Early Cenozoic resetting of potassium–argon dates and geothermal history of north Okanagan area, British Columbia

1981 ◽  
Vol 18 (8) ◽  
pp. 1310-1319 ◽  
Author(s):  
Wm. H. Mathews

Unmetamorphosed Early Eocene sediments and volcanic rocks of the Trinity Hills and Enderby Cliffs yield K–Ar dates of 42–49 Ma. These overlie high-grade gneisses yielding K–Ar ages on biotites, muscovites, and hornblende ranging from 47 to 60 Ma. The Eocene sediments and volcanics rest nearby on low-grade phyllites, greenstones, and schists yielding dates from 83 to 155 Ma. The gneiss dates are regarded as reset by some Late Cretaceous to earliest Cenozoic thermal event that did not affect, at least to the same degree, the nearby less metamorphosed basement rocks. A thermal history has been constructed to account for the decreasing apparent ages of biotite (assumed blocking temperature of 250 °C) with increasing depth below the sub-Eocene unconformity, for the greater ages of hornblende and muscovite in the same rocks (blocking temperatures of 500 and 350 °C), as well as for thermal changes associated with high vitrinite reflectance from coal at one site in the covering sediments. Very rapid stripping (something like 5 km in 12 Ma) is inferred for the areas of reset gneisses, but not for the schist areas, in early Cenozoic time.

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S121-S121
Author(s):  
Muhammad Masood Hassan ◽  
Tammey Naab ◽  
Ali Afsari

Abstract Objectives Low-grade papillary urothelial carcinoma (LGUC) has overall a preserved orderly appearance, minimal variability in architecture, and lack of significant cytologic atypia and mitotic activity without pleomorphism. A total of 53.8% of LGUC cases recur with 18.3% progression to high-grade UC. Even focal HGUC in LGUC can be a harbinger of progression. Accurate pathological interpretation is paramount in predicting recurrence and determining treatment. Methods A 63-year-old male with a past medical history of coronary artery disease, benign prostate hyperplasia, and obesity was referred to urology with a chief complaint of chronic hematuria. Cystoscopy with transurethral resection of bladder tumor was performed, which revealed mainly LGUC with focal high-grade-appearing UC. Results Histologic sections revealed papillary architecture with fused fronds, low-grade nuclear atypia, and scattered mitoses comprising 95% of the tissue submitted. No muscular wall invasion by carcinoma was seen. However, in one section, collections of large cells with well-defined cytoplasmic borders, multinucleation, and rare nuclear grooves were identified. The morphology raised the suspicion of a focal HGUC. Diffuse expression of CK20 and low Ki-67 proliferation index (1%) favored umbrella cells. Conclusion Our case reinforces the fact that sectioning can reveal foci, suspicious for HGUC, especially in urothelium. However, proper interpretation of morphology combined with the help of immunohistochemistry aids in accurate diagnosis, which is critical in determining proper clinical management of the patient.


