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Bansal, M.
- K-Ar and Rb-Sr Ages of Cretaceous Glauconites from Jaisalmer Basin, Rajasthan
Authors
1 Geochemistry Division, KDM Institute of Petroleum Exploration, Oil and Natural Gas Corporation Ltd., Dehra Dun - 248 195, IN
2 Regional Chemical Laboratory, ERBC, ONGC, Sibsagar, Assam - 785 640, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 56, No 1 (2000), Pagination: 15-25Abstract
The importance of dating glauconites is that they are formed under low sedimentation rates connected with marine transgression and are commonly associated with unconformities and other stratigraphic breaks. This paper presents the first quantitative age estimation of glauconite samples separated from subsurface cores of Goru and Pariwar Formations of Jaisalmer basin, Rajasthan, India. SEM studies, X-ray diffraction patterns and high K2O content (6.8 to 7.4%) of these samples indicate that they are highly evolved and are ideal for isotopic dating.The Rb-Sr age of 108 ± 5 Ma and average K-Ar age of 103 ± 3 Ma obtained for the gtauconites from the Goru Formation are indistinguishable within error and agree with their biostratigraphic age. Glauconites from the upper most part of the Pariwar Formation give an average K-Ar age of 106 ± 3 Ma (early Albian), which is slightly lower than their biostratigraphic age.
Keywords
Geochronology, Glauconite, Goru and Pariwar Formations, Jaisalmer Basin, Rajasthan.
- An Echocardiographic Study in Patients with Non Haemorrhagic Cerebral Infarction to Find Cardiac Abnormalities
Authors
1 Medicine Unit 4 Guru Nanak Dev Hospital Govt. Medical College Amritsar, Punjab, IN
Source
International Journal of Medical and Dental Sciences, Vol 5, No 2 (2016), Pagination: 1171-1177Abstract
Background:Strokes are a major cause of morbidity and mortality worldwide. Majority are due to ischemic cerebral infarction. Ischemia may result from occlusion of blood vessels due to a disease process intrinsic to carotid and intracranial vessels or may relate to coexisting heart diseases, predisposing to embolic phenomenon.Objective: Echocardiographic study in patients with cerebrovascular accident, confirmed to be of non hemorrhagic nature on CT scan/MRI, for evidence of potential cardiac abnormalities as a predisposing cause for the vascular event.
Material and Methods: An observational study was conducted in department of medicine, GNDH, Amritsar. 50 patients of ischemic stroke were taken and 2D transthoracic echocardiography was done to find potential cardioembolic abnormalities.
Results: 76% of patients had echocardiographic abnormalities and 42% had potential cardioembolic abnormalities, out of which most common were ventricular wall hypokinesia, calcific aortic valve, rheumatic heart disease and dilated cardiomyopathy. The prevalence was almost similar in different age groups and both the sexes.
Conclusion: Prevalence of potential cardioembolic abnormalities is high (42%) in ischemic stroke patients and 2D echocardiography is therefore recommended in the management and secondary prevention of cardioembolic stroke, which has a higher mortality and more chances of recurrence than atherothrombotic type of ischemic stroke.
Keywords
Stroke, Echocardiography, Potential Cardioembolic Abnormalities, Cardioembolic Stroke.Full Text
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