Raindrop Impressions Research Articles

Rain-drop Impressions?

ABSTRACT Small circular pit-like depressions mostly in fine-grain sediments have long been interpreted as rain-drop impressions. As early as 1850, however, Desor expressed opinion that most, if not all, supposed rain impressions are made by air bubbles rising through sediments. From experimental studies, Twenhofel (1921) reached the opinion that impressions which have been ascribed to falling rain are of such origin in only a small percentage of cases. Twenhofel (1932) also found it extremely doubtful that they really occur so abundantly as literature indicates. Despite these views, practice of ascribing these impressions to action of falling rain drops has continued and geologic literature abounds with examples of such interpretations. Observations on drying muds both in field and in laboratory show, that most, if not all, so-called rain-drop impressions are, as Desor correctly interpreted them in 1850, result of air bubbles rising through sediments. Most of processes that have been invoked to account for these impressions are improbable.

Note paleontologique sur le Permien de Lodeve et de Bourbon-l'Archambault

Abstract An impression of Odontopteris subcrenulata was found during excavations in the Autunian at Bourbon-l'Archambault, and animal and plant remains were found in Permian (Autunian and Saxonian) deposits near Lodeve. The Autunian plants are classic types, but the one found in Saxonian deposits near Lodeve is rare, in that it has never previously been described from the region and is unknown elsewhere in France. It belongs to Callipteris uralensis (or a very similar species), known from the Kuznetsk basin (USSR). Among the vertebrate remains, Acanthodes and Palaeoniscides species are already known from the lower Autunian, but those reported here are from the middle or upper Autunian. Also found in the Saxonian deposits are footprints of small tetrapods (amphibians or reptiles), mollusks, ripple marks, mud cracks, raindrop impressions, and the like, all indicating a climate which was drier than is generally reported.

Impressions made by bubbles, rain-drops, and other agencies

Research Article| December 01, 1921 Impressions made by bubbles, rain-drops, and other agencies W. H. TWENHOFEL W. H. TWENHOFEL Search for other works by this author on: GSW Google Scholar GSA Bulletin (1921) 32 (4): 359–372. https://doi.org/10.1130/GSAB-32-359 Article history received: 03 May 1921 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation W. H. TWENHOFEL; Impressions made by bubbles, rain-drops, and other agencies. GSA Bulletin 1921;; 32 (4): 359–372. doi: https://doi.org/10.1130/GSAB-32-359 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract IntroductionGeologic literature abounds with statements relating to the occurrence of rain-drop impressions, but in few instances is information given as to the appearance of the marks which are so designated. When pitlike structures have been found, they have generally been ascribed to raindrops, and it has been concluded that the containing deposits were those of a region over which at times there was no water. Notes of caution have occasionally appeared, but they do not appear to have been widely read.2The best paper on the subject of rain-drop impressions with which the writer is familiar is that of Lyell, in which are described “rain-marks of the Recent, Triassic, and Carboniferous periods.”3 This paper describes recent and fossil rain-drop impressions and gives some criteria by which they may be recognized. Some data are also given on impressions from the Triassic rocks of the Newark series, which are ascribed to . . . This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.