Morgan County residents: You may begin seeing drill rigs, white vehicles with IGS logos, and hard-hatted geologists on your county roads as the IGS begins a new multiyear mapping project (surficial and bedrock geology). This cooperatively funded project between the IGS and USGS continues mapping efforts northward from Lawrence Monroe Counties to join completed mapping in Marion County. Detailed mapping by the IGS was last conducted in the area during the 1970s.
Esteemed Scientists Collaborating at the Survey
World-renowned paleobotanist David Dilcher and his colleague and former IU graduate student from northeast China, Zhao Miao, will be working together for the next nine months at the Indiana Geological Survey, researching Mesozoic plants. Dilcher, an emeritus professor in IU’s Department of Geological Sciences who has spent more than 50 years working with fossil plants, was recently featured in international science news for finding the world’s “first flower” from the Cretaceous period.
Are These Both Trace Fossils?
Trace fossils are biogenic sedimentary structures produced by the activities of organisms, often by soft-bodied animals that are generally not preserved. The most common trace fossils are tracks, trails, and burrows where the organism either travelled over or through soft sediment. In the Salem Limestone of south-central Indiana, a large burrow occurs that can have regularly-spaced constriction at one or both ends of the structure. These "constricted burrows" occur only in grainstones of the Salem Limestone. Another type of trace fossil is produced by bioerosion where the organism mechanically removes ridged substrate. Is this carving into Salem Limestone a trace fossil of human activity?
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