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The timing and magnitude of Holocene glacial oscillations in most currently ice‐free areas of Antarctica remain unknown. This work focuses on the recent deglaciation in the northern sector of the Fildes Peninsula, King George Island, northern Antarctic Peninsula. The ice cap covering ca. 90% of the island has receded since the Last Glacial Maximum and exposed ca. 29 km2 of ice‐free land. We reconstruct its glacial history based on a dataset of 12 36Cl exposure ages obtained through cosmic‐ray exposure (CRE) dating of moraine boulders, polished surfaces and erratic boulders surrounding the peninsula's northern plateau. Results reveal that the deglaciation of the northern Fildes Peninsula took place during the Holocene Thermal Maximum at 7–6 ka, when warm conditions promoted a massive glacial retreat. The present arrangement of ice‐free areas was in place by 6 ka. Small cirque moraines suggest the subsequent occurrence of favourable climate conditions for glacial expansion fed by intense snow deflation at 4.6 and 1 ka at the foot of the northern plateau. The deglaciation pattern of the Fildes Peninsula resulted from the combined shrinkage of different ice masses, rather than of the long‐term retreat of the King George Ice Cap. No evidence of glacier expansion during more recent cold periods (i.e. the Little Ice Age) was found. These results fit well with regional deglacial histories inferred from lacustrine sediments and raised beaches and complement the existing chronological framework to help better understand the peninsula's Holocene geoecological dynamics. [ABSTRACT FROM AUTHOR]

Although the spatiotemporal oscillations of the Greenland Ice Sheet (GrIS) during the last millennia have played a prominent role in global environmental changes, its glacial response to the natural variability still needs to be better constrained. Here, we focused on the reconstruction of the glacial behavior and deglaciation process along the Tyroler Valley (74° N, 22° E), within the Northeast Greenland National Park. This NW‐SE valley connects with the GrIS via the Pasterze Glacier and divides two ice caps (A.P. Olsen Land and Payer Land), this last one feeding two piedmont glaciers (Copeland and Kløft glaciers). For this study, we combined the interpretation of the spatial pattern of geomorphological features and the chronological framework defined by a new dataset of 15 10Be cosmic‐ray exposure (CRE) ages from glacially polished bedrock surfaces and moraine boulders together with one optically stimulated luminescence (OSL) age of a glaciolacustrine deposit. CRE ages indicate that the deglaciation of the lowest parts of the valley and the exposure of the highest slopes took place during the Early Holocene, at ca. 10–8.5 ka (ka = thousand year [BP]). Furthermore, this ice thinning also favored the disconnection of the valley tributary glaciers. Samples from the moraines of the two tributary glaciers indicate that the deglaciation was not continuous, but it was interrupted by at least three phases of glacial advance during the Neoglacial cooling (before ca. 5.9 ka), and the Little Ice Age (LIA, 0.6, and 0.3 ka). The larger piedmont glacier (Copeland Glacier) occupied the valley floor during these major advances, damming the river and allowing the formation of a proglacial glacial lake upvalley, as confirmed by the OSL date of lacustrine sediments that yielded an age of 0.53 ± 0.06 ka. In short, our study provides new evidence of the relative stability of GrIS and the regional ice caps in the area, in which glacial fronts have been rather stable since their advances during the Neoglacial and the LIA. [ABSTRACT FROM AUTHOR]

