ABSTRACT Lake Coyote, California, which formed in one of five basins along the Mojave River, acted both as a part of the Lake Manix basin and, after the formation of Afton Canyon and draining of Lake Manix ca. 24.5 calibrated (cal) ka, a side basin that was filled episodically for the next 10,000 yr. As such, its record of lake level is an important counterpart to the record of the other terminal basin, Lake Mojave, following the draining of Lake Manix. We studied lake and fluvial deposits and their geomorphology and identified five principal periods of recurring lakes in the Coyote basin by dating mollusks. Several of these periods in detail consist of multiple lake-rise pulses, for which we identified specific fluvial deposits that represent the Mojave River entering the basin. The pulsed record of rapid lake rise and decline is interpreted as switching of the Mojave River between Lake Coyote and Lake Mojave. A composite lake record for both basins shows nearly continuous lake maintenance by the Mojave River from 24.5 cal ka to ca. 14 cal ka. One potential gap in the lake record, ca. 22.7–21.8 cal ka, may indicate either temporary river routing to yet another basin or a dry climatic period. The Mojave River discharge was sufficient to maintain at least one terminal lake throughout most of the Last Glacial Maximum and deglacial periods, indicating that paleoclimate was moist and/or cool well into the Bølling-Allerød and that the lake records may not be sensitive to variations from moderate to high discharge. Nuances of lake-level changes in both the Coyote and Mojave basins are difficult to interpret as paleoclimatic events because the current chronologic control on lake levels from nearshore deposits does not provide the necessary precision. Mojave River avulsion leading to flow to Coyote basin may have been influenced by rupture on a dextral-oblique fault. Earliest post–Lake Manix stream deposits of the Mojave River leading to the Coyote basin are faulted, and most subsequent streams were confined to the downthrown fault block. This fault rupture and possible enhanced river routes to Lake Coyote, rather than Lake Mojave, are bracketed by dated beach deposits to the period ca. 20–19 cal ka. Later, headward erosion through the fluvial plain by the Mojave River eliminated flow to Coyote basin after ca. 14 cal ka and completed incision of the plain after ca. 12 cal ka.

ABSTRACT The northward retreat history of the Laurentide ice sheet through the lowlands of the northeastern United States during the last deglaciation is well constrained, but its vertical thinning history is less well known because of the lack of direct constraints on ice thickness through time and space. In addition, the highest elevations in New England are characterized by gently sloping upland surfaces and weathered block fields, features with an uncertain history. To better constrain ice-sheet history in this area and its relationship to alpine geomorphology, we present 20 new 10 Be and seven in situ 14 C cosmogenic nuclide measurements along an elevation transect at Mount Washington, New Hampshire, the highest mountain in the northeastern United States (1917 m above sea level [a.s.l.]). Our results suggest substantially different exposure and erosion histories on the upper and lower parts of the mountain. Above 1600 m a.s.l., 10 Be and in situ 14 C measurements are consistent with upper reaches of the mountain deglaciating by 18 ka. However, some 10 Be ages are up to several times greater than the age of the last deglaciation, consistent with weakly erosive, cold-based ice that did not deeply erode preglacial surfaces. Below 1600 m a.s.l., 10 Be ages are indistinguishable over a nearly 900 m range in elevation and imply rapid ice-surface lowering ca. 14.1 ± 1.1 ka (1 standard deviation; n = 9). This shift from slow thinning early in the deglaciation on the upper part of the mountain to abrupt thinning across the lower elevations coincided with accelerated ice-margin retreat through the region recorded by Connecticut River valley varve records during the Bølling interstadial. The Mount Washington cosmogenic nuclide vertical transect and the Connecticut River valley varve record, along with other New England cosmogenic nuclide records, suggest rapid ice-volume loss in the interior northeastern United States in response to Bølling warming.

We discuss pollen, soil, geomorphologic, and archaeological records used for reconstructing climatic, biogeographic, and human-environment events in the Crimean Peninsula during the past 130 k.y. Warm and moist conditions conducive to forest growth prevailed during the Eemian Interglacial (marine isotope stage [MIS] 5e). Although sea levels were higher than at present, a review of the stratigraphic and geomorphic data suggests that the peninsula was not detached from the mainland. During the last glacial period (MIS 5d–MIS 2), conditions fluctuated between steppe and tree growth in warmer places during the stadials, and forest-steppe during the interstadials. The Pleistocene–Holocene transition involved forest growth during the Bølling-Allerød interstadials, steppe during the Younger Dryas, and a forest-steppe during the early Holocene. The establishment of the modern Black Sea ca. 7 ka and increasing temperatures led to the formation of the modern vegetation belts, ushering in optimal conditions for the establishment of Neolithic communities. A dry period peaked around 4–3.5 ka, followed by milder conditions that lasted until the colonization of Crimea by Greek farmers during the middle part of the first millennium A.D. Dry conditions at the end of the same millennium led to the abandonment of agriculture and settlement decline. Sea-level oscillations during the late Holocene had an important effect on shoreline configuration, lagoonal systems, coastal wetlands, and human settlements. Data used in this paper were drawn from a number of published papers, mostly in Russian and Ukrainian, as well as records produced by the authors' research.