News Photos
Caption: A timeline shows the geological context of Jack Hills
zircons, ancient minerals that formed when the Earth was less than 500 million
years old. Chemical analysis of these tiny crystals by University of Wisconsin-Madison
geologists Takayuki Ushikubo and John Valley suggests that rocky continents and
liquid water existed on Earth at least 4.3 billion years ago. Evidence of heavy
weathering by a harsh climate may help explain why no rock samples older than
4 billion years have ever been found.
Photo by: courtesy Andree Valley
Date: file provided June 2008
High-resolution JPEG
Caption: Pictured is a false-color microscope image of a 4-billion-year-old
zircon, a tiny mineral used to study the ancient rocks in which it formed. Chemical
analysis of this crystal by University of Wisconsin-Madison geologists Takayuki
Ushikubo and John Valley suggests that rocky continents and liquid water existed
on Earth at least 4.3 billion years ago. Evidence of heavy weathering by a harsh
climate may help explain why no rock samples older than 4 billion years have
ever been found.
Photo by: courtesy Mary Diman and John Valley (UW-Madison)
Date: file provided June 2008
High-resolution JPEG
Photo use
Photographs are available to media organizations and University of Wisconsin-Madison departments for news, editorial and public relations uses, both print and electronic, that are directly related to UW-Madison. They are NOT available for generic use. For university-related use -- including textbooks, commercial products or advertising -- please contact Bryce Richter, photographer, University Communications, (608) 262-7411 or brichter2@wisc.edu.
Published photos must include a credit ("photographer's name/University of Wisconsin-Madison" or "courtesy of"). The specific credit and other details are also embedded in the digital file, which can be viewed by using Photoshop and selecting "file>file info."
None of these images may be modified, altered or used in any way that changes or misrepresents the photograph's content or overall context.