.: D. Marie Weide, Ph.D. :.
.: Lecturer :.
.: Department of Geography and Environmental Sciences :.
.: University of Colorado at Denver :.
.: Denver, CO 80217 :.
.: denise.weide at ucdenver dot edu:.


2016 | Ph.D. – Earth and Atmospheric Sciences | University of Nebraska-Lincoln
2012 | M.S. – Geology | California State University, Long Beach
2001 | Advanced Certificate in Forensic Anthropology | Mercyhurst College
1996 | B.A. – Anthropology | University of Colorado at Denver

Current Research:

I use diatoms in lake sediments to reconstruct past environments in order to understand how humans have changed the landscape and aquatic ecosystems. I work with a group of scientists that include archaeologists, geochemists, and palynologists to gain insight into how we can mitigate the effects of current environmental change.

I am also interested in diatom morphology and how it changes through time. Diatoms appear to have incredibly high within species variation. How do these variations come about and what is their adaptive significance?

Previous Research:

My Ph.D. research, with Dr. Sherilyn Fritz was part of an interdisciplinary project with archaeologists that focused on studying lake processes and aquatic resource use on the shores of Lake Titicaca (Peru/Bolivia) during the Holocene. I used diatoms, freshwater algae, to reconstruct lake-level history at multi-decadal resolution, over the past 7,000 years. The result was the most detailed reconstruction for the Titicaca Basin to date. Our data generally agree with previous reconstructions, but the higher temporal resolution of this record demonstrates that Holocene lowstands were of somewhat shorter durations that previously thought. This record also demonstrates that the lake level fluctuated on a sub-century scale, providing a highly variable environment for the inhabitants of the shoreline. Our group is currently analyzing new archaeological data in light of this new environmental data to understand how aquatic resource use changed over time. This research is being presented at the Society for American Archaeology (Vancouver, BC, 2017).

My Master's thesis with Dr. Lora Stevens (Cal State Long Beach) focused on diatom assemblages from Lac Ba Bê in the northern mountains of Viêt Nam. The sediment core spanned the last 500 years, but the most striking feature of the core is the change in diatom assemblages in the top 4 cm of the core (late 1970s/early 1980s). This section is distinguished by a flora that is characterized by a high planktic to benthic ratio. Furthermore, the dominant species in this section require relatively low nutrients when compared to diatoms in the rest of the core. In addition, it marks the introduction of two Cyclotella species that become the dominant planktic species and a related decline in Aulacoseira species. The change in flora is interpreted as a possible response to a weakened Southeast Asian Monsoon beginning in the 1970s. This research received financial support from the Geological Society of America, Paleontological Society, International Phycological Society and Los Angeles Basin Geological Society/Pacific Section AAPG

Vertebrate Palaeontology:

Prior to my life as a diatomist, I worked on basal synapsids of Tanzania with Dr. Christian Sidor at the University of Washington. These projects focused on the biostratigraphic record of the Upper Permian, Usili Formation in the Ruhuhu Basin and how they differed from the Karoo Fauna.


Weide, DM, Fritz, SC, Hastorf, C, Bruno, M, Baker, P, Salenbien, W, and Guedron, S. 2017. Lake-level fluctuations of Lago Huiñaimarca, Lake Titicaca, (Peru/Bolivia) during human occupation of the Basin during the last ~6,000 years. Quaternary Research 88(2). DOI: 10.1017/qua.2017.49.

Weide, DM, Fritz, SC, Brinson, B, Thompson, LG and Billups. 2017. Freshwater diatoms in the Sajama, Quelccaya, and Coropuna glaciers of the South American Andes. Diatom Research 32(1-2). DOI: 10.1080/0269249X.2017.1335240.

Weide, DM. 2015. Aulacoseira stevensiae sp. nov. (Coscinodiscophyceae, Bacillariophyta), a new diatom from Ho Ba Be, Bac Kan Province, Northern Viet Nam. Diatom Research 30(3): 263-268.DOI: 10.1080/0269249X.2015.1074114.

Sidor, CA, Angielczyk, KD, Weide, DM, Smith, RMH, Nesbitt, S and Tsuji, LA. 2010. Tetrapod fauna of the lowermost Usili Formation (Songea Group, Ruhuhu Basin) of southern Tanzania, with a new burnetiid record. Journal of Vertebrate Paleontology 30:696-703.DOI:10.1080/02724631003758086.

Weide, DM, Sidor, CA, Angielczyk, KD, and Smith, RMH. 2009. A new record of Procynosuchus delaharpeae (Therapsida: Cynodontia) from the Upper Permian Usili Formation, Tanzania. Palaeontologica Africana Dec 2009. DOI: 10539/13808.


Weide, DM, MC Bruno, CA Hastorf & SC Fritz. The decoupling of environment and political change in the prehistoric southern Titicaca Basin. Presented at Society for American Archaeology symposium: Exploring Prehistoric Perceptions of ‘Nature’: Can We Go Beyond Economic Human-Environment Interactions? Vancouver, British Columbia, March 30, 2017.

Weide, DM, Fritz, S, Hastorf, C, Salenbien, W, Baker, P and Guedron, S. A Late Holocene Lake-Level Reconstruction of Lago Huiñaimarca, Southern Lake Titicaca, Peru/Bolivia. Presented at the 6th International Limnogeology Congress, Reno, NV, Jun. 2015.

Salenbien, W, Weide, DM, Develle, AL, Baker, PA, Fritz, SC and Guedron, S. The Influence of Sampling Density on Bayesian Age-Depth Models & Paleoclimatic Reconstructions: Lessons Learned from Lake Titicaca (Bolivia/Peru). Presented at the 47th AGU Fall Meeting, San Francisco, CA, Dec. 2014.

Weide, DM and Stevens, LR. 2012. Late Holocene environmental Change in Lac Ba Be, Viet Nam. Poster presented at the 12th International Paleolimnology Symposium, Glasgow, Scotland, UK, August 2012.

Weide, DM. Biostratigraphy and the Karoo Basins. Poster presented at Northwest Geological Society, Seattle, WA, May 2009. Awarded 2nd place for poster presentation.

Weide, DM, Sidor, CA, Angielczyk, KD, and Smith, RMH. A new record of Procynosuchus delaharpeae (Therapsida: Cynodontia) from the Upper Permian Usili Formation (Ruhuhu Basin), Tanzania. Poster presented at the Society of Vertebrate Paleontology Annual Meeting, Cleveland, OH, Oct 2008.

Weide, DM and Dirkmaat, DC. Description of a Forensic Anthropological Recovery, Identification & Interpretation in Fayette County, PA. Talk presented at North East Forensic Anthropology Association (NEFAA) Annual Meeting, Peabody Museum, Boston, MA, Nov 2000.

©2012, 2017 | D. Marie Weide