ORIGINAL ARTICLE A study of carbonate beach sands from the Yucatan Peninsula, Mexico: a case study J. J. Kasper-Zubillaga 1 • E. Arellano-Torres 2 • J. S. Armstrong-Altrin 1 • A. N. Sial 3 Accepted: 16 November 2015 Ó Springer-Verlag Berlin Heidelberg 2015 Abstract Sedimentological, geochemical, and X-ray diffraction (XRD) analyses in addition to the determination of biogenic fraction components (BFC) were performed in mollusk shells from carbonate beach samples collected on the northern coast of the Yucatan Peninsula, Mexico. The most abundant components of the BFC were bivalves and gastropods shells, ranging from 88.1 to 99.2 % and from 0.1 to 6.0 %, respectively, followed by minor percentages of foraminifera, coral fragments, bryozoa, oolites, spicules, and ostracods. A combination of major element, trace ele- ment, and XRD techniques were performed to show how the Mg/Ca and Mg/Sr ratios determine the possibility of a recrystallization process in bivalves and gastropods, which may be attributed to early diagenetic mechanisms caused by groundwater flows, subaerial exposure, high evaporation rates, and neomorphism. The rare earth element analyses gave the average anomalies for the following ratios (Pr/ Yb) PAAS and MuQ ratio [ 1, (Eu/Eu*) PAAS and MuQ and (Ce/ Ce*) PAAS and MuQ \ 1, suggesting little incorporation of sea water in the BFC of the shells from the Yucatan beach sands. This is also supported by the flat pattern trends of bivalves and gastropods based on the normalized patterns of light rare earth element compared to heavy rare earth ele- ment concentrations. This paper is also a contribution to the methodology of analysis of carbonate sands, i.e., whole bulk composition isolation into their main biogenic com- ponents and the accumulation of major, trace, and rare earth elements deposited into their shells, initially under sub- aquatic marine conditions and currently exposed to sub- aerial coastal influences based on the allochthonous character of the shells. Keywords Sedimentology Á Biogenic fraction components (BFC) Á Geochemistry Á X-ray diffraction Á Yucatan Á Mexico Introduction In the Yucatan Peninsula, southeastern Mexico, carbonate beach sands are mainly composed of biogenic fractions ranging from 80 to 99 % (Nolasco-Montero and Carranza- Edwards 1987). Bivalves, gastropods, coral fragments, calcareous algae, oolites, foraminifera, echinoderm, sponge spicules, bryozoans, and ostracods have been identified. Previous studies conducted in the Yucatan Peninsula and other beach sands composed of carbonate worldwide have analyzed carbonate content and the origin of car- bonate detritus, the geomorphology of carbonate beach sands, and carbonate deposits of eolianites (Folk and Robles 1964; Logan et al. 1969; Ward 1975; Ward and Brady 1979; Karisiddaiah et al. 1988; Caccia and Millero 2007; Cuevas-Jime ´nez and Eua ´n-A ´ vila 2009). Other stud- ies conducted in ancient limestones used the geochemical Electronic supplementary material The online version of this article (doi:10.1007/s13146-015-0283-0) contains supplementary material, which is available to authorized users. & J. J. Kasper-Zubillaga kasper@cmarl.unam.mx 1 Instituto de Ciencias del Mar y Limnologı ´a, Unidad de Procesos Ocea ´nicos y Costeros, Universidad Nacional Auto ´noma de Me ´xico, Circuito Exterior s/n, 04510 Me ´xico, D.F., Mexico 2 Facultad de Ciencias, Universidad Nacional Auto ´noma de Me ´xico, Circuito Exterior s/n, 04510 Me ´xico, D.F., Mexico 3 Nucleo de Estudos Geoquı ´micos e Laborato ´rio de Iso ´topos Esta ´veis (NEG - LABISE), Departmento de Geologia, Universidade Federal de Pernambuco, Caixa Posta 7852, Recife, PE 50670-000, Brazil 123 Carbonates Evaporites DOI 10.1007/s13146-015-0283-0