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Extension Del Campo De Cerro Prieto Y Futuras Zonas Con Probabilidades Geotermicas En El Valle De Mexicali H

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Extension Del Campo De Cerro Prieto Y Futuras Zonas Con Probabilidades Geotermicas En El Valle De Mexicali H EXTENSION DEL CAMPO DE CERRO PRIETO Y FUTURAS ZONAS CON PROBABILIDADES GEOTERMICAS EN EL VALLE DE MEXICALI H. L. Fonseca L., A. de la Pena 1., 1. Puente c., y E. Diaz C. Comisi6n Federal de Electricidad Coordinadora Ejecutiva de Cerro Prieto Mexicali, Baja California, Mexico RESUMEN instalar una capacidad de generaci6n geotermoel~ctrica del orden de 1000 W~ en e1 Valle de 1:1exicali. En una evaluacion de las condi'eiones" geoliigico-estructurales" dentro de sumarco Con el afan de contribuir al desarrollo de las tectonico regional, y con la integracion de los obTas geotermicas de esta regi-on, en e1 presente trabaj os geologicos y geoU.sicos realizados en el traoajo se e:xponen algunas condiciones geologico­ Campo de Cerro Prieto, se intenta estaolecer la es"tTucturales proprcias para la e:xistencia de posible extension del mismo, asi como otras zonas amoientes geotermicos y la relacion de ciertas que podrian tener probaoilidades de desarrollo anomalJ1as geofisicas con zonas que podrlan tener geotermico dentro del Valle de Mexicali, probabilidades de desarrollo incluyendo la posible extensron del Campo de Cerro Prieto. Este trabajo tiene como antecedente la informacion ootenida de los pozos cons·tru:Cdos· a 1a Cabe mencionar que algunas areas interpretadas fecha, y la informacion geologica y geof5!sica como prospectos geotermicos, han sido senaladas disponible con 10 cual se esta contriDuyendo a la tomando en cuenta la posicion formacion del modelo geologico que en forma informacion respecto a los generalizada establece la geometrta de 10 que Valle Im~erial y, 1a podria constituir el yacimiento geot~rmico del de encontrarse en maximos campo de Cerro Prieto. unicamente Salton Sea , No.1). As imISIDO, se hIzo un estudio En 10 que respecta a las areas con riguroso de los maximos ooservados en el Valle de probabilidades dentro del Valle de Mexicali, ooteniendo como conclusion que no todos Mexicali, se ha tornado como apoyo inicial para los" ellos son de prospeccion ya que algunos son subsiguientes estudios, las manifes"taciones" de representativos unicamente de elevacione;.; ·,_.el temperaturas anomalas detectadas en los pozos basamento. construldos para riego. En base a esa prrmera informacion, se a realizar trabajos de gravimetria y magnetometria, para continuar con los ~~TECEDENTES GEOLOGICOS GENERALES de Sismic~~de Reflexion y Refracc~on, aSI+como la El Valle de Mexicali en el cual se encuentra construcc~on de pozos de usc mult~ple de - 1200 m el Campo de Cerro Prieto, forma parte de la de profundidad. provincia fisiografica del Golfo de California. Al describir los resultados en la integracian Topograficamente es una plana en dcnde final de estos trabajos junto con la geologia de la sooresale unicamente la prominencia conocida como region, se inter~s exploratorio en las el Volclln de Cerro Prieto de 225 msnm*. areas de Este de Cerro Prieto, Tulecheck, Riito, Es parte de la region del Delta del Rio Aeropuerto-Algodones y San Luis Rio Colorado, Son. Colorado cuyos" sedimentos Cuaternarios y Terciarios esdIn constitu'ldos predominantemente por rocas INTRODUCCION clasticas, de orIgen Deltaico y de Piedemonte. Los sedimentos delt1licos, se han diJ;erenciado e.n Despues de 15 anos de detalladas dos unidades litologicas: sedimentos no investigaciones, estudios t~cnicos e consolidados y consolidados, srendo en es·tos ininterrumpido esfuerzo y la experiencia obtenida ultimos, en donde se encuentran los- acu'fferos con la operacion de la Central Geotermoel~ctrica de sobrecalentados. Estas rocas consolidadas Cerro Prieto de 180,000 ~~" de capacidad, se (Lutitas y Areniscas), sobreyacen a su vez demostraron los beneficios de la utilizacii3n de la discordantemente a un casamento granitico y energia para la generacian de metasedimentario del Cretasico Superior electricidad. El examen de dichos resultados ha (Fig. No.2). motivado asimismo que la Comisian Federal de Electricidad decidiera desarrollar un programa de Estructuralmente el Valle esta caracterizado construccion de nuevas centrales" geotermoel~ctricas por una serie de grabens y nors"ts resultantes en Cerro Prieto mediante las cuales se contara en de zonas de apertura cortical asociados a 1984 con una capacidad instalada de ~ste tipo de movimientos de rumbo NO-SE de las fallas Cerro 62Q,OOO KW, Prieto, Imperial y San Andr@s (Fig. No, 3). Srmultaneamente. se han ~enido realizando Estas fallas y las del area en general son dwersas e:xploraciones en el Valle de He:xicali parte del sistema San Andr~s que penetra en el cuyos tienen como obj etivo principal Golfo como un cortejo de grandes fallas dispuestas e~trmar potencialidad de algunas areas de en echelon (Fig. No.4) que a su vez componen una anomal~as termicas, que de resultar comercialmente red global de cadenas volcanicas, grietas en el explotaoles, y en adicion a las reservas ya conocidas, s"e e$tima que habrll suficiente vapor p"arr, * msnm- Hetros sobre el nivel del mar, 384 sue10 ocean~co y profundas fosas oceanicas, Todo En la geologIa local del campo de Cerro ello representan los l~mites entre las amplias Prieto se ba analizado y entendido que la falla placas mOviles del PaCIfico y Americana Cerro Prieto (8 San Jacinto) de rumbo NO-SE tiene (Fig. No.5). su evidencia en diferentes estudios desde el Golfo de California basta el volc&n de Cerro Prieto y Esta es una zona que se ha caracterizado por contrariamente a 10 que antes se pensaba, no es una tectoniea con geometr'las de cuencas de regimen aportadora de fluidos sino mas bien actua como transformado, de gran aetividad sIsmica y lImite del campo. terremotos de foeo somero, en donde 1a corteza terrestre ha sufrido adelgazamiento, por Al .norte del campo principal en produccion consecuencia acercamientc de material del con base a estudios de geofisica y correlaci6n de manto, originando con ello algunas areas de alto pozos se determino otra falla denominada Morelia flujo termico. con orienta£1:Q1L SO-NE (Fig. No.8) y esta Dado que el Golfo de California se ubica entre censidexadaasimismo como limitante. Dicha falla forma parte de un sIstema llamado Volcano de la zona de de las placas, estas en su movimiento han provocado esfuerzos en la corteza y orientacion general SO~NE que cuenta ademas con tres zonas de fallas denominadas Delta, Patzcuaro el manto, trayendo como consecuencia e1 e Hidalgo. Este sIstema de afallamientos, desplazamiento de grandes 'hloques (Fig, No.6) 10 obllcuo al patron tectonico regional de que que ha dado lugar a la formacion de fos,as como orientacion NO-SE, es una clara evid~ncia del la Hagner que se conecta a traves de la falla desplazamiento en echelon caracterlstico de las Cerro Prieto con e1 Valle de Mexicali. fallas transformes en el Valle de Mexicali. Ello Es importante hacer notar que la base hace pensar que las fallas del sIstema Volcano al mas relevante de este trabajo, es partir encontrarse en 10 que se ha sugerido como un primeramente de un bosquejo de apertura de corteza centro de dispersion; se pueden considerar como y desprendimiento continental cuyos efectos nan principales conductoras de calor y de fluldos dado lugar a la formacion del Golfo de sobrecalentados. California. Partiendo de panoramas regionales y agrupando argumentos y datos se na comprendido el POSIBLE EXTENSION DEL CA~O DE CERRO PRIETO modelo geologico C\lYo semblante princi1)al es: originalmente en tiempos del Plioceno (?) la Numerosos autores han llevado a cabo estudios Penlnsula de Baja California formaba parte de un de diferente naturaleza sobre el Campo de Cerro macizo granltico continental, pero debido a Prieto. Contribuciones not<"bl,es han sido hechas y complejos esfuerzos de la corteza y del manto, y mucho se ha discutldo sobre los limites del del movimiento de las placas Americana y del yaclmlento. No obstante, aunque este ha sido PaCIfico, se inicia su separacion (Anderson, D, delimitado al SO por la falla Cerro Prieto, 13,1 NO 1971). Esto ha traldo como consecuencia que por una franja que pasarla por los pozos M-3, durante el proceso de d;bi.tensi8n di8 y continua M-172 Y H-2, al SE por el S-262, M-92 Y M-189, dandolugilr al agrietamiento, desplazamietno de queda pendiente la delimitaci6n hacia el E grandes bloques, descubrimiento del piso oceanico, (Fig. No, 8}, ~n Da,ae a ~Q ~nt~~Q~, d~dQ ~u~ y penetrilcion de magma cuyas evidencias mucho se las temperaturas son a.1tas bac.ia es'e rtflllbo, se han publicado. estima que las perforaciones exploratorias deber1l.n Un aspecto local respecto de 10 anterior es que ser enfocadas con esta orientaciSn y ese es'uno de en el caso de los Valles' de· Mexicali e los primeros argumentos que soportan el atractivo justo en la porcion noroccidental del Golfo de al Este de Cerro Prieto al Oriente del Ejido Nuevo Leon. CalifQrni;:q con e1 s~stema de fallas San Andres como tenor l se han 'man:i:fes'tadouna serie de En este resumen se agrupan resultados de un tenClmenos t;ect8nicos que incluyen alta sismicidad analisis efectl1ado a diversos estudios geologico­ en 'La. zona, cl.esprendimientos basamentarios en los geoflsicos llevados a cabo por la C.P,E. en el flancos al'SO y N'E de, los 'Valles. fallas Campo de Cerro Prieto zonas adyacentes, apoyando transformadas con desplazamietnos vertical y tecnicamente el exploratcrio hacia el horizontal, intrusiones magmaticas, existencia de oriente yse describen a continl1acion algunas volcanes, y una variedad de zonas de alto flujo caracterlsticas geologicas que se esperan detectar termico, que son los que prop'lcian los ambientes conforme se realIcen las perforaciones. Dichas ge<;>termicos. Esto ultimo ha motivado las caracterlsticas se pueden resumir en 10 siguiente~ exploraciones tanto en el Valle Imperial como en el Valle de }1exicali dando como resultado en el 1.- Se ha postulado que el Campo de Cerro primero el descubrimien:c> de ocho regiones Prieto se local'lza en un centro de dispersi8n geotermicas denominadas Salton Sea, Heber, East activo producto del· movimiento lateral derecno de 'l'!esa, North Brawley, East Brawley, Glarnis, Dunes y las fallas transformadas Cerro Prieto e Imperial (Elders, et aI, 1972).
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