caa a22 4500 386403082 CHVBK 20180307112207.0 cr unu---uuuuu 161130e198907 xx s 000 0 eng 10.1017/S0016756800006609 doi S0016756800006609 pii (NATIONALLICENCE)cambridge-10.1017/S0016756800006609 Sedimentation of a Lower Cretaceous (Aptian) coral mound complex, Zaraya Mountains, northern Spain [Elektronische Daten] A Lower Cretaceous mixed carbonate-siliciclastic sequence is well exposed in the Zaraya Mountains in Guipuzcoa Province, northern Spain. The sequence begins with interfingering deltaic platform facies and marine patch-reef carbonates. This unit is dominated by mudstones and sandstone with minor interbeds of shallow-water carbonates (calcareous mudstones and sandstones and grainstone-packstones). A thick mixed carbonate-terrigenous unit overlies the siliciclastics and is composed principally of limestones and marls. Periodic influx of terrigenous sediments over a dominantly carbonate sea-floor gave rise to repeated cycles typical of a mixed shallow-water platform. Demise of the southerly derived deltaic input allowed the development of a mainly carbonate third unit. Large (several metres across) bioherms resulted from high in situ organic productivity (mechanical breakage of bioclasts, algal-induced precipitation, trapping and baffling of lime mudstone). The mounds grew making up a coral carbonate mound complex. This prograded to the south, towards a small backreef basin, and slightly retreated in its forereef margin. A period of tectonic instability is thought to have been responsible for the drowning of the shallow-water complex, which was unable to keep pace with relative sea-level rise. Copyright © Cambridge University Press 1989 Fernandez-Mendiola P. A. Dpto. Estratigrafia, Geodinamica y Paleontologia, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao, Spain Garcia-Mondejar J. Dpto. Estratigrafia, Geodinamica y Paleontologia, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao, Spain Geological Magazine Cambridge University Press 126/4(1989-07), 423-434 0016-7568 126:4<423 1989 126 GEO https://doi.org/10.1017/S0016756800006609 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0016756800006609 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fernandez-Mendiola P. A. Dpto. Estratigrafia, Geodinamica y Paleontologia, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao, Spain NATIONALLICENCE 700 1- Garcia-Mondejar J. Dpto. Estratigrafia, Geodinamica y Paleontologia, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao, Spain NATIONALLICENCE 773 0- Geological Magazine Cambridge University Press 126/4(1989-07), 423-434 0016-7568 126:4<423 1989 126 GEO CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge