Type of resources
Contact for the resource
Detrital zircon age data, details of Expedition 362 samples . For more information see published report, https://doi.org/10.1016/j.epsl.2017.07.019 IODP Sites U1480–U1481, located on the Indian oceanic plate, east of the NinetyEast Ridge and west of the north Sumatran subduction margin Site U1480 ~ 3°2.0447'N 91°36.3481'E 4147.5 Site U1481 ~ 2°45.261'N 91°45.5771'E
Provided here are in-situ Si and O isotope compositions of Detrital Jack Hills and Lachlan Fold Belt zircons. These data formed the basis of the research published as: Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon, Trail et al., (2018), PNAS 115 (41), 10287-10292 The data are provided in a single Excel spreadsheet, with multiple tabs, which are as follows: 1. Sample description and analytical method summaries 2. Solution and laser-fluorination data for characterisation of the standards used in the Ion Probe measurement sessions 3. Ion Probe (In-situ) Si and O isotope data for the Lachlan Fold Belt and Duluth Gabbro zircons 4. Ion Probe (In-situ) Si and O isotope data for the detrital Jack Hills zircons, as well as 207Pb/206Pb age estimates 5. Raw Ion Probe Si and O isotope data for LFB samples 6. Raw Ion Probe Si and O isotope data for Jack Hills samples 7. Ion Probe (In-situ) Si isotope data for the Lachlan Fold Belt zircons (utilising O- hyperion source)
Isotope analysis data. Project details: The continental crust is our only archive of Earth history; not just of the crust itself but of the hydrosphere, atmosphere and biosphere, and of the deep Earth through its interactions with the crust. This archive, like the rock record itself, is incomplete and much effort is focused on interrogating the crust to gain a clearer and more complete picture of Earth history. The continental rock record is episodic with, for example, ages of igneous crystallization, metamorphism, continental margins, and seawater and atmospheric proxies distributed about a series of peaks and troughs that in part correspond with the cycle of supercontinent assembly and dispersal. At the core of the debate is what these well-established peaks of ages in the geological record represent and how they develop. The peaks of ages correspond with periods of global assembly of continents to form supercontinents. The project will address whether the peaks of ages are primary features associated with supercontinent assembly or break up, or they are they secondary features representing greater preservation potential at the times of supercontinent assembly. Our work will focus on the Rodinian supercontinent cycle, which extends from initiation of convergent plate interaction around 1.7 Ga, to continental collision at 1.1-1.0 Ga during the Grenville orogeny, to final breakup of the supercontinent by 0.54 Ga. Detrital zircons from sedimentary units throughout the supercontinent cycle provide a record of the magmatic activity for which the igneous rocks are often no longer preserved. We will determine (i) the ages ranges of magmatic activity preserved in the sedimentary rocks in the 600 Ma pre-collision phase, and (ii) how and when the distinctive Grenville peak of ages developed by comparing the zircon record from samples pre-, syn- and post- Rodinian supercontinent assembly with estimated volumes of magma and numbers of zircons produced during the same interval. This will differentiate primary generation processes from secondary processes, constraining when the dominant age peak developed, the tectonic processes that operated, and hence the method by which it developed. The wider implications of when the continental crust formed are considerable. Studies of continental growth continue to uncritically assume that the geological and isotopic record provide insight into processes of crust formation. Until it can be established whether the record is the outcome of generational or preservational processes, or a combination of both, then drawing conclusions on this fundamental question in the Earth Sciences are premature. If the record is a preservational record then this impacts on understanding continental growth through time and on secondary questions of how the crustal record is used to unravel the temporal evolution of the hydrosphere and biosphere, and the distribution of mineral deposits.
The dataset contains detrital zircon U-Pb ages from a large scale detrital provenance study of modern and recent sand and silt from the Chinese Loess Plateau (CLP) and its proposed sources in the Yellow River, its Tibetan headwaters, and the Taklamakan Desert, which lies upwind from the CLP. (NERC grant NE/I009248/1)