1987 ◽  
Vol 24 (4) ◽  
pp. 813-825 ◽  
Author(s):  
Ronald Doig

The Churchill Province north of the Proterozoic Cape Smith volcanic fold belt of Quebec may be divided into two parts. The first is a broad antiform of migmatitic gneisses (Deception gneisses) extending north from the fold belt ~50 km to Sugluk Inlet. The second is a 20 km wide zone of high-grade metasedimentary rocks northwest of Sugluk Inlet. The Deception gneisses yield Rb–Sr isochron ages of 2600–2900 Ma and initial ratios of 0.701–0.703, showing that they are Archean basement to the Cape Smith Belt. The evidence that the basement rocks have been isoclinally refolded in the Proterozoic is clear at the contact with the fold belt. However, the gneisses also contain ubiquitous synclinal keels of metasiltstone with minor metapelite and marble that give isochron ages less than 2150 Ma. These ages, combined with low initial ratios of 0.7036, show that they are not part of the basement, as the average 87Sr/86Sr ratio for the basement rocks was about 0.718 at that time.The rocks west of Sugluk Inlet consist mainly of quartzo-feldspathic sediments, quartzites, para-amphibolites, marbles, and some pelite and iron formation. In contrast to the Proterozoic sediments in the Deception gneisses, these rocks yield dates of 3000–3200 Ma, with high initial ratios of 0.707–0.714. These initial ratios point to an age (or a provenance) much greater than that of the Archean Deception gneisses. The rocks of the Sugluk terrain are intruded by highly deformed sills of granitic rocks with ages of about 1830 Ma, demonstrating again the extent and severity of the Proterozoic overprint. The eastern margin of this possibly early Archean Sugluk block is a discontinuity in age, lithology, and geophysical character that could be a suture between two Archean cratons. It is not known if such a suturing event is of Archean age, or if it is related to the deformation of the Cape Smith Fold Belt.Models of evolution incorporating both the Cape Smith Belt and the Archean rocks to the north need to account for the internal structure of the fold belt, the continental affinity of many of the volcanic rocks, the continuity of basement around the eastern end of the belt, and the increase in metamorphism through the northern part of the belt into a broad area to the north. The Cape Smith volcanic rocks may have been extruded along a continental rift, parallel to a continental margin at Sugluk. Continental collison at Sugluk would have thrust the older and higher grade Sugluk rocks over the Deception gneisses, produced the broad Deception antiform, and displaced the Cape Smith rocks to the south in a series of north-dipping thrust slices.


2010 ◽  
Vol 47 (6) ◽  
pp. 927-940 ◽  
Author(s):  
J. V. Owen ◽  
R. Corney ◽  
J. Dostal ◽  
A. Vaughan

The Liscomb Complex comprises Late Devonian intrusive rocks (principally peraluminous granite) and medium- to high-grade metamorphic rocks (“gneisses”) that collectively are hosted by low-grade (greenschist facies) metasediments of the Cambro-Ordovician Meguma Group. The conventional view that these “gneisses” contain high-grade mineral assemblages and represent basement rocks has recently been challenged, and indeed, some of the rocks previously mapped as gneisses, particularly metapelites, have isotopic compositions resembling the Meguma Group. Amphibole-bearing enclaves in the Liscomb plutons, however, are isotopically distinct and in this regard resemble xenoliths of basement gneisses in the Popes Harbour lamprophyre dyke, south of the Liscomb area. Metasedimentary enclaves with Meguma isotopic signatures can contain garnets with unzoned cores (implying high temperatures) that host high-grade minerals (prismatic sillimanite, spinel, and (or) corundum) and are enclosed by retrograde-zoned rims. These features are interpreted here as having formed during and following the attainment of peak temperatures related to Liscomb magmatism. The amphibole-bearing meta-igneous rocks described here contain cummingtonite or hornblendic amphibole and occur as enclaves in granodioritic to tonalitic plutons. They are mineralogically, texturally, and isotopically distinct from Meguma metasediments and at least some of the plutonic rocks that enclose them, so remain the most likely candidate for basement rocks in the Liscomb Complex.


1997 ◽  
Vol 134 (5) ◽  
pp. 717-725 ◽  
Author(s):  
Z. CYMERMAN ◽  
M. A. J. PIASECKI ◽  
R. SESTON

