.1 572 29.66 199 16.13 0.46 376 25.25 51.24 6.37 27.19 6.72 2.13 6.31 0.99 5.82 1.14 2.96 0.42 2.48 0.39 4.79 0.97 4.94 2.76 0.83 Veracruz CP-140 2265 CCG, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 52.35 1.67 16.8 9.26 0.15 6.61 7.77 3.62 1.29 0.43 0.77 100.72 100.72 0 -0.72 23.9 195 230 29 100 1 95 22.3 528 26.4 219 17.1 0.57 428 27.49 54.18 6.58 27.69 6.42 1.93 5.81 0.91 5.19 1.01 2.92 0.36 2.19 0.34 5.26 1.12 6.15 3.64 1.05 Veracruz CP-141 2266 CCG, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 48.66 1.79 16.4 10.33 0.16 7.96 9 3.53 1.12 0.42 0.07 99.44 99.44 0 0.56 27.8 214 280 36 135 20 92 14.5 559 27.58 185 14.94 0.35 399 25.03 49.59 6.19 26.62 6.46 2.04 6.02 0.94 5.37 1.04 2.61 0.39 2.31 0.36 4.55 0.92 5.22 2.97 0.86 Veracruz CP-48 2267 CCG, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 50.89 1.69 16.48 9.79 0.15 7.25 8.89 3.61 1.28 0.39 0.09 100.51 100.51 0 -0.51 27.9 221 262 39 111 47 86 22.7 553 27.29 186 15.03 0.62 390 24.57 50.15 6.18 26.69 6.6 2 6.07 0.94 5.46 1.06 2.71 0.39 2.29 0.37 4.62 0.92 6.73 2.97 0.89 Veracruz CP-48b 2268 Toxtlacuaya, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 50.96 2.05 17.83 10.66 0.16 3.99 6.58 4.74 1.73 0.67 0.39 99.76 99.76 0 0.24 16.3 143 17 33 23 21 108 30.3 642 35.51 324 32.59 0.83 513 41.21 79.45 9.15 38.12 8.58 2.62 7.74 1.19 6.88 1.37 3.51 0.5 3.04 0.49 7.35 1.94 7.42 5.77 1.59 Veracruz CP-49 2269 Toxtlacuaya, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 49.55 2.07 17.55 10.97 0.16 4.91 7.32 4.43 1.41 0.65 0.46 99.48 99.48 0 0.52 143 17 33 23 21 108 Veracruz CP-51 2270 Rio Naolinco, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 48.42 1.58 16.69 10.57 0.16 8.06 10.19 3.11 0.55 0.22 0.49 100.04 100.04 0 -0.04 35 220 293 51 121 40 79 8.7 371 26.43 132 8.01 0.21 148 11.54 25.17 3.3 15.34 4.35 1.53 4.79 0.81 4.98 1.03 2.7 0.38 2.34 0.36 3.35 0.51 2.33 1.28 0.37 Veracruz CP-57 2271 Rio Naolinco, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 49.09 1.59 16.59 11.81 0.16 7.78 9.86 3.22 0.6 0.19 0.48 101.37 101.37 0 -1.37 34.7 214 233 42 75 42 73 10.2 390 27.16 140 8.95 0.25 168 12.89 27.88 3.58 16.62 4.64 1.6 5.02 0.84 5.16 1.05 2.76 0.4 2.4 0.38 3.47 0.56 2.54 1.54 0.44 Veracruz CP-65 2272 La Joya, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 51.47 1.29 16.78 9.5 0.15 6.75 8.78 3.32 1.02 0.25 0.18 99.49 99.49 0 0.51 31.4 180 204 35 82 9 80 21 393 25.54 139 8.11 0.55 300 16.57 33.25 4.11 17.9 4.58 1.48 4.68 0.78 4.77 0.98 2.56 0.37 2.3 0.36 3.61 0.53 4.62 2.74 0.69 Veracruz CP-70 2273 