The paleoclimate application of speleothem δ13C is influenced by site-specific processes. Here we present four stalagmite δ13C records from two caves in southern China, covering early and late Marine Isotope Stage (MIS) 3 and the Holocene, to investigate the spatio-temporal pattern of calcite δ13C changes and the relationship with Asian monsoon (AM) variability. In each growth period, precessional- to millennial-scale changes are clear in the δ18O record. In contrast, millennial variability is absent in the δ13C record, which characterizes persistent centennial oscillations. However, centennial-scale δ18O variations agree well with those of δ13C, with a larger amplitude in δ13C changes (about twice that of δ18O). This suggests that soil humidity balance associated with regional hydrological circulations is important for these centennial δ13C changes, although evaporation-related kinetic fractionation can induce concurrent enrichments in δ18O and δ13C. In frequency, the detrended δ18O and δ13C records are coupled at a periodicity of about 300 yr during the last glacial period and 150 yr during the Holocene. Those centennial-scale δ13C variations are generally consistent with Greenland temperature variability, indicating a climate response over broad regions. Thus, strong co-variation of δ18O and δ13C records should have a climatic origin, even if it is amplified by kinetic effects.

A study of chironomid remains in the sediments of Lake JR01 on the Boothia Peninsula in the Central Canadian Arctic provides a high-resolution record of mean July air temperatures for the last 6.9 ka. Diatom and pollen studies have previously been published from this core. Peak Holocene temperatures occurred prior to 5.0 ka, a time when overall aquatic and terrestrial biological production was high. Chironomid-inferred summer air temperatures reached up to 7.5°C during this period. The region of Lake JR01 cooled over the mid- to late-Holocene, with high biological production between 6.1 and 5.4 ka. Biological production decreased again at ∼2 ka and the rate of cooling increased in the past 2 ka, with coolest temperatures occurring between 0.46 and 0.36 ka, coinciding with the Little Ice Age. Although biological production increased in the last 150 yr, the reconstructed temperatures do not indicate a warming during this time. During transitions, either warming or cooling, chironomid production increases, suggesting an ecosystem-level response to climate variability, seen at a number of lakes across the Arctic.

Previous research on the small mammal population recovered from archeological excavations at the Wasden Site in southeastern Idaho suggests that changing frequency distributions through time represent a shift in climate during the early Holocene from a cooler, wetter regime to a warmer, drier one. This conclusion was re-evaluated using stable carbon and nitrogen isotope analyses of bone collagen from the three species of small mammals examined in the earlier studies: pocket gophers (Thomomys talpoides), pygmy rabbits (Brachylagus idahoensis), and ground squirrels (Spermophilus townsendii). Resulting carbon and nitrogen isotopic values are consistent with known differences in feeding ecology, suggesting high fidelity as proxies for past vegetation (and thus climate) regimes. Patterns of 15N enrichment and increased representation of C4-CAM vegetation observed in the pocket gophers, and to a lesser extent ground squirrels, suggests increasing warmth and/or aridity from the early Holocene until ∼7000 cal yr BP, thus supporting previous hypotheses of climate change on the eastern Snake River Plain. The results highlight the potential contribution of such studies for archeological research by providing additional proxies for environmental conditions that bear on paleoecological adaptations to climatic change, including past human use and occupation of the region.

Gauged river flow records from China generally span only a few decades, which hampers the detection of long-term, decadal- to centennial-scale cycles and trends in streamflow variability. New and updated tree-ring chronologies help reconstructed the water-year (October–September) streamflow for the Aksu River, which is an important river at the edge of the Taklimakan Desert that drains into the Tarim Basin. The reconstruction dates back to 1692 and has an adjusted r2 of 0.61 (1957–2006). Based on frequency, intensity and duration of droughts and pluvial events, the lowest streamflows occurred in the 1920s. Since then streamflow has continuously increased, and was exceptionally rapidly after the 1960s, until today. The start and end of the 20th century to the present were the highest streamflow periods. The mid-20th century was the longest and driest period over the past 300 yr. The reconstructed streamflow series has a strong positive correlation with the North Atlantic Oscillation Index. Changes in mid-latitude circulation patterns influencing precipitation may have indirectly resulted in streamflow variations along the Aksu River over the past 300 yr. The rapid increase and the exceptional streamflows of the 1960s are likely linked with global warming and mid-latitude atmospheric circulation changes.

