scholarly journals 1990 SYMPOSIUM "NEW AGE DETERMINATIONS IN THE ATLANTIC PROVINCES" WOLFVILLE, NOVA SCOTIA; 1990 COLLOQUIUM "CURRENT RESEARCH IN THE ATLANTIC PROVINCES" WOLFVILLE, NOVA SCOTIA

10.4138/1700 ◽  
1990 ◽  
Vol 26 (2) ◽  
Author(s):  
Atlantic Geoscience Society
Keyword(s):  
Nova Scotia ◽  
New Age ◽  
Age Determinations

Pre-Katangan geochronology of Zambia and adjacent parts of Central Africa

1968 ◽  
Vol 5 (3) ◽  
pp. 621-628 ◽  
Author(s):  
J. R. Vail ◽  
N. J. Snelling ◽  
D. C. Rex
Keyword(s):  
Lake Tanganyika ◽  
Central Africa ◽  
New Age ◽  
Orogenic Belt ◽  
Eastern Africa ◽  
Sedimentary Sequence ◽  
Precambrian Rocks ◽  
Late Precambrian ◽  
Orogenic Belts ◽  
Age Determinations

The significance of new age determinations on pre-Katangan (Late Precambrian) rocks and minerals from Zambia and adjacent parts of Tanzania and Rhodesia is discussed. In northwestern Rhodesia, the Lomagundi-Piriwiri sediments were deposited between 2500 and 2000 m.y. ago and were folded along meridional trends at circa 1940 m.y. A later episode of folding and metamorphism along similar trends occurred about 1700 m.y. ago, but only affected the western part of the sedimentary sequence (the Piriwiri Series). This latter date is comparable to that which appears to characterize the Tumbide trend, a N- to NE-trending fold system, in Zambia.In Zambia the Tumbide trend is the oldest tectonic episode preserved in the basement and is found only in isolated blocks and cores into which later tectonisms have not penetrated. The dominant pre-Katangan tectonism is represented by the NE to ENE Irumide trend. Such tectonic trends are particularly well developed in the Irumide Orogenic Belt of northern Zambia and adjacent Tanzania. Age determinations set a younger limit of circa 900 m.y. to this trend and the existence of an Irumide Cycle between about 1600 and 900 m.y. is suggested. The possibility that the relatively unmetamorphosed sediments of the Upper Plateau Series and Abercorn Sandstones at the southern end of Lake Tanganyika, the Mafingi Series of northern Malawi, and the Konse Series of Tanzania, represent near-contemporaneous platform deposition associated with the Irumide belt is considered.From this and other recent studies the distribution of orogenic belts in central and eastern Africa can be revised and a number of features of their pattern and inter-relationships noted.

A New Age of Projects

2019 ◽  
pp. 197-228
Author(s):  
Owen Stanwood
Keyword(s):  
South Carolina ◽  
Nova Scotia ◽  
New Age ◽  
Religious Toleration ◽  
Age Of Enlightenment

The final chapter examines a new push to create Huguenot colonies in the era of the Seven Years’ War. The drama began back in France, where Protestants and others started a campaign for religious toleration. One plank in this campaign was for Huguenots to threaten to leave, and they began to negotiate with the British to do just that, envisioning colonies in places like Nova Scotia, Florida, and Minorca. The realization of the plan came through the efforts of Jean-Louis Gibert, a Protestant minister who became the founder of New Bordeaux in South Carolina. This colonial vision represented a renewal of themes from the first years of the Refuge. It was driven by desires to make silk and wine as well as the push for religious toleration in France. Thus the Huguenots adapted their old program to an age of Enlightenment.

