2013 ◽  
Vol 44 ◽  
pp. 113-125 ◽  
Author(s):  
Ryan Rabett ◽  
Lucy Farr ◽  
Evan Hill ◽  
Chris Hunt ◽  
Ross Lane ◽  
...  

AbstractThe paper reports on the sixth season of fieldwork of the Cyrenaican Prehistory Project (CPP) undertaken in September 2012. As in the spring 2012 season, work focussed on the Haua Fteah cave and on studies of materials excavated in previous seasons, with no fieldwork undertaken elsewhere in the Gebel Akhdar. An important discovery, in a sounding excavated below the base of McBurney's 1955 Deep Sounding (Trench S), is of a rockfall or roof collapse conceivably dating to the cold climatic regime of Marine Isotope Stage (MIS) 6 (globally dated to c. 190–130 ka) but more likely the result of a seismic event within MIS 5 (globally dated to c. 130–80 ka). The sediments and associated molluscan fauna in Trench S and in Trench D, a trench being cut down the side of the Deep Sounding, indicate that this part of the cave was at least seasonally waterlogged during the accumulation, probably during MIS 5, of the ~6.5 m of sediment cut through by the Deep Sounding. Evidence for human frequentation of the cave in this period is more or less visible depending on how close the trench area was to standing water as it fluctuated through time. Trench M, the trench being cut down the side of McBurney's Middle Trench, has now reached the depth of the latest Middle Stone Age or Middle Palaeolithic (Levalloiso-Mousterian) industries. The preliminary indications from its excavation are that the transition from the Levalloiso-Mousterian to the blade-based Upper Palaeolithic or Late Stone Age Dabban industry was complex and perhaps protracted, at a time when the climate was oscillating between warm-stage stable environmental conditions and colder and more arid environments. The estimated age of the sediments, c. 50–40 ka, places these oscillations within the earlier part of MIS 3 (globally dated to 60–24 ka), when global climates experienced rapid fluctuations as part of an overall trend to increasing aridity and cold.


2012 ◽  
Vol 76 ◽  
pp. 23-32 ◽  
Author(s):  
Guo-qiang Xue ◽  
Chao-ying Bai ◽  
Shu Yan ◽  
Stewart Greenhalgh ◽  
Mei-fang Li ◽  
...  

Author(s):  
P. B. V. Subba Rao ◽  
M. Radhakrishna ◽  
Santu Ghoshal ◽  
P. V. Vijaya Kumar ◽  
A. K. Singh

Geophysics ◽  
2000 ◽  
Vol 65 (6) ◽  
pp. 1871-1881 ◽  
Author(s):  
Don White ◽  
David Boerner ◽  
Jianjun Wu ◽  
Steve Lucas ◽  
Eberhard Berrer ◽  
...  

Seismic reflection and electromagnetic (EM) data were acquired near Thompson, Manitoba, Canada, to map the subsurface extent of the Paleoproterozoic, nickel ore‐bearing Ospwagan Group. These data are supplemented by surface and borehole geology and by laboratory measurements of density, seismic velocity, and electrical conductivity, which indicate that Ospwagan Group rocks are generally more seismically reflective and electrically conductive than the Archean basement rocks that envelop them. The combined seismic/EM interpretation suggests that the Thompson Nappe (cored by Ospwagan Group rocks) lies blind beneath the Archean basement gneisses, to the east of the subvertical Burntwood lineament, in a series of late recumbent folds and/or southeast‐dipping reverse faults. The EM data require that the shallowest of these fold/fault structures occur within the basement gneisses or perhaps less conductive Ospwagan Group rocks. The results of this study demonstrate how seismic and deep sounding EM methods might be utilized as regional exploration tools in the Thompson nickel belt.


Antiquity ◽  
1987 ◽  
Vol 61 (233) ◽  
pp. 433-439 ◽  
Author(s):  
Geoff Bailey ◽  
Gwyn Thomas

How many excavators of deep palaeolithic sites, especially in caves or rock-shelters, dig with any clear knowledge of how deep the deposits they are working in actually are, or of the ages of the lower portions? Here an alternative is offered to the traditional approach by a ‘deep sounding’ of conventional excavation. A crucial element to the strategy at Klithi is the possibility of carbon-dating, by accelerator, samples of the small size commonly obtained from a drilled core.


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