Mercury (Hg) mineral evolution: A mineralogical record of supercontinent assembly, changing ocean geochemistry, and the emerging terrestrial biosphere

• DOI: 10.2138/am.2012.3922
• Publication Date: 2012-06-26T17:40:59Z
• Authors: R. M. Hazen; J. Golden; R. T. Downs; G. Hystad; E. S. Grew; D. Azzolini; D. A. Sverjensky
• Keywords: Supercontinent; Mercury

Analyses of the temporal and geographic distribution earliest recorded appearances 88 IMA-approved mercury minerals plus two potentially valid species exemplify principles mineral evolution. Metacinnabar (HgS) native Hg are only reported from meteorites, specifically, primitive H3 Tieschitz chondrite with an age 4550 Ma. Since first terrestrial appearance cinnabar more than 3 billion years ago, have been present continuously at or near Earth’s surface. Mercury evolution is characterized by episodic deposition diversification, perhaps associated supercontinent cycle. We observe statistically significant increases in number localities new ~2.8-2.6, ~1.9-1.8, ~0.43-0.25 Ga- intervals that correlate episodes presumed assembly orogenies Kenorland (Superia), Columbia (Nuna), Pangea, respectively. In constrast, few deposits stability breakup ~2.5-1.9, ~1.8-1.2, 1.1-0.8 Ga. The interval Pangean (~250-65 Ma) also marked a decline mineralization; however, rocks last 65 million years, during which Pangea has continued to diverge, numerous ephemeral near-surface deposits. period ~1.2-1.0 Ga, Rodinian supercontinent, exception because absence this period. Episodes mineralization reflect metamorphism Hg-enriched marine black shales zones continental convergence. suggest was effectively sequestered as insoluble nanoparticles tiemannite (HgSe) sulfidic “intermediate ocean” (~1.85-0.85 Ga); consequently, formed aggregation Rodinia, whereas several date 800-600 Ma, overlaps rifting Rodinia. Nearly all (87 90 known), well major economic deposits, known occur formations ≤400 old. This relatively recent diversification arises, part, nature many minerals. addition, strongly enhanced interactions organic matter, so pulse may rise biosphere ~400