Remnants of upper Pliocene and early Quaternary formations have recently been discovered at the summit of the Atalaya promontory, the easternmost and highest of three promontories on the northern coast of the island of Minorca (Spain). Study of the beds indicates that the underlying Jurassic-Cretaceous formations were abraded and then subjected to karst erosion. The basal bed of the Pliocene-Quaternary sequence is a decalcification clay, the product of the karst phenomena. Overlying the clay is an organic limestone with abundant foraminifera and Microcodium indicative of littoral conditions produced by partial submergence of the northern coast. Two microbreccias, the upper more compact than the lower, overlie the organic limestone and also contain abundant foraminifera. The microbreccias are clearly marine littoral, evenly bedded below, crossbedded above, and the result of submarine currents. A lighter colored limestone petrographically identical to the lower organic bed overlies the microbreccias. Final uplift (probably Recent) produced the existing cliffs and exposed the Pliocene-Quaternary formations. The age of the sequence is tentatively assigned on the basis of the presence of Microcodium.

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