Summer 2015 Volume 6, Number 1

Newsletter of the Department of Mineral Sciences

| Rocks ∙ Meteorites ∙ Gems ∙ Volcanoes ∙ Minerals |

In this Issue

Columnar Basalts in

NMNH

Expert-Is-In: The Stone

Faces of Teotihuacan

NHRE Summer Interns

Columnar Basalt in NMNH

In July 2015, the National Museum of Natural History

opened a temporary exhibition entitled “Primordial Land-

scapes: Iceland Revealed” which looks at the island coun-

try of Iceland, one of the most geologically active places on

Earth. Mineral Sciences geologist Ben Andrews was part

of the exhibit team and assisted in the script writing and the

selection of geologic specimens. Iceland is built by volcan-

ic activity and the exhibit highlights the Icelandic land-

scape through a series of photographs and a few rock speci-

mens. The dominant rock type on Iceland is basalt, a dark

colored, fine-grained volcanic rock that is found all over

the world and makes up nearly the entire seafloor. One of

the more interesting rock features found on Iceland are

basalt columns which sometimes develop within lava

flows. The “Primordial Landscapes” exhibit contains a

specimen of columnar basalt from the NMNH Rock & Ore

Collection in the Department of Mineral Sciences. Basalt

columns like the ones shown in the exhibition were once

quarried for use in fences and as hitching posts in Iceland.

Upper photo: Part of “Primordial Landscapes: Iceland

Revealed” exhibit. Left photo: Basalt Columns, Asback,

Germany, USNM 52103, Rock & Ore Collection. Photos

by Michael Wise.

Page 2 Volume 6, Number 1 Summer 2015

Columnar jointing may form in lava

flows as it cools on the Earth’s surface.

As it cools, the lava contracts and cracks

or joints (fractures) that are associated

with stress within the rock may develop.

When the contraction occurs at equally

spaced centers, then a hexagonal fracture

pattern will develop. This fracture pattern

will tend to propagate down the lava as it

cools, forming long, geometric columns.

Columnar jointing isn’t restricted to bas-

alts, however. This structure can also

form in other types of igneous rocks

which undergo cooling and contraction.

In the Rocks Gallery of the Janet Annen-

berg Hooker Hall of Geology, Gems &

Minerals (GGM) there is a fantastic ex-

hibit of columnar dacite (see below) from

Bluff Mountain, Randle, Washington.

Like basalt, dacite is also an igneous rock, but with much higher silica content. Dacite is also

typically lighter color than basalt. The dacite columns in the GGM Exhibit were collected from

an abandoned quarry roughly 32 km NE of Mount St. Helens and reassembled at NMNH for

visitors to enjoy. Photo by Michael Wise.

Columnar Basalt in NMNH (cont.)

A diagram explaining how columnar jointing

forms in a cooling body of rock. Diagram from

Dr. Malcolm Reeves's website at the University

of Saskatchewan. Diagram taken from: http://

homepage.usask.ca/~mjr347/prog/geoe118/

geoe118.054.html.

Page 3 Volume 6, Number 1 Summer 2015

Education & Outreach

Tim Rose (Mineral Sciences) and

Jane Walsh (Anthropology) spent a

few hours in the Q?rius facility as part

of the Expert-Is-In series. Tim and

Jane shared some of the results of their

collaborative research on the dramatic

pre-Columbian stone masks of Teoti-

huacan with visitors to the Museum.

During the two-hour session, visitors

were able to learn about the history

behind these central Mexican treasures

including how the masks were made

and what types of materials were used

to make them. Examples of some of

the rocks were available for visitors to

examine. Those who stopped by Tim

and Jane’s table were able to partici-

pate in an hands-on demonstration of

the use of primitive tools that might

have been used to drill holes in the

rock masks. Photos by Michael Wise.

Page 4 Volume 6, Number 1 Summer 2015

NHRE Summer Interns

Sierra Kaufman is inter -

ested in a variety of disci-

plines within the planetary

sciences including meteorites,

cosmochemistry, and outer

solar system satellites. This

summer she worked in the

Mineral Sciences department

with Catherine Corrigan on a

group of meteorites called

enstatite chondrites. The main

goal of the project was to

identify mineral associations

in the meteorites and create a

comprehensive, data support-

ed argument that the associa-

tions also occur on the planet

Mercury, in order to under-

stand the evolution of these planetary bodies. Sierra is an honors student at the State University of

New York at Fredonia and will be graduating in May 2016 with her bachelor’s degree in Geophysics

and Geochemistry. She intends to pursue her PhD in planetary science. Photo by James Di Loreto.