In the Sudetes, seven distinct lithostratigraphic terranes exhibit a symmetric distribution. A central region of basinal/oceanic and ophiolitic rocks, the Central Sudetic terrane is bordered, respectively to the northwest and southeast, by the sialic Saxothuringian and Moldanubian terranes. These exhibit contrasting metasedimentary/metavolcanic successions and tectonic-metamorphic sequences, but both are characterized by Palaeozoic plutonism. These are in turn bordered (again respectively to the northwest and southeast) by the Lusatian and Moravian terranes, which are also sialic, but contain Cadomian granitoids and represent rifted and now widely separated fragments of Gondwana. Along the southwestern flank of the Sudetes, the Barrandian terrane, largely covered by younger sediments, extends to the southwestern margin of the Bohemian Massif. The Sowie Góry terrane forms a klippe of high grade gneisses tectonically emplaced on top of low-grade, sheared ophiolites of the Central Sudetic terrane. The Sowie Góry terrane exhibits a history of three distinct, probably multi-orogenic, regional metamorphic events: an early high-pressure granulite/eclogite metamorphism followed by medium- to low-pressure granulite, and in turn by amphibolite facies metamorphism. All the terrane boundaries are complex zones of ductile to brittle shearing, modified by later brittle movements. Some, such as the Leszczyniec shear zone, mark lines of old, pre-Variscan rift and suture zones, reactivated and overprinted during a series of Variscan ductile to brittle events of extensional shearing with related metamorphism and plutonism.


Author(s):  
Nisha Singla ◽  
Sarita Nibhoria ◽  
Kanwardeep Kaur Tiwana ◽  
Prince Gupta

Introduction: The ovaries are the primary female reproductive organs and endocrine glands. Ovarian carcinoma has often been called as the silent killer because the symptoms may develop so late that the chances of cure are very poor. According to World Health Organisation (WHO) ovarian tumours are classified based upon their most probable tissue of origin: surface epithelial (65%), germ cell (15%), sex cord-stromal (10%), metastases (5%) and miscellaneous. The malignant surface epithelial tumours are further classified by cell type into serous, mucinous, endometrioid, clear cell, brenner, seromucinous and undifferentiated carcinoma. The most widely used tumour marker in ovarian carcinoma is CA-125 which is considered as gold standard. Aim : To find the utility of serum CA-125 levels in histopathological variants of malignant surface epithelial tumours, degree of differentiation and their distribution according to clinical data pertaining to age, parity, history of use of oral contraceptive pills/ovulation inducing drugs and family history of carcinoma ovary/breast or colon. Materials and Methods: A prospective study (cohort study) was done at Guru Gobind Singh Medical College and Hospital, Faridkot over a period of 1.5 year (April 2017-oct 2018) on 50 ovarian masses which were diagnosed as ovarian carcinoma. Data was represented as frequencies and percentages for categorical variables and as means and standard deviations for continuous variables. Analysis was done using Statistical Package for Social Sciences (SPSS) v 20.0.0. Results: Serous carcinoma (80%) topped among all the histological variants. Serous high grade carcinoma was more common than serous low grade carcinoma. Maximum rise of serum CA-125 levels were seen in serous carcinoma. Among serous carcinomas, mean serum CA-125 levels were more in high grade serous carcinoma than low grade serous carcinoma and the results were statistically significant. conclusion: Serum CA-125 level is a great tool for diagnosis, follow-up and prognosis of ovarian carcinomas.


2019 ◽  
Author(s):  
Eiman Siddig Ahmed ◽  
Lubna S. Elnour ◽  
Rowa Hassan ◽  
Emmanuel Edwar Siddig ◽  
Mintu Elsa Chacko ◽  
...  

Abstract Objectives: Prostate cancer (PC) is common cancer worldwide. Several markers have been developed to differentiate between benign prostatic hyperplasia (BPH) from PC. A descriptive retrospective hospital-based study aimed at determining the expression of Cyclin D1 in BPH and PC. the study took place at different histopathology laboratories in Khartoum state, Sudan, from December 2016 to January 2019. Formalin-fixed paraffin-embedded blocks were sectioned and fixed in 3-aminopropyltriethoxysilane coated slides incubated into primary antibody for Cyclin D1. The assessment of immunoreactivity of Cyclin D1 of each section was done using the Gleason scoring system. Results: A total of 153 males’ prostate sections included in this study, of them, 120 (78.4%) were PC, and 33 (21.6%) were BPH. Their age ranged from 45 to 88 years, mean age was 66.19 ± 8.599. 142 (92.8%) did not have a family history of PC, while 11 (7.2%) patients reported having a family history. The Gleason scoring showed a total of 81 (52.9%) patients with high-grade and 39 (25.5%) with low-grade. 118 (97.5%) patients had PC showed positive results for Cyclin D1, while BPH was 3 (2.5%). P value < 0.001. Cyclin D1 staining was associated with high-grade Gleason score and perineural invasion, P value 0.001.


