Allen West

6 Questions 16 Answers 0 Followers

Questions related from Allen West

Where to find elemental abundances in High-Ni cosmic dust?

I am looking for tables of elemental data (percentages of Fe, Ni, Co, Cu, etc.) for flake-like cometary dust particles like those shown below, but have not had much success finding the data. Can...

08 March 2024 1,955 0 View

Can anyone identify the origin of these Ni-Cr-Fe flakes?

These two Fe flakes are highly enriched in Ni and/or Cr. Other similar ones are composed of wustite with low oxygen. They were found in similar-aged end-glacial samples from four ocean cores in...

14 November 2023 9,325 0 View

Has anyone observed amorphous quartz associated with tectonic lamellae, i.e., that did not form during a high-pressure impact cratering event?

Amorphization of quartz is commonly associated with lamellae produced during an impact cratering event. Has anyone ever seen amorphous quartz closely associated with tectonic lamellae in...

06 March 2022 6,674 10 View

Can you help with using Universal stage for potentially shocked quartz?

Universal-stage experts: some advice please. I am analyzing a quartz grain with an apparent single set of lamellae. They are not parallel to the c-axis, based on crossed polars. How does one...

03 March 2021 8,108 0 View

Zircons: what are these cross-cutting lamellae?

Zircon experts -- please help. Most zircon grains display concentric growth zones that almost never cross-cut each other. These attached images show thin-sectioned zircons with sharply-defined,...

06 February 2021 7,295 8 View

Identifying chromite grains in volcanic material?

The attached images show Cr-and-Fe-rich grains in apparent volcanic rock. They appear melted rather than crystalline. Has anyone seen anything like them? If so, are they common or rare in volcanic...

19 April 2016 785 13 View