CCG, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 49.65 1.86 16.41 10.16 0.16 7.31 8.75 3.62 1.28 0.48 0.45 100.13 100.13 0 -0.13 28 210 228 33 104 27 93 24.1 584 27.87 196 16.86 1.07 406 26.93 54.56 6.75 28.69 6.88 2.14 6.32 0.96 5.57 1.06 2.79 0.39 2.28 0.36 4.85 1.05 6.11 2.96 0.86 Veracruz CP-75 2274 Toxtlacuaya, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 50.79 2.05 17.83 10.79 0.16 4.18 6.77 4.7 1.6 0.64 0.38 99.89 99.89 0 0.11 17 161 26 31 31 23 107 27.7 647 35.19 306 60.77 0.73 496 39.74 77.1 9.05 37.29 8.43 2.6 7.66 1.18 6.74 1.35 3.53 0.49 3 0.47 6.97 1.79 6.68 5.08 1.41 Veracruz CP-76 2275 CCG, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 50.01 1.73 16.89 9.72 0.15 6.38 9.04 3.44 1.2 0.39 0.23 99.18 99.18 0 0.82 28.6 226 172 33 75 33 91 21.7 560 29.29 196 14.89 0.57 416 25.71 52.41 6.56 27.89 6.86 2.11 6.31 0.99 5.71 1.12 2.79 0.42 2.46 0.39 4.74 0.9 5.34 2.77 0.82 Veracruz CP-84e 2276 Toxtlacuaya, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 50.28 2.11 17.58 11.15 0.16 4.98 7.4 4.49 1.45 0.57 0.53 100.7 100.7 0 -0.7 19.8 178 50 33 47 26 106 24.5 614 33.94 275 27.72 0.64 436 35.27 68.32 8.02 33.4 7.74 2.47 7.23 1.14 6.59 1.26 3.36 0.48 2.89 0.46 6.37 1.61 5.99 4.51 1.28 Veracruz CP84w 2277 Rio Naolinco, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 48.54 1.63 16.97 10.56 0.16 7.61 10.41 3.2 0.55 0.22 0.47 100.32 100.32 0 -0.32 34.9 225 251 47 94 39 81 8.7 390 27.81 137 8.12 0.2 155 12.14 26.45 3.51 15.89 4.51 1.6 4.93 0.86 5.28 1.06 2.89 0.41 2.46 0.38 3.36 0.51 2.36 1.22 0.35 Veracruz CP-89 2278 Coacotzintla, Cofre de Perote-Citlalteptl Basaltic andesite Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 50.88 1.56 16.55 9.73 0.16 7.89 8.93 3.55 1.11 0.4 0.14 100.9 100.9 0 -0.9 27.4 203 246 38 117 11 84 20 537 26.12 187 14.81 0.53 340 24.05 47.33 5.67 23.93 5.79 1.87 5.45 0.87 5.09 1 2.61 0.38 2.21 0.35 4.62 0.93 4.58 3.25 0.91 Veracruz CP-94 2279 Rio Naolinco, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 49.36 1.6 16.91 9.87 0.16 7.71 9.82 3.15 0.71 0.26 0.58 100.13 100.13 0 -0.13 211 237 42 80 40 73 Veracruz CP-98 2280 Rio Naolinco, Cofre de Perote-Citlalteptl Basalt Holocene 1 3 1 -96.81 19.43 441.6826438 Instituto de Geologia, UNAM Mexico/Washington State Un. 48.97 1.54 16.6 11.01 0.17 8.56 9.66 2.99 0.56 0.22 0.66 100.94 100.94 0 -0.94 31.8 207 306 49 125 52 77 9.8 357 24.95 121 7.95 0.24 151 11.21 23.76 3.07 14.3 4.14 1.45 4.44 0.77 4.83 0.96 2.58 0.36 2.17 0.34 3.03 0.52 2.42 1.38 0.41 Veracruz Method Data 1 NN 480 2 NN 480 3 NN 480 4 NN 480