Origin and palaeo-environmental significance of the Berrazales carbonate spring deposit, North of Gran Canaria Island, Spain

Abstract

The Berrazales carbonate spring deposit is a small outcrop constituted mainly by cascade-like geometries. Four main facies have been identified: Fibrous dense macrocrystalline formed by rapid degassing under high-flow conditions; Framestones of coated plant molds formed in moderate energy flow favoured by the presence of biogenic support; Micrite/Microsparite are primary precipitates in which crystalline aggregates nucleated on organic filaments and/or EPS; Banded micrite-coarse crystalline were the result of alternating physical-chemically and biologically induced precipitation in areas of varying flow-velocities. Most facies underwent different degrees of micritization processes. Micrite is distributed as thin lines penetrating the crystals, as irregular patches or as micrite layers. In the first case organic filaments penetrate crystals, suggesting that micritization is mainly biogenically driven. In the latter cases micritization is caused mostly by partial dissolution. Microbe participation in *Manuscript Click here to download Manuscript: Camuera Berrazales Manuscript Revised.doc Click here to view linked References micrite formation increased micrite MgCO 3 content in comparison with coarse crystalline facies. Isotopic analyses show positive δ 13 C values (+2.63 and +4.29‰ VPDB) and negative δ O (-5.65 and-4.48‰ VPDB) values. Positive δ 13 C values clearly indicate fluids of thermal volcanogenic origin. The Berrazales spring deposit studied here very probably is a small part of a larger carbonate building that was largely eroded by fluvial incision. Calculations of spring water temperature give a range from 20ºC to 35ºC, characteristic of a cold to warm spring favouring precipitation of calcite and important biogenic activity (framestones). Although the study deposit has textural characteristics of tufas, provide that the CO 2 sourced from deep fluids, it should be consider as thermogene travertine, being one more example of the difficulty of using those terms for ancient sedimentary deposits. Carbonate springs deposits, very rare in the Canary Islands, are good archives of recent volcanic activity, fluvial processes and vegetation regimes prevailing in the islands in recent times.

Sedimentology and geochemistry of a human‐induced tufa deposit: Implications for palaeoclimatic research

“…The intercalations of thin micritic laminae indicate slow flows or even drying of the system, allowing the development and preservation of some microbial communities which induce both micrite precipitation and/or micritization of external parts of coarse crystals (Camuera et al ., ; Alonso‐Zarza & Rygaloff, ). Coalescence of stems indicates uninterrupted water flow across the barriers, favouring thickening of coatings.…”

“…Natural carbonate spring deposits (for example, Azuaje, Berrazales and Temisas) occur mostly (but not exclusively) in the northern half of the island. Their formation seems to involve endogenous CO 2 (Rodríguez‐Berriguete et al ., ; Camuera et al ., ; Estrella de Pinho et al ., ), regardless of whether the facies are of tufa or travertine. These deposits are classified as thermogene carbonates because of their positive δ 13 C values, according to Pentecost ().…”

Comparative study of the Pleistocene Cakmak quarry (Denizli Basin, Turkey) and modern Mammoth Hot Springs deposits (Yellowstone National Park, USA)

“…Preliminary, initial estimates of the water temperature during travertine precipitation, based on d 18 O travertine and fluid inclusion temperature data El Desouky et al, 2015), suggest overall temperatures in a broad range between 18 and possibly 46 C in the Ballık area. The phyto fabric of hanging, encrusted macrophyte branches, furthermore resembles those of some cooler spring carbonate deposits (Pedley and Rogerson, 2010;Camuera et al, 2014), called 'barrages'. This might indicate that spring water was substantially cooler during deposition of Facies C2 and possibly during several stages in the evolution of the Cakmak spring system.…”

Crystallization pathways in the Great Artesian Basin (Australia) spring mound carbonates: Implications for life signatures on Earth and beyond

“…• Tufacarbonate tufa deposits were defined by Capezzuoli et al (2014) as: "continental carbonates generally produced from meteoric water at ambient temperature and characterized by low depositional rates, high porosity and high content of microphytes and macrophytes phytohermal or stromatolitic build-ups deposited by ambient temperature waters" (see also Pedley, 1990;Riding, 1991;Ford & Pedley, 1996;Capezzuoli et al, 2010;Camuera et al, 2014).…”

“…2) provided a favourable, passive substrate for nucleation and growth of micrite within the phytoherm tufa facies (e.g. Capezzuoli et al, 2010;Keppel et al, 2011;Camuera et al, 2014). Simultaneously, it may have also had an active role by changing water chemistry by consuming CO 2 through photosynthesis (e.g.…”