Groundwater geochemistry of the Yucatan Peninsula, Mexico: Constraints on stratigraphy and hydrogeology

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Publication Date

March 2009

Abstract

The objective of this study is to use groundwater geochemistry to increase knowledge of the (largely concealed) subsurface stratigraphy of the rocks of the Yucatan Peninsula, Mexico and of the groundwater flow paths within these karstic rocks. The research has practical significance because essentially all municipal, agricultural, and industrial water used on the Peninsula is pumped from the aquifer. Scientific value derives from increased knowledge of an important karst aquifer system and from increased knowledge of the nature and extent of the ejecta blanket produced by the terminal Cretaceous Chicxulub bolide impact. Although soil cover in the area is thin or absent and bedrock exposure is nearly complete, the stratigraphy of the northern and east-central Yucatan Peninsula (here denoting the geographic area encompassed by the states of Yucatan and Quintana Roo) is poorly known. This is because weathering has caused extensive mineral dissolution and recrystallization, accompanied by loss of primary textural detail necessary for microfossil identification. In addition, exposure of Tertiary formations is highly selective because much of the region is a nearly flat plain, uninterrupted by stream valleys. Therefore many persistent rock units, which have dips of only a few degrees and are almost parallel to the land surface, do not crop out. Much of what is known about regional stratigraphy of the Yucatan Peninsula comes from oil exploration (Lopez-Ramos, 1983, Ward, 1985). Rocks of the northern Peninsula, to depths of more than 500 m, are dominantly limestone and dolomite of Cretaceous and younger ages with significant evaporite lenses but rare siliciclastic units (Fig. 1). Drilling and seismic and magnetic exploration have revealed the outlines of the K/T Chicxulub impact crater in the northwestern part of the Peninsula (Rebolledo-Vieyra et al., 2000, Gulick et al., 2008), which has a probable age of 65.96 m.y. (Kuiper et al., 2008). A polymictic impact breccia that contains clasts of limestone, dolomite, and ev

Keywords

Strontium Isotopes, Yucatán, Polje, Chicxulub Impact, Evaporite

Document Type

Article

Notes

Journal of Hydrology, Vol. 367, no. 1-2 (2009-03-30).

Identifier

SFS0055845_00001

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