Dumitru Ioane

Salt Karst in Manzalesti – Romania

The salt in Manzalesti is localized in the Vrancea hilly region, within the East Carpathians Bend, north of the town of Buzau.

Active Fault Systems and Their Significance for Urban Planning in Bucharest, Romania

In urban planning activities, besides a detailed seismic zonation, knowledge of the areal distribution of active faults, and particularly of faults crossing the city in heavily built districts, may be valuable in numerous cases. This chapter aims to identify active faults or fractures in Bucharest, a large city developed over thick layers of Quaternary unconsolidated sediments. To achieve this goal, the research is based on an integrated analysis of all existing relevant data coming from geology, geomorphology, geophysics and seismology. Another purpose is to understand the role of faults in the spatial variability of seismic damaging effects on buildings in view of a better future urban planning. The N–S fault system seems to be involved in neotectonics, affecting the geomorphology between Bucharest and Ploiesti cities. It could represent an active transcrustal fault, the deepest seismic event recorded within Bucharest at subcrustal depth being located on its southern prolongation. Within Bucharest the presence of faults affecting Pleistocene sediments was previously illustrated using borehole data, shallower vertical displacements of Quaternary formations along faults being interpreted in this study. The existing seismic reflection data recorded within Bucharest was used to interpret shallow faults considered as active or capable faults crossing Quaternary sedimentary deposits.

Scenarios for Local Seismic Effects of Tulcea (Romania) Crustal Earthquakes—Preliminary Approach of the Seismic Risk Characterization for Tulcea City

This paper is a multidisciplinary presentation of the seismogenic area situated in the North-Dobrogea Orogen (Tulcea). This zone is characterized by significant crustal seismic activity, with crustal earthquakes of magnitude Ms ≥ 5.0 on the Richter scale. Geological and geophysical data for the area are presented. The seismicity of the region is presented by making use of the latest catalogues, exemplified with maps and a 3D figure. Focal mechanisms with their parameters for several earthquakes are analyzed together with the observation data (provided by different seismological stations). A brief presentation of the main geological features, which are characteristic of the tectonic units that build up the North-Dobrogean Orogene, outlines the diverse petrographic constitution of the various structural levels. In order to discuss the local seismic site effects two scenarios are considered, both of which take into account the characteristics of the seismogenic area. The first one considers the city exposed to an earthquake (superficial) from the E Vrancea zone and the second one considers the city exposed to a seismic event with magnitude Mw = 5.1 from Sf. Gheorghe fault. The earthquake epicentres are located in very active seismic areas. The important features taken into account are the nonlinear behavior of the upper soil strata, the effect of the bedrock elasticity, and different shear modulus and damping of the linear-equivalent-type system. Additionally, several local amplification functions are presented.

Rupestrian Settlements in the Alunis Area

The rupestrian settlements located in the area of Alunis, Buzau County, Romania, are generally considered to have begun as ancient sites of refuge and cult in the Buzau Mountains. They are situated 6 km north-east of Alunis village and spread over an area of about 3 km2.

Ancient Gold Mining in Rosia Montana (Apuseni Mts, Romania)

Rosia Montana, or Alburnus Maior as was called by the Romans, is a famous ancient gold mining area located in the Apuseni Mts, at the western boundary of Transylvania, Romania. Its richness in gold was known and valued by ancient exploitations of river sediments or shallow veins long before the Roman conquest of Dacia (Motiu, 2004). In fact, the gold of Dacia was the very reason for the two wars between the Romans and the Dacians; in 106 AD. Dacia became a Roman province located at the northern limit of the empire.