Geo-Marine Letters

, Volume 14, Issue 2, pp 177–184

Petrography and stable isotope aspects of cold-vent activity imprinted on Miocene-age “calcari aLucina” from Tuscan and Romagna Apennines, Italy

  • Claudia Terzi
  • Franco Ricci Lucchi
  • Gian Battista Vai
  • Paul Aharon
Article

DOI: 10.1007/BF01203729

Cite this article as:
Terzi, C., Lucchi, F.R., Vai, G.B. et al. Geo-Marine Letters (1994) 14: 177. doi:10.1007/BF01203729

Abstract

Over 20 occurrences of discontinuous limestone blocks, locally called “calcari aLucina,” were mapped in the Tuscan—Romagna region of the northern Italian Apennines. The limestones, consisting of a variable mixture of authigenic carbonates (calcite, dolomite, and aragonite), sulfides (primarily pyrite), and allogenic silicates, occur in association with turbidite and hemipelagite units that were deposited in foredeep basins during early to late Miocene times. The limestone blocks are interpreted to represent relicts of carbonate buildups formed around methane-rich fluid vents on the basis of their (1) striking petrographic similarities to carbonates from cold vents in the modern oceans; (2) unique chemosynthetic-like fauna, and (3) anomalously negativeδ13C values (δ13C = − 16‰ to − 58‰ PDB). The contemporaneous tectonism of the Apennine orogeny is likely to be the primary cause for the expulsion of the methane-rich fluids to the seabed in a manner analogous to the fluid-flow processes occurring at modern accretionary prisms.

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • Claudia Terzi
    • 1
  • Franco Ricci Lucchi
    • 1
  • Gian Battista Vai
    • 1
  • Paul Aharon
    • 2
  1. 1.Dipartimento di Scienze GeologicheUniversità di BolognaBolognaItaly
  2. 2.Department of Geology and GeophysicsLouisiana State UniversityBaton RougeUSA