The revegetation of islands following retreat of Pleistocene glaciers is of great biogeographical interest. The San Juan Islands, Washington, feature regionally distinctive xerophytic plant communities, yet their vegetation history, as it relates to past climate and sea level, is poorly known. We describe a 13,700-year-old pollen record from Killebrew Lake Fen and compare the vegetation reconstruction with others from the region. The data suggest that the narrow channels surrounding Orcas Island were not a barrier to early postglacial immigration of plants. Between 13,700 and 12,000 cal yr BP, Pinus, Tsuga, Picea, Alnus viridis, and possibly Juniperus maritima were present in a mosaic that supported Bison antiquus and Megalonyx. The rise of Alnus rubra-type pollen and Pteridium spores at ca. 12,000 cal yr BP suggests a warming trend and probably more fires. Temperate conifer taxa, including Cupressaceae, Pseudotsuga, Tsuga heterophylla, and Abies, increased after 11,000 cal yr BP and especially in the last 7000 cal yr BP. After 6000 cal yr BP, Pseudotsuga and Cupressaceae dominated the vegetation. The last 1500 yr were the wettest period of the record. Due to its rain shadow location, Orcas Island experienced drier conditions than on the mainland during most of the postglacial period.

The lake-level record from Tulare Lake, CA has been shown to provide valuable constraints on late Pleistocene and Holocene runoff from the Sierra Nevada mountain range into the San Joaquin Valley of California, one of the world's most prolific agricultural centers. This project uses the magnetic properties of the Tulare Lake sediments in order to date the sediments and to constrain the relative lake level at the time of deposition. Shallowing lake conditions were identified leading up to a prominent unconformity; magnetic mineralogy and grain size indicators, primarily decreasing ARM/IRM and S-Ratio values suggest coarser grain sizes and more oxidizing conditions. Approximately half of the samples possessed well-behaved paleomagnetic directions suitable for paleomagnetic secular variation dating. The results indicate that the sediments below the unconformity were deposited approximately 7600–8500 cal yr BP, and the sediments above the unconformity were deposited approximately 2500–800 cal yr BP. The ages of the corresponding sediments are consistent with the time intervals during which previous studies indicate that lake level was above the elevation of this site, before and after a mid Holocene regression.

Deltas formed in Lake Hitchcock, a glacial lake that developed in the Connecticut River Valley, New England, between ∼18.3 and 12.5 ka. The heights of topset/foreset contacts of these deltas presently increase northward, linearly, at rate of ∼0.9 m/km. Others have interpreted this as indicating that isostatic rebound did not begin until after the lake drained, several kiloyears after glacial retreat began. However, (non-elastic) adjustment of Earth's lithosphere to changing loads is known to occur on time scales of years. Late-glacial shoreline features elsewhere in New England also increase in elevation with distance from the LGM margin at ∼0.9 m/km, suggesting that this is a result of fundamental properties of the crust and mantle, and independent of the history of glacier retreat. On the basis of a numerical model of flexure of the lithosphere beneath a circular load, we suggest that deflection of the lithosphere is remarkably linear in a zone 50–200 km wide between the retreating ice margin and a forebulge, and that initial rebound of this zone is spatially quite uniform for some kiloyears before differential rebound starts. Thus, lake shorelines, formed over a period of some centuries during deglaciation would, today, rise linearly northward.

