Type of Submission
Poster
Keywords
Raindrop prints, impression, fossil, sedimentary structures, bubble
Abstract
Raindrop imprints have been identified many times in the rock record as stated in papers by Rindsberg, Shul’ga 2004 and Kahle 2009. However, there is a question of whether those raindrops have been determined accurately or if the spherical depressions are caused by some other occurrence. Studies by Twenhofel have been done that describe raindrop prints in modern sediment, and the research conducted during this project continues to broaden that field of information. During this research project, experiments were carried out to collect the appearance of raindrop prints in sand, both wet and dry. After photographs of the imprints were taken, the pictures and measurements of the gathered raindrop prints were compared to fossil raindrop prints, so as to determine if the depressions identified as raindrop prints in the rock record are accurately labeled, or were caused by some other process, such as air bubbles. The method to simulate raindrops consists of dropping 0.1mL drops of water from a third floor down to the first floor, onto a flat pan of sand sifted to 3 phi (φ) size and under. At this distance, raindrops are properly replicated as they would be in nature. The imprints were then examined, measured – both their width and their depth, and photographed. Most raindrop imprints in dry sand were 4-2mm deep and 7mm wide, while those in wet sand were wider, 1cm and a little over, but not as deep, ranging from 1.5-2mm deep. These raindrop prints have distinctive features, such as their wide spherical shape and the ledge around the imprint from pushed sand, and while some fossil depressions have these characteristics and may be fossilized raindrop prints, many do not and need to be reexamined under the new information and perhaps categorized as gas escape structures.
Faculty Sponsor or Advisor’s Name
Dr. John Whitmore
Campus Venue
Stevens Student Center
Location
Cedarville, OH
Start Date
4-16-2014 11:00 AM
End Date
4-16-2014 2:00 PM
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Developing Criteria for Identifying Fossil Raindrop Prints
Cedarville, OH
Raindrop imprints have been identified many times in the rock record as stated in papers by Rindsberg, Shul’ga 2004 and Kahle 2009. However, there is a question of whether those raindrops have been determined accurately or if the spherical depressions are caused by some other occurrence. Studies by Twenhofel have been done that describe raindrop prints in modern sediment, and the research conducted during this project continues to broaden that field of information. During this research project, experiments were carried out to collect the appearance of raindrop prints in sand, both wet and dry. After photographs of the imprints were taken, the pictures and measurements of the gathered raindrop prints were compared to fossil raindrop prints, so as to determine if the depressions identified as raindrop prints in the rock record are accurately labeled, or were caused by some other process, such as air bubbles. The method to simulate raindrops consists of dropping 0.1mL drops of water from a third floor down to the first floor, onto a flat pan of sand sifted to 3 phi (φ) size and under. At this distance, raindrops are properly replicated as they would be in nature. The imprints were then examined, measured – both their width and their depth, and photographed. Most raindrop imprints in dry sand were 4-2mm deep and 7mm wide, while those in wet sand were wider, 1cm and a little over, but not as deep, ranging from 1.5-2mm deep. These raindrop prints have distinctive features, such as their wide spherical shape and the ledge around the imprint from pushed sand, and while some fossil depressions have these characteristics and may be fossilized raindrop prints, many do not and need to be reexamined under the new information and perhaps categorized as gas escape structures.
