Friends of the Florissant Fossil Beds Volume 2004, Issue 2 June, 2004 Inside this issue: The Geology of Crystal Peak by Andy Weinzapfel, zonite, a relatively rare and derived from the earth’s deep Florissant Lahars 2 Geologist beautiful variant of a common mantle and injected upward to a mineral, microcline feldspar. depth of 3 miles or less below Centered on the cover of the Feldspar, along with quartz, is a the surface. Crystal Peak is part official park brochure of this batholith. The Colorado’s First 3 of Florissant Fossil Pikes Peak Granite, Beds National Monu- Fossils extending over an ment is a prominent area of 1200 square natural topographic miles, is exposed at Princeton 3 feature shaped like a the surface today only pyramid. Variously Scientific Expedi- because the rocks called by old-timers that once covered it tion Cheop’s Pyramid, have gradually eroded Topaz Butte, and The Big Stump 4 away. Crystal Beds at Florissant, today it is The Ute Indians were known formally as A view of Crystal Peak, a significant geological the first collectors of Crystal Peak. It is A view of Crystaland Peak, historical a significant point geological of interest. and historical point crystals from this 35th Anniversary 7 both a significant of interest.Photo byPhoto author. by author. area, used for spiritual of the Florissant geological and his- major constituent of granite, the purposes. In the Fossil Beds torical point of interest. most prevalent igneous rock 1870s, Dr. A. E. Foote of Phila- National found in continental mountain delphia, systematically explored Exceptional mineral specimens Monument ranges. the area, employing 19 men, and from the Crystal Peak area can shipped many specimens back be found in many of the best Seminar Series— 8 The geology of the Pikes Peak east. Arthur Lakes, who accom- national and international muse- region is dominated by the 1.07- panied Samuel Scudder of Har- 2004 ums. Most notable are greenish 1.09 billion-year-old Pikes Peak vard University on an early or greenish-blue euhedral batholith, a large body of once- (Continued on page 6) (smooth-faced) crystals of ama- molten rock that was likely Pikes Peak Gem & 11 Mineral Show Vincent Matthews Appointed State Geologist the University of Georgia and tecture, and the University of On March 9, Dr. Vincent Mat- the Ph.D. from the University of Texas of the Permian Basin. thews was appointed Colo- California, Santa Cruz. rado’s third State Geologist Matthews has conducted re- since the Colorado Geological Before joining the CGS in 2000, search and published on the San Survey was reactivated in 1967. Vince spent over 20 years in the Andreas Fault, global tectonics, In his previous position as Sen- petroleum industry, working for subduction zone tectonics, igne- ior Science Advisor, Matthews four public companies. Addition- ous and metamorphic petrology, was responsible for CGS' geo- ally, he taught at the University and Laramide deformation. He logic mapping, earthquake haz- of California, University of is the author of more than 40 ards research, and outreach Northern Colorado, Arizona technical articles and abstracts. programs. A native of east Ten- State University, the Frank nessee, he received B.S. and Lloyd Wright School of Archi- Matthews is a Fellow in the M.S. degrees in Geology from (Continued on Page 6) Volume 2004, Issue 2 Page 2 Florissant Lahars By John M. Ghist see, it is made up of a variety of different size clasts, most vol- canic, some not. Photo 2 (page 7) is a more detailed picture of Lahar, such an exotic sounding word, brings to mind all sorts of the lahar. Although not definitive, pyroclastic flows tend to show images, such as a dinner toast, a French rabbit, or even some stratification while lahars do not. Although you tend to envision ancient battle cry. Lahars, however, are dirty, wet and often hot pyroclastic flows as very violent and chaotic flows, they are, with mudflows associated with volcanoes. The word is Indonesian in the exception of the very bottom layer, very planar in their flow origin and based on this, you might expect these forms of mass characteristics, oftentimes preserving stratigraphic relationships wasting to be found only in far-away exotic areas of the world, as they move hundreds or even thousands of meters. Lahars, far from Colorado. This is not the case. We have lahars too and however, are like avalanche deposits, unsorted, containing frag- they are closer than you might think. ments from fine mud to boulders as large as houses. There is usually no trace of bedding except perhaps near the bottom of What is a lahar and how we can recognize one? A lahar is a vol- the flow and more rarely at the very top (Francis, 1998). As you canic debris flow or a rapid