This book provides the first analysis and synthesis of the evidence of the earliest inhabitants of Asia before the appearance of modern humans 100,000 years ago. Asia has received far less attention than Africa and Europe in the search for human origins, but is no longer considered of marginal importance. Indeed, a global understanding of human origins cannot be properly understood without a detailed consideration of the largest continent. In this study, Robin Dennell examines a variety of sources, including the archaeological evidence, the fossil hominin record, and the environmental and climatic background from Southwest, Central, South, and Southeast Asia, as well as China. He presents an authoritative and comprehensive framework for investigations of Asia's oldest societies, challenges many long-standing assumptions about its earliest inhabitants, and places Asia centrally in the discussions of human evolution in the past two million years.

https://www.paleoanthro.org/static/journal/content/PA20090179.pdf

The paleolithic settlement of Asia

A Quaternary geomagnetic instability time scale

https://people.clas.ufl.edu/jetc/files/lundetal2006.pdf

A summary of Brunhes paleomagnetic field variability recorded in Ocean Drilling Program cores

Magnetostratigraphic dating of early humans in China

[1] A detailed study of 43 lava flows comprising two stratigraphic sequences exposed along the north and south walls of Barranco de los Tilos on the island of La Palma, Canary Islands, reveals a complex, temporally segmented record of geodynamo behavior that contains no less than three distinct geomagnetic events. The Matuyama-Brunhes (M-B) reversal is recorded in five transitionally magnetized lava flows from the north (TN) section. The isochrons obtained from three of the lower four M-B lavas are defined by 14 incremental heating experiments that, together with a previous age determination, yielded a weighted mean of 798.4 ± 6.2 ka (all uncertainties ±2s). In addition, a 780.3 ± 10.3 ka isochron was determined for the overlying transitionally magnetized flow, indicating that it was erupted during a distinctly younger portion of the transition. Near the base of the south (TS) section one finds a sequence of weakly magnetized flows associated with virtual geomagnetic pole (VGP) positions in the southwest Indian Ocean between latitudes 56� S and 65� S, suggesting instability of the geomagnetic field beyond that of typical secular variation. 40 Ar/ 39 Ar isochrons from three of these flows, defined by 11 separate incremental heating experiments, gave a weighted mean of 822.2 ± 8.7 ka. This anomalous field behavior recorded 24 ± 11 kyr prior to the M-B reversal may coincide with an event featured in several marine sediment records. Directly above two normal polarity flows ( 40 Ar/ 39 Ar isochrons of 751.9 ± 18.1 ka and 675.0 ± 15.7 ka) are nine transitionally magnetized lavas having magnetization directions associated with low to midlatitude VGPs spanning 23� –60� N. These flows are then capped by a single flow possessing normal polarity. Based on 12 incremental heating experiments, 40 Ar/ 39 Ar isochrons of five of these nine lavas, along with the uppermost flow, gave a weighted mean age of 580.2 ± 7.8 ka for this period of transitional to normal field behavior. From these same transitional lavas, Quidelleur et al. [1999] reported three unspiked K-Ar ages with a weighted mean of 602 ± 24 ka and proposed a new event called the ‘‘La Palma’’ excursion. However, the 40 Ar/ 39 Ar age presented here is three times more precise than the K-Ar age and is indistinguishable at the 95% confidence level from the 40 Ar/ 39 Ar age of a lava from the Snake River Plain, Idaho, that originally defined the Big Lost event. Transitional field behavior of similar age observed in astronomically dated marine cores further establishes that the Big Lost event recorded at La Palma was indeed global in extent. Rigorous temporal and geomagnetic constraints for several additional periods of geomagnetic field instability during the last several million years will comprise a geomagnetic instability timescale that can be factored confidently into models of the dynamo process. INDEX TERMS: 1560 Geomagnetism and Paleomagnetism: Time variations—secular and long term; 1520 Geomagnetism and Paleomagnetism: Magnetostratigraphy; 1035 Geochemistry: Geochronology; 1513 Geomagnetism and Paleomagnetism: Geomagnetic excursions; KEYWORDS: argonargon, dating, lavas, excursion, paleomagnetism, reversal

/pdf/ar-ar-ages-from-transitionally-magnetized-lavas-on-la-palma-13jysi3w00.pdf

Ar/Ar ages from transitionally magnetized lavas on La Palma, Canary Islands, and the geomagnetic instability timescale

Magnetostratigraphy of Plio-Pleistocene sediments in a 1700-m core from Osaka Bay, southwestern Japan and short geomagnetic events in the middle Matuyama and early Brunhes chrons

Accelerated creep, primarily through vertical displacement, has been occurring along 15 en-echelon faults belonging to a 15 km-long and 1.5 km-wide, N-S-trending dilational jog of the active West Valley Fault (or West Marikina Valley Fault), on the southeastern part of Metro Manila, Philippines. The much-larger-than-known tectonic slip rates had been the only reliable evidence in support of excessive groundwater withdrawal as the trigger of creep in the 1990s. Recently available groundwater extraction data (1977–2019) could more directly and consistently link groundwater withdrawal to accelerated creep in the 1990s. Twenty years (1999–2019) of precise displacement measurements could also reveal significant spatial and temporal links between slip rate changes and patterns of groundwater extraction. Our analysis shows that greater rates of vertical displacement are related to the timing of faster extraction rates. Variations in slip rates between the northern and southern measurement sites are primarily due to regional differences in groundwater extraction, which are influenced by differences in the implementation of water extraction reduction regulations. Proximity to the key source of groundwater recharge (Laguna Lake) is also an influencing factor. Although there are many unknowns inherent to this type of study, continued depressurization could induce static stress changes that could modulate the timescale of earthquake occurrence due to the natural course of stress loading driven by regional tectonics. The current and potential effects of continued depressurization in the areas with high slip rates and surrounding regions are paramount considerations in crafting and implementing tighter and extended groundwater extraction regulations.

/pdf/spatial-and-temporal-variation-of-aseismic-creep-along-the-203t9nky.pdf

Y Kinugasa

Papers

Magnetostratigraphy of Plio-Pleistocene sediments in a 1700-m core from Osaka Bay, southwestern Japan and short geomagnetic events in the middle Matuyama and early Brunhes chrons

Spatial and temporal variation of aseismic creep along the dilational jog of the West Valley Fault, Philippines: Hazard implications