This article discusses the double-apsed churches (single-naved churches with two high altars) of Kythnos in the western Cyclades. The reasons for this uncommon configuration, although much debated, are not entirely clear. According to local tradition, during the period of Latin rule (thirteenth–seventeenth centuries) double-apsed churches were designed to accommodate both Orthodox and Catholic liturgies, or even some combination of the two. Combining information from written sources with architectural surveys at Oria Kastro, the island's ruined medieval capital, an attempt is made here to document Kythnos’ double-apsed churches and identify how these small provincial monuments reflect socio-religious conditions and inter-faith relations in the late medieval Aegean.

This study corroborates interpretations suggesting that the Makrotantalon Unit on Andros represents a tectonic slice with Pelagonian affinity in the nappe stack of the Cycladic Blueschist Unit. Previously reported Cretaceous 40Ar–39Ar dates of a garnet-glaucophane schist from the Makrotantalon Unit could not be reproduced by Rb–Sr geochronology, but this is not an indication of contamination with excess Ar. Instead, the newly dated samples record disturbance of the Rb–Sr isotope system by partial recrystallization. Subsets of these phengite populations, representing the smaller grain-size fractions, yielded low-precision dates ranging from c. 21 to c. 15 Ma that document deformation-related resetting and recrystallization of a presumably Cretaceous white mica population. Although these Miocene dates cannot be linked with blueschist-facies metamorphism, they provide time constraints on the formation of shear zones that overprinted the original thrust contact during exhumation. The geological relevance of a Cretaceous high-pressure event is confirmed by a Rb–Sr date of c. 121 Ma for an epidote-glaucophane schist collected further away from the tectonic contact. The occurrence of a second blueschist-facies event in the Eocene is verified by Rb–Sr dates of two epidote-glaucophane schists (c. 40 Ma and c. 44 Ma) that can unambiguously be assigned to the Makrotantalon Unit.

The Small Cycladic Islands Project is a diachronic archaeological survey of several small, currently uninhabited islands located in the Cyclades, Greece. In 2019 and 2020, surface investigations focused on the multi-method, comparative documentation of 21 islets surrounding Paros and Antiparos, revealing oscillating patterns of use and non-use from prehistory to the present.

The Early Bronze Age (EBA) is associated with technological and cultural changes that may suggest the onset of a new culture. The question usually posed is whether the spread of the EBA culture is a matter of contemporary evolutionary practices or a matter of migration of peoples. We contribute to this discussion by tracing the appearance and spread of the EBA in the Aegean using an absolute time-frame provided by more than 200 radiocarbon (14C) dates from 25 different Aegean sites. These have been compiled and statistically treated, individually, and in geographical groups to allow temporal and spatial comparisons. A new model is constructed for the first time for northern Greece. The dates are compared between various settlements and areas in each of the traditional cultural divisions EBA I, EBA II, and EBA III and possible subdivisions. The statistical treatment and comparisons indicate that the EBA appeared slightly earlier, around 3300 BC, in northern Greece than in southern Greece, and the Cycladic Islands and also lasted longer in some areas in northern Greece, ending at around 1900 BC.

Human history has been marked by major episodes of climate change and human response, sometimes accompanied by independent innovations. In the Bronze Age, the sequencing of causes and reactions is dependent in part on dendrochronology and radiocarbon dating. This paper explores the interaction of a major, prolonged desiccation event between c. 2300 and 2000 BC and human agency including migrations, the displacement of trading networks, warfare, the appearance of weapons made of bronze, and the first appearance of sailing vessels in the Mediterranean.

This study focuses on the status of the Makrotantalon Unit (Andros, Greece) within the framework of the Cycladic nappe stack. We document unambiguous evidence that this unit has experienced blueschist-facies metamorphism and identify previously unknown lawsonite ± pumpellyite assemblages in glaucophane-free metasediments. The position of the presumed tectonic contact at the base of this unit is vague, but roughly outlined by serpentinites. Only a single outcrop displays a weak angular unconformity with cohesive cataclasites in the footwall. Rb–Sr geochronology was carried out on 11 samples representing various rock types collected within or close to inferred or visible fault zones. Owing to a lack of initial isotopic equilibration and/or subsequent disturbance of the Rb–Sr isotope systematics, isochron relationships are poorly developed or non-existing. In NW Andros, direct dating of distinct displacement events has not been possible, but a lower age limit of ~ 40 Ma for final thrusting is constrained by the new data. Sporadically preserved Cretaceous ages either indicate regional differences in the P–T–d history or a different duration of metamorphic overprinting, which failed to completely eliminate inherited ages. The detachment on the NE coast records a later stage of the structural evolution and accommodates extension-related deformation. Apparent ages of ~ 29–25 Ma for samples from this location are interpreted to constrain the time of a significant deformation increment. On a regional scale, the Makrotantalon Unit can be correlated with the South Evia Blueschist Belt, but assignment to a specific subunit is as yet unconfirmed.

