Abstract Southwestern Bulgaria belongs to the southern marginal parts of the central Balkan neotectonic region and borders the northern side of the highly seismic north Aegean region. The recent horizontal and vertical motion of the tectonic structures is controlled primarily by the collision stage, caused by continuing ENE palaeosubduction in the Ionian and Adriatic seas and extensional processes northwards of the North Aegean Trough. The present-day generation of small to moderate seismicity and crustal faulting suggests that the complex tectonic processes in the SW Bulgaria region are active. To monitor and study the tectonic deformation in SW Bulgaria, a global positioning system (GPS) network was established in early 2001. Analysis of GPS data from 1996 to 2004 resulted in a horizontal velocity field representing active surface deformations. Horizontal velocities at 38 GPS sites with respect to stable Eurasia are obtained. A new map of the recent vertical velocities is compiled, based on recomputed data from the repeated precise levelling for the period 1929–1991. We obtained evidence of recent active faulting. Based on the geological and geodetic data the SW Bulgaria is separated into five blocks with homogeneous kinematic behaviour. The average motion of each block varies from 1.3 to 3.4 mm a −1 , and the whole region velocity is c . 1.8±0.7 mm a −1 in a direction N154° with respect to stable Eurasia. Geodetic data correlate well with the geological data on neotectonic motions in SW Bulgaria.

Abstract Southwest Bulgaria forms the northern margin of the Aegean extensional province. Since the Early Pliocene ( c. 4 Ma), this region has accommodated southward or SSE extension at several millimetres per year, superimposed on c. 400 m of post-Early Pliocene regional uplift. This sense of deformation superseded earlier extension, oriented ENE— WSW, which is estimated to have begun in the early Late Miocene ( c. 10–9 Ma) and lasted until c. 4 Ma. The regional topography is dominated by NNW—SSE-striking grabens and normal fault escarpments, relics from this time. Normal faults that are now active cut across these older structures, although in some localities normal faults that were oriented obliquely to the earlier extension have remained active, also oblique to the modern extension sense. It is suggested that this present phase of extension relates to the modern sense of deformation throughout the Aegean region and to the modern geometry of the North Anatolian Fault Zone (NAFZ), which is independently inferred to have existed since c. 4 Ma. The earlier ENE—WSW extension is inferred to have involved two phases, the first predating the NAFZ and the second synkinematic with its initial phase of slip during c. 7–4 Ma, when its geometry and the overall sense of deformation in the Aegean region were different from at present. Some previous studies have inferred that SW Bulgaria experienced large-scale extension on low-angle normal faults in the Mid-Miocene or earlier. However, the limited evidence in support of this view is open to other interpretations, and after due consideration can be discounted.

Abstract Fourteen mountains in the eastern Mediterranean, between southern Turkey and Lebanon, are high enough to support Quaternary valley glaciers or ice caps. The timing of the glaciations has been established mainly by cosmogenic dating. We re-evaluated the dated sites and recalculated some of the published cosmogenic ages using up-to-date production rates. The oldest geochronological records reported from the region belong to glaciations before the globally defined Last Glacial Maximum (LGM). These glaciers probably developed during the beginning of the last glaciation (Marine Isotope Stage (MIS) 4; around 71 ka) and stopped advancing at the end of MIS 3 (at 29–35 ka). Later, glaciers expanded and reached their most extensive positions during MIS 2 (after 29 ka). This locally occurred between 21.5 and 18.5 ka, which was synchronous with the global LGM. After the LGM, glaciers started to retreat to less extensive positions and deposited their moraines ∼16 ka during the late-glacial. Younger Dryas (∼12 ka) advances have also been reported from a few mountains. Rare early Holocene glaciations were dated to 8.5 ka in the interior regions. Late Holocene (1–4 ka) and Little Ice Age advances have also been observed on mountains higher than 3500 m.