Structure of Alluvial Valleys from 3-D Gravity Inversion: The Low Andarax Valley (Almería, Spain) Test Case

This paper presents a gravimetric study (based on 382 gravimetric stations in an area about 32 km2) of a nearly flat basin: the Low Andarax valley. This alluvial basin, close to its river mouth, is located in the extreme south of the province of Almería and coincides with one of the existing depressions in the Betic Cordillera. The paper presents new methodological work to adapt a published inversion approach (GROWTH method) to the case of an alluvial valley (sedimentary stratification, with density increase downward). The adjusted 3D density model reveals several features in the topography of the discontinuity layers between the calcareous basement (2,700 kg/m3) and two sedimentary layers (2,400 and 2,250 kg/m3). We interpret several low density alignments as corresponding to SE faults striking about N140?145°E. Some detected basement elevations (such as the one, previously known by boreholes, in Viator village) are apparently connected with the fault pattern. The outcomes of this work are: (1) new gravimetric data, (2) new methodological options, and (3) the resulting structural conclusions.

(Table 1) Soil density and concentration of 10Beryllium and 26Aluminium in samples from two ash deposits in the McMurdo Dry Valleys

The McMurdo Dry Valleys, Antarctica (MDV) are among the oldest landscapes on Earth, and some landforms there present an intriguing apparent contradiction such that millions of years old surface deposits maintain their meter-scale morphology despite the fact that measured erosion rates are 0.1-4 m/Ma. We analyzed the concentration of cosmic ray-produced 10Be and 26Al in quartz sands from regolith directly above and below two well-documented ash deposits in the MDV, the Arena Valley ash (40Ar/39Ar age of 4.33 Ma) and the Hart ash (K-Ar age of 3.9 Ma). Measured concentrations of 10Be and 26Al are significantly less than expected given the age of the in situ air fall ashes and are best interpreted as reflecting the degradation rate of the overlying sediments. The erosion rate of the material above the Arena Valley ash that best explains the observed isotope profiles is 3.5 ± 0.41 x 10**-5 g/cm**2/yr (~0.19 m/Ma) for the past ~4 Ma. For the Hart ash, the erosion rate is 4.8 ± 0.21 x 10**-4 g/cm**2/yr (~2.6 m/Ma) for the past ~1 Ma. The concentration profiles do not show signs of mixing, creep, or deflation caused by sublimation of ground ice. These results indicate that the slow, steady lowering of the surface without vertical mixing may allow landforms to maintain their meter-scale morphology even though they are actively eroding.

Cotton production in the lower desert valleys of California /

Mode of access: Internet.

Western Americana; an extraordinary collection dealing with the local history and march of events in the regions lying within the Ohio and Mississippi Valleys and westward to the Pacific Ocean ... to be sold by auction ... December third, fourth, fifth ...

"To be sold by auction Monday, Tuesday, Wednesday evenings, December Third, Fourth, Fifth."

Notes and recollections of an angler: rambles among the mountains, valleys, and solitudes of Wales.

Mode of access: Internet.

Summer outings in the old Granite state. A guide to pleasant places among the mountains, lakes and valleys of New Hampshire. Via the Merrimack valley route.

Disbound Original Held in Oak Street Library Facility.

Geothermal gradients in the Missoula and Bitterroot Valleys, west-central Montana /

Mode of access: Internet.

Hanging valleys.

From American Geographical Society. Bulletin. Vol. XLI, no. 11.

The Waldenses: sketches of the evangelical Christians of the valleys of Piedmont. With illustrations on wood, drawn by Doepler, and Beaulieu, and engraved by Louderback, Orr, and Roberts.

Compiled chiefly from "The Israel of the Alps" by Alexis Muston.

Mary Derwent, a tale of Wyoming and Mohawk Valleys in 1778,

Mode of access: Internet.

Meandering valleys and underfit rivers /

Mode of access: Internet.

Flood flows and stages in Sacramento and northern San Joaquin Valleys.

Title varies slightly.

Hydrogeology of the Green River Lowland and associated bedrock valleys in Northwestern Illinois /

Includes bibliographical references (p. 19-20).

The glorious recovery by the Vaudois of their valleys /

Translation of Histoire de la glorieuse rentrée des Vaudois dans leurs valées.

Panorama of the beauties, curiosities, and antiquities of North Wales, exhibited in its mountains, valleys, waterfalls, lakes, cities and towns, castles and ruins, etc. Intended as a pocket companion to the tourist and traveller.

Some later ed. have title: The illustrated hand-book of North Wales.