Evolution of the Taebaeksan Basin, Korea: I, early Paleozoic sedimentation in an epeiric sea and break-up of the Sino-Korean Craton from Gondwana

Island Arc ◽  
2018 ◽  
Vol 28 (1) ◽  
pp. e12275 ◽  
Author(s):  
Duck K. Choi
Keyword(s):  
Early Paleozoic ◽  
Taebaeksan Basin ◽  
Epeiric Sea ◽  
Break Up

U-Pb detrital zircon ages of Cambrian−Ordovician sandstones from the Taebaeksan Basin, Korea: Provenance variability in platform shelf sequences and paleogeographic implications

2020 ◽  
Author(s):  
Moonsup Cho ◽  
Wonseok Cheong ◽  
W.G. Ernst ◽  
Yoonsup Kim ◽  
Keewook Yi
Keyword(s):  
Distribution Patterns ◽  
Isotopic Signature ◽  
Detrital Zircons ◽  
Data Sets ◽  
Early Paleozoic ◽  
Fine Grained ◽  
Taebaeksan Basin ◽  
Double Peaks ◽  
The North ◽  
Detrital Zircon Ages

The early Paleozoic paleogeography of East Gondwanan terranes, including the North China Craton (NCC), is contentious, primarily reflecting the paucity of integrated geochronological, biogeographic, and tectonic data sets. Our new sensitive high-resolution ion microprobe data from 14 sandstones of the Taebaeksan Basin, Korea, indicate that its platform shelf sequences, typified by trilobite faunal assemblages diagnostic of the NCC, record the vestige of coeval arc magmatism. Detrital zircons analyzed from the sandstones yielded Eoarchean to Early Ordovician ages, which define three distinct types of distribution patterns characterized by: (1) double peaks at ca. 1.85 Ga and 2.50 Ga diagnostic of basement rocks in the NCC; (2) minor peaks at ca. 1.75, 1.6, and 1.2−1.1 Ga in addition to double peaks; and finally (3) a scattered array of late Paleoproterozoic to Neoproterozoic zircons lacking double peaks. The marked contrasts among the three types reflect significant changes in provenance, most likely linked to variations in paleo-water depths during the “Sauk” transgression. Longshore- or onshore-directed currents, associated with an increase in water depth, apparently brought outboard oceanic detritus and benthic trilobites into the relatively flat outer shelf of the Taebaeksan Basin. As a result, fine-grained sandstones received a large amount of detritus from distal sources, yielding mixed signatures in zircon age patterns and trilobite assemblages. Excluding the basal sandstone-conglomerate unit, five siliciclastic formations contain syndepositional zircon populations, and their weighted mean 206Pb/238U ages decrease upsection from 512 ± 5 Ma to 483 ± 2 Ma, indicating a sedimentary influx from contemporaneous volcanic activity. In conjunction with arc-related bulk-rock geochemistry and juvenile Nd isotopic signature, early Paleozoic detrital zircons likely represent the first-cycle detritus supplied for ∼30 m.y. from the proto-Japan arc that initially formed at ca. 520 Ma. Together with the occurrence of ca. 700−500 Ma detrital Pacific Gondwana zircons in fine-grained sandstones, Paleozoic arc-sourced detritus suggests that the Korean Peninsula was paleogeographically linked to an ancient convergent margin, perhaps extending from the Terra Australis orogen.

Epeiric Sea Formation on Neoproterozoic Supercontinent Break-up: A Distinctive Signature in Coastal Storm Bed Amalgamation

2004 ◽  
Vol 7 (2) ◽  
pp. 313-322 ◽  
Author(s):  
Subir Sarkar ◽  
Patrick G. Eriksson ◽  
Snehasis Chakraborty
Keyword(s):  
Epeiric Sea ◽  
Break Up

Variations in Surface Textures of Quartz Sand using Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 494-495
Author(s):  
Eugene J. Amaral
Keyword(s):  
Electron Microscopy ◽  
Glass Industry ◽  
Glass Slide ◽  
Distilled Water ◽  
Early Paleozoic ◽  
Secondary Effects ◽  
Surface Textures ◽  
High Silica ◽  
Sand Deposit ◽  
The U.S

Examination of sand grain surfaces from early Paleozoic sandstones by electron microscopy reveals a variety of secondary effects caused by rock-forming processes after final deposition of the sand. Detailed studies were conducted on both coarse (≥0.71mm) and fine (=0.25mm) fractions of St. Peter Sandstone, a widespread sand deposit underlying much of the U.S. Central Interior and used in the glass industry because of its remarkably high silica purity.The very friable sandstone was disaggregated and sieved to obtain the two size fractions, and then cleaned by boiling in HCl to remove any iron impurities and rinsed in distilled water. The sand grains were then partially embedded by sprinkling them onto a glass slide coated with a thin tacky layer of latex. Direct platinum shadowed carbon replicas were made of the exposed sand grain surfaces, and were separated by dissolution of the silica in HF acid.

The calamity of family break-up

Nature ◽  
1998 ◽  
Author(s):  
Henry Gee
Keyword(s):  
Break Up

Why No Break-Up – So Far?

2007 ◽  
Vol 60 (First Serie (1) ◽  
pp. 94-114
Author(s):  
Bob Tait
Keyword(s):  
Break Up
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