AMT and gravity across praTertiary rock complex of Kebumen, Central Java, Indonesia

Laesanpura, Agus; Dahrin, Darharta; Sugianto, Asep

doi:10.1063/1.4990916

Cited by 4 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The result contradicts the theory of Dakah as the center of the volcanism (Setiawan et al, 2011), and the idea of an intrusion in Mount Parang (Kamtono, 1995). The resistivity model agrees with Laesanpura et al (2017), who suggested the sill nature of the volcanic rock due to the discontinuity to the depth. However, we prefer the non-in-situ origin of the volcanic bodies because of their singularity and relatively small characteristics.…”

Section: Discussionsupporting

confidence: 87%

See 1 more Smart Citation

Determining the origin of volcanic rocks in the mélange complex of Karangsambung based on the electrical resistivity imaging

et al. 2020

View full text Add to dashboard Cite

An ENE-WSW-trending localized basalt-diabase outcrop along the SE margin of Luk Ulo Mélange Complex has been suggested as intrusive rocks cut through the Paleogene Totogan and Karangsambung formations. However, the absolute dating of the volcanics is older than the inferred relative age of the sedimentary formations, hence the in-situ intrusion theory is less likely. A subsurface imaging should delineate the possibility of the in-situ nature of volcanic rock by looking at the continuation of the rocks to the depth. In this study, we did a subsurface imaging by electrical resistivity method. The electrical resistivity surveys were conducted at 3 (three) lines across the ENE-WSW trend of the volcanic distribution. From those three measurements, we obtained three inversion models that present the distribution of the resistivity. We could differentiate between the high resistivity of volcanic rocks and the low resistivity of the clay-dominated sediments. Instead of the deep-rooted intrusions, the geometry of the volcanic rocks is concordant with the sedimentary strata. Since we do not observe any spatial continuity of the bodies, both laterally and vertically, the volcanic rocks might be part of broken intrusive rocks. Furthermore, the size and the sporadically distributed of the rocks also indicated that they are more likely as fragments during the olistostrome deposition, transported from its original location.

show abstract

Section: Discussionsupporting

confidence: 87%

“…He described an igneous body of intrusion cut through the higher densities environment, which is associated with the tectonic mélange complex. Later, Laesanpura (Laesanpura, Dahrin, & Sugianto, 2017) applied the 1-D Audio-magnetotellurics (AMT) at 3 (three) stations. The three 1D inversion models did not show any continuity in the subsurface layers.…”

mentioning

confidence: 99%

Determining the origin of volcanic rocks in the mélange complex of Karangsambung based on the electrical resistivity imaging

et al. 2020

View full text Add to dashboard Cite

show abstract

“…More interesting results could be shown with 3D model for the next work. More integrated results form the lattest publication in this area (such as: [15], [16], [17], and [18]) can be integrated in the next interpretation report.…”

Section: Inverse Modelingmentioning

confidence: 99%

Gravity data processing of field camp geophysics in Karangsambung (2005-2019)

Wahyudi

Laesanpura

Aji

2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Gravity data was collected from a previous survey in Karangsambung 2005-2019 (before the restriction of field camp activities due to the Covid-19 pandemic). Luk-Ulo Mélange Complex in the Karangsambung area has been the subject of local and regional studies for geoscience students due to the interesting exposure of outcrops that have been interpreted as product of subduction (the Indo-Australian plate under the Eurasian plate in the Late Cretaceous to Early Paleocene time). The data for this gravimetric study based on 2592 observations over an area of inside (9.1 × 9.1) square kilometers. The gravity data were observed by students in the field camps for several years and then we compile. In this work we present simple data processing and simple calculation for modeling. The Bouguer anomaly map was processed using a density estimate of 2.31 g/cc for slab-Bouguer and terrain correction/reduction. The residual anomaly map was obtained by simple calculation of trend surface analysis (second order polynomial order). The inverse model was calculated using a simple algorithm for 2.5D and the program was built by accomodate topographic variations in the study area. Slice sections (SW-NE) of residual anomalies with a length of more than 8 km were inverted to obtain the contrast density distribution as a subsurface model. The subsurface images can then be analyzed and correlated with geological surface maps in the study area. The work in this paper is mainly presented as an ilustration of simple data processing and inverse modeling, so that the outcomes of this work are: (1) Bouguer anomaly map, (2) residual anomaly map, and (3) contrast density distribution as SW-NE section in the Karangsambung area. The value of the Bouguer anomaly map from this study is in the range of 88 to 112 mGal, and the value of the residual anomaly map is in the range of -12 to 10 mGal. The contrast density distribution from the inverse model in this study is in the range of -0.3 to 0.6 g/cc.

show abstract

Preliminary Gravity Study of Pre-Tertiary and Tertiary Rock in Northern Kebumen, Central Java, Indonesia

Ahmady

Santoso

2019

IOP Conf. Ser.: Earth Environ. Sci.

View full text Add to dashboard Cite

Luk Ulo Melange Complex is a Pre-Tertiary rock formation consisting of various lithological background and complicated geological structure. Located in Northern Kebumen Regency, this rock is originally interpreted as products of tectonic process caused by paleo-subduction between Indian Oceanic Plate beneath Eurasian Plate in Cretaceous age. According to previous study on geological surface investigation shows that the melange complex is tectonically overlain by Tertiary sedimentary formation. On the contrary, geophysical study of the subsurface condition of the area is still under discussion due to limited of measured data. In order to obtain detailed subsurface image, gravity profiling was measured and interpreted across both Tertiary and pre-Tertiary rock. Frequency domain filter and designed moving average filter were used to separate residual and regional anomaly. The results denote gravity value of residual anomaly varying from -5 to +5 mGal, while regional anomaly is ranging from 150-180 mGal respectively. The preliminary interpretation was developed by taking into account the geological information and also the data that was collected during field campaign. Overall, high gravity anomaly is interpreted as diabase intrusion in the middle of research area. Meanwhile, low gravity anomaly indicated clay rich rock material related to matrix content of Luk-Ulo Melange Complex in the northern area.

show abstract

AMT and gravity across praTertiary rock complex of Kebumen, Central Java, Indonesia

Cited by 4 publications

References 3 publications

Determining the origin of volcanic rocks in the mélange complex of Karangsambung based on the electrical resistivity imaging

Determining the origin of volcanic rocks in the mélange complex of Karangsambung based on the electrical resistivity imaging

Gravity data processing of field camp geophysics in Karangsambung (2005-2019)

Preliminary Gravity Study of Pre-Tertiary and Tertiary Rock in Northern Kebumen, Central Java, Indonesia

Contact Info

Product

Resources

About