Geological Definition of the Day (#4)

Sorry folks, I did not have time to do this over my lunch break today. Here is a fun one to go with my post from last night:

diluvium (di-lu'-vi-um) 1. An archaic term once applied to widespread surficial deposits that were believed to be produced by extraordinary floods of vast extent, esp. the Noachian Flood; these deposits are now known to be mostly glacial drift. 2. A general term used in continental Europe for Pleistocene glacial deposits, as distinguished from younger alluvium. (page 141)

"Along the western base the range diluvium is accumulated in large quantities but in general this formation is not as abundant to the west as to the east of Connecticut river." [link]

From Bates, R.L. and J.A. Jackson. 1984. Dictionary of Geologic Terms. American Geological Institute.

Geological Definition of the Day (#3)

Here is an old favorite from my days at the University of Arkansas where Dr. Manger would have us memorize this one for SGE initiation:

cactolith: a quasihorizontal chonolith composed of anastomosing ductoliths whose distal ends curl like a harpolith, thin like a sphenolith, or bulge discordantly like an akmolith or ethmolith.

From the paper: Hunt, C.B. 1953. Geology and geography of the Henry Mountains region, Utah.

Unfortunately I do not have the dictionary from whence it came, so I had to google it. Risky, I know. But this is one I could never forget. Wikipedia has an interesting blurb about it: "Whilst he was in fact describing an actual geological feature - a laccolith which he saw as resembling a cactus [1] - he was also, tongue-in-cheek, commenting on what he saw as an absurd number of "-lith" words in the field of Geology." But it is Wikipedia after all, so take the story as you like.

Geological Definition of the Day (#2)

For lack of anything better, here is the second installment; bear with me, the 'B' section was a bit on the boring side. Feel free to send me any suggestions you may have!

blastopsammitic (blas'-to-psam-mit'-ic) Said of the texture of a metamorphosed sandstone that contains relicts of the parent rock. (page 58)

"The quartzite shows granoblastic and blastopsammitic texture, with grain sizes varying from coarse sand to very fine pebble and with minor microcrystals of sericite, fuchsite, andalusite and iron oxide, besides detrital tourmaline, rutile, and zircon." [link]


From Bates, R.L. and J.A. Jackson. 1984. Dictionary of Geologic Terms. American Geological Institute.

Geological Definition of the Day (#1)

I thought I would try something new this week - a different geological definition every day. All terms will come from the third edition of the Dictionary of Geologic Terms*. Let me know if you hate this ;) Happy St. Patrick's Day!

arthrophycus (ar-thro-phy'-cus) A sand-filled rounded furrow, curving and branching, with faint but regularly spaced transverse ridges commonly bearing a median depression, probably representing a feeding burrow but also variously regarded as an inorganic structure or a trail produced by a worm, mollusk, or arthropod crawling over a soft-mud surface. The "branches" of the trace fossil may reach 60 cm in length. It was originally described as a plant fossil (seaweed) and assigned to the genus Arthrophycus. (page 29)

"Arthrophycus and other trace fossils in the Red Mountain Formation form a group related by interconnection, intergradation, similar dimensions, and morphologic similarities that, taken together, strongly suggest a common tracemaker." [link]

*Bates, R.L. and J.A. Jackson. 1984. Dictionary of Geologic Terms. American Geological Institute.