Reconstructing mountainous landscape evolution throughout the Quaternary is challenging because of the poor long-term preservation of geomorphic records in a context of rapid surface dynamics and topographic rejuvenation. The Quaternary geomorphic evolution of the western European Alps has been strongly controlled by climatic oscillations between glacial and interglacial periods. Significant erosion and sediment remobilization during these glacial/interglacial cycles have left very few sedimentary archives to quantify the surface dynamics and paleo-environmental conditions within the mountain belt over the last hundreds of thousands of years. Alpine valleys within the periglacial zone are potential candidates to target long-term geological archives, since they may contain alluvial deposits that have been preserved from subsequent glaciations. In the Drac valley (French western Alps), three generations of paleo-valleys are preserved, each of which was filled with alluvial and lacustrine sediments in response to glacial damming downstream. The valleys were incised during subsequent times of glacial retreat, leading to the formation of epigenetic valleys. Detailed 3D mapping of the paleo-valleys was carried out using photogrammetric models to constrain their geometry. Mapping was combined with luminescence dating of alluvial deposits to reconstruct the temporal evolution of the Drac valley. This chronological framework, together with additional data from the literature, allowed us to quantitatively constrain the complex alluvial dynamics along the Drac river during the last ca. 230 ka. Poly-phased alluvial deposition occurred in the most recent paleo-valley between ca. 90 and 20 ka (i.e., from late MIS 5 to MIS 2) in a context of global climate cooling and major Alpine glaciation. Sediment infilling of the intermediate paleo-valley is dated at around 130 ka; i.e., during the late-glacial phase of the penultimate glaciation, at the abrupt warming transition between MIS 6 and MIS 5. Finally, the oldest paleo-valley was filled around 230 ka (during a sub-stage of MIS 7) probably in a cooling and glacial context. The overall alluviation pattern and chronology of the study area highlight the asynchronous and partially contrasting glacial dynamics between the different glacier systems (i.e., Drac, Bonne and Romanche/Isère glaciers) within the Ecrins-Pelvoux massif of the French western Alps. • Record of Pleistocene epigenic paleo-valley evolution in the French western Alps. • Alluvial sediment aggradation recorded during early, pleni & late-glacial periods. • Diachronous response of local Alpine glaciers to Pleistocene climate forcing. • Long-term estimate of fluvial incision rate (0.6–0.8 mm/yr) over the last 250 ka. [ABSTRACT FROM AUTHOR]

The Upper Garonne Basin included the largest glacial system in the Pyrenees during the last glacial cycle. Within the long‐term glacial retreat during Termination‐1 (T‐1), glacier fluctuations left geomorphic evidence in the area. However, the chronology of T‐1 glacial oscillations on the northern slopes of the Central Pyrenees is still poorly constrained. Here, we introduce new geomorphological observations and a 12‐sample dataset of 10Be cosmic‐ray exposure ages from the Ruda Valley. This U‐shaped valley, surrounded by peaks exceeding 2800 m a.s.l., includes a sequence of moraines and polished surfaces that enabled a reconstruction of the chronology of the last deglaciation. Following the maximum ice extent, warmer conditions prevailing at ~15–14 ka, during the Bølling–Allerød (B–A) Interstadial, favoured glacial retreat in the Ruda Valley. Within the B–A, glaciers experienced two phases of advance/stillstand with moraine formation at 13.5 and 13.0 ka. During the early Younger Dryas (YD), glacial retreat exposed the highest surfaces of the Saboredo Cirque (~2300–2350 m) at 12.7 ka. Small glaciers persisted only inside the highest cirques (~2470 m), such as in Sendrosa Cirque, with moraines stabilising at 12.6 ka. The results of this work present the most complete chronology for Pyrenean glacial oscillations from the B–A to the YD. [ABSTRACT FROM AUTHOR]

The Upper Garonne Basin included the longest glacier in the Pyrenees during the Late Pleistocene. During major glacial advances, the Garonne palaeoglacier flowed northwards along ~ 80 km from peaks of the axial Pyrenees exceeding 2800–3000 m until the foreland of this mountain range at the Loures–Barousse–Barbazan basin (LBBb), at 420–440 m. Here, the palaeoglacier formed a terminal moraine complex that is examined in this work. Based on geomorphological observations and a 12-sample data set of 10Be Cosmic-Ray Exposure (CRE) ages, the timing of the maximum glacial extent was constrained as well as the onset of the deglaciation from the end of the Last Glacial Cycle (LGC). Chronological data shows evidence that the external moraines in this basin were abandoned by the ice at the end of the Penultimate Glacial Cycle (PGC) and the onset of the Eemian Interglacial, at ~ 129 ka. No evidence of subsequent glacial advances or standstills occurred during the LGC in this basin were found, as the few existing datable boulders provided in the internal moraine showed inconsistent ages, thus probably being affected by post-glacial processes. The terminal basin was already deglaciated during the global Last Glacial Maximum at 24–21 ka, as revealed by exposure ages of polished surfaces at the confluence of the Garonne-La Pique valleys, 13 km south of the entrance of the LBBb. This study introduces the first CRE ages in the Pyrenees for the glacial advance occurred during the PGC and provides also new evidence that glaciers had already significantly shrunk during the LGM. [ABSTRACT FROM AUTHOR]

