Abstract I basically agree with the viewpoints of Shanmugam (2018) and Zavala (2019) who cited, refined and interpreted the definitions of hypopycnal flow, homopycnal flow and hyperpycnal flow. I appreciate two typical case studies of hyperpycnal flows induced by the Yellow River and Yangtze River, and the Gaoping River. The former is a normal type while the latter is catastrophic. They make up a complete knowledge about hyperpycnal flows and hyperpycnites. According to the interpretation of the word “hyperpycnal” from Greek to English, the “hypopycnal flow” should be “less density flow” or “lower density flow” (“���ܶ���”), the “homopycnal flow” should be “equal density flow” (“���ܶ���”), and the “hyperpycnal flow” should be “higher density flow” or “over density flow” (“���ܶ���” or “���ܶ���”). Some geologists called the “hypopycnal flow” as “������” (“abnormally light flow”) and called the “hyperpycnal flow” as “������” (“abnormally heavy flow”). There are at least more than 10 names or terms about the “density flows” and the “deposits of density flows”. It is a problem indeed. In addition, the density could be changed by salinity, temperature and pressure of water. Therefore, the term “density flow” may be problematic either. Another problem is that reliable and irrefutable identification markers of ancient hyperpycnites are lacking. We should observe the policy of “A hundred flowers blossom and a hundred schools of thought contend” to discuss these problems and to promote progress and development of hyperpycnal flows and hyperpycnites.
. Words of the Editor-in-Chief —— Some ideas about the comments and discussions of hyperpycnal flows and hyperpycnites[J]. , 2019, 8(3): 301-305.
. Words of the Editor-in-Chief —— Some ideas about the comments and discussions of hyperpycnal flows and hyperpycnites[J]. Journal of Palaeogeography, 2019, 8(3): 301-305.
Bates C.C.1953. Rational theory of delta formation. Bulletin of the American Association of Petroleum Geologists, 37(9):2119-2162.
[2]
Chiang, C.C., Yu, H.S.2008. Evidence of hyperpycnal flows at the head of the meandering Kaoping Canyon off SW Taiwan. Geo-Marine Letters 28: 161-169.
[3]
Deng X.Q., Fu J.H., Yao J.L., Pang J.L., Sun B.2011. Sedimentary facies of the Middle-Upper Triassic Yanchang Formation in Ordos Basin and breakthrough in petroleum exploration. Journal of Palaeogeography (Chinese Edition), 13(4): 443-455(in Chinese with English abstract).
[4]
Feng Z.Z.2018. Theoretical innovation can only be started from problem: Reply to comments of 3 review papers. China Terminology, 20(6): 47-49(in Chinese with English abstract).
[5]
Feng Z.Z., Bao H.P., Jia J.H., Wang Y.G., Deng X.Q.2013. Lithofacies palaeogeography as a guide to petroleum exploration. In: Feng, Z.Z. (Chief Editor) 2013. Sedimentology of China, Second Edition, Vol. 2, Chapter 30, 1760-1792(in Chinese with English preface and contents).
[6]
Liu J.T., Hsu R.T., Hung J.J., Chang Y.P., Wang Y.H., Rendle-Bühuring R.H., Lee C.L., Huh C.A., Yang R.J.2016. From the highest to the deeper: The Gaoping River—Gaoping Submarine Canyon dispersal system. Earth-Science Reviews, 153(2016)274-300.
[7]
Liu J.T., Wang Y.H., Yang R.J., Hsu R.T., Kao S.T., Lin H.L., Kuo F.H.2012. Cyclone-induced hyperpycnal turbidity currents. Journal of Geophysical Research, 117 CO4033, 1-12.
[8]
Shanmugam G.2018. The hyperpycnite problem. Journal of Palaeogeography. 7(3):197-238.
[9]
Shanmugam G.2019. Reply to discussions by Zavala (2019) and by Van Loon, Hüeneke, and Mulder (2019)on Shanmugam (2018). Journal of Palaeogeography. 8(3):
[10]
Van Loon A.J., Hüneke H., Mulder T.2019. The hyperpycnite problem: comment. Journal of Palaeogeography. 8(3):
[11]
Xi J.P.2016. Develop philosophy and social sciences with Chinese features. In: Xi Jinping, The Governance of China, II. Beijing: Foreign Language Press, pp. 366-377.
[12]
Yang R.C., Yin W., Fan A.P., Han Z.Z., Van Loon A.J.2017a. Fine-grained, lacustrine gravity-flow deposits and their hyper hydrocarbon significance in the Triassic Yanchang Formation in southern Ordos Basin. Journal of Palaeogeography (Chinese Edition), 19(5): 791-806 (in Chinese with English abstract).
[13]
Yang R.C., Jin Z.J., Van Loon A.J., Han Z.Z., Fan A.P.2017b. Climatic and tectonic controls of lacustrine hyperpycnite origination in the Late Triassic Ordos Basin, central China: Implications for unconventional petroleum development. AAPG Bulletin, 101(1):95-117.
[14]
Zavala C.2019. The new knowledge is written on sedimentary rocks — a comment on Shanmugam’s paper “The hyperpycnite problem”. Journal of Palaeogeography. 8(3):
[15]
Zavala, C., Pan, S.X.2018a. Hyperpycnal flows and hyperpycnites: Origin and distinctive characteristic. Lithologic Reservoirs, 30(1):1-27.
[16]
Zavala, C., Pan, S.X.2018b. Chinese version of “Hyperpycnal flows and hyperpycnites: Origin and distinctive characteristics”. Lithologic Reservoirs, 30(1):1-18 (in Chinese).
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