Magnetic and Geochemical Characterization of the Paleogene Carbonate Sequence in the Tekax Borehole, Yucatan, Mexico
Caracterización magnética y geoquímica de la secuencia carbonatada del Paleógeno en el pozo Tekax, Yucatán, México
Ligia Pérez-Cruz1,2,3,*, Daniel J. Salomón-Dávila1,2, Claudio Vázquez-Sánchez 1,2, Alejandro Ortega-Nieto2, , Elia J Escobar-Sánchez 4, Marysol Valdés-Hernández 1,2, Rafael Venegas-Ferrer1, Jaime Urrutia-Fucugauchi 1,2
1 Programa Universitario de Perforaciones en Océanos y Continentes, Instituto de Geofísica. Universidad Nacional Autónoma de México, Coyoacán 04510, México
2 Instituto de Investigación Científica y Estudios Avanzados Chicxulub, Parque Científico y Tecnológico de Yucatán, Sierra Papacal, Mérida, Yucatán 97302, Mexico
3 Coordinación de Plataformas Oceanográficas, Coordinación de la Investigación Científica, Universidad Nacional Autónoma de México, Coyoacán 04510, México
4 Escuela Nacional de Estudios Superiores, Unidad Mérida, Universidad Nacional Autónoma de México, Mérida, Yucatán 97357, México
Corresponding author: (L. Pérez Cruz) This email address is being protected from spambots. You need JavaScript enabled to view it.
How to cite this article:
Pérez-Cruz, L., Salomón-Dávila, D.J, Vázquez-Sánchez, C., Ortega-Nieto, A., Escobar-Sánchez, E.J., Váldes-Hernández, M., Venegas-Ferrer, R., Urrutia-Fucugauchi J., 2024, Magnetic and Geochemical Characterization of the Paleogene Carbonate Sequence in the Tekax Borehole, Yucatan, Mexico: Boletín de la Sociedad Geológica Mexicana, 76 (3), A010324. http://dx.doi.org/10.18268/BSGM2024v76n3a010324
Manuscript received: October 25, 2023; corrected manuscript received: February 10, 2024; manuscript accepted: February 28, 2024.
ABSTRACT
Formation of carbonates involve an interplay of processes, including climate, ocean circulation, marine organisms, sediment sources, transport, deposition and diagenesis. The Yucatan peninsula is characterized by a thick carbonate sequence, which has been studied by geological-geophysical surveys and drilling. Characterizing carbonate systems remains an important yet complex undertaking. Here, results of a magnetic susceptibility and X-ray fluorescence geochemical study are used to characterize the Paleogene carbonate sequence in the Tekax borehole of the Chicxulub Drilling Program. The carbonate sequence is ~222 m thick, formed by limestones, dolomites, carbonate breccias and evaporites. Changes in Si, Ca, Fe, Mg, Al, Ti and magnetic susceptibility correlate with lithology downcore. The Ca contents vary through the sequence with a trend around 24% and low discrete values. The upper unit shows higher Ca contents. The Si contents vary downhole, between about 0.03 to 38 %. The carbonates show weak magnetic susceptibilities associated with diamagnetic and paramagnetic minerals, characteristic of carbonate sediments and reduced terrigenous input. Magnetic hysteresis shows fine grained low coercivity magnetite and titanomagnetites, with PSD and MD domain states. Six units are identified through the lithological column. The carbonate sequence shows effects of varying dissolution, fracturing and dolomitization. The lower carbonate unit above the breccia contact shows evaporites, with gypsum and anhydrites.
Keywords: Chicxulub crater, Tekax borehole, Yucatan peninsula, Paleogene carbonate sequence, Magnetic susceptibility, X-ray fluorescence.