Abstract An accurate review of the literature on surface exposure dating methods shows evidence of the difficulty in applying cosmogenic dating methods to old moraines because of the intensity of late Quaternary erosion processes. Moreover, as in some previous cases, we also found special difficulties in applying these methods to LIA moraines, caused by the intensity of current paraglacial processes. The objective of this study is to apply cosmogenic dating methods to very old and very young moraines, which in both cases have been or are being affected intensively by erosion. With this purpose, we collected samples of boulders from moraines corresponding to (i) the penultimate glaciation and (ii) the Little Ice Age (LIA), both from Sierra Nevada in the south of the Iberian Peninsula. The sampling strategy was based on a preliminary accurate analysis of the geomorphological settings of two valley sites that resulted in the collection of only four boulder samples from an old moraine and three more from a very recent moraine. Using in situ-produced cosmogenic 10Be to date these boulders, the old samples yielded an age of ca. 130–135 ka for moraine stabilization. The younger samples indicate that the LIA moraine accretion probably occurred between the fourteenth and seventeenth centuries, with a subsequent stage of accumulation during the nineteenth century as suggested by historical documents. Dating a glaciation that occurred prior to the last Pleistocene glacial cycle and dating LIA glacial stages are novel in the context of Iberian glaciations and agree with other palaeoenvironmental studies in Iberian and in other Europe an mountains. The limited number of boulders adequate for cosmic-ray exposure dating prevents statistical methods to be applied, and therefore highlights the need to improve geomorphological criteria in sample selection. Highlights • We examine old and young glaciations in Sierra Nevada (Sothern Spain). • Seven moraine boulders have been CRE dated using 10Be isotope. • The Naute valley includes a moraine of the penultimate glaciation (130–134 ka). • During the LIA a moraine developed in the Veleta cirque (14–17th centuries). • Geomorphological criteria are preferred over dating large number of samples. [ABSTRACT FROM AUTHOR]

We report the first glacial chronology of Mt. Karanfil (3059 m above sea level; a.s.l.), a small mountain in the south-central Taurus Range in Turkey. Well-preserved terminal and lateral moraines are clustered in four groups; M1, M2, M3, and M4, between ∼2000 and ∼2400 m a.s.l., composed of limestone blocks. Each moraine group originated from one to three cirque areas (C1, C2, C3, and C4 cirques) on the mountain's northern face between 2400 and 2600 m a.s.l. The best estimated mean ages of moraines M1 (17.3 ± 2.4 ka), M2 (18.6 ± 1.6 ka), and M3 (20.0 ± 2.6 ka) indicate that glaciers reached their maximum extents on the global Last Glacial Maximum (LGM), and they were persistent till the Late Glacial. The last moraine group (M4), more oriented towards the north, is dated to 14.6 ± 2.4 ka, implying that the M4 glacier lasted a few thousand years more. Also, a relict rock glacier in the C1 cirque floor was dated to 9.9 ± 0.9 ka and testifies to the development of permafrost conditions at the onset of Holocene. The timing of glaciation on Mt. Karanfil is close to the global LGM, as similar terrestrial cosmogenic nuclide chronologies were obtained from other mountains in the eastern Mediterranean. We also used the Parallel Ice Sheet Model (PISM) to reconstruct the glaciers and climate during the LGM on Mt. Karanfil. Twenty-one palaeoclimate simulations were run as a function of present temperature and precipitation to reach the steady-state glacier extents, and the modelled glacial areas were compared with the field-observed ice extents. The best-fit scenarios indicate that the LGM climate on Mt. Karanfil was 8.3 ± 0.5 °C colder than today if the precipitation levels were the same as today. More humid (20% wetter) or arid (20% drier) conditions than today bring the palaeotemperature estimates to 6.9 ± 0.4 °C or 10.4 ± 0.6 °C lower than the present, respectively. • First glacial chronology using twenty-one cosmogenic 36Cl samples on Mt. Karanfil. • Glaciers reached their maximum extents at the end of LGM. • Parallel Ice Sheet Model (PISM) was used to reconstruct palaeoglaciers. • Modelled and observed ice extents were matched to infer palaeoclimate. • LGM climate would be 8.3 ± 0.5 °C colder than today if the precipitation levels were same as today. [ABSTRACT FROM AUTHOR]