The sanctuary on the island of Keros takes the form of deposits of broken marble vessels and figurines, probably brought severally for deposition from elsewhere in the Cyclades. These acts of devotion have now been accurately dated, thanks to Bayesian analyses of the contemporary stratigraphic sequence on the neighbouring islet of Dhaskalio. The period of use—from 2750 to 2300 cal BC—precedes any identified worship of gods in the Aegean and the site is among the earliest ritual destinations only accessible by sea. The authors offer some preliminary thoughts on the definition of these precocious acts of pilgrimage.

A research team at Akrotiri, Thera, here examine the Bronze Age frescoes and show that the artists were making use of templates of well known geometric curves. Some of the spirals, hyperbolae and ellipses which all feature in the repertoire do not occur in nature and must have their origin in some still unknown human science or aesthetic.

This paper reports new geochronological data from the island of Andros, one of the less-studied islands of the Cycladic blueschist belt in the central Aegean Sea. On Andros, two tectonic units can be distinguished, the Makrotantalon unit and the Lower unit, which are separated by a low-angle normal fault, related to large-scale regional extension. Mineral assemblages indicate greenschist-facies P–T conditions for the last metamorphic overprint of both units. In contrast to the structurally lower unit, unambiguous indications for an earlier high-pressure stage were not recognized in rocks collected above the tectonic contact. Owing to a polyphase metamorphic evolution and incomplete resetting of the Rb–Sr isotope system during overprinting, phengite geochronology indicates a wide range in dates between c. 104 and 21 Ma for the Makrotantalon unit, as observed in rocks of similar structural position elsewhere in the Cyclades. The new Rb–Sr data support the interpretation, but are not conclusive evidence, that tectonic slices within the hanging wall were affected by two periods of Cretaceous metamorphism (c. 100–90 Ma and c. 80–70 Ma) and a Miocene event (c. 21 Ma). Tectonic juxtaposition was accomplished around c. 21 Ma. The Lower unit is correlative with the Cycladic high-pressure occurrences. Rb–Sr phengite dating yielded the same range in ages as determined elsewhere in the region for white mica of high-pressure rocks (c. 50–40 Ma) and their overprinted, greenschist-facies derivatives (c. 23–21 Ma). An age gradient towards the tectonic contact with the overlying Makrotantalon unit is not developed. The new results fit well into the previously established chronological framework for the larger study area. Indications for regional differences in the timing of the HP stage and/or the greenschist-facies overprint have not yet been found.

Scattered occurrences of ophiolitic rocks are widespread in the Cyclades islands of Greece and are important for understanding the later Mesozoic ocean spreading and collisional history of the region, which has been obscured by Cenozoic nappe stacking, metamorphism, plutonism and extension. Ophiolitic rocks in the Upper Tectonic Unit of Ikaria are preserved in a mélange underlying Triassic limestones in the Kefala Unit and in a coarse-grained conglomerate at Faros directly overlying the mid-crustal detachment fault. The geochemistry of these rocks has been determined, their mineralogy investigated by electron microprobe, and K–Ar radiometric dating was carried out. Sole rocks are amphibolite of alkaline basalt protolith. Most ophiolitic samples from Ikaria consist of hornblende gabbro with MORB geochemistry that underwent sea-floor hydration, deformation and metamorphism. The large variation in degree of deformation, grade of metamorphism, and radiometric ages suggest syn-spreading extensional deformation at a slow-spreading ridge. The ophiolitic mélange on Ikaria, because it is unaffected by younger metamorphism, provides clear evidence for Late Cretaceous ocean-crust formation in the Cyclades region.

Wood charcoal from stratified layers at Akrotiri is helping to map the ecology of the island of Santorini before the volcanic eruption in the second millennium BC which brought Bronze Age settlement to an end. Far from being treeless like today, the island had a relatively moist and cool climate with diverse vegetation including open oak woodland. Olive cultivation can be traced back to the Early Bronze Age. Cedar, yew and beech were also imported from Lebanon, Cyprus and Anatolia as artefacts, or for building.

Markedly different cooling histories for the hanging- and footwall of the Vari detachment on Syros and Tinos islands, Greece, are revealed by zircon and apatite fission-track data. The Vari/Akrotiri unit in the hangingwall cooled slowly at rates of 5–15 °C Myr−1 since Late Cretaceous times. Samples from the Cycladic blueschist unit in the footwall of the detachment on Tinos Island have a mean zircon fission-track age of 10.0±1.0 Ma, which together with a published mean apatite fission-track age of 9.4±0.5 Ma indicates rapid cooling at rates of at least ∼60 °C Myr−1. We derive a minimum slip rate of ∼6.5 km Myr−1 and a displacement of <∼20 km and propose that the development of the detachment in the thermally softened magmatic arc aided fast displacement. Intra-arc extension accomplished the final ∼6–9 km of exhumation of the Cycladic blueschists from ∼60 km depth. The fast-slipping intra-arc detachments did not cause much exhumation, but were important for regional-scale extension and the formation of the Aegean Sea.