Brianna Marshall worked as an intern in the

Department of Mineral

Sciences with Benjamin

Andrews this summer to

better understand pyro-

clastic density currents

(PDC’s) and their behav-

ior. These hot and dense

currents of rock and gas,

resulting from volcanic

activity, pose numerous

hazards when they mix

and entrain with the ambient atmosphere.

Much of Brianna’s pro-

ject involves simulating

PDC’s in an experimental

tank to capture useful information about the processes and parameters driving air entrainment in

these currents. Brianna recently graduated cum laude with a bachelor's degree in Geology from Cal-

vin College in Grand Rapids, Michigan. In August, she will begin a two year appointment as a GIS

Research Specialist at the Center for Social Research in Grand Rapids. Upon finishing her appoint-

ment, Brianna plans to continue her education by pursuing a master's degree in Geology studying

volcanic hazards and mitigation. Photo by James Di Loreto.

Page 5 Volume 6, Number 1 Summer 2015

NHRE Summer Interns (cont.)

Oxygen fugacity (fO2), the partial pressure of

oxygen, is believed to be at the core of under-

standing mantle evolution through time. Meena

Said worked with Elizabeth Cottrell and

graduate student, Suzanne Birner, in the Depart-

ment of Mineral Sciences to analyze the fO2 of

abyssal peridotites – mantle rock located on the

deep seafloor of Gakkel Ridge in the Arctic. Her

data collection will contribute to the global fO2

data set. Meena is an Honors student at Lock

Haven University of Pennsylvania majoring in

applied geology. As an active officer of the

Geoscience Club, her passion for learning is

displayed both in and out of the classroom.

Meena plans on pursuing her PhD with an inter-

disciplinary approach of either biology or mate-

rials science. Photo by James Di Loreto.

Staff Changes

Emma Bullock has left the Smithsonian Institution (Division of Meteor ites ) to join the

Geophysical Laboratory at the Carnegie Institution as their Microbeam Specialist. She will be

responsible for maintaining and operating the focused ion beam - scanning electron microscope

(FIB-SEM) crossbeam system and other microbeam instruments, but also plans to continue her

work on meteorites.

After 5 years as a member of the Division of Mineralogy, Cara Santelli will be joining the fac-

ulty of the Department of Earth Sciences at the University of Minnesota as an Assistant Professor

of Geomicrobiology. There she will continue her research on the impact of microbial actibity on

geological processes that she started while employed at the Smithsonian Institution.

Mineral Sciences also bid a fond farewell to Pam Salyer who since 2014 had been helping us in

the Meteorite Collection.

New Meteorites Collections Manager, Julie Hoskin

joined Minerals Sciences in August. Julie has worked

with a wide variety of collection artifacts and speci-

mens from numerous museums, including; the National

Museum of American History, the Hirshhorn Museum,

the Virginia Museum of Natural History, the National

Gallery of Art, and the National Museum of Natural

History. Julie is an expert in environmental monitoring

and control, constructing specialized housing and sup-

ports for objects, appropriate chemicals and materials to

use with various specimens, digital imaging of speci-

mens and associated information, as well as cataloging

objects and recording specimen data.

Page 6 Volume 6, Number 1

Bohu, T., Santelli, C.M., Akob, D.M., Neu,

T.R., Ciobota, V., Rösch, P., Popp, J., Nie-

tzsche, S. & Küsel, K. (2015) Characteriza-

tion of pH dependent Mn(II) oxidation strate-

gies and formation of a bixbyite-like phase by

Mesorhizobium australicum T-G1. Frontiers

in Microbiology, 6, 734 doi:10.3389/

fmicb.2015.00734

Brounce, M., Kelley, K.A., Cottrell, E. &

Reagan, M.K. (2015) Temporal evolution of

mantle wedge oxygen fugacity during sub-

duction initiation. Geology, 46, 775-778.

Corrigan, C.M., Velbel, M.A. & Vicenzi,

E.P. (2015) Modal abundances of pyroxene,

olivine, and mesostasis in nakhlites: Hetero-

geneity, variation, and implications for na-

khlite emplacement. Meteoritics & Planetary

Science, 50, 1497-1511.

Evans, L.G., Peplowski, P.N., McCubbin,

F.M., McCoy, T.J., Nittler, L.R., Zolotov,

M.Y., Ebel, D.S., Lawrence, D.J., Starr, R.D.,

Weider, S.Z. & Solomon, S.C. (2015) Chlo-

rine on the Surface of Mercury: MESSEN-

GER Gamma-Ray Measurements and Impli-

cations for the Planet's Formation and Evolu-

tion. Icarus, 257, 417-427.

Harlow, G.E., Tsujimori, T. & Sorensen, S.S.

