Factors governing travertine deposition in fluvial systems: The Bagni San Filippo (central Italy) case study

Although fossil fluvial travertines have been described, factors controlling their formation are poorly understood because of the paucity modern counterparts. To disclose processes affecting deposition, a travertine system at Bagni San Filippo (Siena, central Italy) was studied here and compared with other cases. The occur in valley an ephemeral stream, but continuous water influx from hot springs on hillside makes part stream become perennial. Four sub-environments were recognized: slopes, waterfalls, pools, channels. first two mainly composed laminated crystalline crust-boundstone. In contrast, pools covered by lime mud some post-flood travertine-encrusted breccia, while channels commonly display abundant breccia. Many erosional features products also found largely result episodic erosion triggered heavy rainfalls accompanied floods. predominant might include abrasion plucking. Based environment distribution, bed morphology, distinctions, distinguished into slope-pool-waterfall channel-pool-waterfall subsystems. Such differentiation is attributed to original difference: wide beds promoted development narrow encouraged subsequent gravel accumulation during flood events, favoring comparison shows that deposition occurs within existing rivers. relative contribution spring river controls deposit composition (the higher ratios, more carbonate/travertine facies). Furthermore, be common unavoidable reported all formed non-arid regions. These findings suggest influenced topography, contribution, geometry, erosion, aid interpretation ancient systems. Additionally, downstream systems show similar characteristics tufas, clearly influenced, indicating importance analyzing facies distribution ? 13 C-? 18 O signatures carbonate studies.