TY  - JOUR
A1  - Oetting, A.
A1  - Schmedemann, N.
A1  - Hiesinger, H.
A1  - van der Bogert, C. H.
T1  - Slopes of Lunar Crater Size‐Frequency Distributions at Copernican‐Aged Craters
Y1  - 2023-10-18
VL  - 128
IS  - 10
SP  - 
EP  - 
JF  - Journal of Geophysical Research: Planets
DO  - 10.1029/2023JE007816
PB  - 
N2  - <title xmlns:mml="http://www.w3.org/1998/Math/MathML">Abstract</title><p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en">Craters on the lunar surface can provide valuable information about the timing and sequence of surface‐forming processes on the Moon. A commonly used method for age determination is the analysis of the crater size‐frequency distribution (CSFD) to which a production function (PF) is fitted that represents the size‐frequency distribution of the impactors. However, the commonly used PF of Neukum (1983) is valid for crater diameters between 10 m and 300 km. Neukum et al. (2001, <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1007/978-94-017-1035-0_3">https://doi.org/10.1007/978-94-017-1035-0_3</ext-link>) revised the PF for crater diameters of 100 m–200 km. However, it is suggested to also be valid for the diameter range of 10 m–300 km as well. To assess whether we can extend a PF to craters ≤10 m in diameter, we investigated the slopes of the CSFDs of small craters formed on ejecta of young Copernican‐aged craters Giordano Bruno, Moore F, North Ray, and South Ray. A PF for smaller diameters would allow dating of young geological units, which are typically small, and would reduce the statistical error in age determinations, since smaller craters are more abundant. However, small craters are strongly influenced by geological factors, such as target properties, crater degradation, and secondary craters. For craters between 10 and 20 m we obtain a steeper CSFD slope than Neukum's proposed −3 slope (cumulative), whereas for craters ≤10 m the slope is about −3. We conclude that the PF of Neukum (1983) provides a reasonable CSFD slope for smaller craters, although it was not developed for this crater diameter range.</p>
N2  - Plain Language Summary: Since the formation of the Moon, impactors have randomly hit the lunar surface. Older areas have larger and more abundant craters compared to younger areas. This relationship allows the determination of relative ages for different surfaces. A mathematical function can be fitted to the number and size of craters. This function has a specific shape and can be used to date a surface. Frequently used functions are valid between crater diameters of 10 m and 300 km. Dating young geological units is only possible if the observed craters are <bold>≥</bold>10 m in diameter. Therefore, an extension of these functions to crater diameters ≤10 m would be beneficial. However, small craters are strongly influenced by geological factors, such as target properties, crater degradation, and secondary craters. We consider these influences in our investigation. To compare our results with previous findings, we look more closely at the slope of the function that results from the number and size of the craters. Generally, we find that one function fits well for craters ≤10 m, even though it was not designed for this diameter range. This allows a more robust age determination because small craters are more abundant, reducing the statistical error.</p>
N2  - Key Points: <list list-type="bullet"> <list-item> <p xml:lang="en">We studied small craters on young ejecta blankets to evaluate if the lunar production function (PF) is viable for craters ≤10 m</p></list-item> <list-item> <p xml:lang="en">The crater size‐frequency distributions (CSFDs) indicate that the PF can indeed be extended to crater diameters ≤10 m</p></list-item> <list-item> <p xml:lang="en">Our observed slopes of CSFDs at the studied Copernican‐aged craters are consistent with previous findings</p></list-item> </list> </p>
UR  - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11782
ER  -