Geology is the way - Flute casts are structures produced by currents that scour scoop-shaped marks on the bottom of a basin (e.g. by turbidity currents) These ones are positive marks filled
![Close-up photographs of flute casts (1 to 6). (1) Flute casts at Site... | Download Scientific Diagram Close-up photographs of flute casts (1 to 6). (1) Flute casts at Site... | Download Scientific Diagram](https://www.researchgate.net/profile/Yoshiro-Ishihara/publication/298827964/figure/fig6/AS:349443917402113@1460325330249/Close-up-photographs-of-flute-casts-1-to-6-1-Flute-casts-at-Site-1-2-Flute-casts.png)
Close-up photographs of flute casts (1 to 6). (1) Flute casts at Site... | Download Scientific Diagram
![GC81V1P Paleocurrent Indicators: Flute Casts (Earthcache) in North West England, United Kingdom created by Team Microdot GC81V1P Paleocurrent Indicators: Flute Casts (Earthcache) in North West England, United Kingdom created by Team Microdot](https://img.geocaching.com/cache/large/8f18e5e5-3127-4ba0-9e3f-c54a1f9b71d5.png)
GC81V1P Paleocurrent Indicators: Flute Casts (Earthcache) in North West England, United Kingdom created by Team Microdot
![Mechanical and biological sole marks. A-flute casts; B-doubly ruffled... | Download Scientific Diagram Mechanical and biological sole marks. A-flute casts; B-doubly ruffled... | Download Scientific Diagram](https://www.researchgate.net/profile/Tomas-Fuksi/publication/319187759/figure/fig6/AS:631641303175239@1527606430813/Mechanical-and-biological-sole-marks-A-flute-casts-B-doubly-ruffled-groove-C-a-small.png)
Mechanical and biological sole marks. A-flute casts; B-doubly ruffled... | Download Scientific Diagram
![GC81V1P Paleocurrent Indicators: Flute Casts (Earthcache) in North West England, United Kingdom created by Team Microdot GC81V1P Paleocurrent Indicators: Flute Casts (Earthcache) in North West England, United Kingdom created by Team Microdot](https://img.geocaching.com/cache/large/ce6860e7-9f23-4007-bcf0-87d30fb93aa6.jpg)