Dr. Jeff Marshall
Undergraduate Research Advising



Lauren Annis

Research Project:

Age correlation of uplifted Quaternary marine terraces, Nicoya Peninsula, Costa Rica


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File written by Adobe Photoshop® 4.0

Lauren Annis examining fault slickenlines in Cretaceous Nicoya Complex seafloor basalt, northern Nicoya Peninsula, Costa Rica (March 2003)


Cal Poly Pomona geology students Lauren Annis (r), Julie Parra, and Fookgiin Khaw looking at coastal cliff outcrop of Nicoya Complex seafloor basalt, Playa Junquillal, Nicoya Peninsula, Costa Rica (March 2003).


Images:  Project photos and illustrations


Project Overview:

The goal of Lauren’s research was to develop a preliminary age correlation between two flights of uplifted Pleistocene marine terraces on Costa Rica’s Nicoya Peninsula (Iguanazul and Cobano terrace sequences). The Nicoya Peninsula is an emergent segment of the northern Costa Rican fore arc that has undergone rapid Quaternary uplift in response to the subduction earthquake cycle at the Middle America Trench.

In March 2003, Lauren traveled to Costa Rica with Dr. Marshall and fellow students Jonathan Khaw and Julie Parra. Using aerial photographs, hand-held GPS, and differential barometric altimetry, they mapped and surveyed uplifted terraces within the Iguanazul geomorphic surface along the northern Nicoya coastline between Playa Tamarindo and Marbella. In addition, they collected samples of uplifted Holocene beachrock for radiocarbon dating in order to constrain Holocene uplift rates.

The Iguanazul terrace-mapping project was the primary focus of Jonathan Khaw’s senior thesis. Lauren’s project was designed to link the results of this fieldwork with previous map and survey data collected by Dr. Marshall from the Cobano terrace sequence at the Nicoya peninsula’s southern tip near Cabo Blanco. Using aerial photography and the survey data, Lauren produced maps and topographic profiles of marine terrace sequences. She then developed preliminary age constraints by correlating terrace inner edges to a Quaternary sea level curve.  


Research Abstracts:

AGU Abstract 2004: American Geophysical Union Meeting, San Francisco, California, 2004

GSA Abstract 2003: Geological Society of America Annual Meeting, Salt Lake City, Utah, 2005


Senior Thesis:

Annis, L.K., in progress, Age correlation of uplifted Quaternary marine terraces, Nicoya Peninsula, Costa Rica: [B.S. Thesis] Cal Poly Pomona University, Pomona, California.