flowing mixture of mostly volcanic can see in the above photos, the distribution of clasts is chaotic. rock and water originating on the slopes of a volcano. Although most vulcanologists would So, lahars are terrifying, destructive acts of Nature! Something prefer that it be caused by a to be feared, avoided, and volcanic eruption, it is not that we should never want to always possible to be sure that happen. This is true. Modern it was or whether it was lahars have destroyed whole caused by remobilization of towns and killed thousands of volcanic materials long after an people. They have caused eruption. For modern lahars, it some of the most destructive is fairly easy to make the dis- modern catastrophes. How- tinction; for ancient deposits, it ever, we owe a great deal to is not. the lahars around Florissant. Thanks to them we have the Lahars are not all that different Florissant Fossil Beds. from pyroclastic flows (or nuées ardentes). Both are asso- About 35 million years ago, ciated with volcanoes and are the area around Florissant composed primarily of volcanic was covered by a beautiful forest of gigantic sequoias, material. The difference is in Photo 1: General view of the road cut 6.5 miles south of the Florissant Fossil Beds much like those seen today in the delivery method. The ma- Monument along Teller County 1. Photo date March 2004 by J. M. Ghist. terial carried with pyroclastic California. These large trees flows is supported by air as grew to tremendous heights opposed to lahars where it is carried by water. So how do you towering over everything around them and providing shelter for tell the difference? Photo 1 is that of a lahar about 6.5 miles wide and varied forms of life. south of the Florissant Fossil Beds Visitor Center. As you can (Continued on Page 7) Dr. Ralph Root about 60 additional buried stumps. Through his work, plans for On the verge of retirement from government service, Dr. Ralph the new visitor’s center were drawn and the administration Root, one of Florissant’s ardent supporters and researchers, died building now being constructed depended on Ralph’s study. from prostate cancer on January 15, 2004. Originally hailing from Erie, Pennsylvania, Ralph was trained in geology at Allegheny “Root’s Gulley” is a deep entrenched stream just east of Teller College in Meadville, Pennsylvania, earned his Master’s at Indiana County One south of Lower Twin Rocks Road was named for University, and his Ph.D. in remote sensing from Colorado State Ralph. There he studied the stratigraphy of that little known University at Fort Collins. Since locating in Colorado, he worked section of shale and ash layers, lending insight to the origins of for thirty years for the National Park Service and the Geological the lake. Survey, receiving a citation for those many years of service just before he died. Ralph Root’s role in the initial geologic mapping of Florissant fossil beds is akin to Harry Macginitie’s work on the fossil plants Ralph’s first job with the National Park Service was the mapping and Samuel Scudder’s work on the fossil insects. The Monument of the geology of the Fossil Beds. Using remote sensing tech- owes a great deal to Ralph Root’s love of and work at the niques across the monument, he plotted the potential location of Florissant Fossil Beds. Volume 2004, Issue 2 Page 3 Colorado’s First Fossil Insects Were Fifth Ever Found in US By Beth Simmons bone fragments and perfect fossil turtles, some two feet in length. Under the sandstone the beds of petroleum shale, a By 1871, how much was known about the fossil insects of Colo- thousand feet in thickness, were filled with innumerable leaves of rado? What paleontological work had been accomplished? How deciduous trees. were the results disseminated to those interested in the fossil “Throughout the remains of insects abound.” About fifty speci- wealth of the vast Rocky Mountain region? mens found their way to Samuel Scudder at Harvard, but some A number of scientists, well versed in geology, were among the were so fragmentary or imperfectly preserved that they were early arrivals in Colorado Territory. Among them were E.L. Ber- impossible to identify. The most abundant forms were Diptera thoud, a great engineer and Robert Old, a mining engineer who (flies), either in larval or perfect state, minute Coleoptera worked together to publish the first topographic maps and geo- (beetles), several Homoptera (Cicadas), an ant, a night-flying logical sections of the strata along the Front Range. Each de- moth, and a larvae of slug-caterpillar or Limacode. The flies scribed fossils they found. Old used Berthoud’s work to sell were mostly small species of Mycetophilidae, a family whose Colorado mines to the British.