scholarly journals Dendritic reidite from the Chesapeake Bay impact horizon, Ocean Drilling Program Site 1073 (offshore northeastern USA): A fingerprint of distal ejecta?

Geology ◽  
2020 ◽  
Author(s):  
Aaron J. Cavosie ◽  
Marc B. Biren ◽  
Kip V. Hodges ◽  
Jo-Anne Wartho ◽  
J. Wright Horton ◽  
...  
Keyword(s):  
High Pressure ◽  
Chesapeake Bay ◽  
Shock Compression ◽  
Polymorphic Transformation ◽  
Intermediate Phase ◽  
Ocean Drilling Program ◽  
Impact Ejecta ◽  
History Of ◽  
Formation Conditions ◽  
Experimental And Theoretical Studies

High-pressure minerals provide records of processes not normally preserved in Earth’s crust. Reidite, a quenchable polymorph of zircon, forms at pressures >20 GPa during shock compression. However, there is no broad consensus among empirical, experimental, and theoretical studies on the nature of the polymorphic transformation. Here we decipher a multistage history of reidite growth recorded in a zircon grain in distal impact ejecta (offshore northeastern United States) from the ca. 35 Ma Chesapeake Bay impact event which, remarkably, experienced near-complete conversion (89%) to reidite. The grain displays two distinctive reidite habits: (1) intersecting sets of planar lamellae that are dark in cathodoluminescence (CL); and (2) dendritic epitaxial overgrowths on the lamellae that are luminescent in CL. While the former is similar to that described in literature, the latter has not been previously reported. A two-stage growth model is proposed for reidite formation at >40 GPa in Chesapeake Bay impact ejecta: formation of lamellar reidite by shearing during shock compression, followed by dendrite growth, also at high pressure, via recrystallization. The dendritic reidite is interpreted to nucleate on lamellae and replace damaged zircon adjacent to lamellae, which may be amorphous ZrSiO4 or possibly an intermediate phase, all before quenching. These results provide new insights on the microstructural evolution of the highpressure polymorphic transformation over the microseconds-long interval of reidite stability during meteorite impact. Given the formation conditions, dendritic reidite may be a unique indicator of distal ejecta.

scholarly journals IODP Expedition 318: From Greenhouse to Icehouse at the Wilkes Land Antarctic Margin

2011 ◽  
Vol 12 ◽  
pp. 15-23 ◽  
Author(s):  
C. Escutia ◽  
H. Brinkhuis ◽  
A. Klaus ◽  
Keyword(s):  
Middle Eocene ◽  
Second Phase ◽  
Last Deglaciation ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program ◽  
Tectonic History ◽  
Wilkes Land ◽  
History Of

Integrated Ocean Drilling Program (IODP) Expedition 318, Wilkes Land Glacial History, drilled a transect of sites across the Wilkes Land margin of Antarctica to provide a long-term record of the sedimentary archives of Cenozoic Antarctic glaciation and its intimate relationships with global climatic and oceanographic change. The Wilkes Land drilling program was undertaken to constrain the age, nature, and paleoenvironment of the previously only seismically inferred glacial sequences. The expedition (January–March 2010) recovered ~2000 meters of high-quality middle Eocene–Holocene sediments from water depths between 400 m and 4000 m at four sites on the Wilkes Land rise (U1355, U1356, U1359, and U1361) and three sites on the Wilkes Land shelf (U1357, U1358, and U1360). <br><br> These records span ~53 million years of Antarctic history, and the various seismic units (WL-S4–WL-S9) have been successfully dated. The cores reveal the history of the Wilkes Land Antarctic margin from an ice-free “greenhouse” Antarctica, to the first cooling, to the onset and erosional consequences of the first glaciation and the subsequent dynamics of the waxing and waning ice sheets, all the way to thick, unprecedented "tree ring style" records with seasonal resolution of the last deglaciation that began ~10,000 y ago. The cores also reveal details of the tectonic history of the Australo-Antarctic Gulf from 53 Ma, portraying the onset of the second phase of rifting between Australia and Antarctica, to ever-subsiding margins and deepening, to the present continental and ever-widening ocean/continent configuration. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.12.02.2011" target="_blank">10.2204/iodp.sd.12.02.2011</a>

scholarly journals 3. Equation-of-State Measurements by Laser-Induced Shock Compression: 3.1 High-Pressure Physics Using Laser-Driven Shocks

2004 ◽  
Vol 80 (6) ◽  
pp. 438-441
Author(s):  
Michel KOENIG ◽  
Alessandra BENUZZI-MOUNAIX ◽  
Emeric HENRY ◽  
Gaël HUSER ◽  
Dimitri BATANI
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Shock Compression

Panfish

2019 ◽  
pp. 104-118
Author(s):  
Bernard L. Herman
Keyword(s):  
Oral History ◽  
Chesapeake Bay ◽  
Small Fish ◽  
Documentary Evidence ◽  
Eastern Shore ◽  
History Of ◽  
History Of Place

Panfish on the Eastern Shore of Virginia simply refers to a host of small fish that include spot, croaker, sand mullet, jumping mullet, hogfish, swelling toads, and more. The idea of the panfish relies on four characteristics: size (they fit whole into a skillet), status (they tend to be associated with less desirable fish—often linked to qualities of oiliness or boniness), procurement (although netted, seined, or trapped commercially, panfish are commonly associated with amateur angling), and preparation (largely fried). In essence, panfish, spot in particular, are notable for their everydayness, remarkable only in the moments of their absence. The spot's culinary associations are tightly knit into the history of place. This chapter explores that connection through documentary evidence, oral history, local foodways, and the Chesapeake Bay fishery.

Review of Deep-Ocean High-Pressure Simulation Systems

2020 ◽  
Vol 54 (3) ◽  
pp. 68-84
Author(s):  
Wentao Song ◽  
Weicheng Cui
Keyword(s):  
High Pressure ◽  
Coming Out ◽  
Deep Sea ◽  
Mathematical Theory ◽  
Deep Ocean ◽  
Cold Isostatic Pressing ◽  
Future Design ◽  
Stress Coefficient ◽  
History Of ◽  
Simulation Systems

AbstractDeep-sea technology and equipment are required to explore the oceans and utilize ocean resources in the 21st century. Deep-ocean simulation systems (DOSs) play an essential role in the development of deep-sea equipment. This paper gives a detailed overview of deep-ocean high-pressure simulation systems (DOHPSs) worldwide. First, the history of DOS is introduced, and then the primary available equipment, particularly coming out of China, is described. Next, the new concept of the cold isostatic pressing (CIP) chamber and its technology and equipment are reviewed. Then, the basic mathematical theory for the design of pressure chambers is introduced to illustrate the limitations of the traditional monobloc chamber. To easily understand the pre-stressed wire-wound (PSWW) design, the pre-stress coefficient is introduced in theoretical analysis. Some valuable researches of PSWW are presented. Finally, the sealing design of DOS, especially tooth-locked quick-actuating closures (TLQAC), is discussed. The paper aims to inspire readers to develop innovative ideas about the future design of DOS.

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