Geomorphic, stratigraphic and geochronological evidence from northeast British Columbia (Canada) indicates that, during the late Wisconsinan (approximately equivalent to marine oxygen isotope stage [MIS] 2), a major lobe of western-sourced ice coalesced with the northeastern-sourced Laurentide Ice Sheet (LIS). High-resolution digital elevation models reveal a continuous 75 km-long field of streamlined landforms that indicate the ice flow direction of a major northeast-flowing lobe of the Cordilleran Ice Sheet (CIS) or a montane glacier (>200 km wide) was deflected to a north-northwest trajectory as it coalesced with the retreating LIS. The streamlined landforms are composed of till containing clasts of eastern provenance that imply that the LIS reached its maximum extent before the western-sourced ice flow crossed the area. Since the LIS only reached this region in the late Wisconsinan, the CIS/montane ice responsible for the streamlined landforms must have occupied the area after the LIS withdrew. Stratigraphy from the Murray and Pine river valleys supports a late Wisconsinan age for the surface landforms and records two glacial events separated by a non-glacial interval that was dated to be of middle Wisconsinan (MIS 3) age.

Immense late Wisconsin floods from glacial Lake Missoula drowned the Wenatchee reach of Washington's Columbia valley by different routes. The earliest debacles, nearly 19,000 cal yr BP, raged 335 m deep down the Columbia and built high Pangborn bar at Wenatchee. As advancing ice blocked the northwest of Columbia valley, several giant floods descended Moses Coulee and backflooded up the Columbia past Wenatchee. Ice then blocked Moses Coulee, and Grand Coulee to Quincy basin became the westmost floodway. From Quincy basin many Missoula floods backflowed 50 km upvalley to Wenatchee 18,000 to 15,500 years ago. Receding ice dammed glacial Lake Columbia centuries more—till it burst about 15,000 years ago. After Glacier Peak ashfall about 13,600 years ago, smaller great flood(s) swept down the Columbia from glacial Lake Kootenay in British Columbia. The East Wenatchee cache of huge fluted Clovis points had been laid atop Pangborn bar after the Glacier Peak ashfall, then buried by loess. Clovis people came five and a half millennia after the early gigantic Missoula floods, two and a half millennia after the last small Missoula flood, and two millennia after the glacial Lake Columbia flood. People likely saw outburst flood(s) from glacial Lake Kootenay.

Solitary limestone blocks and groups of blocks occur on Risnjak and Velebit Mountains and on the northern Adriatic islands of Krk and Rab. Previous researchers have interpreted some of these as a) erratic blocks, b) corrosional remnants, or c) rockfalls. We have studied their mode of occurrence and composition, and revised previous interpretations of their origin in the light of transport mechanism and depositional processes. After analyzing the context of the block positions and the physical processes responsible for their emplacement, and taking into account their sedimentological context (their association with glaciogenic sediments), we herein propose a glacial origin for most of these blocks. However, some blocks are indeed shaped by sub-soil corrosion, as evidenced by their structure. The interpreted erratic blocks on the inner northern Adriatic Sea islands document the presence of middle Pleistocene glaciation of Dinaric Mountains though not its maximal extent, which is still unclear as the ice terminus was in the area that is inundated by postglacial rise of Adriatic Sea. The reconstructed ice cap area, which extended along the coastal mountains from Risnjak Mt. to south Velebit Mt. and across the range from Lika Polje to Rab Island, is conservatively estimated to be 5400 km2.

The Nihewan Basin is a key region for studying the Palaeolithic archaeology of East Asia. However, because of the lack of suitable dating methods and representative lithic technologies in this region, the ‘Middle Palaeolithic’ sites in this basin have been designated based mainly on stratigraphic correlation, which may be unreliable. In this study, three Palaeolithic sites, Motianling, Queergou and Banjingzi, which have been assigned previously to the ‘Middle Palaeolithic’, are dated based on luminescence dating of K-feldspar grains. Our results show that the cultural layers at Motianling, Queergou and Banjingzi have ages of 315 ± 13, 268 ± 13 and 86 ± 4 ka (corresponding to Marine Isotope Stages 9, 8 and 5), respectively, suggesting that Motianling and Queergou should be assigned to the Lower Palaeolithic, while the age of Banjingzi is consistent with a Middle Palaeolithic attribution. Our results suggest that reassessing the age of ‘Middle Palaeolithic’ sites in the Nihewan Basin, and elsewhere in North China, is crucial for understanding the presence or absence of the Middle Palaeolithic phase in China. Our dating results also indicate that the Sanggan River developed sometime between about 270 and 86 ka ago.