During the Late Pleistocene, the main mountain ranges of the Iberian Peninsula were covered by small icefields and cirque and alpine glaciers. The deglaciation triggered paraglacial processes that generated landforms, mostly within the ice-free glacial cirques. In this research we analyse the deglaciation process in the Muxivén Cirque (42°15′N – 6°16′W), in the upper Sil River Basin, which includes some of the largest relict rock glaciers of the Cantabrian Mountains. We addressed this objective by means of accurate geomorphological reconstructions, sedimentological analysis, Schmidt-hammer surface weathering measurements and a dataset of 10 10Be Cosmic-Ray Exposure ages. Results reveal that after ~16 ka, glaciers retreated to the bottom of the cirques at the headwaters of the valley, leaving the walls free of ice and triggering rock avalanches onto the remnants of these glaciers. This paraglacial process supplied debris to a small glacier within Muxivén Cirque, which transformed in two rock glaciers. These debris isolated the ice inside the rock glaciers only for a very short period of time and ended up melting completely before the Younger Dryas. The lower sector of the largest one stabilized at 14.5 ± 1.5 ka, while the upper sector remained active until 13.5 ± 0.8 ka. Previous to the stabilization of the lower sector of the northern rock glacier, at its margin a high-energy debris avalanche occurred at ~14.0 ± 0.9 ka. These data agree with previous research, corroborating the paraglacial origin of most Iberian rock glaciers during the Bølling-Allerød interstadial. [Display omitted] • Glacier retreat triggered rock avalanches that favoured rock glacier formation. • Rock glacier activity lasted for a short time, collapsing before the Younger Dryas. • Rock glaciers stabilized at 14.5 ± 1.5 ka and 13.5 ± 0.8 ka (lower and upper sectors). • A high-energy debris avalanche occurred at ~14.0 ± 0.9 ka at the rock glacier margin. • A good example of the paraglacial origin of many Iberian rock glaciers [ABSTRACT FROM AUTHOR]

