Cosmic ray exposure ages for formation of perched alluvial terraces and for abandonment of an alluvial/debrisflow fan on opposite sides of the Tangtse Valley (the outflow at the northwest end of Lake Panggong, which is in the Karakorum Range of Western Tibet) provide evidence of a humid period at V11.5 to V7 ka. This is consistent with other regional records and supports a controversial chronol...

An investigation of shallow ground water quality revealed that high arsenic (As) concentrations were found in both aquifers and aquitards in the southern Choushui River alluvial fan of Taiwan. A total of 655 geological core samples from 13 drilling wells were collected and analyzed. High As contents were found primarily in aquitards, to a maximum of 590 mg/kg. The contents were correlated with ...

Pleistocene alluvial fan surfaces of the Campo de Cartagena-Mar Menor Basin (Murcia, SE Spain) are capped by thick mature calcretes. Calcrete profiles consist mainly of six different horizons: prismatic, chalky, nodular, massive, laminar and coated-gravels. Petrographic study of the calcretes has shown the occurrence of features such as alveolar septal structures, calcified filaments, coated gr...

River deltas and alluvial fans have channelization and deposition dynamics that are not entirely understood, but which dictate the evolution of landscapes of great social, economic, and ecologic value. Our lack of a process-based understanding of fan dynamics hampers our ability to construct accurate prediction and hazard models, leaving these regions vulnerable. Here we describe the growth of ...

Varnish microlamination (VML) dating is a correlative age determination technique that can be used to date and correlate various geomorphic features in deserts. In this study, we establish a generalized late Quaternary (i.e., 0–300 ka) varnish layering sequence for the drylands of western USA and tentatively correlate it with the SPECMAP oxygen isotope record. We then use this climatically corr...

[1] Alluvial fan deltas are built by aggrading and avulsing river channels. A numerical model of flow and sediment transport in channels is combined with a condition for channel avulsion to describe evolution of the fan surface. The model combines elements of two recent approaches: (1) diffusional models of depositional basin filling, which describe the evolution of overall morphology, and (2) ...

Introduction: We have previously demonstrated the viability of using thermal infrared images for mapping surface grain size distributions on terrestrial allu-vial fans [1, 2, 3]. For a well characterized alluvial fan in Owens Valley, CA we have used a quantitative analysis between aerial thermal images and ground-based grain size counts as well as a qualitative analysis between our thermal imag...