Carbonate preservation reconstructed from ODP Sites 154-927 and 154-929 at Ceará Rise

Enhanced Atlantic overturning during the Pliocene was first proposed almost 10 yrs ago. Evidence for this Pliocene super conveyor scenario has been collected using a number of proxies (e.g., benthic d13C, Nd isotopic composition of manganese crusts). The present study contributes to the existing evidences by using carbonate dissolution and current vigour history of early Pliocene sediments from the Ceará Rise (ODP Sites 927 and 929). In order to reveal carbonate dissolution history, a number of commonly used and newly established proxies were applied, i.e., sand and carbonate contents, foraminifer fragmentation index, Bulloides Dissolution Index and carbonate silt grain-size distributions. Terrigenous silt grain-size distributions were used to unravel variations in relative current strength and sediment input to the two sites. Overall good carbonate preservation at the shallow Site 927 (3314 m water depth) shows that this level was bathed in North Atlantic Deep Water throughout the early Pliocene. The contrastingly poor carbonate preservation record of the deeper Site 929 (4358 m water depth, at present exposed to Antarctic Bottom Water) is frequently interrupted by phases of good carbonate preservation. These results indicate that the depth of the calcite lysocline was mainly tied to present level (ab. 4200 m water depth), and sometimes even dropped to water depths greater than 4360 m due to even more enhanced circulation. Surprisingly the expansion of NADW is not clearly reflected by an increase in current speed as shown by continuously fine terrigenous grain size.

Revista do Instituto do Ceará.

Tomos 74-<80> also called v. 78-<84>.

Entre veados, carneiros e formigas: conflito pela posse de terra na ribeira do Ceará-Mirim, e concepções de mentalidade possessória, 1725-1761

Shaping the Luso-Brazilian space in Portuguese America was through constant conflicts between different individuals and institutions. Regarding to land ownership, such conflicts were aggravated, depending on the individuals involved and their context. The captaincy of Rio Grande, there is conflict over land ownership Cidade dos Veados and Olho d' Água Azul and its stakeholders: priests of the Society of missionaries of the village Guajiru; indian mission Guajiru; and members of Carneiro da Cunha family. In 1725, the jesuit mission Guajiru requested a league of land at a place called Cidade dos Veados for the indians of his mission claiming that the land that the mission had was not sufficient for the subsistence of the same. In 1727, priest requested another league of land in place Olho d'Água Azul, stating that the mission had more than 192 couples. Both lands were properly required for the mission guajiru. however, in 1760, with the changes imposed by the indian directorate ombudsman responsible for investigating indigenous possessions realized that the indians did not occupy the two lands requested in the 1720s , due to the fact João Carneiro da Cunha has taken possession of the same. As a result, the impasse over land are ligth. This conflict over land ownership Cidade dos Veados and Olho d'Água Azul, we intend to highlight in particular the motivations and mindsets about possessory property of each party involved. We seek to understand the motivations of each group involved allowed the use of specific strategies and set out to try to take possession of the lands of the Cidade dos Veados e Olho d'Água Azul

Indicadores do nível relativo do mar e evolução costeira durante o holoceno tardio no litoral oeste do Ceará, NE do Brasil

In the coastal region of Ceará, between the municipalities of Acaraú and Itapipoca, thirteen sites were identified containing indicators of relative sea level, six of these being dated by optically stimulated luminescence (OSL) and radiocarbon. Ages obtained supports that were formed prograding beaches in the study area. In the eastern portion, beaches in coastal plain deposits occur while a system lagoon/barrier paleomangrove occurs in the western portion of the study area. In both cases the coastal deposits prograde from east to west. Higher sea levels were identified between the current: (a) 3.110-2.830 cal. yr. BP; (b) 1.830 yr. BP (OSL) - 1.490 cal. yr. BP; (c) between 1.240-1.060 cal. yr. BP; (d) 845-715 yr. BP (OSL). Since then the sea level suffered by lowering the current level. Variations in sea level are interpreted as responses to changes in the pattern of marine circulation and do not exclude possible tectonic disturbances in the basin of the continental margin. The indicators of relative sea level west coast of Ceará present differently from other curves constructed in the coastal northeast, suggesting that local factors mentioned above contributed to sea level fluctuations.