caa a22 4500 469045582 CHVBK 20180323132823.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF02536809 doi (NATIONALLICENCE)springer-10.1007/BF02536809 Facies of sunken early cretaceous atoll reefs and their capping Late Albian drowning succession (Northwestern Pacific) [Elektronische Daten] [Jürgen Grötsch, Erik Flügel] Summary: Since first described in detail byHamilton (1956), the causes and timing of the drowning of several hundred guyots in the northwestern Pacific is a puzzling question. Thus, the northwestern Pacific is one of the key areas in deciphering the demise of flat-topped platforms throughout the earth's history. Based on older paleontological data and the newly found shallow-water benthic foraminifera, the atoll reefs probably had a major period of vertical aggradation during the Barremian and the Aptian into the Late Albian depending on the stage of atoll development (type of guyot). New sedimentologic and stratigraphic data suggest a strong fall in sea level, leading to karstification and the formation of lowstand fringing reefs, prior to an even rapid rise of greater amplitude in the Late AlbianRotalipora appenninica zone ultimately causing drowning. After climatic relaxation, a sea level rise led to the final formation of small barrier reefs, rimming the top of many guyots in the Japanese Group, the Wake Group and the Mid-Pacific Mountains. They can be interpreted as "give-up” structures indicating a final shallow-water carbonate production on top of the atolls during drowning. The facies of the syn- and post-drowning sediments on the guyot tops are strikingly similar even when vast distances apart. This and the biostratigraphic data suggest a synchronous drowning of many seamounts investigated up to now. Biotic composition and facies of the final Albian reefs are very similar to Albian caprinid-dominated reefs in the Caribbean region, indicating comparable environmental controls. In the case of the northwestern Pacific guyots, the simultaneous demise of reefs could be due to a short-term cooling event in the Late Albian, connected with a strong regressive-transgressive cycle with an amplitude of about 180 m. This event is also known from the Tethys and the Atlantic. Climatic disturbances triggering short-term cooling and inducing a high amplitude regressive-transgressive sea level cycle, might be responsible not only for the Late Albian event, but also perhaps for other reef drownings throughout the earth's history. Institut für Paläontologie, Universität Erlangen, 1992 Sedimentology nationallicence Facies nationallicence Carbonates nationallicence Reef nationallicence sunken atolls nationallicence Guyots nationallicence Pacific nationallicence Cretaceous (Aptian, Albian) nationallicence Grötsch Jürgen Shell Research BV, KSEPL, P.O. Box 60, NE-2280 AB, Rijswijk, The Netherlands aut Flügel Erik Institut für Paläontologie, Universität Erlangen-Nürnberg, Loewenichstr. 28, D-8520, Erlangen aut Facies Springer-Verlag 27/1(1992-12-01), 153-174 0172-9179 27:1<153 1992 27 10347 https://doi.org/10.1007/BF02536809 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02536809 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Grötsch Jürgen Shell Research BV, KSEPL, P.O. Box 60, NE-2280 AB, Rijswijk, The Netherlands aut NATIONALLICENCE 700 1- Flügel Erik Institut für Paläontologie, Universität Erlangen-Nürnberg, Loewenichstr. 28, D-8520, Erlangen aut NATIONALLICENCE 773 0- Facies Springer-Verlag 27/1(1992-12-01), 153-174 0172-9179 27:1<153 1992 27 10347 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer