This is not a new proposition. It has been a popular belief among amateur astronomers that such modern-day extraterrestrial dust can be collected on roofs in urban environments. A study from 1941 reported large numbers of magnetic spherules collected in urban areas, but Genge and colleagues cite two studies in the 1950s that asserted that such spherules are artificial.

Despite these studies, write Genge and colleagues, amateur collection projects in built-up areas are common. Micrometeorites are thought to include materials derived from both asteroids and comets. Although some smaller dust particles survive atmospheric entry without significant heating, reports show that the majority of particles undergo melting during their passage through the atmosphere. According to Genge and colleagues, the most abundant of these, particularly at large sizes, are cosmic spherules (completely melted droplets dominated by quench textures).

In Geology, Genge and colleagues report the results of a study of 500 MMs collected among particles recovered by Project Stardust (Oslo, Norway; http://project-stardust. com) in urban areas. They show that a subset of 48 particles are cosmic spherules, representing the youngest large MMs yet recovered.

FEATURED ARTICLE

An urban collection of modern-day large micrometeorites: Evidence for variations in the extraterrestrial dust flux through the Quaternary

M.J. Genge, J. Larsen, M. Van Ginneken, and M.D. Suttle; v, 45, p. 119-122, OPEN ACCESS

http://geology.gsapubs.org/cgi/content/abstract/45/2/119

Geology articles are online http://geology.gsapubs.org/. Representatives of the media may obtain complimentary articles by contacting Kea Giles at the e-mail address above. Please discuss articles of interest with the authors before publishing stories on their work, and please make reference to GEOLOGY in articles published. Non-media requests for articles may be directed to GSA Sales and Service, Questo indirizzo email è protetto dagli spambots. È necessario abilitare JavaScript per vederlo..

Other recently published articles

Tidal rhythmites in the southern Bouse Formation as evidence for post-Miocene uplift of the lower Colorado River corridor

Brennan O’Connell, Rebecca J. Dorsey, and Eugene D. Humphreys; v. 45, p. 99-102, OPEN ACCESS

http://geology.gsapubs.org/cgi/content/abstract/45/2/99

Tracing crustal evolution by U-Th-Pb, Sm-Nd, and Lu-Hf isotopes in detrital monazite and zircon from modern rivers

Xiao-Chi Liu, Yuan-Bao Wu, Christopher M. Fisher, John M. Hanchar, Luke Beranek, Shan Gao, and Hao Wang; v. 45, p. 103-106

http://geology.gsapubs.org/cgi/content/abstract/45/2/103

Overbank sedimentation from the historic A.D. 2011 flood along the Lower Mississippi River, USA

Franklin T. Heitmuller, Paul F. Hudson, and Richard H. Kesel; v. 45, p. 107-110

http://geology.gsapubs.org/cgi/content/abstract/45/2/107

Regional variability in the frequency and magnitude of large explosive volcanic eruptions

Tom Sheldrake and Luca Caricchi; v. 45, p. 111-114 Open Access

http://geology.gsapubs.org/cgi/content/abstract/45/2/111

Silicified glendonites in the Ediacaran Doushantuo Formation (South China) and their potential paleoclimatic implications

Zhou Wang, Jiasheng Wang, Erwin Suess, Guangzhe Wang, Can Chen, and Shuhai Xiao; v. 45, p. 115-118

http://geology.gsapubs.org/cgi/content/abstract/45/2/115

Barrier island migration dominates ecogeomorphic feedbacks and drives salt marsh loss along the Virginia Atlantic Coast, USA

Charles D. Deaton, Christopher J. Hein, and Matthew L. Kirwan

Geology 2017, v. 45, p. 123-126

http://geology.gsapubs.org/cgi/content/abstract/45/2/123

The dynamics of gold in regolith change with differing environmental conditions over time

Ravi Anand, Mel Lintern, Rob Hough, Ryan Noble, Mike Verrall, Walid Salama, Jens Balkau, and Nigel Radford

Geology 2017, v. 45, p. 127-130

http://geology.gsapubs.org/cgi/content/abstract/45/2/127

A new attraction-detachment model for explaining flow sliding in clay-rich tephras

Max O. Kluger, Vicki G. Moon, Stefan Kreiter, David J. Lowe, G.J. Churchman, Daniel A. Hepp, David Seibel, M. Ehsan Jorat, and Tobias Mo¨rz

Geology 2017, v. 45, p. 131-134

http://geology.gsapubs.org/cgi/content/abstract/45/2/131

A probabilistic analysis of meteorically altered ?13C chemostratigraphy from late Paleozoic ice age carbonate platforms

Blake Dyer, John A. Higgins, and Adam C. Maloof

Geology 2017, v. 45, p. 135-138

http://geology.gsapubs.org/cgi/content/abstract/45/2/135

Foreland exhumation controlled by crustal thickening in the Western Alps

Stéphane Schwartz, Cécile Gautheron, Laurence Audin, Thierry Dumont, Jérôme Nomade, Jocelyn Barbarand, Rosella Pinna-Jamme, and Peter van der Beek

Geology 2017, v. 45, p. 139-142

http://geology.gsapubs.org/cgi/content/abstract/45/2/139

Evidence of an axial magma chamber beneath the ultraslow-spreading Southwest Indian Ridge

Hanchao Jian, Satish C. Singh, Yongshun John Chen, and Jiabiao Li

Geology 2017, v. 45, p. 143-146

http://geology.gsapubs.org/cgi/content/abstract/45/2/143

Contrasting magmatic cannibalism forms evolved phonolitic magmas in the Canary Islands

S. Turner, T. Kokfelt, K. Hoernle, T.S. Johansen, F. Hauff, C. Lundstrom, P. van den Bogaard, and A. Klu¨gel

Geology 2017, v. 45, p. 147-150

http://geology.gsapubs.org/cgi/content/abstract/45/2/147

Storage filters upland suspended sediment signals delivered from watersheds

James Pizzuto, Jeremy Keeler, Katherine Skalak, and Diana Karwan

Geology 2017, v. 45, p. 151-154

http://geology.gsapubs.org/cgi/content/abstract/45/2/151

Mantle earthquakes, crustal structure, and gravitational instability beneath western North Island, New Zealand

Jesse-Lee Dimech, Tim Stern, and Simon Lamb

Geology 2017, v. 45, p. 155-158

http://geology.gsapubs.org/cgi/content/abstract/45/2/155

Large subglacial meltwater features in the central Barents Sea

L.R. Bjarnadóttir, M.C.M. Winsborrow, and K. Andreassen

Geology 2017, v. 45, p. 159-162, OPEN ACCESS

http://geology.gsapubs.org/cgi/content/abstract/45/2/159

Global-ocean redox variation during the middle-late Permian through Early Triassic based on uranium isotope and Th/U trends of marine carbonates

Maya Elrick, Victor Polyak, Thomas J. Algeo, Stephen Romaniello, Yemane Asmerom, Achim D. Herrmann, Ariel D. Anbar, Laishi Zhao, and Zhong-Qiang Chen

Geology 2017, v. 45, p. 163-166

http://geology.gsapubs.org/cgi/content/abstract/45/2/163

Resolving the role of carbonaceous material in gold precipitation in metasediment-hosted orogenic gold deposits

Si-Yu Hu, Katy Evans, Dave Craw, Kirsten Rempel, and Kliti Grice

Geology 2017, v. 45, p. 167-170

http://geology.gsapubs.org/cgi/content/abstract/45/2/167

Combining radiocarbon and cosmogenic ages to constrain the timing of the last glacial-interglacial transition in the Uinta Mountains, Utah, USA

Jeffrey S. Munroe and Benjamin J.C. Laabs

Geology 2017, v. 45, p. 171-174

http://geology.gsapubs.org/cgi/content/abstract/45/2/171

Explosive eruption of El Chichón volcano (Mexico) disrupted 6th century Maya civilization and contributed to global cooling

Kees Nooren, Wim Z. Hoek, Hans van der Plicht, Michael Sigl, Manfred J. van Bergen, Didier Galop, Nuria Torrescano-Valle, Gerald Islebe, Annika Huizinga, Tim Winkels, and Hans Middelkoop

Geology 2017, v. 45, p. 175-178

http://geology.gsapubs.org/cgi/content/abstract/45/2/175

Late Quaternary climatic control of Lake Baikal (Russia) turbidite systems: Implications for turbidite systems worldwide

Dimitris Evangelinos, C. Hans Nelson, Carlota Escutia, Marc De Batist, and Oleg Khlystov

Geology 2017, v. 45, p. 179-182

http://geology.gsapubs.org/cgi/content/abstract/45/2/179

Nonequilibrium degassing, regassing, and vapor fluxing in magmatic feeder systems

J.M. Watkins, J.E. Gardner, and K.S. Befus

Geology 2017, v. 45, p. 183-186

http://geology.gsapubs.org/cgi/content/abstract/45/2/183

Early Cenozoic drainage reorganization of the United States Western Interior–Gulf of Mexico sediment routing system

Glenn R. Sharman, Jacob A. Covault, Daniel F. Stockli, Anton F.-J. Wroblewski, and Meredith A. Bush

Geology 2017, v. 45, p. 187-190

http://geology.gsapubs.org/cgi/content/abstract/45/2/187

Research Focus: Tracking large volcanic eruptions and their regional variability

José Luis Macías

Geology 2017, v. 45, p. 191-192 Open Access

http://geology.gsapubs.org/cgi/content/full/45/2/191

http://www.geosociety.org/GSA/News/Releases/GSA/News/pr/2017/17-01.aspx