negligible disturbance
The term “casual collecting” means the collecting of a reasonable amount of common invertebrate and plant paleontological resources for non-commercial personal use, either by surface collection or the use of non-powered hand tools resulting in only negligible disturbance to the Earth’s surface and other resources. As used in this paragraph, the terms “reasonable amount”, “common invertebrate and plant paleontological resources” and “negligible disturbance” shall be determined by the Secretary.