ATLAS OF ZIRCONS FROM COLOMBIA: "GEMS" FROM THE ANDEAN, INTER-ANDEAN, CARIBBEAN, PACIFIC AND CRATONIC REALMS OF NORTHWESTERN SOUTH AMERICA

Over the past decade zircon crystals have found expedite and productive ways into the geological discipline in Colombia. The virtually ubiquitous nature of this accessory phase, a characteristic derived from its chemical and physical refractory nature, makes zircon a common mineral in a broad range of lithologies and geological environments; and hence a valuable repository of information regarding important rock-forming events. Some of this information can be directly extracted from zircon´s morphological features (internal and external). In addition, some of the chemical components in zircon make it a powerful tool for a variety of purposes including radiometric dating (U/Pb), thermochronology (helium and fission track analyses), isotopic determinations (Hf, O), etc. This complex set of morphological and geochemical tools are valuable in addressing geologic problems in an ample realm. Researchers from Colombia and elsewhere have been using zircon grains for myriad applications to tackle many of the interesting geological questions posed by the natural laboratory offered by the Northern Andes of Colombia. Such applications range from tephrochronology and magmatism, to radiometric dating of an ample range of lithologic units, to morphotectonic evolution, to provenance analyses and basin evolution.

We present a preview of the Atlas of Zircons from Colombia, encompassing a variety of samples from the Northern Andes including cordilleran massifs and sedimentary basins, i.e., zones of sediment production and zones of sediment accumulation. The atlas incorporates amazing graphic material related to zircons, as seen under high-resolution optic microscopes and SEM-CL/BS images, as well as short contributions in the form of articles written by experts in the field of “zirconology” alluding to many of the topics at hand, e.g., sample preparation, analytical techniques and instrumentation, magmatism/volcanism, metamorphism, provenance and basin evolution, U/Pb ages and Hf dataset compilations, paleogeography, etc. The Atlas is conceived in a geographic fashion that separates mountainous/cordilleran, sedimentary basins (past and modern), and cratonic provinces of Colombia.