K-Ar ages of dikes in Northeast Japan.
نویسندگان
چکیده
منابع مشابه
TABLE 1 K - Ar Ages for Samples from Tasmanian Regions
Sixteen new K-Ar dates are presented from Tasmanian and Bass Basin basalts, more than doubling the previously published number. Eight volcanic regions are described, based on boundaries established on the range of the basalt types contained in each geographic region. Volcanism occurred within the span from Eocene to Miocene (47 to 13+ Ma), but mainly within the time range Middle Eocene to Early...
متن کاملK-Ar ages of Pleistocene lava dams in the Grand Canyon in Arizona.
At least 13 times during the Pleistocene Epoch lava flowed into the inner gorge of the Grand Canyon and formed lava dams, as high as 600 m, that temporarily blocked the flow of the Colorado River. K-Ar ages on these lava dams indicate that the seven youngest formed within a short period of time between about 0.6 and 0.4 mega-annum (Ma). The physiography of the lava dam remnants within the canyo...
متن کاملAr/Ar ages of CAMP in North America: Implications for the Triassic–Jurassic boundary and the K decay constant bias
Article history: The Central Atlantic magma Received 12 July 2008 Accepted 13 December 2008 Available online 13 January 2009
متن کاملNEW K-Ar ISOTOPIC AGES OF EPITHERMAL ALTERATION FROM THE TOODOGGONE RIVER AREA, BRITISH COLUMBIA
This report presents three new potassium-argon isotopic age determinations of minerals associated with epithermal alteration from the Toodoggone district, north-central British Columbia. The Toodoggone area has received extensive exploration attention over the past 10 years. In addition to a former goldsilver producer (Baker mine), the district contains a major new gold-silver mine in developme...
متن کاملAr-ar Impact Ages of Shocked Ll Chondrites
Introduction: Due to the relatively low closure temperature of feldspar, Ar-Ar ages of shocked meteorites typically record the age of an impact, not the formation age. Ar-Ar dating of lunar rocks has shown an increase in the impact rate around 3.9Ga [1], and many eucrites [2] and H chondrites [3] give similar ages, but with a larger spread than in the lunar case. Although only a small number of...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: GEOCHEMICAL JOURNAL
سال: 1983
ISSN: 0016-7002
DOI: 10.2343/geochemj.17.269