Figure 3 from Finney and Edwards (IMAGE) Geological Society of America Caption Golden spike emplaced in bed that is Global Standard Stratotype Section and Point (GSSP) for the Thenetian Stage. Length of "rock hammer": 5 cm. Credit Stan Finney and Lucy Edwards; GSA Today Usage Restrictions Credit: Stan Finney and Lucy Edwards; GSA Today License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.