The Precambrian geochronology of Rajasthan and Bundelkhand, northern India

1970 ◽  
Vol 7 (1) ◽  
pp. 91-110 ◽  
Author(s):  
A. R. Crawford
Keyword(s):  
Field Studies ◽  
New Age ◽  
Peninsular India ◽  
Northern India ◽  
Gneiss Complex ◽  
Granitic Intrusion ◽  
Age Determinations

Many new age determinations are reported for the Precambrian of Rajasthan and Bundelkhand in northern peninsular India. All are by Rb–Sr and mostly from total-rock analyses. They show that the oldest rocks in the area are undated sediments intruded by the Bundelkhand and Berach Granites, dated at about 2550 m.y. The overlying Aravalli System was intruded by granites dated at between 1900 and 2100 m.y., and is succeeded by the Delhi System, which was intruded by granite dated at 1650 m.y. Other granitic intrusion at 950–1000 m.y. was followed by repeated pegmatitic intrusion. The Banded Gneiss Complex of Rajasthan contains components of ages varying from at least 2000 m.y. to less than 1000 m.y. Nepheline-syenites at Kishangarh have an age of 1490 ± 150 m.y., but a biotite in an inclusion gives 970 m.y., which is the age of the Newania carbonatite.These determinations show that the Precambrian sequence in Rajasthan is much older than previously suggested. They confirm the antiquity of the Bundelkhand–Berach craton suggested by field studies, denying its derivation from Aravalli System rocks by granitization.

NEW AGE DETERMINATIONS BY THE LEAD METHOD

1954 ◽  
Vol 60 (3) ◽  
pp. 511-520 ◽  
Author(s):  
J. Laurence Kulp ◽  
George L. Bate ◽  
Bruno J. Giletti
Keyword(s):  
New Age ◽  
Age Determinations

Early Carboniferous deformation and mineralization in the Cobequid shear zone, Nova Scotia: an 40Ar/39Ar geochronology study

2004 ◽  
Vol 41 (12) ◽  
pp. 1425-1436 ◽  
Author(s):  
Georgia Pe-Piper ◽  
Peter H Reynolds ◽  
Joe Nearing ◽  
David JW Piper
Keyword(s):  
Nova Scotia ◽  
Shear Zone ◽  
Hydrothermal Alteration ◽  
Early Carboniferous ◽  
Fault Zones ◽  
Igneous Rocks ◽  
Pluton Emplacement ◽  
History Of ◽  
Temperature Shear ◽  
Age Determinations

Latest Devonian to Early Carboniferous igneous rocks along the Cobequid shear zone of central Nova Scotia record a complex history of intrusion, volcanism, deformation, and hydrothermal alteration. Twenty new 40Ar/39Ar age determinations have been made on biotite and hornblende separates from rocks that constrain these events. The mafic plutons of the Cobequid shear zone are synchronous with the previously dated granitoid plutons (363–355 ± 4 Ma), with the exception of the younger Folly Lake gabbro (355–350 ± 4 Ma). High temperature shear deformation continued along the Cobequid shear zone during this entire period of pluton emplacement. Several samples from mylonitic and hydrothermally altered rocks with dates ca. 340 Ma indicate renewed movement along the Cobequid shear zone at this time, accompanied by minor magmatism. Younger ∼330–320 Ma ages reflect final movement along the Rockland Brook fault resulting in mid-Namurian uplift of the Cobequid Highlands. Following this regional Alleghenian event, there was no significant motion on the northern faults of the Cobequid shear zone and deformation moved southward to the Cobequid fault and its continuation in the Hollow and Chedabucto fault zones. Hydrothermal alteration, probably driven by a mid-crustal gabbro heat source, was widespread along the Cobequid and Rockland Brook faults in the early Carboniferous, resulting in albitization, potassic alteration, and iron mineralization.