2015 ◽  
Vol 59 (1) ◽  
pp. 109-112 ◽  
Author(s):  
Shuanzeng Wei ◽  
Zhanyong Bing ◽  
Yuan Yao ◽  
Stephen R. Master ◽  
Prabodh Gupta

Objective: MicroRNAs (miRs) are short noncoding RNA molecules that posttranscriptionally modulate protein expression. There are distinct miR alterations characterizing urothelial cell carcinoma (UCC) of the urinary bladder. Study Design: In this study, we investigate the possibility of using miR as a noninvasive marker in the screening of UCC. The total RNA was extracted from 75 cytology specimens including bladder or renal washings and voided urines. Cases comprise UCC (21 high grade and 6 low grade), 25 normal controls and 23 cases with a history of UCC but negative at the time of testing (negative with a positive history). The expressions of miR-96, miR-182, miR-183, miR-200c, miR-21, miR-141 and miR-30b were determined using quantitative TaqMan real-time PCR. Results and Conclusion: This study shows that the level of miR-182 is higher in cytology specimens from high-grade UCC patients as compared to normal controls. Measuring miR-182 may provide a potential alternative or adjunct approach for screening high-grade UCC.


2016 ◽  
Vol 43 (2) ◽  
pp. 103 ◽  
Author(s):  
Deanne Van Rooyen ◽  
Sharon D. Carr

The Thor-Odin dome is a basement-cored tectonothermal culmination in southern British Columbia containing high-grade metamorphic rocks that were polydeformed in the Late Cretaceous to Eocene. The rocks south of the Thor-Odin dome that extend ca. 20 km to the Pinnacles culmination and Whatshan batholith comprise a heterogeneous tract of polydeformed medium- to high-grade metamorphic rocks and host the South Fosthall pluton near the base of the structural section. They lie in the footwall of the Columbia River fault (CRF) zone, a moderately east-dipping, ductile-brittle, normal fault that was active after ca. 55 Ma and reactivated periodically up to 30 Ma. This tract of rocks has been interpreted as a mid-crustal zone that was exhumed and cooled during Eocene extension or, alternatively, a mid-crustal channel that was bounded at the top by the CRF and was active during the Late Cretaceous to Eocene. However, the timing of metamorphism, deformation, anatexis in basement rocks, and intrusion of leucogranite plutons reveals that there are four tectonothermal domains within the tract that each experienced metamorphism, deformation and cooling at different times. These rocks record Cretaceous metamorphism and cooling in the upper structural levels and three stages of progressive metamorphism and penetrative deformation that migrated into deeper crustal levels in the Paleocene and Eocene producing a complex structural section that was exhumed in part due to motion on the Columbia River fault zone, and in part due to NE-directed transport over a basement ramp.RÉSUMÉLe dôme de Thor-Odin correspond à une culmination tectonothermique d’un noyau de socle dans le sud de la Colombie-Britannique renfermant des roches métamorphiques de haute intensité polydéformées entre le Crétacé supérieur et l’Éocène. Les roches au sud du dôme de Thor-Odin qui s’étendent sur environ 20 km jusqu’à la culmination des Pinnacles et du batholite de Whatshan sont constituées d’une bande hétérogène de roches polydéformées à faciès métamorphique d’intensité moyenne à élevée qui constitue l’encaissant du pluton de South Fosthall près de la base de la colonne structurale. Elles se trouvent dans l'éponte inférieure de la zone de faille de la rivière Columbia (CRF), une faille normale à pendage modéré vers l’est, ductile-fragile, qui a été active après 55 Ma environ et a été réactivée périodiquement jusqu'à 30 Ma. Cette bande de roches a été interprétée comme une zone de mi-croûte qui a été exhumée et a refroidi durant l’extension éocène ou alors comme un canal mi-crustal qui a été limité au sommet par la CRF, et qui a été actif de la fin du Crétacé jusqu’à l’Éocène. Toutefois, la chronologie du métamorphisme, de la déformation, de l’anatexie dans les roches du socle, et de l'intrusion de plutons de leucogranite, montre qu'il existe quatre domaines tectonothermiques pour chaque bande qui ont subit du métamorphisme, de la déformation et du refroidissement à différents moments. Ces roches exhibent un métamorphisme et un refroidissement crétacé dans les niveaux structuraux supérieurs et trois stades de métamorphisme progressif et de déformation pénétrative qui ont migré dans les niveaux crustaux profonds au Paléocène et à l’Eocène constituant ainsi une colonne structurale complexe qui a été exhumée en partie en raison du mouvement de la zone de faille de Columbia River, et en partie en raison du transport vers le N.-E. sur une rampe de socle.


