Spatiotemporal distribution of giant magnetofossils holds clues to their biological origin.

Bibliographic Details
Title: Spatiotemporal distribution of giant magnetofossils holds clues to their biological origin.
Authors: Pengfei Xue1,2, Liao Chang2,3 liao.chang@pku.edu.cn
Source: Geology. Jun2024, Vol. 52 Issue 6, p453-457. 5p.
Subject Terms: *MAGNETITE crystals, *EOCENE Epoch, *CRYSTAL morphology, *MARINE sediments, *ELECTRON microscopes, *MAGNETITE
Abstract: Micrometer-size magnetite crystals with peculiar morphologies, such as spearhead, spindle, needle, and giant bullet, known as giant magnetofossils, were previously identified in marine sediments mainly during the Eocene epoch. The origin of these unusual magnetite crystals remains unclear because no known modern analogues have been found, and data about their spatiotemporal distribution are sparse. Here, using electron microscope observations, we performed a large-scale spatiotemporal search for these mysterious magnetite crystals. We report the occurrence of giant magnetofossils in variable marine sedimentary environments, including the first report in modern South Atlantic and Indian Ocean environments and the oldest occurrence at ca. 93 Ma in the North Atlantic Ocean. Grain-size data for the giant magnetofossils in the Southwest Pacific and North Atlantic Oceans suggest that the dimension of spearheads is sensitive to regional environments during similar warming periods but is insensitive to environmental conditions across the distinct geological periods at the same locality. The grain-size distributions of needles and giant bullets do not show significant changes in diverse environments. These observations greatly expand the known temporal and geographic distribution of giant magnetofossils, shedding new light on their likely biological origin. [ABSTRACT FROM AUTHOR]
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Database: Academic Search Complete
More Details
ISSN:00917613
DOI:10.1130/G51809.1
Published in:Geology
Language:English