عنوان

Himalaya gneiss dome formation, focused radiogenic heating in southern Madagascar, and fertilization of the Neoproterozoic ocean by mantle-derived phosphorus

شماره

TL2jz9898c

زبان متن نوشتاري يا گفتاري و مانند آن

انگلیسی

عنوان اصلي

Himalaya gneiss dome formation, focused radiogenic heating in southern Madagascar, and fertilization of the Neoproterozoic ocean by mantle-derived phosphorus

نام عام مواد

[Thesis]

نام نخستين پديدآور

Horton, Forrest Miller

نام ساير پديدآوران

Hacker, Bradley

نام ناشر، پخش کننده و غيره

UC Santa Barbara

تاریخ نشرو بخش و غیره

2015

کسي که مدرک را اعطا کرده

UC Santa Barbara

امتياز متن

2015

متن يادداشت

(I) Geochronology, thermochronology, and structural observations across Gianbul gneiss dome provide insight about the exhumation of middle crust in the India-Asia collision zone: Doming (1) initiated during the early stages of extension; (2) was driven by a positive feedback among dehydration melting, buoyancy, and decompression; and (3) culminated with the injection of anatectic melts into the upper levels of the dome. The dome was subsequently exhumed as part of a footwall block beneath a brittle normal fault.(II) Focused internal heating led to melting, metamorphism, and crustal weakening during the Neoproterozoic continent-continent collision between East and West Gondwana. Numerical models based on chronologic and thermal constraints across southern Madagascar indicate that radioactive decay of thorium was the principal heat source responsible for regional metamorphism at temperatures >900° C in the middle to lower crust. (III) The Neoproterozoic era was punctuated by profound tectonic, evolutionary, and environmental change. Biologic and climatic conditions may have been especially sensitive to fluxes of phosphorus (P) from the weathering of continental crust. Large igneous provinces-containing abundant P and highly susceptible to chemical weathering-occurred regularly during the breakup of the Rodinia supercontinent. An estimated bioavailable P flux to the ocean from the weathering of basalt peaked at ~720 Ma, immediately prior to rapid biologic diversification and the Sturtian glaciation; I postulate that the burial of organic carbon that resulted from this unprecedented P flux helped facilitate glaciation and triggered the oxidation of the ocean-atmosphere system.

مستند نام اشخاص تاييد نشده

Horton, Forrest Miller

مستند نام اشخاص تاييد نشده

Hacker, Bradley

مستند نام تنالگان تاييد نشده

UC Santa Barbara

نام الکترونيکي

فرمت انتشار

p

نوع ماده

[Thesis]

کد کاربرگه

276903

سطح دسترسي

a

تكميل شده

Y