The Central Pyrenees hosted a large ice cap during the Late Pleistocene. The cirques under relatively low-altitude peaks (2200–2800 m) include the greatest variety of glacial landforms (moraines, fossil debris-covered glaciers and rock glaciers), but their age and formation process are poorly known. Here, we focus on the headwaters of the Garonne River, namely on the low-altitude Bacivèr Cirque (highest peaks at ~2600 m), with widespread erosive and depositional glacial and periglacial landforms. We reconstruct the pattern of deglaciation from geomorphological observations and a 17-sample dataset of 10Be Cosmic-Ray Exposure (CRE) ages. Ice thickness in the Bacivèr Cirque must have reached ~200 m during the maximum ice extent of the last glacial cycle, when it flowed down towards the Garonne paleoglacier. However, by ~15 ka, during the Bølling-Allerød (B-A) Interstadial, the mouth of the cirque was deglaciated as the tributary glacier shrank and disconnected from the Garonne paleoglacier. Glacial retreat was rapid, and the whole cirque was likely to have been deglaciated in only a few centuries, while paraglacial processes accelerated, leading to the transformation of debris-free glaciers into debris-covered and rock glaciers in their final stages. Climate conditions prevailing at the transition between the B-A and the Younger Dryas (YD) favored glacial growth and the likely development of small moraines within the slopes of the cirque walls by ~12.9 ka, but the dating uncertainties make it impossible to state whether these moraines formed during the B-A or the YD. The melting of these glaciers favored paraglacial dynamics, which promoted the development of rock glaciers as well as debris-covered glaciers. These remained active throughout the Early Holocene until at least ~7 ka. Since then, the landscape of the Bacivèr Cirque has seen a period of relative stability. A similar chronological sequence of deglaciation has been also detected in other cirques of the Pyrenees below 3000 m. As in other mid-latitude mountain regions, the B-A triggered the complete deglaciation of the Garonne paleoglacier and promoted the development of the wide variety of glacial and periglacial landforms existing in the Bacivèr cirque. • We reconstruct the deglaciation of the Bacivèr cirque, in the Central Pyrenees. • The cirque hosts a wide range of glacial and periglacial processes and landforms. • A rapid deglaciation occurred during the Bølling-Allerød (B-A) by 15–14 ka. • Paraglacial dynamics subsequently formed debris-covered glaciers and rock glaciers. • As in other mountain regions, the B-A played a major role shaping the landscape. [ABSTRACT FROM AUTHOR]

Through a detailed geomorphological study, including thourough mapping of the geomorphic features as well as 10Be Cosmic-Ray Exposure (CRE) dating, the geomorphological evolution of the Mulhacén cirque since the maximum ice extent of the last glacial cycle until nowadays was determined. This glacial cirque is shaped on the northern face of the Mulhacén peak (3479 m a.s.l. 37°03′12″N/3°18′41″W), Sierra Nevada, southern Spain. It includes several depositional and erosional glacial landforms that allowed reconstructing its environmental evolution since the last glacial cycle. Furthermore, the sequence of glacial oscillations from this site was compared to that of other cirques of the massif, evidencing that: (i) new glaciers formed in these cirques during the Younger Dryas (YD), and (ii) disappeared at 11.7 ± 1.0 ka. Depending on the altitude, orientation and height of the cirque walls, the final deglaciation of the cirques generated a diversity of landscapes, including a wide range of glacial and periglacial landforms, such as polished surfaces, sequences of moraines, proto-rock glaciers or large rock glacier systems. No glaciers existed in the Sierra Nevada during the Middle Holocene. Only the cirques whose summits exceed 3300 m, are north-exposed and whose walls exceed 300 m high (i.e. Mulhacén and Veleta) hosted glaciers during Neoglacial phases, including the Little Ice Age (LIA) (approx. 1300–1850 CE). During these periods, climate oscillations favoured the formation of small glaciers in these cirques, which generated large moraine systems with either one polygenic ridge or a sequence of spaced frontal arcs. The existence of glaciers impeded the formation of permafrost-related landforms, such as rock glaciers and protalus lobes until the end of the LIA, when they started to form. These results are compared with the deglacial evolution in 55 cirques from Iberian mountains as well as from glacial cirques from other mid-latitude mountains and subpolar regions. The chronology of their deglaciation as well as the landforms generated during glacial retreat followed similar patterns, with no significant differences at regional scale. For each mountain range, the geomorphological diversity existing in each cirque depends on the local topographic characteristics although they formed during the same climatic phases. • We examine the climatic sensitivity of geomorphic processes in glacial cirques. • We focus on the variety of landforms in glacial cirques of Sierra Nevada, Spain. • In this massif glacial cirques were deglaciated around 14 ka. • Glaciers formed again during the Younger Dryas and disappeared around 11.7 ka. • Most cirques of the North Hemisphere followed the same chronological sequence. [ABSTRACT FROM AUTHOR]