000 02449nab a2200241 4500
005 20260520000315.0
008 260224s2012 xxu
245 0 0 _aSequence development influenced by intermittent cooling events in the Cretaceous Aptian greenhouse, Adriatic platform, Croatia
260 _a
_b
_cdic. 2012
270 _a21/01/2013 ; 21/01/2013
300 _a29 p. ; 2215-2244
520 _aTranscripción del resumen del autor: Depositional sequences capped by peritidal carbonates and breccias on the Aptian Adriatic carbonate platform, Croatia, were studied to evaluate evidence for glacioeustasy within an age framework constrained by carbon-isotope chemostratigraphy. Sequence Ad1 (17–60-m [56–197-ft] thick; uppermost Barremian–lower Aptian) is dominated by shallow subtidal parasequences. Sequence Ad2 (7–13-m [23–43-ft] thick; lower Aptian–lowermost upper Aptian) contains oceanic anoxic event (OAE) 1a, associated with lagoonal laminated carbonates. Sequence Ad3 (3–8-m [10–26-ft] thick) probably is lower upper Aptian and likely is separated by a major hiatus from sequence Ad4 (8–20-m [26–66-ft] thick; uppermost Aptian), which spans OAE1b. Both Ad2 and Ad3 are dominated by peritidal parasequences updip in the lower transgressive systems tract and upper highstand systems tract and by subtidal parasequences elsewhere, whereas sequence Ad4 is dominated by shallow subtidal parasequences. Low accommodation rates (4.0–6.0 cm [1.6–2.4 in.] in the earliest Aptian, decreasing to approximately 1.0 cm/k.y. [0.3 in./k.y.] later) promoted widespread breccia development during relative sea level falls, aided by tectonic warping. The sequence-capping breccias, eccentricity-dominated cyclicity, restriction of peritidal facies to late highstands, and coeval off-shelf oxygen-isotope records all suggest that sea level falls occurred during times of cooling and had a significant glacioeustatic component. These intermittent cooler periods and continental ice buildup punctuated the Aptian greenhouse climate.
581 _a12
773 0 _tAAPG Bulletin
_g96
942 _cARTICULO
100 1 _aHusinec, Antun
_952904
100 1 _aHarman, Charles A.
_952905
100 1 _aRegan, Sean P.
_952906
100 1 _aMosher, David A.
_952907
100 1 _aSweeney, Rafferty J.
_952908
100 1 _aRead, J. Fred
_952909
999 _c187531
_d187531