Neotectónica y facies sedimentarias cuaternarias en el suroeste del Golfo de México, dentro del marco tectono-estratigráfico regional evolutivo del Sur de México

Abstract

THE STUDIED AREA COMPRISES THE SOUTH WESTERN GULF OF MEXICO AND THE EXTERNAL MARGIN OF THE SOUTH EASTERN COASTAL PLAIN OF MEXICO, WITH AN EXTENSIÓN OF 150 000 KM² . THE GEOLOGICAL PROVINCE RESULTED FROM THE INTERMITTENT MOVEMENTS OF FIVE MAJOR TECTONIC PLATES THROUGH SPACE AND TIME: NORTHAMERICA PLATE (1); THE CIRCUM-PACIFIC PLATES: KULA (2), FARALLON (3) AND COCOS (5), AND THE CARIBBEAN PLATE (5). DUE TO THESE CORTICAL MOVEMENTS, 12 TO 14 KM OF SEDIMENTARY COLUMN WERE DE POSITED IN THE MARGINAL CONTINENTAL ACCRETIONARY PRISM IN ENVIRONMENTS WHICH VARIED FROM CONTINENTAL TO DEEP MARIN, SINCE LATE TRIASSIC TROUGH RECENT. BASED ON THE GE LOGICAL AND GE PHYSICAL DATA FROM THE MARINE AND CONTINENTAL SUBSURFACE FACILITED BY PEMEX-IMP; SUCH INFORMATION WAS INTEGRATED WITH THE ONE PREVIOUSLY ESTABLISHED BY SEVERAL AUTHORS, FROM THE OUT CROPPING STRATIGRAPHIC SEQUENCES OF THE SIERRA DE CHIAPAS, WHICH WERE VERIFIED AT SELECTED LOCALITIES, AND ALSO WITH THE QUATERNARY DATA OBTAINED DURING THIS RESEARCH, WITH ALL THESE DATA IT IS HEREIN INTERPRETED THE FOLLOWING STRATIGRAPHIC MEGA SEQUENCES AT SOUTH EASTERN MEXICO AND SOUTH WESTERN GULF OF MEXICO: 1) MESOZOIC TRANSGRESSION, 2) PALEOGENE REGRESSION, 3) NEOGENE REGRESSION, 4) PLEIS TO CENE-LATE HOLOCENE REGRESSION AND TRANSGRESSION, AND 5) EUSTATIC STABILITY SINCE LATE HOLOCENE. AT THE STUDIED AREA MORPHO-BATHYMETRY MAP OF THE SEA FLOOR BY MEANS OF A CONTINUOUS LINEAR HYDRO-ACOUSTIC SOUNDER OF THE R/V “JUSTO SIERRA” OWNED BY UNAM. IN THIS MAP, MOST PROMINENT FAULT SYSTEMS AND SALT DIAPIRS OUT CROPPING ON THE SEA FLOOR MAKE CONSPICUOUS, THIS DATA WAS COMPLEMENTED WITH THAT FROM THE STRATIGRAPHIC WELLS AND SEIS MIC-STRATIGRAPHY PROFILES FROM THE SUBSURFACE MARINE PROVINCES PROVIDED BY PEMEX-IMP. IT IS HEREIN INTERPRETED WITH THE INTEGRATED INFORMATION, THE CLOCK WISE ROTATION OF THE YUCATAN BLOCK WHICH MOVES IN ITS SOUTH ERNPORTION IN CENTRAL AMERICA, ALONG THE GEOLOGICAL PROVINCE OF THE LIBERTAD ARCH AND OF THE POLOCHIC LEFT-LATERAL FAULTING SYSTEM. THE CLOCK WISE TECTONIC MOVEMENTS OF THE YUCATAN MICROPLATE WERE SPECIALLY IMPORTANT DURING LATE MIO CENE-EARLY PLIOCENE, BECAUSE IT CAUSED THE RE ACTIVATION AND SUBSIDENCE OF THE TERTIARY TENSIONAL BASINS OF MACUSPANA, COMALCALCO AND SALINA DEL ISTMO AT SOUTH EASTERN MEXICO.