DETERMINATION OF THE AGE KIMBERLITES IN THE YAKUT DIAMOND-BEARING PROVINCE BY THE PALEOMAGNETIC METHOD

Abstract

Oriented kimberlite specimens (total of 200 pieces) were collected on the benches and in the bed of an exploratory opencut that exposed bedrock to a depth of 7 to 8 m at about the center of the pipe. The porphyric kimberlite forms a reliably identifiable bedrock outcrop over an area of about 40 × 15 m in the opencut. The composition of the paramagnetic minerals in both these kimberlite varieties were studied in polished sections., The magnetic properties of the oriented specimens were studied with an M-14f magnetometer. Study results are discussed. The available geologic data and absolute dates indicate that the pipes were formed in the Late Devonian-Early Carboniferous, agreeing with paleomagnetic data and indicating that the paleomagnetic method can be used to determine the age of kimberlites in this region.