New Dates for the Solutrean and Magdalenian of Cantabrian Spain: El Miron and La Riera Caves

Radiocarbon ◽  
2018 ◽  
Vol 60 (3) ◽  
pp. 1013-1016 ◽  
Author(s):  
Lawrence G Straus ◽  
Manuel R González Morales
Keyword(s):  
New Age ◽  
Paleolithic Site ◽  
Rock Wall ◽  
Age Determinations

ABSTRACTThis sixth date list for the prehistoric site of El Mirón Cave (Cantabria, Spain) reports on new age determinations for the earliest and last Solutrean occupations (20.4 and 18.0 14C kyr BP) and for a Lower/Initial Magdalenian level with a possible rock wall (16.75 14C kyr BP). The site has now been dated by 92 radiocarbon (14C) assays. In addition, to help resolve inconsistencies in the 14C chronology of La Riera Cave (Asturias)—the first Paleolithic site in Spain to be extensively 14C-dated back in the 1970s—two AMS assays were done on bones from the Lower and Upper Magdalenian collections (15.1 and 13.5 14C kyr BP).

New age controls on the tephrochronology of the southernmost Andean Southern Volcanic Zone, Chile

2018 ◽  
Vol 91 (1) ◽  
pp. 250-264 ◽  
Author(s):  
DJ Weller ◽  
ME de Porras ◽  
A Maldonado ◽  
C Méndez ◽  
CR Stern
Keyword(s):  
Late Glacial ◽  
New Age ◽  
Explosive Eruptions ◽  
Volcanic Zone ◽  
Radiocarbon Age ◽  
Southern Volcanic Zone ◽  
Tephra Layers ◽  
Andean Southern Volcanic Zone ◽  
Lake Cores ◽  
Age Determinations

AbstractThe chronology of over 50 tephra layers preserved in a lake sediment core from Laguna La Trapananda (LLT) in the southern portion of the Andean Southern Volcanic Zone (SSVZ), Chile, is constrained by new radiocarbon age determinations, which span the period from late Pleistocene glacial retreat to the late Holocene. The tephra are correlative with tephra previously described from other lake cores in the region and are attributed to explosive eruptions of the SSVZ volcanoes Mentolat, Hudson, Macá, and potentially Cay. The new age determinations are used to estimate the ages of the >50 tephra in the LLT core, as well as those from the other previously described lake cores in the area, by a Bayesian statistical method. The results constrain the frequency of explosive eruptions of the volcanic centers in the southernmost SSVZ. They indicate that there was essentially no increase in the rate of eruptions from late-glacial to recent times due to deglaciation. They also provide isochrones used to constrain the depositional histories of the small lacustrine systems within which they were deposited and they provide a tephrochronologic tool for other paleoclimatic, paleoecologic, archaeologic and tephrochronologic studies in central Patagonia.

ABSOLUTE AGE OF THE FISSET BROOK FORMATION AND THE DEVONIAN-MISSISSIPPIAN BOUNDARY, CAPE BRETON ISLAND, NOVA SCOTIA

1964 ◽  
Vol 1 (3) ◽  
pp. 159-166 ◽  
Author(s):  
R. F. Cormier ◽  
A. M. Kelly
Keyword(s):  
Nova Scotia ◽  
Volcanic Rocks ◽  
Age Determination ◽  
Cape Breton Island ◽  
Rock Samples ◽  
Cape Breton ◽  
Absolute Age ◽  
Age Determinations ◽  
Good Agreement

The Fisset Brook formation of sedimentary and volcanic rocks crops out in the Cheticamp area of Cape Breton Island, Nova Scotia. Its stratigraphic age has been determined as earliest Mississippian using spores contained in the sedimentary members. A rubidium–strontium age determination using whole-rock samples of the volcanic members has yielded an age of 349 ± 15 million years. This is in good agreement with age determinations elsewhere for the Devonian–Mississippian boundary. Similar rocks exposed to the east of Lake Ainslie, some thirty miles to the southwest, give an identical age, 348 ± 20 million years. These rocks are clearly correlative with the Fisset Brook formation. Mixed sedimentary and volcanic rocks in the Cape St. Lawrence area, some thirty miles to the northeast of Fisset Brook, appear to be significantly older, 462 ± 25 million years, and should be considered tentatively as Ordovician in age.

Sign in / Sign up

Export Citation Format

Share Document