Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

John S. Armstrong-Altrin ¹, J. Madhavaraju ², Alcides N. Sial ³, Juan J. Kasper-Zubillaga ¹, R. Nagarajan ⁴, K. Flores-Castro ⁵, Janet Luna Rodriguez ⁵

Affiliations
1 Instituto de Ciencias del Mar y Limnologia, Unidad de Geologia Marina y Ambiental, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, 04510, Mexico D.F., MX
2 Estacion Regional del Noroeste, Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Hermosillo 83000, Sonora, MX
3 Nucleo de Estudos Geoquimicos e Laboratorio de Isotopos Estaveis (NEG - LABISE), Departmento de Geologia, Universidade Federal de Pernambuco, Caixa Posta 7852, 50670-000 Recife, BR
4 Department of Applied Geology, School of Engineering and Science, Curtin University of Technology, CDT 250, 98009, Miri, Sarawak, MY
5 Universidad Autonoma del Estado de Hidalgo, Centro de Investigaciones en Ciencias de la Tierra, Ciudad Universitaria, Carretera Pachuca-Tulancingo Km. 4.5, 42184 Pachuca, Hidalgo,, MX

Abstract

Petrography and stable isotopes (carbon and oxygen) geochemistry of limestones from the El Abra Formation, Actopan, were studied to identify their digenetic environments. The major petrographic types identified are mudstone, wackestone, grainstone, and boundstone. Most of the studied samples show positive δ¹³C values, except two samples (2 and 28), which are slightly negative values (-0.27‰ and -0.02‰). The organic remains identified in foraminiferal wackestone type can be responsible for the negative δ¹³C values. The δ¹⁸O values range from -12.41‰ to -4.02‰ and indicate meteoric diagenesis.

Keywords

Carbonate Rocks, Carbon and Oxygen Isotopes, Diagenesis, Hidalgo State, Mexico.

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