A serious accident occurred to the helicopter that should carry the members of the expedition on the Auyan Tepui, together with critical weather conditions, forced us to give up the original plan, including the exploration of new caves on the Auyan Tepui. After several days spent in the attempt to adhere to the original schedule, the group decided to take a short survey on the Roraima Tepui, the only one reachable by land with two intense days of walking. During the few days left, in prohibitive weather conditions, are made some surveys to detect new possible caves and are carried out some geological studies, aimed at enriching the knowledge framework of the Tepui and of the alteration processes the quartzite rocks are subjected to in these particular environments.