Thursday, September 15, 2011

Find Arkansas Fossils

Limestone quarries in Arkansas are a source for fossil hunters.


Sedimentary rock underlies more than 99 percent of Arkansas, making the state a hotbed for fossil collectors. Fossils in the state date back to the Late Pre-Cambrian era, more than 750 million years ago. Five geological provinces have been identified in Arkansas: the Ozark Plateaus, West Gulf Coastal Plain, Arkansas River Valley, Ouachita Mountains and Mississippi Embayment. In 2003, the world's largest straight-shelled cephalopod (squid-like creature) was found in Fayetteville. Arkansas fossil hunting requires knowledge and the proper tools.


Instructions


1. The most common fossil record of Arkansas vertebrates is fossilized teeth.


Map your route to fossil dig sites. Plant, animal and marine-life fossils are found in Arkansas. Depending on what you wish to find, designate the area where you plan to dig.


In the Ozark Plateaus, the predominant fossils are invertebrates. Marine-life sediments are not as common but include fish and shark teeth. Wolf and alligator bones have been recovered in Native American sites.


Stream beds and quarries in the West Gulf Coastal Plain yield marine vertebrates like shark and mosasaur (an extinct marine lizard). Rare dinosaur specimens have been recovered in this region.


Plant fossils are found in the Arkansas River Valley, and can be found in layers of sedimentary rock and coal.


Shallow-water organisms such as graptolites are sparse but can be found in the Ouachita Mountains.


The Mississippi Embayment, or delta, offers fossils such as Bacylisaurus (toothed whale), catfish skulls, shark teeth and mammoth remains.


2. Hempstead, Nevada and Clark counties are among the most fossil-rich counties in Arkansas.


Acquire fossil-dig tools. Choose a shovel with a short handle, as you may be kneeling or sitting while seeking fossils. A sifter is necessary for stream bed and loose soil areas, such as ditches. Rock hammers and chisels work well in quarries to break fossils from hard rock. Use a sturdy cloth bag to hold your fossils. According to the Arkansas Geological Survey, "The rocks in Arkansas also contain microfossils or fossils that can only be seen with the aid of a microscope." Consider buying a hand-held pocket microscope for use on your dig.


3. The diversity of Arkansas offers many fossil-hunting experiences.


Dig and collect your fossils. Carefully chisel away at any large areas of fossil discovery, and refer to a fossil guidebook with photos if you are unsure of your finds. Fossil-hunting is an activity that may or may not produce tangible treasures, so consider moving to another Arkansas dig site if you are not have positive results.







Tags: have been, Arkansas River, Arkansas River Valley, been recovered, Coastal Plain