(2015) Jadeitites and Plate Tectonics. Annual

Review of Earth and Planetary Sciences, 43,

105-138.

Helz, R.T., Clague, D.A., Mastin, L.G. &

Rose, T.R. (2015) Electron microprobe analyses of glasses from Kilauea Tephra

Units, Kilauea Volcano, Hawaii. U.G. Geolo-

cial Survey Open-File Report 2015-1090,

24 p., plus 2 appendixes in separate files.

Summer 2015

Selected Publications

Meetings & Abstracts

Corrigan, C.M., Lunning, N.G., Fr iedr ich, J .M. & McCoy, T.J. (2015) An H chondr ite

clast in an LL chondrite: impact melt or incipient partial melt?

Kita, N.T., Tenner, T.J., Ushikubo, T., Bouvier, A., Wadhwa, M., Bullock, E.S., & MacPher-

son, G.J. (2015) Why do U-Pb ages of chondrules and CAIs have more spread than their 26Al

ages?

Mayne, R.G. & McCoy, T.J. (2015) Pallasites: does density matter after all?

McCoy, T.J. & Bullock, E.S. (2015) Volatile-rich phases in aubrites: clues to understanding

the mineralogy of Mercury?

Wise, M.A. & Brown, C.D. (2015) Distr ibution of

granitic pegmatites in the Peninsular Ranges of south-

ern California, USA: a reassessment of the southern

California pegmatite province.

Page 7 Volume 6, Number 1

Ivanova, M.A., Lorenz, C.A., Krot, A.N. &

MacPherson, G.J. (2015) A compound Ca-,

Al-rich inclusion from CV3 chondrite North-

west Africa 3118: Implications for under-

standing processes during CAI formation.

Meteoritics & Planetary Science, 50, 1512-

1528.

Jenner, F.E., Hauri, E.H., Bullock, E.S., Kö-

nig, S., Arculus, R.J., Mavrogenes, J.A., Mik-

kelson, N. & Goddard, C. (2015) The com-

peting effects of sulfide saturation versus

degassing on the behavior of the chalcophile

elements during the differentiation of hydrous

melts. Geochemistry, Geophysics, Geosys-

tems, 16, 1490-1507.

McCormick, B., Popp, C., Andrews, B. &

Cottrell, E.. (2015 Ten years of satellite

observations reveal highly variable sulphur

dioxide emissions at Anatahan Volcano, Mar-

iana Islands. Journal of Geophysical Re-

search: Atmospheres, 120, 7258-7282.

McCoy, T.J. (2015) [Review]: Atlas of Me-

teorites, by Grady Monica, Pratesi Giovanni,

and Moggi Cecchi Vanni. Cambridge, UK:

Cambridge University Press, 2014, 384 p.

$150, hardcover (ISBN # 9780521840354).

Meteoritics & Planetary Science, 50, 1495-

1496.

Pistone, M., Arzilli, F., Dobson, K.J ., Cor -

donnier, B., Reusser, E., Ulmer, P., Marone,

F., Whittington, A.G., Mancini, L., Fife, J.L.

& Blundy, J.D. (2015) Gas-driven filter

pressing in magmas: Insights into in-situ melt

segregation from crystal mushes. Geology,

43, 699-702.

Pohwat, P.W. (2015) Connoisseur ' s

Choice: Willemite, Tsumeb Mine, Tsumeb,

Otjikoto, Namibia. Rocks & Minerals, 90,

358-365.

Tang, M. Jr, Ricardo A., Goreva, Y. &

McDonough, W.F. (2015) Elemental fraction-

ation during condensation of plasma plumes

generated by laser ablation: a ToF-SIMS

study of condensate blankets. Journal of Ana-

lytical Atomic Spectrometry, doi:10.1039/

C5JA00320B

Vázquez-Rodríguez, A.I., Hansel, Colleen

M., Zhang, Tong, Lamborg, C.H., Santelli,

C.M., Webb, S.M. & Brooks, S.C. (2015)

Microbial- and thiosulfate-mediated dissolu-

tion of mercury sulfide minerals and transfor-

mation to gaseous mercury. Frontiers in Mi-

crobiology, 6: 596 doi:10.3389/

fmicb.2015.00596

Walsh, J.M. & Rose, T.R. (2015) Mascaras

de Teotihuacan. Una tipologia preliminar.

Arqueologia Mexicana, XXI, 126, 78-85.

Waters, L.E., Andrews, B.J. & Lange, R.A.

(2015) Rapid Crystallization of Plagioclase

Phenocrysts in Silicic Melts during Fluid-

saturated Ascent: Phase Equilibrium and De-

compression Experiments. Journal of Petrolo-

gy, 56, 981-1006.

Summer 2015

Selected Publications