2020 ◽  
pp. 289-311
Author(s):  
Warwick S. Board ◽  
Duncan F. McLeish ◽  
Charles J. Greig ◽  
Octavia E. Bath ◽  
Joel E. Ashburner ◽  
...  

Abstract The Brucejack intermediate-sulfidation epithermal Au-Ag deposit, located 65 km north of Stewart, BC, forms part of a well-mineralized, structurally controlled, north-south gossanous trend associated with Early Jurassic intrusions straddling the Late Triassic-Early Jurassic Stuhini-Hazelton Group unconformity in the Sulphurets mineral district. Mining of the deposit commenced in mid-2017 after a long history of exploration dating back to the 1880s. Mineralization is hosted in deformed Lower Jurassic island-arc volcanic rocks of the Hazelton Group exposed on the eastern limb of the Cretaceous McTagg anticlinorium. High-grade Au-Ag mineralization was formed from ~184 to 183 Ma in association with a telescoped, multipulsed magmatic-hydrothermal system beneath an active local volcanic center. Precious metal mineralization occurs as coarse aggregates of electrum and silver sulfosalts in steeply dipping, E- to SE-trending quartz-carbonate vein stockwork zones cutting low-grade intrusion-related phyllic alteration. Epithermal vein development is interpreted to have occurred during the waning stages of Early Jurassic sinistral transpression in a compressive arc environment, followed by a limited Cretaceous deformation overprint.


2012 ◽  
Vol 30 (3) ◽  
pp. 151-158 ◽  
Author(s):  
Lubna Khondker ◽  
Md Obaidur Rahman Shah ◽  
Md Shirajul Shirajul Islam Khan

Verruca or warts are common significant cause of cosmetic concern and frustration of the patient. Social activities may  be affected. Verruca are formed by benign proliferations of the skin and mucosa that are caused by infection with  Human papilloma virus (HPV). These viruses do not produce acute signs or symptoms but induce a slow, focal expansion of epithelial cells. There are 100 types of Human papilloma virus (HPV). The natural history of common warts is for most of them to spontaneously resolve. But lesions are sometime uncomfortable. Warts typically continue to increase in size and distribution and may become more resistant to treatment over time. A significant  proportion of women with genital HPV infection develops  low-grade cervical lesions. Most of these low-grade lesions regress spontaneously; one study suggests that  approximately 15 percent progress to high-grade cervical  lesions within two years. High-grade cervical lesions have  a strong malignant potential; one study found that about one-third of high-grade lesions progress to cancer within ten years. DOI: http://dx.doi.org/10.3329/jbcps.v30i3.12465 J Bangladesh Coll Phys Surg 2012; 30: 151-158


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