|
contents | business | |||||||||
| Sonic drilling cores may shed light on ancient ground formations Core samples taken from drilling groundwater monitoring wells in the Skyway Homes Subdivision area are providing important information about the geology in the Chico vicinity. What is known about the geological history of the area was compiled through the review of existing literature, examination of material brought to the surface as a result of the rotary drilling of wells and other borings that cut into the soil and rock, and the examination of rock and sedimentary formations, such as the hilltop cliff located in Upper Bidwell Park. With sonic drilling technology, a continuous core is recovered intact from the bore hole as it was formed through the millennia, layer upon layer. The core samples recovered by ABB go down 250 feet, although sonic drilling can go as deep as 500 feet. Sarah L. Raker, a geologist and MACTEC Consulting's on-site project manager for ABB, said, "These core samples might help geologists determine the relationship between rock formations and local aquifer systems to identify potential drought-related implications." ABB, realizing the potential research value of these cores, made them available to California State University – Chico, California Department of Water Resources, Department of Toxic Substances Control and California Regional Water Quality Control Board. Comparing the cores removed from the monitoring wells with the hilltop cliff in Upper Bidwell Park has helped geologists identify a distinct rock unit that is present at the well drilling locations, the Tuscan Formation (3.3 to 2 million years ago). The Tuscan Formation is mainly derived from the Mt. Yana volcanic center. write your comments about the article :: © 2009 Construction News :: home page |