Sediments Reveal Their Age
Article Abstract:
A challenging problem for geologists is determining when sedimentary rocks were deposited. The rocks, composed of coarse crystals or rock fragments and found throughout the geological record. Large ion microprobe have been used to measure lead isotopes in microscopic crystals of rare-earth element phosphate mineral. The lead content is a direct chronometer or the diagenetic process. Radioactive decay sequence of elements have been increasingly used since the early 1950s.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1999
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Tropical Paradise at the Cretaceous Poles?
Article Abstract:
The discovery of fossil wood near the northern part of the Antarctic Peninsula prompted many researchers to attempt to redefine an area thought to have polar climates. The plants and fossils found in this region are listed as well as the polar warmth of the Cretaceous period. The results from research conducted in the area are noted.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1998
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Patagonian dinosaurs reveal a cosmopolitan Cretaceous
Article Abstract:
Paleontologists Rodolfo Coria, Leonardo Salgado and Jorge Calvo discovered lineages of northern dinosaurs in South America. The finding provides an opportunity for others to study how continental migration affected dinosaurs' evolution patterns.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1995
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