Major palaeoenvironmental changes in the Campanian to Palaeocene sequence of Caravaca (Subbetic zone, Spain)

Abstract

[EN] An integrated sedimentological and biostratigraphical study of the Campanian to Palaeocene succession of Caravaca de la Cruz
\n(SE Spain) has allowed to recognize the palaeoenvironmental evolution of this area, located within the pelagic/hemipelagic domains
\nof the ancient southern continental margin of Iberia. This succession has been divided in four stratigraphic intervals on the basis
\nof their sedimentological and palaeoecological features. The fi rst interval (middle to upper Campanian, Globotruncana ventricosa,
\nGlobotruncanita calcarata, and , Globotruncana falsostuarti biozones) consists in rhythmically bedded limestones formed by a slow
\nand relatively steady fallout of biogenic debris in an upper bathyal setting. The second interval (latest Campanian to lower Maastrichtian,
\nlower to middle part of the Gansserina gansseri biozone) is defi ned by the presence of fi ne-grained calcarenites deposited
\nunder the infl uence of bottom currents. The onset of that infl uence was probably related with the beginning of the convergence
\nbetween Iberia and Africa that led to a narrowing of the passage between them, and thus to an intensifi cation and a deepening of
\nthe oceanic currents in the area. The third interval (upper Maastrichtian, upper part of the G. gansseri biozone and the Abathomphalus
\nmayaroensis biozone) is formed by marls deposited in a mixed hemipelagic environment, deeper than that of the previous
\nunit, and with high fi ne terrigenous input. Towards the end of this interval, this environment began to receive sporadic turbiditic
\ndeposits. During the fourth interval (Palaeocene, Parasubbotina pseudobulloides, Praemurica trinidadensis, Praemurica uncinata,
\nMorozovella angulata, Igorina pusilla, and Globanomalina pseudomenardii biozones) the same type of sedimentation, including
\nturbidite input, prevailed.
\nThe four intervals are bounded by episodes of rapid environmental change, refl ected in the stratigraphic succession by abrupt transitions
\nin facies. These episodes, latest Campanian, “middle” Maastrichtian and latest Maastrichtian to earliest Palaeocene in age,
\ncan be correlated with regional stratigraphic unconformities in the more proximal and shallower sections of the Prebetic domain,
\nand be interpreted as regional events. The origin of these events, according to their regional features, is mainly tectonic, probably
\nrelated to the onset of the alpine convergence in that continental margin.